<p><p>I investigated the usefulness of phytoplankton for the removal of surface water contaminants. Three experiments, consisting of nine large mesocosms (92.2 m³) were suspended in the flooded DJX uranium pit at Cluff Lake (Saskatchewan, Canada), and filled with contaminated mine water. During the summer of 2003, each mesocosm was fertilized with a different amount of phosphorus throughout the 35 day experiment to stimulate phytoplankton growth, and to create a range in phosphorus load (g) to examine how contaminants may be affected by different nutrient regimes. Algal growth was rapid in fertilized mesocosms as demonstrated by chlorophyll a profiles. As phosphorus loads increased there were significant declines in the surface water concentrations of As, Co, Cu, Mn, Ni, and Zn. This decline was near significant for uranium. The surface water concentrations of Ra²²⁶, Mo, and Se showed no relationship to phosphorus load. Contaminant concentrations in sediment traps suspended at the bottom of each mesocosm generally showed the opposite trend to that observed in the surface water, with most contaminants (As, Co, Cu, Mn, Ni, Ra²²⁶, U, and Zn) exhibiting a significant positive relationship (<i>P</i> < 0.05) with phosphorus load. Sediment trap concentration of Se and Mo did not respond to nutrient treatments.</p> <p>Similar experiments were repeated during the mid- and late-summer of 2004, with 5 mesocosms being fertilized with phosphorus, and another 4 with both phosphorus and ammonium to create different nutrient gradients. Results from these experiments were much more variable than those seen in the experiment conducted in 2003, and small samples (<i>n</i> = 5 for phosphorus treatments and <i>n</i> = 4 for both phosphorus and ammonium treatments) yielded insufficient statistical power to effectively determine statistically significant trends. However, contaminant sedimentation tended to respond to phosphorus treatments in a similar manner as results from 2003; phosphorus-with-ammonium treatments had little positive effect on contaminant sedimentation rates.</p> <p>My results suggest that phytoremediation has the potential to lower many surface water contaminants through the sedimentation of phytoplankton. Based on our results from 2003, we estimate that the Saskatchewan Surface Water Quality Objectives (SSWQO) for the DJX pit would be met in approximately 45 weeks for Co, 65 weeks for Ni, 15 weeks for U, and 5 weeks for Zn if treated using phytoremediation.</p><p>Note:</p><p>Appendix A content (pages 92-95) contains copyrighted material which has been removed. It can be viewed in the original thesis upon request.</p>

<p><p>I investigated the usefulness of phytoplankton for the removal of surface water contaminants. Three experiments, consisting of nine large mesocosms (92.2 m³) were suspended in the flooded DJX uranium pit at Cluff Lake (Saskatchewan, Canada), and filled with contaminated mine water. During the summer of 2003, each mesocosm was fertilized with a different amount of phosphorus throughout the 35 day experiment to stimulate phytoplankton growth, and to create a range in phosphorus load (g) to examine how contaminants may be affected by different nutrient regimes. Algal growth was rapid in fertilized mesocosms as demonstrated by chlorophyll a profiles. As phosphorus loads increased there were significant declines in the surface water concentrations of As, Co, Cu, Mn, Ni, and Zn. This decline was near significant for uranium. The surface water concentrations of Ra²²⁶, Mo, and Se showed no relationship to phosphorus load. Contaminant concentrations in sediment traps suspended at the bottom of each mesocosm generally showed the opposite trend to that observed in the surface water, with most contaminants (As, Co, Cu, Mn, Ni, Ra²²⁶, U, and Zn) exhibiting a significant positive relationship (<i>P</i> < 0.05) with phosphorus load. Sediment trap concentration of Se and Mo did not respond to nutrient treatments.</p> <p>Similar experiments were repeated during the mid- and late-summer of 2004, with 5 mesocosms being fertilized with phosphorus, and another 4 with both phosphorus and ammonium to create different nutrient gradients. Results from these experiments were much more variable than those seen in the experiment conducted in 2003, and small samples (<i>n</i> = 5 for phosphorus treatments and <i>n</i> = 4 for both phosphorus and ammonium treatments) yielded insufficient statistical power to effectively determine statistically significant trends. However, contaminant sedimentation tended to respond to phosphorus treatments in a similar manner as results from 2003; phosphorus-with-ammonium treatments had little positive effect on contaminant sedimentation rates.</p> <p>My results suggest that phytoremediation has the potential to lower many surface water contaminants through the sedimentation of phytoplankton. Based on our results from 2003, we estimate that the Saskatchewan Surface Water Quality Objectives (SSWQO) for the DJX pit would be met in approximately 45 weeks for Co, 65 weeks for Ni, 15 weeks for U, and 5 weeks for Zn if treated using phytoremediation.</p><p>Note:</p><p>Appendix A content (pages 92-95) contains copyrighted material which has been removed. It can be viewed in the original thesis upon request.</p>

I investigated the usefulness of phytoplankton for the removal of surface water contaminants. Three experiments, consisting of nine large mesocosms (92.2 m3) were suspended in the flooded DJX uranium pit at Cluff Lake (Saskatchewan, Canada), and filled with contaminated mine water. During the summer of 2003, each mesocosm was fertilized with a different amount of phosphorus throughout the 35 day experiment to stimulate phytoplankton growth, and to create a range in phosphorus load (g) to examine how contaminants may be affected by different nutrient regimes. Algal growth was rapid in fertilized mesocosms as demonstrated by chlorophyll a profiles. As phosphorus loads increased there were significant declines in the surface water concentrations of As, Co, Cu, Mn, Ni, and Zn. This decline was near significant for uranium. The surface water concentrations of Ra226, Mo, and Se showed no relationship to phosphorus load. Contaminant concentrations in sediment traps suspended at the bottom of each mesocosm generally showed the opposite trend to that observed in the surface water, with most contaminants (As, Co, Cu, Mn, Ni, Ra226, U, and Zn) exhibiting a significant positive relationship (P < 0.05) with phosphorus load. Sediment trap concentration of Se and Mo did not respond to nutrient treatments. Similar experiments were repeated during the mid- and late-summer of 2004, with 5 mesocosms being fertilized with phosphorus, and another 4 with both phosphorus and ammonium to create different nutrient gradients. Results from these experiments were much more variable than those seen in the experiment conducted in 2003, and small samples (n = 5 for phosphorus treatments and n = 4 for both phosphorus and ammonium treatments) yielded insufficient statistical power to effectively determine statistically significant trends. However, contaminant sedimentation tended to respond to phosphorus treatments in a similar manner as results from 2003; phosphorus-with-ammonium treatments had little positive effect on contaminant sedimentation rates. My results suggest that phytoremediation has the potential to lower many surface water contaminants through the sedimentation of phytoplankton. Based on our results from 2003, we estimate that the Saskatchewan Surface Water Quality Objectives (SSWQO) for the DJX pit would be met in approximately 45 weeks for Co, 65 weeks for Ni, 15 weeks for U, and 5 weeks for Zn if treated using phytoremediation.Note:Appendix A content (pages 92-95) contains copyrighted material which has been removed. It can be viewed in the original thesis upon request.

<p>Sa&nbsp; jedne&nbsp; strane&nbsp; se&nbsp; eksploatacija&nbsp; &scaron;ljunka&nbsp; navodi kao&nbsp; značajan&nbsp; ugrožavajući&nbsp; faktor&nbsp; sa&nbsp; velikim negativnim&nbsp; uticajem&nbsp; na&nbsp; vodena&nbsp; stani&scaron;ta&nbsp; i biodiverzitet,&nbsp; dok&nbsp; same&nbsp; &scaron;ljunkare&nbsp; mogu predstavljati&nbsp; vredne&nbsp; refugijume&nbsp; akavtičnog&nbsp; biodiverziteta.&nbsp; Osnovni&nbsp; cilj&nbsp; disertacije&nbsp; je određivanje&nbsp; najznačajnijih&nbsp; i&nbsp; relevantnih hidromorfolo&scaron;kih&nbsp; parametara&nbsp; koji&nbsp; utiču&nbsp; na strukturiranje&nbsp; makrofitskih&nbsp; zajednica&nbsp; u &scaron;ljunkarama&nbsp; duž&nbsp; plavnog&nbsp; područja&nbsp; reke&nbsp; Drine&nbsp; i određivanje&nbsp; korelacije&nbsp; između&nbsp; izdvojenih parametara&nbsp; i&nbsp; kvantitativnih&nbsp; indeksa&nbsp; makrofita.Istraživanje&nbsp; je&nbsp; vr&scaron;eno&nbsp; u&nbsp; toku&nbsp; letnjih&nbsp; meseci 2015, 2016, 2017 i 2018. godine na 18 &scaron;ljunkara (60 istraživačkih vegetacijskih sektora) u okviru tri&nbsp;&nbsp; eksploataciona&nbsp; polja&nbsp; u&nbsp; Crnoj&nbsp; Bari, Badovincima&nbsp; i&nbsp; Lipničkom&nbsp; &Scaron;oru&nbsp; i&nbsp; na&nbsp; četiri prirodna&nbsp; fluvijalna&nbsp; jezera&nbsp; (13&nbsp; istraživačkih vegetacijskih&nbsp; sektora)&nbsp; u&nbsp; plavnom&nbsp; području&nbsp; reke Drine.&nbsp; Makrofitska&nbsp; vegetacija&nbsp; je&nbsp; konstatovana na svih 18 istraţivanih &scaron;ljunkara, prikupljenih na tri eksploataciona polja (Badovinci, Crna Bara&nbsp; i<br />Lipniĉki &Scaron;or). Zabeležena je 31 biljna vrsta. Kao najučestalije,&nbsp; sa&nbsp; najvećom&nbsp; apsolutnom pokrovno&scaron;ću izdvojile su se vrste:&nbsp;<em> Potamogeton nodosus</em>&nbsp; Poiret,&nbsp; <em>Ceratophyllum&nbsp; demersum&nbsp; L subsp.&nbsp; demersum,&nbsp; Myriophyllum&nbsp; spicatum&nbsp; L,Najas&nbsp; marina&nbsp; L&nbsp; i&nbsp;&nbsp; Chara&nbsp; globularis&nbsp; Thuill&nbsp;</em> Na četiri prirodna fluvijalna jezera zabeleženo je 13 vrsta.&nbsp; Vrste&nbsp; <em>Vallisneria&nbsp; spiralis&nbsp; L,&nbsp; Elodea canadensis&nbsp; Michx,&nbsp; Callitriche&nbsp; palustris&nbsp; L, Potamogeton&nbsp; natans&nbsp; L&nbsp; i&nbsp; Nuphar&nbsp; lutea&nbsp; (L)&nbsp;</em> Sm izdvojile&nbsp; su&nbsp; se&nbsp; kao&nbsp; konstantne&nbsp; i&nbsp; dominantne. Vrednosti svih kvantitativnih indeksa makrofita,<br />značajno&nbsp; su&nbsp; veće&nbsp; za&nbsp; &scaron;ljunkare&nbsp; u&nbsp; poređenju&nbsp; sa prirodnim&nbsp; fluvijalnim&nbsp; jezerima&nbsp; na&nbsp; nivouLEAFPACS&nbsp; sektora.&nbsp; Na&nbsp; istraživanim &scaron;ljunkarama,&nbsp; analizom&nbsp; klasterovanja&nbsp; je<br />izdvojeno&nbsp; 13&nbsp; vegetacijskih&nbsp; grupa&nbsp; (VG):&nbsp; VG1<em> Ceratophyllum&nbsp; demersum</em>,&nbsp; VG2&nbsp; <em>Ceratophyllum demersum&nbsp; -&nbsp; Valisneria&nbsp; spiralis</em>,&nbsp; VG3&nbsp; <em>Chara contraria,</em>&nbsp; VG4&nbsp; <em>Chara</em>&nbsp; <em>globularis,</em>&nbsp; VG5&nbsp; <em>Elodea canadensis,</em>&nbsp; VG6&nbsp; <em>Elodea&nbsp; nuttallii</em>,&nbsp; VG7&nbsp; <em>Najas marina</em>,&nbsp; VG8&nbsp; <em>Najas&nbsp; minor,</em>&nbsp; VG9&nbsp; <em>Nitellopsis obtusa</em>,&nbsp; VG10&nbsp;<em> Nuphar&nbsp; lutea</em>,&nbsp; VG11 <em>Potamogeton&nbsp; nodosus</em>,&nbsp; VG12&nbsp;<em> Potamogeton natans&nbsp;</em> i&nbsp;&nbsp; VG13&nbsp; <em>Potamogeton&nbsp; pectinatus</em>.&nbsp; Na prirodnim&nbsp; fluvijalnim&nbsp; jezerima&nbsp; konstatovane&nbsp; su četiri&nbsp; vegetacijske&nbsp; grupe:&nbsp; VG5&nbsp;<em> Elodea canadensis</em>,&nbsp; VG10&nbsp; <em>Nuphar&nbsp; lutea,</em>&nbsp; VG12<em> Potamogeton natans&nbsp;</em> i&nbsp; VG14&nbsp; <em>Typha latifolia</em>.&nbsp; Na osnovu izmerenih fizičko-hemijskih parametara,kvalitet vode u većini &scaron;ljunkara odgovara II klasi kvaliteta, na osnovu čega se mogu okarakterisati kao&nbsp; vodna&nbsp; tela&nbsp; sa&nbsp; dobrim&nbsp; i&nbsp; boljim&nbsp; ekolo&scaron;kim potencijalom. Sve &scaron;ljunkare i fluvijalna jezera se klasifikuju&nbsp; kao&nbsp; visoko&nbsp; alkalna.&nbsp; Kvalitet&nbsp; vode&nbsp; u prirodnim&nbsp; fluvijalnim&nbsp; jezerima&nbsp; odgovara&nbsp; III&nbsp; &ndash; IV&nbsp; klasi&nbsp; kvaliteta&nbsp; voda,&nbsp; pri&nbsp; čemu&nbsp; se&nbsp; mogu okarakterisati&nbsp; kao&nbsp; vodna&nbsp; tela&nbsp; sa&nbsp; slabim&nbsp; do umerenim&nbsp; ekolo&scaron;kim&nbsp; statusom.&nbsp; Značajno&nbsp; veće<br />vrednosti&nbsp; ukupnih&nbsp; suspendovanih&nbsp; materija, hemijske&nbsp; i&nbsp; biolo&scaron;ke&nbsp; potro&scaron;nje&nbsp; kiseonika, ukupnog&nbsp; organskog&nbsp; kiseonika&nbsp; i&nbsp; nitrata zabeležene su na prirodnim fluvijalnim jezerima u poređenju sa &scaron;ljunkarama. Izmerene vrednosti fizičko-hemijskih&nbsp; parametara&nbsp; ukazuju&nbsp; na mezotrofni&nbsp; karakter&nbsp; lokaliteta&nbsp; u&nbsp; Badovincima&nbsp; i mezo-eutrofni&nbsp; karakter&nbsp; lokaliteta&nbsp; u&nbsp; Lipničkom &Scaron;oru,&nbsp; dok&nbsp; se&nbsp; &scaron;ljunkare&nbsp; na&nbsp; teritoriji&nbsp; Crne&nbsp; Bare mogu&nbsp; okarakterisati&nbsp; kao&nbsp; eutrofna&nbsp; jezera.Vrednosti&nbsp; LHMS&nbsp; (modifikacionog)&nbsp; skora&nbsp; za &scaron;ljunkare kretale su se u rasponu od 9&nbsp; &ndash;&nbsp; 15, dok su vrednosti LHQA skora (stani&scaron;nog diverziteta) bile u rasponu izmeĊu 33&nbsp; &ndash;&nbsp; 44. Sliĉne vrednosti za&nbsp; LHQA&nbsp; skor&nbsp; su&nbsp; izraĉunate&nbsp; i&nbsp; za&nbsp; prirodna fluvijalna&nbsp; jezera&nbsp; (36&nbsp; &ndash;&nbsp; 49).&nbsp; MeĊutim,&nbsp; vrednosti<br />LHMS&nbsp; skora&nbsp; za&nbsp; prirodna&nbsp; fluvijalna&nbsp; jezera&nbsp; su znaĉajno&nbsp; veće&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; vrednosti&nbsp; LHMS skora za &scaron;ljunkare. Ovi podaci ukazuju na manje prisustvo&nbsp; antropogenog&nbsp; pritiska&nbsp; na&nbsp; &scaron;ljunkarama u poređenju sa prirodnim fluvijalnim jezerima uistraţivanom&nbsp; podruĉju.&nbsp; Fizičko -hemijski&nbsp; i hidromorfolo&scaron;ki&nbsp; parametri&nbsp; zajedno&nbsp; su&nbsp; objasnili 57.07&nbsp; %&nbsp; od&nbsp; ukupne&nbsp; varijanse&nbsp; vegetacijskih podataka,&nbsp; sa&nbsp; 16.57&nbsp; %&nbsp; deljenog&nbsp; efekta.&nbsp; Fizičkohemijski&nbsp; parametri&nbsp; kvaliteta&nbsp; vode&nbsp; objasnili&nbsp; su 17.02&nbsp; %&nbsp; varijabilnosti&nbsp; u&nbsp; strukturi&nbsp; makrofitske vegetacije.&nbsp; Kao&nbsp; najsignifikantniji&nbsp; parametri<br />izdvojili&nbsp; su&nbsp; se:&nbsp; saturacija&nbsp; vode&nbsp; kiseonikom,ukupni&nbsp; organski&nbsp; ugljenik,&nbsp; povr&scaron;inski&nbsp; aktivne materije, temperatura, elektroprovodljivost, pH i ukpni&nbsp; alkalitet.&nbsp; Hidromorfolo&scaron;ki&nbsp; parametri&nbsp; su objasnili&nbsp; 23.48&nbsp; %&nbsp; varijabilnosti&nbsp; u&nbsp; strukturi makrofitske&nbsp; vegetacije.&nbsp; Kao&nbsp; najsignifikantnije varijable,&nbsp; izdvojile&nbsp; su&nbsp; se:&nbsp; struktura&nbsp; vegetacije&nbsp; u priobalnoj&nbsp; zoni,&nbsp; diverzitet&nbsp; prirodnih&nbsp; tipova stani&scaron;ta&nbsp; priobalne&nbsp; zone,&nbsp; prirodnost&nbsp; obale, diverzitet&nbsp; prirodnog&nbsp; supstrata&nbsp; litorala,masimalna dubina &scaron;ljunkara, povr&scaron;ina &scaron;ljunkara,indeks relativne dubine, udaljenost &scaron;ljunkara od glavnog&nbsp; reĉnog&nbsp; toka&nbsp; i&nbsp; starost&nbsp; &scaron;ljunkara. Hidrolo&scaron;ki&nbsp; parametri&nbsp; su&nbsp; objasnili&nbsp; 8.38&nbsp; % varijabilnosti u strukturi&nbsp; makrofitske vegetacije. Kao&nbsp; najsignifikantnije&nbsp; varijable,&nbsp; izdvojile&nbsp; su&nbsp; se broj plavnih talasa u vegetacionoj sezoni tokom godine u kojoj je vr&scaron;eno uzorkovanje vegetacije i broj plavnih talasa u prolećnom periodu za sve četiri&nbsp; godine.&nbsp; Ovi&nbsp; rezultati&nbsp; potvrđuju&nbsp; direktni destruktivni&nbsp; uticaj&nbsp; plavnih&nbsp; talasa&nbsp; na&nbsp; vodenu vegetaciju u vegetacionoj sezoni, kao i indirektni uticaj prolećnih poplava, usled uticaja na trofički status&nbsp; vode.&nbsp; Sumarno,&nbsp; &scaron;ljunkare&nbsp; u&nbsp; plavnom području&nbsp; reke&nbsp; Drine&nbsp; predstavljaju&nbsp; optimalno stani&scaron;te&nbsp; za&nbsp; razvoj&nbsp; retke&nbsp; i&nbsp; ugroţene&nbsp; makrofitske flore.&nbsp; Od&nbsp; ukupnog&nbsp; broja&nbsp; zabeleženih&nbsp; vrsta makrofita,&nbsp; 30&nbsp; %&nbsp; se&nbsp; kategori&scaron;e&nbsp; kao&nbsp; za&scaron;tićeno&nbsp; ili ugroženo na nacionalnom nivou.&nbsp; Značajno veće vrednosti&nbsp; konzervacionih&nbsp; indeksa&nbsp; ustanovljene su&nbsp; za&nbsp; &scaron;ljunkare&nbsp; u&nbsp; poređenju&nbsp; sa&nbsp; prirodnim fluvijalnim jezerima, &scaron;to ukazuje na njihov visok ekolo&scaron;ki&nbsp; potencijal.&nbsp; Ustanovljen&nbsp; je&nbsp; visok diverzitet&nbsp; prioritetnih&nbsp; tipova&nbsp; akvatiĉnih&nbsp; stani&scaron;ta prema&nbsp; Pravilniku&nbsp; o&nbsp; kriterijumima&nbsp; za&nbsp; izdvajanje tipova&nbsp; stani&scaron;ta,&nbsp; o&nbsp; tipovima&nbsp; stani&scaron;ta,&nbsp; osetljivim, ugroženim,&nbsp; retkim&nbsp; i&nbsp; za&nbsp; za&scaron;titu&nbsp; prioritetnim tipovima&nbsp; stani&scaron;ta&nbsp; i&nbsp; o&nbsp; merama&nbsp; za&scaron;tite&nbsp; za&nbsp; njihovo očuvanje, Aneksu I, Direktive Evropske unije oza&scaron;titi&nbsp; prirodnih&nbsp; stani&scaron;ta&nbsp; i&nbsp; divlje&nbsp; flore&nbsp; i&nbsp; faune (Natura&nbsp; 2000),&nbsp; Rezoluciji&nbsp; br.&nbsp; 4&nbsp; Konvencije&nbsp; o očuvanju&nbsp; evropske&nbsp; divlje&nbsp; flore&nbsp; i&nbsp; faune&nbsp; i prirodnih&nbsp; stani&scaron;ta (EMERALD)&nbsp; i&nbsp; Evropskoj crvenoj&nbsp; listi&nbsp; stani&scaron;ta.&nbsp; Vrednosti&nbsp; izdvojenih atributa&nbsp; &scaron;ljunkara&nbsp; mogli&nbsp; bi&nbsp; se&nbsp; iskoristiti&nbsp; u procesu&nbsp; ranog&nbsp; planiranja&nbsp; i&nbsp; projektovanja eksploatacionih&nbsp; polja&nbsp; u&nbsp; plavnom&nbsp; području&nbsp; reke Drine&nbsp; i&nbsp; na&nbsp; drugim,&nbsp; sličnim&nbsp; lokalitetima. Generalna preporuka je da se dva tipa &scaron;ljunkara kreiraju&nbsp; u&nbsp; okviru&nbsp; jednog&nbsp; eksploatacionog&nbsp; polja. Prvi&nbsp; tip,&nbsp; odnosno&nbsp; &scaron;ljunkare&nbsp; koje&nbsp; bi&nbsp; podržavale pionirsku&nbsp; vegetaciju&nbsp; pr&scaron;ljenčica&nbsp; trebale&nbsp; bi&nbsp; da budu locirane na razdaljini do 100 m od glavnog rečnog&nbsp; toka,&nbsp; povr&scaron;ine&nbsp; do&nbsp; 1000&nbsp; m 2 i&nbsp; da&nbsp; imaju vrednost indeksa relativne dubine &gt; 5 %. Drugi tip&nbsp; &scaron;ljunkara&nbsp; koje&nbsp; bi&nbsp; podržavale&nbsp; vegetaciju karakterističnu&nbsp; za&nbsp; nizijska&nbsp; fluvijalna&nbsp; jezera trebale bi da budu locirane na razdaljani od oko 300 m od glavnog rečnog toka, dubine 3&nbsp; &ndash;&nbsp; 4&nbsp; m (najmanje 2 m), povr&scaron;ine između 10000 i 20000 m ²(najmanje&nbsp; 4000&nbsp; m² ),&nbsp; različitih&nbsp; vrednosti indeksa relativne dubine, ali&nbsp; ne preko 5 %. Sva eksploataciona&nbsp; polja&nbsp; bi&nbsp; trebalo&nbsp; isplanirati&nbsp; i isprojektovati&nbsp; kako&nbsp; bi&nbsp; se&nbsp; minimizirao&nbsp; uticaj&nbsp; na priobalnu&nbsp; i&nbsp; obalnu&nbsp; zonu.&nbsp; Pridržavanjem&nbsp; datih smernica&nbsp; povećao&nbsp; bi&nbsp; se&nbsp; diverzitet&nbsp; i&nbsp; kvalitet stani&scaron;ta,&nbsp; kao&nbsp; i&nbsp; konzervacioni&nbsp; potencijal &scaron;ljunkara. Kreiranjem &scaron;ljunkara na naĉin kao &scaron;to je predloženo u ovoj disertaciji omogućila bi se spontana&nbsp; rekultivacija&nbsp; eksploatacionih polja,odnosno&nbsp; remedijacija&nbsp; u&nbsp; cilju&nbsp; pobolj&scaron;anja kvaliteta vode i renaturalizacija stani&scaron;ta, čime bi se&nbsp; znatno&nbsp; smanjili,&nbsp; ili&nbsp; u&nbsp; potpunosti&nbsp; eliminisali, tro&scaron;kovi tehničke rekultivacije terena.</p> / <p>Gravel pit lakes in the river floodplains represent a kind of ecological paradox. Gravel exploitation was recognised&nbsp; as&nbsp; important&nbsp; factor&nbsp; significantlyaffecting&nbsp; aquatic&nbsp; habitats&nbsp; and&nbsp; biodiversity.&nbsp; On the&nbsp; other&nbsp; hand,&nbsp; gravel&nbsp; pit&nbsp; lakes&nbsp; are&nbsp; valuable biodiversity&nbsp; refugiums,&nbsp; potentially&nbsp; supporting rarae&nbsp; species&nbsp; and&nbsp; habitats.&nbsp; The&nbsp; aim&nbsp; of&nbsp; this dissertation&nbsp; was&nbsp; to&nbsp; determine&nbsp; the&nbsp; most significant&nbsp; and&nbsp; relevant&nbsp; hydromorphological parameters&nbsp; in&nbsp; structuring&nbsp; macrophyte assemblages&nbsp; in gravel pit&nbsp; lakes along the Drina River floodplain and to determine the correlation between&nbsp; selected&nbsp; parameters&nbsp; and&nbsp; macrophyte quantitative&nbsp; indices.&nbsp; The&nbsp; research&nbsp; was&nbsp; carried out at the 18 gravel pit lakes (60 survey sectors) in&nbsp; Crna&nbsp; Bara,&nbsp; Badovinci&nbsp; and&nbsp; Lipnicki&nbsp; Sor&nbsp; and four natural fluvial lakes (13 survey sectors), in the&nbsp; Drina&nbsp; River&nbsp; floodplain&nbsp; during&nbsp; the&nbsp; summer months&nbsp; of&nbsp; 2015,&nbsp; 2016,&nbsp; 2017&nbsp; and&nbsp; 2018.Macrophyte&nbsp; vegetation&nbsp; was&nbsp; recorded&nbsp; in&nbsp; all&nbsp; 18 gravel pit lakes, in total supporting 31 taxa.&nbsp; The most&nbsp; abundant&nbsp; species,&nbsp; with&nbsp; highest&nbsp; tot al&nbsp; cover value&nbsp; were <em>Potamogeton</em>&nbsp; <em>nodosus,Ceratophyllum&nbsp;</em> demersum&nbsp; subsp.&nbsp; demersum,<em> Myriophyllum&nbsp; spicatum,&nbsp;</em> <em>Najas&nbsp; marina&nbsp;</em> and<em> Chara&nbsp; globularis</em>.&nbsp; Fluvial&nbsp; lakes&nbsp; supported&nbsp; 13 macrophyte&nbsp; taxa&nbsp; with&nbsp;<em> Vallisneria&nbsp; spiralis, Elodea&nbsp; canadensis,&nbsp; Callitriche&nbsp; palustris,Potamogeton&nbsp;</em> <em>natans&nbsp;</em> and&nbsp;<em> Nuphar&nbsp; lutea</em>&nbsp; as constant and dominant&nbsp; species.&nbsp; The values of all macrophyte&nbsp; quantitative&nbsp; indices&nbsp; found&nbsp; to&nbsp; be significantly&nbsp; higher&nbsp; in&nbsp; the&nbsp; gravel&nbsp; pit&nbsp; lakes compared&nbsp; to&nbsp; the&nbsp; fluvial&nbsp; ones.&nbsp; The&nbsp; cluster analysis&nbsp; revealed&nbsp; 14&nbsp; aquatic&nbsp; vegetation&nbsp; groups (VG).&nbsp; At&nbsp; 16&nbsp; out&nbsp; of&nbsp; 18&nbsp; gravel&nbsp; pit&nbsp; lakes&nbsp; 13 vegetation&nbsp; groups&nbsp; were&nbsp; revealed:&nbsp; VG1<em>Ceratophyllum&nbsp; demersum</em>,&nbsp; VG2&nbsp; <em>Ceratophyllum demersum- Valisneria&nbsp; spiralis</em>,&nbsp; VG3&nbsp;<em> Chara contraria</em>,&nbsp; VG4&nbsp; <em>Chara&nbsp; globularis</em>,&nbsp; VG5&nbsp;<em> Elodea&nbsp; canadensis,</em>&nbsp; VG6&nbsp;<em> Elodea&nbsp; nuttallii,</em>&nbsp; VG7&nbsp; <em>Najas marina,&nbsp;</em> VG8&nbsp;<em> Najas&nbsp; minor,</em>&nbsp; VG9&nbsp; <em>Nitellopsis obtusa</em>,&nbsp; VG10&nbsp; <em>Nuphar&nbsp; lutea,</em>&nbsp; VG11 <em>Potamogeton&nbsp; nodosus</em>,&nbsp; VG12&nbsp; <em>Potamogeton natans,</em> VG13&nbsp;<em> Potamogeton pectinatus</em>), Natural fluvial&nbsp; lakes&nbsp; supported&nbsp; 4&nbsp; vegetation&nbsp; groups: VG5&nbsp; <em>Elodea&nbsp; canadensis</em>,&nbsp; VG10&nbsp; <em>Nuphar&nbsp; lutea</em>, VG12&nbsp; <em>Potamogeton&nbsp; natans&nbsp;</em> and&nbsp; VG14&nbsp;<em> Typha latifolia</em>.&nbsp; All&nbsp; gravel&nbsp; pit&nbsp; lakes&nbsp; can&nbsp; be characterized&nbsp; as&nbsp; water&nbsp; bodies&nbsp; with&nbsp; good&nbsp; to maximal&nbsp; ecological&nbsp; potential,&nbsp; while&nbsp; all&nbsp; the fluvial ones can be characterized as water bidies with&nbsp; poor&nbsp; to&nbsp; moderate&nbsp; ecological&nbsp; status.&nbsp; The values&nbsp; of&nbsp; total&nbsp; suspended&nbsp; supstances,&nbsp; chemical and&nbsp; biological&nbsp; oxygen&nbsp; demand,&nbsp; total&nbsp; organic carbon&nbsp; and&nbsp; nitrates&nbsp; were&nbsp; significantly&nbsp; higher&nbsp; in the natural&nbsp; fluvial&nbsp; lakes compared to the gravel pit&nbsp; ones.&nbsp; Measured&nbsp; level&nbsp; of&nbsp; physico-chemical parameters&nbsp; indicating&nbsp; mesotrophic&nbsp; character&nbsp; of gravel&nbsp; pit&nbsp; lakes&nbsp; in&nbsp; Badovinci&nbsp; and&nbsp; mesoeutrophic&nbsp; in&nbsp; Lipnicki&nbsp; Sor,&nbsp; while&nbsp; all&nbsp; the&nbsp; gravel pits&nbsp; in&nbsp; Crna&nbsp; Bara&nbsp; could&nbsp; be&nbsp; characterized&nbsp; as eutrophic.&nbsp; Similar&nbsp; range&nbsp; values&nbsp; were&nbsp; calculated for&nbsp; LHQA&nbsp; for&nbsp; gravel&nbsp; pit&nbsp; and&nbsp; fluvial&nbsp; lakes&nbsp; (36 &ndash; 49). However, natural lakes&nbsp; showed significantly higher&nbsp; values&nbsp; for&nbsp; LHMS&nbsp; score.&nbsp; The&nbsp; above mentioned,&nbsp; indicates&nbsp; higher&nbsp; anthropogenic pressures&nbsp; on&nbsp; natural&nbsp; fluvial&nbsp; lakes&nbsp; compared&nbsp; to gravel&nbsp; pit&nbsp; ones.&nbsp; Physico-chemical&nbsp; and hydromorphological&nbsp; parameters&nbsp; together explained&nbsp; about&nbsp; 57&nbsp; %&nbsp; of&nbsp; the&nbsp; total&nbsp; variance&nbsp; of macrophyte&nbsp; assemblages&nbsp; with&nbsp; 16.57&nbsp; %&nbsp; of&nbsp; the shared effect. After accounting for the effects of physico-chemical&nbsp; parameters&nbsp; (17.02&nbsp; %), hydromorphological&nbsp; variables&nbsp; explained&nbsp; around 23 % of the total variance.&nbsp; The most significant water&nbsp; quality variables&nbsp; were: oxygen saturation, total&nbsp; organic&nbsp; carbon,&nbsp; surfactants, ,electroconductivity,&nbsp; pH&nbsp; and total alkalinity. The The most significant hydromorphology&nbsp; variables for&nbsp; structuring&nbsp; macrophyte&nbsp; assemblages&nbsp; were: riparian&nbsp; vegetation&nbsp; structural&nbsp; complexity, diversity&nbsp; of&nbsp; natural&nbsp; landcover&nbsp; types&nbsp; in&nbsp; riparianzone, shore structural habitat&nbsp; diversity, diversity of&nbsp; natural littoral zone, maximal&nbsp; lake depth, lake surface&nbsp; area,&nbsp; relative&nbsp; depth&nbsp; ratio,&nbsp; lake&nbsp; distance from&nbsp; r iver&nbsp; main&nbsp; channel&nbsp; and&nbsp; lake&nbsp;&nbsp; age.Hydrologycal parameters were explained 8.38 % of&nbsp; variance&nbsp; in&nbsp; structuring&nbsp; macrophyte assemblages.&nbsp; The&nbsp; most&nbsp; significant&nbsp; hydrology variables&nbsp; were&nbsp; the&nbsp; number&nbsp; of&nbsp; floods&nbsp; in vegetation&nbsp; season&nbsp; in&nbsp; first&nbsp; year&nbsp; when&nbsp; vegetation was sampled, and the number of spring floods in all four research years. These results&nbsp;&nbsp; confirm the direct destructive influence of summer floods&nbsp; on aquatic vegetation, as&nbsp;&nbsp; well as the indirect impact of&nbsp; spring&nbsp; floods,&nbsp; due&nbsp; to&nbsp; the&nbsp; impact&nbsp; on&nbsp; trophic status&nbsp; of&nbsp; water.&nbsp; Gravel&nbsp; pit&nbsp; lakes&nbsp; in&nbsp; te&nbsp; Drina River floodplain&nbsp; represent an optimal habitat&nbsp;&nbsp; for rare&nbsp; and&nbsp; threatened&nbsp; macrophyte&nbsp; flora.&nbsp; Of&nbsp; the total&nbsp; macrophyte&nbsp; species&nbsp; recorded,&nbsp; 30&nbsp; %&nbsp; were categorized&nbsp; as&nbsp; protected&nbsp; or threatened.&nbsp; At&nbsp; least one&nbsp; strictly&nbsp; protected,&nbsp; protected&nbsp; or&nbsp; threatened species&nbsp; was&nbsp; recorded&nbsp; in&nbsp; each&nbsp; gravel&nbsp; pit&nbsp; lake. Significantly&nbsp; higher&nbsp; values&nbsp; of&nbsp; conservation indices&nbsp; (C&nbsp; and&nbsp; Csp&nbsp; score)&nbsp; found&nbsp; to&nbsp; be significantly&nbsp; higher&nbsp; in&nbsp; the&nbsp; gravel&nbsp; pit&nbsp; lakes compared&nbsp; to&nbsp; the&nbsp; fluvial&nbsp; ones.&nbsp; High&nbsp; habitat diversity&nbsp; and&nbsp; conservation&nbsp; value&nbsp; of&nbsp; the&nbsp; sites have&nbsp; been&nbsp; recorded&nbsp; according&nbsp; to&nbsp; the&nbsp; National Rulebook,&nbsp; Annex&nbsp; I&nbsp; of&nbsp; Habitats&nbsp; Directive (NATURA 2000), Resolution&nbsp; no. 4 of the Bern Convention (EMERALD) and the European Red List&nbsp; of&nbsp; Habitats.&nbsp; Values&nbsp; of&nbsp; selected&nbsp; lake attributes can be used for early-design phases of future&nbsp; gravel&nbsp; extraction&nbsp; in&nbsp; the&nbsp; Drina&nbsp; River floodplain&nbsp; area,&nbsp; and&nbsp; in&nbsp; other&nbsp; similar&nbsp; sites. Therefore,&nbsp; general&nbsp; recommendations&nbsp; are&nbsp; that two gravel pit types should be excavated within the&nbsp; single&nbsp; extraction&nbsp; area&nbsp; in&nbsp; order&nbsp; to&nbsp; support pioneering charophyte vegetation and vegetation of typical eutrophic lowland floodplain lakes as well.&nbsp; The&nbsp; first&nbsp; hydromorphological&nbsp; lake&nbsp; type, suitable&nbsp; for&nbsp; stonewort&nbsp; species,&nbsp; should&nbsp; be excavated up to 100 m from river main channel, saving&nbsp; a&nbsp; surface&nbsp; area&nbsp; up&nbsp; to&nbsp; 1000&nbsp; m 2 and&nbsp; a relative depth ratio &gt; 5 %. The second gravel pit type&nbsp; should&nbsp; be&nbsp; located&nbsp; about&nbsp; 300&nbsp; m&nbsp; from&nbsp; river main channel, with preferable maximal depth inrange&nbsp; 3&ndash;4&nbsp; m&nbsp; (at&nbsp; least&nbsp; 2&nbsp; m&nbsp; depth),&nbsp; and&nbsp; a&nbsp; lake surface area between 10000 m 2 and 20000 m 2 (at least&nbsp; 4000&nbsp; m 2 ).&nbsp; Relative&nbsp; depth&nbsp; ratio&nbsp; may&nbsp; vary, but should be less than 5 %. Generally, all sites should&nbsp; be&nbsp; designed&nbsp; with&nbsp; the&nbsp; minimal&nbsp; impact to the&nbsp; riparian&nbsp; and&nbsp; shore&nbsp; zones.&nbsp; These&nbsp; proposed measures&nbsp; would&nbsp; considerably&nbsp; increase&nbsp; lake habitat diversity and their conservation potential. Creating&nbsp; gravel&nbsp; pit&nbsp; lakes&nbsp; as&nbsp; proposed&nbsp; in&nbsp; this dissertation&nbsp;&nbsp;&nbsp; would&nbsp; allow&nbsp; spontaneous recultivation&nbsp; of&nbsp; exploitation&nbsp; fields,&nbsp; remediation in&nbsp; order&nbsp; to&nbsp; improve&nbsp; water&nbsp; quality&nbsp; and renaturalization&nbsp; of&nbsp; habitats,&nbsp; which&nbsp; will significantly reduce, or completely eliminate, the costs of terrain technical recultivation.</p>

Mining of lignite in Lusatia has a long history of over 100 years. The extracted brown coal is utilized to generate electricity in three large power plants: Jänschwalde, Boxberg, and Schwarze Pumpe. With an annual carbon dioxide (CO2) output of approximately 50 million tons, these power plants are among Germany’s large-scale CO2 emitters. The environmental impact from open-pit mining is of a considerable degree and currently poses a challenging problem. The groundwater deficit in 1990 was 7 billion m3 over a surface area of approximately 2100 km2 (Luckner, 2006a) and was bisected in value until today. Due to the decline of mining activity and the termination of mine drainage at most open pits in the Lusatian region, the groundwater table has recovered forming 28 pit lakes (Zschiedrich, 2011). The majority of the post mining lakes do not meet the quality standards for pH, iron or sulfate parameters; because of pyrite oxidation that produces acid mine drainage (Luckner, 2006b, Klapper and Schultze, 1995, Schultze et al., 2010). The post mining lakes in Lusatia have low pH values (3 – 4), high sulfate contents (up to 2800 ppm) as well as high iron concentrations (100 – 150 ppm). Lakes are flooded by groundwater and using surface water from Spree and Neisse River to achieve fast filling and dilution; however, due to the limited availability of surface water, further rehabilitation strategies for the region had to be investigated. Between 1970 and 1990, approximately 26 million m3 of suspended fly ash were deposited in the lake Burghammer and settled as an ash body at its base; where it may be used for rehabilitation. In a first experiment conducted in 2001 material from the ash body was picked up and redistributed throughout the lake. By this treatment the pH of the lake was raised temporarily; however, a sustainable remediation was not achieved. Based on these experiments it was investigated whether the ash reacts more sufficiently through additional CO2 injection or not. Aim was to combine the rehabilitation of acid mine lakes with the utilization of atmospheric carbon dioxide emissions from coal-fired power plants. The CO2 sequestration is achieved through the generation and accumulation of carbonates in the lake. The following equations describe the precipitation of carbonate by using CO2 and alkaline earth cations M: CO2 + MO → MCO3 (s) CO2 + M(OH)2 → MCO3 (s) + H2O Therefore, neutral pH conditions are necessary for the long-term accumulation of carbonates in the lakes. In laboratory investigations it was shown, that the 20 to 30 years old fly ash deposits of lake Burghammer can be used for carbonate sequestration and lake water treatment. Bivalent ions (Ca2+, Mg2+) are eluable and available for carbonate precipitation; on average we assumed 1 wt.-% of reactive calcium to be contained in the settled ash sediments. Settled fly ash sediments are less reactive than fresh fly ash from a power plant (e.g. Schwarze Pumpe). During batch experiments, we increased the buffering capacity to maximum values of 7 mmol/L. Beforehand no buffering capacity exists due to the low pH of 2.9 in the lake. Batch investigations provided a sequestration potential of 17 g CO2/kg ash sediment; in comparison fresh fly ash results in a sequestration potential of 33 g CO2/kg ash (Schipek and Merkel, 2008b, Schipek and Merkel, 2008a, Schipek, 2009). Based on the laboratory results a field experiment was conducted. In this field experiment gas injection lances were installed to a sediment depth of 12 m. Gaseous CO2 was applied with a pressure of 2.2 bar and 2.2 m³/h for 3 months and lake water was monitored during injection. Variations in total inorganic carbon due to diffusion processes of CO2 saturated pore waters could be observed. As the pilot experiment comprised only a small area of lake Burghammer no initial neutralisition (e.g. by a suction excavator) was possible. Thus, no further changes in water chemistry were observed. Drilling cores in the vicinity of the injection area provided mineralogical and geochemical conditions before and after CO2 treatment. No trace metal mobilization was found during CO2 injection. Most elements showed decreasing trends or didn’t change significantly. Calculated saturation indices for calcite indicated equilibrium conditions or slightly oversaturated conditions (SICalcite,average +0.12; SICalcite,median +0.31). Geochemical and mineralogical investigations proved that CO2 sequestration is possible with an average precipitation rate of 0.5 wt.-% (2.2 g CO2/kg). The maximum rate for carbonate precipitation was determined with 7.4 wt.-% Calcite, according to 32.6 g CO2 per kilogram treated ash. Besides the use of the settled fly ash as neutralizing agent in acidic mining lakes, laboratory and field investigations were conducted in order to improve in-lake liming. In batch and columns experiments, different liming agents (synthetic marble powder and industrial products) were tested and investigated. Significant differences in reactivity were obvious at pCO2 > 3.8 • 10-4 atm. Ions typical for acid mine drainage (e.g. Mn2+, Cd2+, SO42-) do have different effects on the kinetic of carbonate dissolution. Manganese concentrations typical for acidic mining lakes inhibit calcite dissolution. Cadmium has as well a significant influence on dissolution and kinetics. Only circa 50 % of the calcium concentration was reached with cadmium as inhibitor compared to the dissolution in pure water. Increased CO2 partial pressure might be used to compensate inhibtion by material impurities and/or water constituents. Column experiments showed that a multi-stage application of liming agent increases the efficiency of a lake treatment. The combination of a first application of calcite (up to pH 4.5) and further application of Ca(OH)2 seemed to be the most promising method. This treatment sheme was successfully applied in lake Burghammer from March 2009 – December 2010 (initial neutralisation and 6 follow-up treatments). Finally, it can be concluded, that in lignite mining districts in-lake treatment of acidic mining lakes is a seminal method to handle water quality problems. Using gaseous CO2 in combination with industrial by-products can be accounted as sustainable method for CO2 sequestration and for treatment of AMD. The advantage for mining areas lays in the prevention during treatment of acid mine lakes. Nevertheless, this method presents only a niche solution due to the dependence on alkaline materials, e.g. fly ash. The development of further strategies and optimization during lake water treatment by in-lake liming might improve the effectiveness of the method. Using calcite instead of NaOH or CaO as liming agent will provide advantages in being more economic and ecological (CO2 bilance). In order to enhance efficiency the use of calcite in combination with CO2 can be a worth considering suggesting. If meteorological parameters (wind) and lake specific characteristics (morphology, currents, etc.) will be considered efforts and costs for in-lake liming will be minimized. / Der Abbau von Braunkohle im Lausitzer Bergbaurevier hat seit über 100 Jahren Tradition. Die abgebaute Braunkohle wird dabei hauptsächliche zur Energieerzeugung in den drei großen Kraftwerken Jänschwalde, Boxberg und Schwarze Pumpe genutzt. Mit einem jährlichen Kohlenstoffdioxid (CO2) – Ausstoß von circa 50 Millionen Tonnen gehören diese Kraftwerke zu Deutschlands größten CO2-Emittenten. Der Einfluss auf die Umwelt durch Tagebau-Betrieb ist von beträchtlichem Ausmaß und bringt große Probleme mit sich. Im Jahr 1990 betrug das Grundwasser-Defizit im Lausitzer Bergbaurevier 7 Milliarden m³ auf einer Fläche von circa 2100 km² (Luckner, 2006a). Dieses Defizit hat sich bis zum heutigen Zeitpunkt halbiert. Durch den Rückgang der Bergbauaktivitäten und die Beendigung der Wasserhaltungsmaßnahmen in den meisten Tagebauen, hat der ansteigende Grundwasserspiegel 28 Tagebaufolgeseen geschaffen (Zschiedrich, 2011). Der überwiegende Teil der Tagebaufolgeseen ist aufgrund der Pyritoxidation, welche AMD (acid mine drainage) produziert, hinsichtlich der Wasserqualitätsparameter stark beeinflusst (Luckner, 2006b, Klapper and Schultze, 1995, Schultze et al., 2010). Die Tagebaufolgeseen im Lausitzer Bergbaurevier sind durch niedrige pH-Werte (3 – 4), hoche Sulfat-Konzentrationen (bis zu 2800 ppm) und hohe Eisengehalte (100 – 150 ppm) gekennzeichnet. Die entstehenden Seen sind hauptsächlich durch aufsteigendes Grundwasser und Oberflächenwasser aus den Flüssen Spree und Neisse geflutet. Aufgrund der geringen Verfügbarkeit von Oberflächenwasser mussten weitere Sanierungsmaßnahmen für die Region untersucht werden. Zwischen 1970 und 1990 wurden im Tagebaufolgesee Burghammer circa 26 Millionen m³ Flugasche-Suspension als Aschekörper abgelagert, wobei eine Nutzung zu Sanierungszwecken angedacht war. Im Rahmen einer Aschesedimentumlagerung im Jahr 2001 wurde der pH-Wert des Seewassers kurzzeitig angehoben, eine nachhaltige Sanierung fand jedoch nicht statt. Auf Grundlage dieser Ergebnisse wurde im Rahmen dieser Dissertation untersucht, ob die abgelagerten Aschesedimente nachhaltiger durch Einsatz von CO2 reagieren. Ziel war es die Sanierung von Tagebaufolgeseen mit der Reduktion von CO2-Emissionen aus Kohlekraftwerken zu kombinieren. Diese CO2-Sequestrierung sollte durch die Bildung und Ablagerung von Carbonaten im Seesediment erfolgen. Die Gleichungen (1) und (2) beschreiben dabei die Fällungsreaktion von Carbonaten aus CO2 mit dem Alkalimetall M (aus Oxiden bzw. Hydroxiden): CO2 + MO → MCO3 (s) CO2 + M(OH)2 → MCO3 (s) + H2O Zur Carbonatfällung und nachhaltigen Ablagerung sind neutrale pH-Bedingungen notwendig. In Laboruntersuchungen konnte gezeigt werden, dass die 20 bis 30 Jahre alten Flugaschesedimente zur CO2-Sequestrierung in Kombination mit Seewasserbehandlung genutzt werden können. Zweiwertige Ionen (Ca2+, Mg2+) sind aus den Aschesedimenten eluierbar und stehen für die Fällungsreaktion zur Verfügung. Durchschnittlich 1 Masse-% reaktives Calcium befindet sich in den Sedimenten. Die abgelagerten Aschesedimente sind dabei weniger reaktiv als frische Flugaschen aus Kohlekraftwerken (z.B. Schwarze Pumpe). In Batch-Versuchen mit Tagebaufolgesee-Wasser konnte die Säure-Pufferkapazität auf maximal 7 mmol/L erhöht werden. Sequestrierungs-Raten von 17 g CO2/kg Aschesediment wurden im Rahmen der Versuche erreicht. Im Vergleich dazu betrugen die Sequestrierungs-Raten in Versuchen mit frischen Flugaschen bis 33 g CO2/kg Asche (Schipek and Merkel, 2008b, Schipek and Merkel, 2008a, Schipek, 2009). Auf Grundlage dieser Laborergebnisse wurde ein Feldversuch im Tagebaufolgesee Burghammer geplant. Während diesem wurden Gasinjektionslanzen bis in eine Sedimenttiefe von 12 m im abgelagerten Aschesediment installiert. Gasförmiges CO2 wurde mit einem durchschnittlichen Druck von 2.2 bar und 2.2 m³/h für eine Dauer von 3 Monaten injiziert. Während dieser Zeit fand ein kontinuierliches Monitoring des Seewassers im Bereich der Injektion statt. Veränderungen des Gehaltes an TIC (total inorganic carbon) aufgrund von Diffusionprozessen von CO2-gesättigtem Porenwasser aus dem Aschekörper waren beobachtbar. Da der Feldversuch nur in einem begrenzten Bereich des Tagebaufolgesees Burghammer stattfand und keine Initialneutralisierung vorsah, konnten keine weiteren, großmaßstäblichen Veränderungen im Wasserkörper festgestellt werden. Bohrkernentnahmen im Umfeld des Behandlungsgebietes lieferten Aussagen bezüglich der mineralogischen und geochemischen Beschaffenheit vor und nach CO2-Injektion. Im Porenwasser wurde keine Spurenmetall-(re)-mobilisierung durch die Behandlung mit CO2 festgestellt. Nahezu alle Elemente zeigten einen abnehmenden Trend durch die Behandlung mit CO2, bzw. keine signifikanten Veränderungen. Modellierte Sättigungsindizes für Calcit wiesen auf Gleichgewichtsbedingungen oder leichte Übersättigung bzgl. Calcit hin (SICalcit, Mittelwert +0.12; SICalcit, Median +0.31). Geochemische und mineralogische Untersuchungen zeigten, daß CO2-Sequestrierung mit einer durchschnittlichen Fällungsrate von 0.5 Masse-% (2.2 g CO2/kg Aschesediment) erreicht wurde. Die maximale Fällungsrate wurde mit 7.4 Masse-% Calcit bestimmt, dies entspricht einer Festlegung von 32.6 g CO2/ kg Aschesediment. Neben der Nutzung der abgelagerten Aschesedimente zur Behandlung des Tagebaufolgeseewassers wurden desweiteren Labor- und Feldversuche durchgeführt um In-Lake-Behandlungen mit industriellen Kalkprodukten zu optimieren. In Batch- und Säulenversuchen wurden verschiedene Kalkprodukte (synthetisches Marmorpulver und industrielle Produkte) getestet und untersucht. Signifikante Unterschiede auf die Reaktivität wurde bei erhöhten CO2-Partialdrücken (pCO2 > 3.8 • 10-4 bar) beobachtet. Wasserinhaltsstoffe, die typisch für AMD sind (z.B.. Mn2+, Cd2+, SO42-) zeigten einen signifikanten Einfluss auf die Calcit-Lösungskinetik. Mangankonzentrationen, wie sie in Lausitzer Tagebaufolgeseen vorkommen, zeigten – ebenso wie Cadmium - eine inhibitierende Wirkung auf die Kinetik. Im Vergleich zu Versuchen mit destilliertem Wasser wurden nur ungefähr 50 % der Calcium-Gleichgewichtskonzentration mit Cadmium als Inhibitor erreicht. Erhöhte CO2-Partialdrücke könnten genutzt werden, um die inhibitierende Wirkung von vorhanden Materialverunreinigungen und/oder Wasserinhaltsstoffen zu kompensieren. Säulenversuche zeigten, dass der mehrstufige Einsatz von Kalkprodukten die Effizienz während einer Seewasserbehandlung erhöht. Die Kombination einer Erstbehandlung mit Kalksteinmehl (bis pH 4.5), und einer Behandlungsfortsetzung mit Ca(OH)2 erwies sich als wirkungsvollste Methode. Dieses Behandlungsschema (Initialneutralisation, 6 Nachfolgebehandlungen) wurde im Tagebaufolgesee Burghammer von März 2009 – Dezember 2010 erfolgreich angewandt. Zusammenfassend lässt sich sagen, dass in ehemaligen Bergbaurevieren die In-Lake-Behandlung von Tagebaufolgeseen eine zukunftsträchtige Methode zur Behandlung von Wasserqualitätsproblemen darstellt. Die Nutzung von gasförmigen CO2 in Kombination mit industriellen „Abfall-Produkten“ kann als nachhaltige Methode zur CO2-Sequestrierung und zur Behandlung von AMD bezeichnet werden. Der Vorteil in Bergbaurevieren liegt dabei in der Vorbeugung der Entstehung von Wasserqualitätsproblemen. Dennoch stellt diese Methode nur eine Nischenlösung aufgrund der Verfügbarkeit der alkalischen Materialien (Flugasche) dar. Die Entwicklung und Optimierung weiterführender Strategien zur In-Lake-Behandlung durch Kalkung wird zur Effizienzerhöhung beitragen. Die Nutzung von Kalksteinmehl anstelle von NaOH bzw. CaO als Neutralisationsprodukt wird Vorteile hinsichtlich ökonomischer und ökologischer Sicht (CO2-Bilanz) mit sich führen. Um die Effizienz beim Einsatz von Kalksteinmehl zu steigern, kann der Einsatz von CO2 in Betracht gezogen werden. Sobald meteorologische Parameter (Wind) und see-spezifische Merkmale (Morphologie, Strömungen, etc.) berücksichtigt werden, kann der Aufwand und die Kosten für In-Lake-Behandlungen minimiert werden.

Mining of lignite in Lusatia has a long history of over 100 years. The extracted brown coal is utilized to generate electricity in three large power plants: Jänschwalde, Boxberg, and Schwarze Pumpe. With an annual carbon dioxide (CO2) output of approximately 50 million tons, these power plants are among Germany’s large-scale CO2 emitters. The environmental impact from open-pit mining is of a considerable degree and currently poses a challenging problem. The groundwater deficit in 1990 was 7 billion m3 over a surface area of approximately 2100 km2 (Luckner, 2006a) and was bisected in value until today. Due to the decline of mining activity and the termination of mine drainage at most open pits in the Lusatian region, the groundwater table has recovered forming 28 pit lakes (Zschiedrich, 2011). The majority of the post mining lakes do not meet the quality standards for pH, iron or sulfate parameters; because of pyrite oxidation that produces acid mine drainage (Luckner, 2006b, Klapper and Schultze, 1995, Schultze et al., 2010). The post mining lakes in Lusatia have low pH values (3 – 4), high sulfate contents (up to 2800 ppm) as well as high iron concentrations (100 – 150 ppm). Lakes are flooded by groundwater and using surface water from Spree and Neisse River to achieve fast filling and dilution; however, due to the limited availability of surface water, further rehabilitation strategies for the region had to be investigated. Between 1970 and 1990, approximately 26 million m3 of suspended fly ash were deposited in the lake Burghammer and settled as an ash body at its base; where it may be used for rehabilitation. In a first experiment conducted in 2001 material from the ash body was picked up and redistributed throughout the lake. By this treatment the pH of the lake was raised temporarily; however, a sustainable remediation was not achieved. Based on these experiments it was investigated whether the ash reacts more sufficiently through additional CO2 injection or not. Aim was to combine the rehabilitation of acid mine lakes with the utilization of atmospheric carbon dioxide emissions from coal-fired power plants. The CO2 sequestration is achieved through the generation and accumulation of carbonates in the lake. The following equations describe the precipitation of carbonate by using CO2 and alkaline earth cations M: CO2 + MO → MCO3 (s) CO2 + M(OH)2 → MCO3 (s) + H2O Therefore, neutral pH conditions are necessary for the long-term accumulation of carbonates in the lakes. In laboratory investigations it was shown, that the 20 to 30 years old fly ash deposits of lake Burghammer can be used for carbonate sequestration and lake water treatment. Bivalent ions (Ca2+, Mg2+) are eluable and available for carbonate precipitation; on average we assumed 1 wt.-% of reactive calcium to be contained in the settled ash sediments. Settled fly ash sediments are less reactive than fresh fly ash from a power plant (e.g. Schwarze Pumpe). During batch experiments, we increased the buffering capacity to maximum values of 7 mmol/L. Beforehand no buffering capacity exists due to the low pH of 2.9 in the lake. Batch investigations provided a sequestration potential of 17 g CO2/kg ash sediment; in comparison fresh fly ash results in a sequestration potential of 33 g CO2/kg ash (Schipek and Merkel, 2008b, Schipek and Merkel, 2008a, Schipek, 2009). Based on the laboratory results a field experiment was conducted. In this field experiment gas injection lances were installed to a sediment depth of 12 m. Gaseous CO2 was applied with a pressure of 2.2 bar and 2.2 m³/h for 3 months and lake water was monitored during injection. Variations in total inorganic carbon due to diffusion processes of CO2 saturated pore waters could be observed. As the pilot experiment comprised only a small area of lake Burghammer no initial neutralisition (e.g. by a suction excavator) was possible. Thus, no further changes in water chemistry were observed. Drilling cores in the vicinity of the injection area provided mineralogical and geochemical conditions before and after CO2 treatment. No trace metal mobilization was found during CO2 injection. Most elements showed decreasing trends or didn’t change significantly. Calculated saturation indices for calcite indicated equilibrium conditions or slightly oversaturated conditions (SICalcite,average +0.12; SICalcite,median +0.31). Geochemical and mineralogical investigations proved that CO2 sequestration is possible with an average precipitation rate of 0.5 wt.-% (2.2 g CO2/kg). The maximum rate for carbonate precipitation was determined with 7.4 wt.-% Calcite, according to 32.6 g CO2 per kilogram treated ash. Besides the use of the settled fly ash as neutralizing agent in acidic mining lakes, laboratory and field investigations were conducted in order to improve in-lake liming. In batch and columns experiments, different liming agents (synthetic marble powder and industrial products) were tested and investigated. Significant differences in reactivity were obvious at pCO2 > 3.8 • 10-4 atm. Ions typical for acid mine drainage (e.g. Mn2+, Cd2+, SO42-) do have different effects on the kinetic of carbonate dissolution. Manganese concentrations typical for acidic mining lakes inhibit calcite dissolution. Cadmium has as well a significant influence on dissolution and kinetics. Only circa 50 % of the calcium concentration was reached with cadmium as inhibitor compared to the dissolution in pure water. Increased CO2 partial pressure might be used to compensate inhibtion by material impurities and/or water constituents. Column experiments showed that a multi-stage application of liming agent increases the efficiency of a lake treatment. The combination of a first application of calcite (up to pH 4.5) and further application of Ca(OH)2 seemed to be the most promising method. This treatment sheme was successfully applied in lake Burghammer from March 2009 – December 2010 (initial neutralisation and 6 follow-up treatments). Finally, it can be concluded, that in lignite mining districts in-lake treatment of acidic mining lakes is a seminal method to handle water quality problems. Using gaseous CO2 in combination with industrial by-products can be accounted as sustainable method for CO2 sequestration and for treatment of AMD. The advantage for mining areas lays in the prevention during treatment of acid mine lakes. Nevertheless, this method presents only a niche solution due to the dependence on alkaline materials, e.g. fly ash. The development of further strategies and optimization during lake water treatment by in-lake liming might improve the effectiveness of the method. Using calcite instead of NaOH or CaO as liming agent will provide advantages in being more economic and ecological (CO2 bilance). In order to enhance efficiency the use of calcite in combination with CO2 can be a worth considering suggesting. If meteorological parameters (wind) and lake specific characteristics (morphology, currents, etc.) will be considered efforts and costs for in-lake liming will be minimized. / Der Abbau von Braunkohle im Lausitzer Bergbaurevier hat seit über 100 Jahren Tradition. Die abgebaute Braunkohle wird dabei hauptsächliche zur Energieerzeugung in den drei großen Kraftwerken Jänschwalde, Boxberg und Schwarze Pumpe genutzt. Mit einem jährlichen Kohlenstoffdioxid (CO2) – Ausstoß von circa 50 Millionen Tonnen gehören diese Kraftwerke zu Deutschlands größten CO2-Emittenten. Der Einfluss auf die Umwelt durch Tagebau-Betrieb ist von beträchtlichem Ausmaß und bringt große Probleme mit sich. Im Jahr 1990 betrug das Grundwasser-Defizit im Lausitzer Bergbaurevier 7 Milliarden m³ auf einer Fläche von circa 2100 km² (Luckner, 2006a). Dieses Defizit hat sich bis zum heutigen Zeitpunkt halbiert. Durch den Rückgang der Bergbauaktivitäten und die Beendigung der Wasserhaltungsmaßnahmen in den meisten Tagebauen, hat der ansteigende Grundwasserspiegel 28 Tagebaufolgeseen geschaffen (Zschiedrich, 2011). Der überwiegende Teil der Tagebaufolgeseen ist aufgrund der Pyritoxidation, welche AMD (acid mine drainage) produziert, hinsichtlich der Wasserqualitätsparameter stark beeinflusst (Luckner, 2006b, Klapper and Schultze, 1995, Schultze et al., 2010). Die Tagebaufolgeseen im Lausitzer Bergbaurevier sind durch niedrige pH-Werte (3 – 4), hoche Sulfat-Konzentrationen (bis zu 2800 ppm) und hohe Eisengehalte (100 – 150 ppm) gekennzeichnet. Die entstehenden Seen sind hauptsächlich durch aufsteigendes Grundwasser und Oberflächenwasser aus den Flüssen Spree und Neisse geflutet. Aufgrund der geringen Verfügbarkeit von Oberflächenwasser mussten weitere Sanierungsmaßnahmen für die Region untersucht werden. Zwischen 1970 und 1990 wurden im Tagebaufolgesee Burghammer circa 26 Millionen m³ Flugasche-Suspension als Aschekörper abgelagert, wobei eine Nutzung zu Sanierungszwecken angedacht war. Im Rahmen einer Aschesedimentumlagerung im Jahr 2001 wurde der pH-Wert des Seewassers kurzzeitig angehoben, eine nachhaltige Sanierung fand jedoch nicht statt. Auf Grundlage dieser Ergebnisse wurde im Rahmen dieser Dissertation untersucht, ob die abgelagerten Aschesedimente nachhaltiger durch Einsatz von CO2 reagieren. Ziel war es die Sanierung von Tagebaufolgeseen mit der Reduktion von CO2-Emissionen aus Kohlekraftwerken zu kombinieren. Diese CO2-Sequestrierung sollte durch die Bildung und Ablagerung von Carbonaten im Seesediment erfolgen. Die Gleichungen (1) und (2) beschreiben dabei die Fällungsreaktion von Carbonaten aus CO2 mit dem Alkalimetall M (aus Oxiden bzw. Hydroxiden): CO2 + MO → MCO3 (s) CO2 + M(OH)2 → MCO3 (s) + H2O Zur Carbonatfällung und nachhaltigen Ablagerung sind neutrale pH-Bedingungen notwendig. In Laboruntersuchungen konnte gezeigt werden, dass die 20 bis 30 Jahre alten Flugaschesedimente zur CO2-Sequestrierung in Kombination mit Seewasserbehandlung genutzt werden können. Zweiwertige Ionen (Ca2+, Mg2+) sind aus den Aschesedimenten eluierbar und stehen für die Fällungsreaktion zur Verfügung. Durchschnittlich 1 Masse-% reaktives Calcium befindet sich in den Sedimenten. Die abgelagerten Aschesedimente sind dabei weniger reaktiv als frische Flugaschen aus Kohlekraftwerken (z.B. Schwarze Pumpe). In Batch-Versuchen mit Tagebaufolgesee-Wasser konnte die Säure-Pufferkapazität auf maximal 7 mmol/L erhöht werden. Sequestrierungs-Raten von 17 g CO2/kg Aschesediment wurden im Rahmen der Versuche erreicht. Im Vergleich dazu betrugen die Sequestrierungs-Raten in Versuchen mit frischen Flugaschen bis 33 g CO2/kg Asche (Schipek and Merkel, 2008b, Schipek and Merkel, 2008a, Schipek, 2009). Auf Grundlage dieser Laborergebnisse wurde ein Feldversuch im Tagebaufolgesee Burghammer geplant. Während diesem wurden Gasinjektionslanzen bis in eine Sedimenttiefe von 12 m im abgelagerten Aschesediment installiert. Gasförmiges CO2 wurde mit einem durchschnittlichen Druck von 2.2 bar und 2.2 m³/h für eine Dauer von 3 Monaten injiziert. Während dieser Zeit fand ein kontinuierliches Monitoring des Seewassers im Bereich der Injektion statt. Veränderungen des Gehaltes an TIC (total inorganic carbon) aufgrund von Diffusionprozessen von CO2-gesättigtem Porenwasser aus dem Aschekörper waren beobachtbar. Da der Feldversuch nur in einem begrenzten Bereich des Tagebaufolgesees Burghammer stattfand und keine Initialneutralisierung vorsah, konnten keine weiteren, großmaßstäblichen Veränderungen im Wasserkörper festgestellt werden. Bohrkernentnahmen im Umfeld des Behandlungsgebietes lieferten Aussagen bezüglich der mineralogischen und geochemischen Beschaffenheit vor und nach CO2-Injektion. Im Porenwasser wurde keine Spurenmetall-(re)-mobilisierung durch die Behandlung mit CO2 festgestellt. Nahezu alle Elemente zeigten einen abnehmenden Trend durch die Behandlung mit CO2, bzw. keine signifikanten Veränderungen. Modellierte Sättigungsindizes für Calcit wiesen auf Gleichgewichtsbedingungen oder leichte Übersättigung bzgl. Calcit hin (SICalcit, Mittelwert +0.12; SICalcit, Median +0.31). Geochemische und mineralogische Untersuchungen zeigten, daß CO2-Sequestrierung mit einer durchschnittlichen Fällungsrate von 0.5 Masse-% (2.2 g CO2/kg Aschesediment) erreicht wurde. Die maximale Fällungsrate wurde mit 7.4 Masse-% Calcit bestimmt, dies entspricht einer Festlegung von 32.6 g CO2/ kg Aschesediment. Neben der Nutzung der abgelagerten Aschesedimente zur Behandlung des Tagebaufolgeseewassers wurden desweiteren Labor- und Feldversuche durchgeführt um In-Lake-Behandlungen mit industriellen Kalkprodukten zu optimieren. In Batch- und Säulenversuchen wurden verschiedene Kalkprodukte (synthetisches Marmorpulver und industrielle Produkte) getestet und untersucht. Signifikante Unterschiede auf die Reaktivität wurde bei erhöhten CO2-Partialdrücken (pCO2 > 3.8 • 10-4 bar) beobachtet. Wasserinhaltsstoffe, die typisch für AMD sind (z.B.. Mn2+, Cd2+, SO42-) zeigten einen signifikanten Einfluss auf die Calcit-Lösungskinetik. Mangankonzentrationen, wie sie in Lausitzer Tagebaufolgeseen vorkommen, zeigten – ebenso wie Cadmium - eine inhibitierende Wirkung auf die Kinetik. Im Vergleich zu Versuchen mit destilliertem Wasser wurden nur ungefähr 50 % der Calcium-Gleichgewichtskonzentration mit Cadmium als Inhibitor erreicht. Erhöhte CO2-Partialdrücke könnten genutzt werden, um die inhibitierende Wirkung von vorhanden Materialverunreinigungen und/oder Wasserinhaltsstoffen zu kompensieren. Säulenversuche zeigten, dass der mehrstufige Einsatz von Kalkprodukten die Effizienz während einer Seewasserbehandlung erhöht. Die Kombination einer Erstbehandlung mit Kalksteinmehl (bis pH 4.5), und einer Behandlungsfortsetzung mit Ca(OH)2 erwies sich als wirkungsvollste Methode. Dieses Behandlungsschema (Initialneutralisation, 6 Nachfolgebehandlungen) wurde im Tagebaufolgesee Burghammer von März 2009 – Dezember 2010 erfolgreich angewandt. Zusammenfassend lässt sich sagen, dass in ehemaligen Bergbaurevieren die In-Lake-Behandlung von Tagebaufolgeseen eine zukunftsträchtige Methode zur Behandlung von Wasserqualitätsproblemen darstellt. Die Nutzung von gasförmigen CO2 in Kombination mit industriellen „Abfall-Produkten“ kann als nachhaltige Methode zur CO2-Sequestrierung und zur Behandlung von AMD bezeichnet werden. Der Vorteil in Bergbaurevieren liegt dabei in der Vorbeugung der Entstehung von Wasserqualitätsproblemen. Dennoch stellt diese Methode nur eine Nischenlösung aufgrund der Verfügbarkeit der alkalischen Materialien (Flugasche) dar. Die Entwicklung und Optimierung weiterführender Strategien zur In-Lake-Behandlung durch Kalkung wird zur Effizienzerhöhung beitragen. Die Nutzung von Kalksteinmehl anstelle von NaOH bzw. CaO als Neutralisationsprodukt wird Vorteile hinsichtlich ökonomischer und ökologischer Sicht (CO2-Bilanz) mit sich führen. Um die Effizienz beim Einsatz von Kalksteinmehl zu steigern, kann der Einsatz von CO2 in Betracht gezogen werden. Sobald meteorologische Parameter (Wind) und see-spezifische Merkmale (Morphologie, Strömungen, etc.) berücksichtigt werden, kann der Aufwand und die Kosten für In-Lake-Behandlungen minimiert werden.

Anthropogenic lakes constitute a significant part of the Czech countryside water component which has not been given sufficient attention so far. The presented thesis deals with the assessment of variability of physico-chemical properties of water in 30 selected pit lakes in order to identify specific features associated with quarrying of different mineral raw materials, basin morphometry and trophic level of the lakes affecting the quality of accumulated water. In the second part of the thesis the author deals with the comprehensive limnological study of the Hromnické Lake with extreme water chemism resulting from excavation of pyritic shales and focuses on the phenomenon of meromixis especially. The results are based on the evaluation of physical properties of water in the lake vertical profile (temperature, conductivity, dissolved oxygen, pH, transparency and colour) and chemical analyzes of water samples collected from the surface and bottom of the lakes during the four seasons in 2003-07 (determination of Ca, Mg, Na, K, Nammon., NO3 - , SO4 2- , Cl- and alkalinity), including determination of chlorophyll-a. In the case study of the Hromnické Lake conducted in 2010-11, the analysis of hydrological regime of the lake, determination of PO4 3- , TOC, selected metals (Fe, Mn, Al, Zn, Ni, Cu, Co,...