<p>Benzofenoni&nbsp; i&nbsp; kofein&nbsp; su&nbsp; sveprisutni,&nbsp; kako&nbsp; u&nbsp; otpadnim,&nbsp; tako&nbsp; i&nbsp; u<br />povr&scaron;inskim vodama, u koncentracijama od nekoliko ng/l do mg/l. Koriste se<br />u proizvodnji kozmetičkih preparata, kao&nbsp; pojačivači mirisa i ukusa, fiksatori<br />u&nbsp; parfemima,&nbsp; aditivi&nbsp; u&nbsp; plastici,&nbsp; sredstvima&nbsp; za&nbsp; či&scaron;ćenje,&nbsp; u&nbsp; proizvodnji<br />pesticida.&nbsp; Benzofenoni&nbsp; su&nbsp; UV&nbsp; filteri&nbsp; pa&nbsp; se&nbsp; često&nbsp; koriste&nbsp; u&nbsp; proizvodnji<br />sunčanih&nbsp; naočara,&nbsp; kao&nbsp; i&nbsp; u&nbsp; proizvodnji&nbsp; sapuna&nbsp; i&nbsp; parfema,&nbsp; sprečavajući&nbsp; UV<br />zrake&nbsp; da&nbsp; o&scaron;tete&nbsp; miris&nbsp; ili&nbsp; boju&nbsp; proizvoda.&nbsp; BP-3&nbsp; se&nbsp; najče&scaron;će&nbsp; koristi&nbsp; u<br />kozmetičkoj&nbsp; industriji&nbsp; kao&nbsp; UV&nbsp; filter&nbsp; u&nbsp; kremama&nbsp; za&nbsp; sunčanje,&nbsp; losionima&nbsp; za<br />telo,&nbsp; &scaron;amponima,&nbsp; bojama&nbsp; i&nbsp; sprejevima&nbsp; za&nbsp; kosu.&nbsp; Kofein&nbsp; se&nbsp; primenjuje&nbsp; u<br />proizvodnji&nbsp; prehrambenih&nbsp; proizvoda,&nbsp; lekova&nbsp; i&nbsp; kozmetičkih&nbsp; preparata.<br />Značajno&nbsp; se&nbsp; razlikuju&nbsp; po&nbsp; hidrofilnosti&nbsp; (benzofenon&nbsp; log&nbsp; Kow&nbsp; 3,18;<br />benzofenon-3&nbsp; log&nbsp; Kow&nbsp; 3,79;&nbsp; kofein&nbsp; log&nbsp; Kow&nbsp; -0,07).&nbsp; Usled&nbsp; nedostatka<br />podataka o sadržaju odabranih predstavnika benzofenona (benzofenon (BP) i<br />benzofenon-3(BP-3)) i kofeina (CF)&nbsp; u različitim tipovima vode&nbsp; (pre svega u<br />lokalnim&nbsp; otpadnim&nbsp; vodama&nbsp; i&nbsp; rečnoj&nbsp; vodi)&nbsp; i&nbsp; njihovom&nbsp; pona&scaron;anju&nbsp; u<br />tretmanima&nbsp; voda,&nbsp; izvr&scaron;ena&nbsp; su&nbsp; ispitivanja&nbsp; u&nbsp; efluentu&nbsp; tipičnog&nbsp; postrojenja&nbsp; za<br />preradu&nbsp; otpadnih&nbsp; voda&nbsp; i&nbsp; rečnoj&nbsp; vodi&nbsp; Dunava.&nbsp; Utvrđeno&nbsp; je&nbsp; da&nbsp; su&nbsp; sve&nbsp; tri<br />komponente&nbsp; prisutne&nbsp; u&nbsp; efluentu&nbsp; WWTP&nbsp; (BP&nbsp; od&nbsp; 0,112&nbsp; &micro;g/l&nbsp; do&nbsp; 0,146&nbsp; &micro;g/l;<br />BP-3 od 0,00718 &micro;g/l do 0,42 &micro;g/l; CF od 0,2 &micro;g/l do 12 &micro;g/l) i u Dunavu<br />(maksimalno detektovana koncentracija je za BP 0,95 &micro;g/l, za BP-3 0,62 &micro;g/l<br />i&nbsp; za&nbsp; CF&nbsp; 0,7&nbsp; &micro;g/l).&nbsp; Pored&nbsp; ispitivanja&nbsp; sadržaja&nbsp; ovih&nbsp; jedinjenja&nbsp; ispitana&nbsp; je<br />efikasnost nekonvencionalnih procesa u obradi efluenta WWTP&nbsp; (adsorpcija,<br />koagulacije,&nbsp; PAC/CoA,&nbsp; PAC/UF)&nbsp; i&nbsp; konvencionalnih&nbsp; (adsorpcija,<br />koagulacija)&nbsp; i&nbsp; nekonvencionalnih procesa (PAC/CoA, PAC/UF, CoA/UF)&nbsp; u<br />obradi&nbsp; rečne&nbsp; vode.&nbsp; Pored&nbsp; toga&nbsp; ispitani&nbsp; su&nbsp; efekti&nbsp; prirodnih&nbsp; procesa<br />preči&scaron;ćavanja u rečnoj vodi.<br />Nekonvencionalni&nbsp; procesi&nbsp; za&nbsp; preči&scaron;ćavanje&nbsp; otpadnih&nbsp; voda&nbsp; su&nbsp; ispitani&nbsp; pri<br />početnoj&nbsp; koncentraciji&nbsp; supstanci&nbsp; od&nbsp; 0,96&nbsp; &micro;g/l&nbsp; do&nbsp; 2&nbsp; &micro;g/l.&nbsp; Adsorpcija&nbsp; naaktivnom&nbsp; uglju&nbsp; u&nbsp; prahu&nbsp; se&nbsp; pokazala&nbsp; efikasnom&nbsp; (benzofenoni&nbsp; se&nbsp; uklanjaju<br />&gt;84%&nbsp; -&nbsp; &gt;94% u zavisnosti od doze uglja, a kofein je moguće ukloniti i do<br />84%).&nbsp; Koagulacija&nbsp; dozama&nbsp; prirodnog&nbsp; koagulanta&nbsp; od&nbsp; 0,0375&nbsp; ml/l&nbsp; i<br />komercijalnog koagulanta&nbsp; FeCl₃od 4 mg Fe ³⁺ /l se&nbsp; pokazala&nbsp; neefikasnom za<br />sve&nbsp; supstance&nbsp; (&lt;20%).&nbsp; Hibridni&nbsp; PAC/CoA&nbsp; koji&nbsp; je&nbsp; ispitivan&nbsp; sa&nbsp; različitim<br />dozama&nbsp; aktivnog&nbsp; uglja&nbsp; u&nbsp; prahu&nbsp; (5&nbsp; i&nbsp; 20&nbsp; mg/l),&nbsp; prirodnim&nbsp; koagulantom<br />(0,0375 ml/l)&nbsp; ili&nbsp; komercijalnim&nbsp; koagulantom&nbsp; (4 mg Fe ³⁺ /l),&nbsp; pokazao&nbsp; se&nbsp; kao<br />efikasan za uklanjanje BP, BP-3 i CF sa većom dozom&nbsp; uglja A od 20 mg/l (&gt;88%).&nbsp; Hibridni membranski proces&nbsp; PAC/UF je pokazao&nbsp; visoku efikasnost za uklanjanje BP-3 (&gt;68%) i CF (&gt;99,95%) sa dozom uglja od 20 mg/l. Ispitivanjem&nbsp; biodegradacije&nbsp; BP,&nbsp; BP-3&nbsp; i&nbsp; CF&nbsp; primenom&nbsp; laboratorijskog&nbsp; test filtra, postignuta je efikasnost uklanjanja pri koncentraciji od 20 &micro;g/l od&nbsp; 90% do&nbsp; 99%&nbsp; i&nbsp; pokazano&nbsp; da&nbsp; su&nbsp; supstance&nbsp; biodegradabilne.&nbsp; Testovi&nbsp; toksičnosti pokazali&nbsp; su&nbsp; značajno&nbsp; smanjenje&nbsp; ukupne&nbsp; toksičnosti&nbsp; sme&scaron;a&nbsp; tokom laboratorijskog&nbsp; testa,&nbsp; a&nbsp; rezidualna&nbsp; toksičnost&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; <em>D.&nbsp; magna</em>&nbsp; može biti&nbsp; posledica&nbsp; nedetektovanih&nbsp; transformacionih&nbsp; produkata.&nbsp; Transportom supstanci kroz sediment Dunava&nbsp; uočeno je da&nbsp; sediment predstavlja efikasnu barijeru&nbsp; za&nbsp; oba&nbsp; testirana&nbsp; benzofenona,&nbsp; dok&nbsp; CF&nbsp; lako&nbsp; prolazi&nbsp; usled&nbsp; svoje mobilnosti (log Kow -0,07). Eksperimentima fotodegradacije potvrđeno je da degradacija benzofenona UV zračanjem&nbsp; zavisi od prisustva&nbsp; anjona (HCO₃ -, Cl i SO₄^2-)&nbsp; i DOC&nbsp; u vodenom matriksu. Iako primenjeno UV zračenje nije bilo&nbsp; realno&nbsp; za&nbsp; dezinfekciju&nbsp; u&nbsp; tretmanima&nbsp; voda,&nbsp; rezultati&nbsp; su&nbsp; pokazali značaj detaljnije&nbsp; procene&nbsp; kvaliteta&nbsp; vode&nbsp; u&nbsp; slučajevima&nbsp; kada&nbsp; se&nbsp; UV&nbsp; zračenje primenjuje.Za uklanjanje odabranih supstanci iz rečne vode ispitani su&nbsp; konvencionalni procesi&nbsp; (zasebno&nbsp; adsorpcija&nbsp; na&nbsp; aktivnom&nbsp; uglju&nbsp; u&nbsp; prahu&nbsp; i&nbsp; koagulacija komercijalnim&nbsp; koagulantom,&nbsp; BOPAC &reg; )&nbsp; i&nbsp; hibridni&nbsp; ili&nbsp; nekonvencionalni<br />procesi&nbsp; adsorpcije/koagulacije&nbsp; (PAC/CoA),&nbsp; adsorpcije/ultrafiltracije (PAC/UF) kao i koagulacije/ultrafiltracije (CoA/UF). Tokom ispitivanja PAC/CoA sa ugljem B (2 mg/l) i BOPAC &reg; (2 mg Al ³⁺ /l) u određenim&nbsp; procesnim&nbsp; kombinacijama,&nbsp; (tokom&nbsp; sukcesivnog&nbsp; dodavanja&nbsp; prvo uglja&nbsp; B,&nbsp; a&nbsp; zatim&nbsp; koagulanta)&nbsp; uočene&nbsp; su&nbsp; specifičnosti&nbsp; za&nbsp; BP,&nbsp; efikasnost uklanjanja BP je iznosila 92%. U slučaju doziranja prvo koagulanta, a zatim uglja&nbsp; B&nbsp; i&nbsp; tokom&nbsp; simultanog&nbsp; doziranja&nbsp; koagulanta&nbsp; i&nbsp; uglja&nbsp; B,&nbsp; efikasnosti&nbsp; su iznosile&nbsp; 23&nbsp; i&nbsp; 20%,&nbsp; redom.&nbsp; To&nbsp; je&nbsp; verovatno&nbsp; posledica&nbsp; kompeticije&nbsp; iliblokiranja pora&nbsp; uglja&nbsp; POM iz rečne vode.&nbsp; BP-3 se efikasno uklanjao tokom svih procesnih kombinacija sa ugljem B (87-93%), dok je za CF efikasnost<br />uklanjanja iznosila&nbsp; od 0-12%.&nbsp; Hibridni procesi su se pokazali efikasniji pri<br />primeni uglja C. U slučaju BP efikasnost je iznosila 81-90% i za CF 17-27% ,dok&nbsp; je&nbsp; za&nbsp; BP-3&nbsp; efikasnost&nbsp; iznosila&nbsp; od&nbsp; 71%&nbsp; do&nbsp; 96%.&nbsp; Hibridni&nbsp; membranski procesi&nbsp; PAC/UF&nbsp; i&nbsp; CoA/UF&nbsp; u&nbsp; obradi&nbsp; rečne&nbsp; vode&nbsp; efikasni&nbsp; su&nbsp; u&nbsp; uklanjanju supstanci&nbsp; sa&nbsp; visokim&nbsp; log&nbsp; Kow.&nbsp; Benzofenoni&nbsp; su&nbsp; u&nbsp; hibridnim&nbsp; membranskim procesima&nbsp; uklonjeni&nbsp; od&nbsp; 69%-96% iz rečne&nbsp; vode, dok su za kofein utvrđeni promenljivi rezultati i potreba za daljim istraživanjima.</p> / <p>Benzophenones and caffeine are ubiquitous&nbsp; in wastewaters&nbsp; and in surface&nbsp; waters,&nbsp; in&nbsp; concentrations&nbsp; that&nbsp; vary&nbsp; from&nbsp; ng/L&nbsp; to&nbsp; mg/L. Benzophenones&nbsp; are&nbsp; used&nbsp; as:&nbsp; smell&nbsp; and&nbsp; flavor&nbsp; enhancers,&nbsp; perfume&nbsp; fixers, plastic additives, cleaning agents, as well as in the pesticide manufacturing processes.&nbsp; Their&nbsp; UV-resistant&nbsp; properties,&nbsp; makes&nbsp; benzophenones&nbsp; a&nbsp; suitable packaging component&nbsp; &ndash;&nbsp; to&nbsp; prevent UV light from damaging the odor or the color of the product. Similarly, benzophenone-3 is most commonly used in the&nbsp; cosmetics&nbsp; industry;&nbsp; as&nbsp; a&nbsp; UV&nbsp; filter&nbsp; agent&nbsp; in&nbsp; sunscreens,&nbsp; body&nbsp; lotions, shampoos, paints and hair sprays.&nbsp; On the other hand, caffeine is prevalent in food-,&nbsp; pharmaceutical-&nbsp; and&nbsp; cosmetics-manufacturing.&nbsp; However, benzophenones&nbsp; and&nbsp; caffeine&nbsp; have&nbsp; significantly&nbsp; different&nbsp; log&nbsp; Kow&nbsp; values. Log Kow values for benzophenone and benzophenone-3 are 3.18 and 3.79,respectively, while for caffeine log Kow is&nbsp; -0.07.&nbsp; Due to the lack of data on the&nbsp; content&nbsp; of&nbsp; selected&nbsp; benzophenones,&nbsp; (benzophenone&nbsp; (BP)&nbsp; and benzophenone-3&nbsp; (BP-3))&nbsp; and&nbsp; caffeine&nbsp; (CF)&nbsp; in&nbsp; different&nbsp; types&nbsp; of&nbsp; water (primarily in local wastewater and&nbsp; river water) and their behavior in water treatments, tests were&nbsp; carried out: a) in the effluent of a typical wastewater treatment&nbsp; plant (WWTP);&nbsp; b) and&nbsp; in&nbsp; the river Danube.&nbsp; In case of the WWTP effluent, the presence of all three compounds was detected in the following ranges: 0.112 &mu;g/L to 0.146 &mu;g/L for BP, 0.00718 &mu;g/L to 0.42 &mu;g/L for BP-3,&nbsp; and&nbsp; 0.2&nbsp; &mu;g/L&nbsp; to&nbsp; 12&nbsp; &mu;g/L&nbsp; for&nbsp; CF.&nbsp; With&nbsp; respect&nbsp; to&nbsp; the&nbsp; Danube&nbsp; river,&nbsp; the highest&nbsp; detected&nbsp; concentration&nbsp; for&nbsp; BP&nbsp; was&nbsp; 0.95 &mu;g/L,&nbsp; for&nbsp; BP-3&nbsp; was 0.62 &mu;g/L,&nbsp; while&nbsp; CF&nbsp; in&nbsp; Danube&nbsp; river&nbsp; sample&nbsp; was&nbsp; measured&nbsp; in&nbsp; only&nbsp; one sample, resulting in a concentration of 0.7 &mu;g/L. In addition, this&nbsp; work has investigated&nbsp; the&nbsp; efficacy&nbsp; of&nbsp; several&nbsp; treatment&nbsp; processes:&nbsp; unconventional processes&nbsp; in&nbsp; the&nbsp; WWTP&nbsp; effluent&nbsp; treatment&nbsp; (adsorption,&nbsp; coagulation, PAC/CoA, PAC/UF);&nbsp; as well as the&nbsp; conventional (adsorption, coagulation) and&nbsp; unconventional&nbsp; processes&nbsp; (PAC/CoA,&nbsp; PAC/UF,&nbsp; CoA/UF)&nbsp; in&nbsp; the treatment&nbsp; of&nbsp; river&nbsp; waters.&nbsp; Furthermore,&nbsp; the&nbsp; effects&nbsp; of&nbsp; natural&nbsp; purification processes&nbsp; in&nbsp; river&nbsp; water&nbsp; had&nbsp; also&nbsp; been&nbsp; examined&nbsp; within&nbsp; the&nbsp; scope&nbsp; of&nbsp; this research.Unconventional&nbsp; wastewater&nbsp; treatment&nbsp; processes&nbsp; were&nbsp; investigated&nbsp; at&nbsp; initial concentrations&nbsp; of&nbsp; selected substances&nbsp; that ranged&nbsp; from 0.96 &mu;g/L to 2 &mu;g/L. Adsorption&nbsp; on&nbsp; powder&nbsp; activated&nbsp; carbon&nbsp; was&nbsp; effective&nbsp; for&nbsp; removal&nbsp; of benzophenones&nbsp; (&gt; 84%&nbsp; -&gt; 94%)&nbsp; and caffeine&nbsp; (84%),&nbsp; depending on the&nbsp; dose of PAC A. Coagulation with doses of&nbsp; natural coagulant of 0.0375 mL/L&nbsp; and commercial&nbsp; coagulant&nbsp; FeCl 3 of&nbsp; 4&nbsp; mg&nbsp; Fe 3+ /L&nbsp; was&nbsp; ineffective&nbsp; for&nbsp; all substances&nbsp; (&lt;20%).&nbsp; Hybrid&nbsp; PAC/CoA&nbsp; process,&nbsp; investigated&nbsp; with&nbsp; different doses&nbsp; of&nbsp; PAC&nbsp; A&nbsp; (5&nbsp; and&nbsp; 20&nbsp; mg/L),&nbsp; natural&nbsp; coagulant&nbsp; (0.0375&nbsp; mL/L)&nbsp; or commercial coagulant (4 mg Fe 3+ /L), proved to be effective for&nbsp; the removal of BP, BP-3 and CF at a higher PAC A dose of 20 mg/L (&gt; 88%). The hybrid membrane process PAC/UF proved to be highly effective in the&nbsp; removal of BP-3 (&gt; 68%) and CF (&gt; 99.95%) with&nbsp; 20 mg/L&nbsp; of&nbsp; PAC A.&nbsp; Biodegradation of BP, BP-3 and CF had been confirmed in Danube river water sample using a&nbsp; laboratory&nbsp; test&nbsp; filter&nbsp; filled&nbsp; with&nbsp; inert&nbsp; material.&nbsp; The&nbsp; removal&nbsp; efficacy&nbsp; was 90-99%&nbsp; at&nbsp; a&nbsp; concentration&nbsp; of&nbsp; 20&nbsp; &mu;g/L.&nbsp; Toxicity&nbsp; tests&nbsp; showed&nbsp; significant reduction in total toxicity of the mixture during the&nbsp; course of the&nbsp; laboratory test,&nbsp; whereas&nbsp; the&nbsp; residual&nbsp; toxicity&nbsp; in&nbsp; relation&nbsp; to&nbsp; D.&nbsp; magna&nbsp; may&nbsp; be&nbsp; due&nbsp; to undetected transformation products. Transportation of the substances through the&nbsp; Danube&nbsp; sediment,&nbsp; indicated that sediment&nbsp; acts as&nbsp; an&nbsp; effective barrier for both tested benzophenones, while&nbsp; this is not&nbsp; the&nbsp; case with&nbsp; CF.&nbsp; Its mobility (log Kow&nbsp; -0.07) allows CF to pass through the sediment.&nbsp; Photodegradation experiments have confirmed that&nbsp; BP&nbsp; degradation&nbsp; occurs due to&nbsp; the presence of&nbsp; anions&nbsp; (HCO 3-, Cl&nbsp; 2-) and DOC in the aqueous matrix. Although the applied UV radiation was&nbsp; not a realistic representation of disinfection in conventional water treatments, the results showed the importance of a more detailed&nbsp; assessment&nbsp; of&nbsp; the&nbsp; water&nbsp; quality&nbsp; in&nbsp; cases&nbsp; where&nbsp; UV&nbsp; radiation&nbsp; is applied.&nbsp; Herien&nbsp; investigated&nbsp; are&nbsp; also&nbsp; conventional&nbsp; processes&nbsp; (separately adsorption on PAC,&nbsp; and coagulation&nbsp; with commercial coagulant -&nbsp; BOPAC &reg; ) and hybrid or unconventional&nbsp; adsorption/coagulation&nbsp; processes (PAC/CoA), adsorption/ultrafiltration (PAC/UF) and coagulation/ultrafiltration (CoA/UF) for the&nbsp; removal of the selected substances from river water.The efficiency of BP&nbsp; removal&nbsp; via&nbsp; PAC/CoA&nbsp; with&nbsp; PAC&nbsp; B&nbsp; (2&nbsp; mg/L)&nbsp; and&nbsp; BOPAC &reg; (2 mg Al 3+ /L)&nbsp; observed&nbsp; specificity&nbsp; of&nbsp; removal&nbsp; of&nbsp; BP&nbsp; in&nbsp; certain&nbsp; process combinations, such as successive addition of first PAC B and then coagulant. The efficacy of such BP removal was 92%. In case of the initial coagulant dosing, then PAC B, and in the case of simultaneous dosage of coagulant anPAC&nbsp; B,&nbsp; efficacy&nbsp; were:&nbsp; 23%&nbsp; and&nbsp; 20%,&nbsp; respectively.&nbsp; Such&nbsp; outcome&nbsp; is probably&nbsp; a&nbsp; result&nbsp; of&nbsp; the&nbsp; competition/blocking&nbsp; of&nbsp; natural&nbsp; organic&nbsp; matter&nbsp; in river&nbsp; water.&nbsp; BP-3&nbsp; was&nbsp; efficiently&nbsp; removed&nbsp; during&nbsp; all&nbsp; process&nbsp; combinations with&nbsp; PAC&nbsp; B&nbsp; (87-93%),&nbsp; while&nbsp; the&nbsp; efficiency&nbsp; of&nbsp; CF&nbsp; ranged&nbsp; from&nbsp; 0-12%.&nbsp; In general, hybrid process proved to be more efficient in case of PAC C. For BP and&nbsp; CF,&nbsp; the&nbsp; efficacy&nbsp; of&nbsp; removal&nbsp; amounted&nbsp; to&nbsp; 81-90%&nbsp; and&nbsp; 17-27%, respectively, wheareas the efficiency of BP-3 removal was found to be in the range&nbsp; of&nbsp; 71-96%.&nbsp; For&nbsp; the&nbsp; treatment&nbsp; of&nbsp; river&nbsp; water,&nbsp; hybrid&nbsp; membrane processes PAC/UF and&nbsp; CoA/UF are effective in the removal of&nbsp; substances with&nbsp; high&nbsp; log&nbsp; Kow.&nbsp; Benzophenones&nbsp; were&nbsp; removed&nbsp; from&nbsp; hybrid&nbsp; membrane processes&nbsp; by&nbsp; 69%-96% from river water, while caffeine was found to have less consistent results and requires further research.</p>

<p>Fluoride has been detected in groundwater in many places throughout the world and its concentration is often higher than the WHO standard of 1.5 mg/L. Too much fluoride can cause teeth and skeletal issues in the body and inhibit local economic growth. Fluoride concentration in the local groundwater in the Rajasthan region of India is above 5 mg/L and poses significant health risks to local people. Electrocoagulation and electrodialysis have been used for fluoride removal but information on their application for cost-effective removal of fluoride in groundwater is still limited. The aim of this study was to develop and evaluate cost-effective defluoridation systems to remove fluoride from 5 mg/L to below 1 mg/L in the groundwater. Multiple electrocoagulation reactors were fabricated with an aluminum anode and copper/steel cathode. Fluoride concentrations decreased from 5 mg/L to below 1 mg/L within 2 hours of electrocoagulation under an applied potential of 8 V. Under a lower applied potential of 5 V, fluoride concentration was reduced to below 1 mg/L after 6 hours 30 minutes and further reduced to 0.191 mg/L after 9 hours 30 minutes. Our results showed that higher voltage led to higher removal efficiency at a cost of higher energy consumption. The results showed that aluminum alloy used as the anode released impurities into the water during electrocoagulation and could affect fluoride removal efficiency. In addition, synthesized groundwater with different hardness levels was prepared to simulate water quality in the groundwater in the Rajasthan region of India. The results showed that high hardness inhibited fluoride removal efficiency. An electrodialysis reactor was tested as well on the removal performance of anions, including fluoride and chloride. Fluoride concentration after one hour of electrodialysis did not decrease below 1 mg/L but showed a promising trend for effective fluoride removal. However, cation permeable membrane and anion permeable membrane are relatively expensive and could affect the overall cost-effectiveness of fluoride removal with electrodialysis. These results showed that both electrocoagulation and electrodialysis were effective in removing fluoride from groundwater. Their long-term performance and overall cost-effectiveness need further investigation.  </p>

Humic substances are macromolecules that naturally occur in all environments in which vegetation matter are present. In general, humic acid is part of humic substances which form the major fraction of the dissolved organic matters in surface water and represents 90% of dissolved organic carbon. Humic acid plays a fundamental role in many ecosystems since it interacts with toxic metal ions present in the system, resulting in a decrease in the bio-availability of such ions. Moreover, the availability of humic acid in water can react with other chemical compounds, such as chlorine to form trihalomethanes (including chloroform) and causes an increasing risk of cancer and may be linked to heart, lung, kidney, liver, and central nervous system damage. Therefore, humic acid removal in water treatment processes is very important in order to achieve the drinking water standards. Heavy metals are significant contaminants in aqueous system. All heavy metals can produce toxicity when ingested in sufficient quantities, but there are several important ones such as lead, mercury, copper, cadmium, arsenic, nickel and silver. These heavy metals are so pervasive and produce toxicity at low concentrations. Moreover, they may build up in biological systems and become a significant health hazard. / Adsorption is approved as an effective and simple method for water and wastewater treatment process. Many adsorbents then are developed for use in adsorption process such as montmorillonite, peat, activated carbon, etc. In this research, humic acid and heavy metals were mainly selected for adsorption study. In the sorption experiment, several adsorbents such as synthesised zeolite (SZ), natural zeolite (NZ), powdered activated carbon (PAC) and fly ash (FA), were selected to examine the application of HA and heavy metals both in individual and simultaneous adsorption, The characteristics and interactions of the adsorbents with HA and heavy metals were systematically studied by batch laboratory experiments. In the beginning, the adsorption of HA onto SZ, NZ, PAC and FA was investigated and their adsorption capacity was compared. The equilibrium adsorption of HA on SZ, NZ, PAC and FA was found to be 84.1, 67.8, 81.2 and 34.1 mg/g, respectively, at 30 oC and pH 5.0. Dynamic adsorption data show that these adsorbents could reach their adsorption equilibrium after 50 hours. From pH analysis, HA adsorption is favoured at low pH and an increase in pH will lead to the reduction of HA adsorption. SZ and NZ adsorption capacity were affected by the changing of solution temperature; however, in PAC and FA sorption study, there was no significant effect observed. Two heavy metal ions (Cu, Pb) removal by the adsorbents was then conducted. The results showed that the equilibrium sorption capacity of Cu and Pb ions on SZ, NZ, PAC and FA were 43.5, 24.2, 19.7, 28.6 and 190.7, 129.0, 76.8 mg/g, respectively at 30 oC and a pH value of 5. The appropriate pH for Cu and Pb removal was found to be 5 and 6. In most dynamic cases, these adsorbents needed at least 50 hours to reach the adsorption equilibrium. Only adsorption on FA required more than 150 hours to reach the equilibrium. / In simultaneous adsorption experiments, the influences of HA and heavy metal concentration (in the range of 10 to 50 mg/L for HA and 10 to 30 mg/l for heavy metals) on the HA-heavy metal complexation were investigated. The results demonstrated that increasing HA concentration mostly affected Cu adsorbed on SZ, FA and PAC and Pb adsorbed on SZ, NZ and PAC. For HA adsorption, the adsorption rate decreased rapidly with increased initial metal ion concentration. Moreover, the adsorption of heavy metals increased with increased heavy metals concentration in the presence of HA. In the presence of heavy metal ions, the order of HA adsorption followed PAC > FA > SZ > NZ. According to the results, the individual and simultaneous adsorption of HA and heavy metals on each adsorbent achieved a different trend. It mainly depended on the adsorption property of both adsorbates (HA and heavy metals) and adsorbents (SZ, NZ, PAC and FA) and also the operation factors such as pH, concentration, temperature and operation time. Even though this experiment could not obtain high adsorption performance, especially in coadsorption, as compared with other adsorbents, the adsorbents in this study represented a higher adsorption capacity and provide the potential for further development.

<div> Here, the quartz crystal microbalance with dissipation monitoring (QCM-D) is employed to explore the interaction of the various free oxidant species with condensed PA model membranes in order to improve our understanding of how the interaction with these species affects rates of membrane chlorination and alter membrane structure. Molecular-scale mass uptake and changes in the dissipative nature of the of the model membranes as measured by the QCM is correlated to performance changes in interfacially polymerized PA reverse osmosis (RO) membranes. Leveraging newly gained insights from these measured interactions, new strategies are explored to improve flux and chlorine resistance using novel membrane structure and chemistry.<br></div>

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology, 2016 / Natural organic matter if not removed from water used for electricity generation has dire consequences that affect the long term plant health. The main problem is that organic matter at higher temperature and pressure disintegrate into smaller organic acids and carbon dioxide. This causes the cycle water and steam to be acidic and this can result in corrosion of the plant. The raw water from the Komati (Arnot power station) and Usutu (Kriel power station) scheme were analysed to determine the organic profile and seasonal variation. There was a noticeable variation in the quality of the water with an increase in DOC during rainy season. The water was found to be containing hydrophobic as well as hydrophilic molecules that could be quantified with a liquid chromatography organic detector (LC-OCD). Current water treatment processes employed at the two stations, Arnot and Kriel, has demonstrated the capability of removing organics to just over 50 percent at the pre-treatment section. The water treatment plant includes demineralisation plant that was able to produce water that met Eskom’s target specifications of less than 250 ppb DOC values. Qualitative and quantitative analysis of the steam-condensate water was done by use of an ion chromatography method. The determined organic anions were found to be acetates, formats and lactates.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The purpose of this study was to develop modi ed tract-etched membranes using nanocomposite TiO2 for advanced water treatment processes. Photocatalytic oxidation and reduction reactions take place on TiO2 surfaces under UV light irradiation, therefore sunlight and even normal indoor lighting could be utilised to achieve this effect. In membrane ltration, caking is a major problem, by enhancing the anti-fouling properties of photocatalysts to mineralise organic compounds the membrane life and e ciency can be improved upon. In this study the rst approach in nanocomposite membrane development was to directly modify the surface of polyethylenetherephthalate (PET) track-etched membranes (TMs) with titanium dioxide (TiO2) using inverted cylindrical magnetron sputtering (ICMS) for TiO2 thin lm deposition. The second approach was rst to thermally evaporate silver (Ag) over the entire TM surface, followed by sputtering TiO2 over the silver-coated TM. As a result a noble metal-titania nanocomposite thin lm layer is produced on top of the TM surface with both self-cleaning and superhydrophilic properties. Reactive inverted cylindrical magnetron sputtering is a physical vapour deposition method, where material is separated from a target using high energy ions and then re-assimilated on a substrate to grow thin lms. Argon gas is introduced simultaneously into the deposition chamber along with O2 (the reactive gas) to form TiO2. The photocatalytic activity and other lm properties, such as crystallinity can be in uenced by changing the sputtering power, chamber pressure, target-to-substrate distance, substrate temperature, sputtering gas composition and ow rate. These characteristics make sputtering the perfect tool for the preparation of di erent kinds of TiO2 lms and nanostructures for photocatalysis. In this work, the utilisation of ICMS to prepare photocatalytic TiO2 thin lms deposited on track-etched membranes was studied in detail with emphasis on bandgap reduction and TM surface regeneration. Nanostructured TiO2 photocatalysts were prepared through template directed deposition on track-etched membrane substrates by exploiting the good qualities of ICMS. The TiO2-TM as well as Ag-TiO2-TM thin lms were thoroughly characterised. ICMS prepared TiO2 lms were shown to exhibit good photocatalytic activities. However, the nanocomposite Ag-TiO2 thin lms were identi ed to be a much better choice than TiO2 thin lms on their own. Finally a clear enhancement in the photocatalytic activity was achieved by forming the Ag-TiO2 nanocomposite TMs. This was evident from the band-gap improvement from 3.05 eV of the TiO2 thin lms to the 2.76 eV of the Ag-TiO2 thin lms as well as the superior surface regenerative properties of the Ag-TiO2-TMs. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om verbeterde baan-ge etste membrane (BMe) met behulp van nano-saamgestelde titaandioksied (TiO2) vir gevorderde water behandeling prosesse te ontwikkel. Fotokatalitiese oksidasie- en reduksie reaksies vind plaas op die TiO2 oppervlaktes onder UV-lig bestraling, en dus kan sonlig en selfs gewone binnenshuise beligting gebruik word om die gewenste uitwerking te verkry. In membraan ltrasie is die aanpaksel van onsuiwerhede 'n groot probleem, maar die verbetering van die self-reinigende eienskappe van fotokatalisators deur organiese verbindings te mineraliseer, kan die membraan se leeftyd en doeltre endheid verbeter word. In hierdie studie was die eerste benadering om nano-saamgestelde membraan ontwikkeling direk te verander deur die oppervlak van polyethylenetherephthalate (PET) BMe met 'n dun lagie TiO2 te bedek, met behulp van reaktiewe omgekeerde silindriese magnetron verstuiwing (OSMV).Die tweede benadering was eers om silwer (Ag) termies te verdamp oor die hele BM oppervlak, gevolg deur TiO2 verstuiwing bo-oor die silwer bedekte BM. As gevolg hiervan is 'n edelmetaal-titanium nano-saamgestelde dun lm laag gevorm bo-op die oppervlak van die BM, met beide self-reinigende en verhoogde hidro liese eienskappe. OSMV is 'n siese damp neerslag metode, waar materiaal van 'n teiken, met behulp van ho e-energie-ione, geskei word, en dan weer opgeneem word op 'n substraat om dun lms te vorm. Argon gas word gelyktydig in die neerslag kamer, saam met O2 (die reaktiewe gas), vrygestel om TiO2 te vorm. Die fotokatalitiese aktiwiteit en ander lm eienskappe, soos kristalliniteit, kan be nvloed word deur die verandering van byvoorbeeld die verstuiwingskrag, die druk in die reaksiekamer, teiken-tot-substraat afstand, substraattemperatuur, verstuiwing gassamestelling en vloeitempo. Hierdie eienskappe maak verstuiwing die ideale hulpmiddel vir die voorbereiding van die verskillende soorte TiO2 lms en nanostrukture vir fotokatalisasie. In hierdie tesis word OSMV gebruik ter voorbereiding van fotokatalitiese TiO2 dun lms, wat gedeponeer is op BMe. Hierdie lms word dan in diepte bestudeer, met die klem op bandgaping vermindering en BM oppervlak hergenerasie. Nanogestruktureerde TiO2 fotokataliste is voorberei deur middel van sjabloongerigte neerslag op BM substrate deur die ontginning van die goeie eienskappe van OSMV. Die TiO2-BM dun lms, sowel as Ag-TiO2-BM dun lms, is deeglik gekarakteriseer. OSMV voorbereide TiO2 dun lms toon goeie fotokatalitiese aktiwiteite. Nano-saamgestelde Ag-TiO2 dun lms is egter ge denti seer as 'n veel beter keuse as TiO2 dun lms. Ten slotte is 'n duidelike verbetering in die fotokatalitiese aktiwiteit bereik deur die vorming van die Ag-TiO2 nano-saamgestelde BMe. Dit was duidelik uit die bandgapingverbetering van 3,05 eV van TiO2 dun lms in vergelyking met die 2,76 eV van Ag-TiO2 dun lms. 'n Duidelike verbetering is behaal in die fotokatalitiese aktiwiteit deur die vorming van die Ag-TiO2 nano-saamgestelde TMs.

The diploma thesis deals with micro-fuels in drinking water sources and their subsequent removal. In the thesis mainly pesticides and pharmaceuticals are described. The reader is first introduced to the most common pesticides occurring in water and their consumption. Drugs are described in a similar context. In addition, there are practical studies on the occurrence, degradation and removal of micro-pollutants from water. The final thesis is a laboratory experiment dealing with the removal of salicylic acid from water by filtration through the filtration material Bayoxide E33 and activated carbon. The thesis describes the procedure and results of the experiment.

The Swedish water sector faces many challenges in terms of climate change, worn out facilities and distribution systems as many of them were built in the 50-, 60- and 70s, but also increased cyber security concerns. Collaborations between different actors are therefore required to address these challenges. This thesis work's purpose is to examine the opportunities a collaboration between water treatment plants could bring for the water sector to achieve a more sustainable drinking water production. The purpose is also to examine the most efficient way to establish a collaboration between them through digital means. A workshop and several interviews with representatives from different water treatment plants were conducted to gather information on possibilities of data/information sharing between them, but also to make a security classification of data/information generated at the water treatment plants. The representatives included process engineers, process technicians, security associates and an associate at Svenskt vatten, an interest organization for the water sector. The result showed that data/information sharing is already taking place in the sector under limited conditions. Smaller VA organizations have more challenges due to lack of skilled workers, partners and time. It is difficult for many in the sector to know where to turn to when in need of help, particularly for smaller VA organizations who usually are the ones with fewer contact networks. It is not to say that only smaller VA organizations are affected but they are more likely to lack contact with other water organizations. The majority of water treatment plants agree on that data/information on treatment processes would be allowed to share under limited conditions. The information classification is a matter for each plant due to different security realities which determines the information classification. This makes it difficult to decide on what parameters could be shared by every water treatment plant. This needs to be investigated further in order to determine what data/information could be shared by most water treatment plants on a platform. Most participants thought that a platform of some kind would be the best solution to simplify data/information sharing between water treatment plants. The suggested platform is a good start for making contacts between water treatment plants and has the potential to enable storage and sharing of data/information in the future. / Den svenska VA sektorn står inför många utmaningar så som klimatförändringar, slitna anläggningar och distributionsnät då många av dem byggdes under 50-, 60- och 70-talet. Även oron kring cybersäkerheten ökar. Samarbeten mellan olika aktörer krävs för att lösa dessa utmaningar. Syftet med examensarbetet är att undersöka de möjligheter som samarbeten mellan vattenverk skulle medföra för att nå en mer hållbar dricksvattenproduktion. Syftet är också att undersöka det mest effektiva sättet att få till ett samarbete mellan vattenverken med digitala medel. En workshop och flertalet intervjuer genomfördes med olika representanter från vattenverk för att samla information om möjligheten med att dela data/information mellan dem. Men också för att göra en säkerhetsklassning av data/information som genereras på vattenverken. Representanterna inkluderade processingenjörer, processtekniker, säkerhetsansvariga samt en medarbetare från Svenskt vatten, en intresseorganisation för vattensektorn. Resultatet visade att delning av data/information redan sker inom sektorn, dock under begränsade former. Mindre VA organisationer har fler utmaningar på grund av brist på anställda med rätt kompetens, samarbetspartners och tid. Många inom sektorn har utmaningar när det kommer till att söka och få hjälp, särskilt för de mindre VA organisationerna som vanligtvis har färre kontakter. Men de är inte bara de små som är påverkade av detta problem, men det är vanligare att de inte har kontakter med andra VA organisationer. De flesta vattenverken ansåg att data/information från reningssteg skulle vara möjligt att dela under begränsade former. Informationssäkerhetsklassning är en enskild fråga för varje vattenverk som baseras på de hot som varje vattenverk står inför. Detta medför att det är svårt att bestämma vilken data/information som kan delas av varje vattenverk. Detta område behöver vidare utredas innan ett beslut kan fattas om vilken data/information alla vattenverk ska dela på en plattform. De flesta deltagarna tyckte att en plattform av något slag skulle vara lösningen för att förenkla delning av data/information mellan vattenverken. Den föreslagna plattformen är en bra start för vattenverk att skapa kontakter och har potentialen att möjliggöra lagring och delning av data/information i framtiden.

Phytoplankton blooms compromise the quality of freshwater ecosystems and the efficient processing of water by treatment works worldwide. This research aims to determine whether in-situ filamentous biofiltration processes mediated by living roots and synthetic filters as media can reduce or remove the phytoplankton loading (micro-algae and cyanobacteria) prior to a potable water treatment works intake. The underlying biofiltration mechanisms were investigated using field and laboratory studies. A novel macroscale biofilter with three plant species, named the "Living-Filter", installed in Farmoor II reservoir, UK, was surveyed weekly for physicochemical and biological variables under continuous flow conditions during 17 weeks. The efficiency of a mesoscale biofilter using the aquatic plant Phalaris arundinacea and synthetic filters, was tested with Microcystis aeruginosa under continuous flow conditions and in batch experiments. The 'simultaneous allelochemical method' was developed for quantifying allelochemicals from Phalaris in aqueous samples. Microscale studies were used to investigate biofilter allelochemical release in response to environmental stressors and Microcystis growth inhibition in filtered and unfiltered aqueous root exudate. Results demonstrate that the removal of phytoplankton biomass by physical mechanisms has a removal efficiency of &le;45% in the "Living-Filter" (filamentous biofilter plus synthetic fabric) and that the removal of Microcystis biomass using only biofilters was 25%. Chemical mechanisms that reduce Microcystis cell numbers are mediated by allelochemicals released from biofilter roots. Root exudate treatments on Microcystis revealed that Microcystis growth is inhibited by allelochemicals, not by nutrient competition, and that protists and invertebrates play a role in removing Microcystis. Filamentous biofilters can remove phytoplankton biomass by physical, chemical and biological mechanisms. Biofilters and synthetic filters in combination improve removal efficiency. Application of macroscale biofilters prior to potable water treatment works benefits the ecosystem. Plant properties, biofilter size to surface water ratio, and retention time must be considered to maximise the benefits of biofiltration processes.