<p>The aim of the study was to quantify the extent of inorganic chemical pollution of the Franschhoek River and draw relationships between contaminants in water, sediment and plants. The invasive Acacia mearnsii and Salix babylonica and indigenous Brabejum stellatifolium species were chosen as biomonitors due to their wide spread distribution along the river and their apparent ability to accumulate heavy metals. The sites chosen allowed for comparison of the river quality upstream with that of the river further down stream as it meandered through residential, agricultural and recreational areas, until it joined with the Berg River further downstream. The general aim of the study was to assess the degree of inorganic pollution in the Franschhoek River to evaluate its contribution to pollution of the Berg River, of which it is an important tributary. Also understanding the sources of the pollution would contribute to the ability to reduce pollution.</p>

Heavy metals are well-known environmental pollutants. In this thesis predictive models for heavy metals in urban lakes are discussed and new models presented. The base of predictive modelling is empirical data from field investigations of many ecosystems covering a wide range of ecosystem characteristics. Predictive models focus on the variabilities among lakes and processes controlling the major metal fluxes. Sediment and water data for this study were collected from ten small lakes in the Stockholm area, the Eastern parts of Lake Mälaren, the innermost areas of the Stockholm archipelago and from literature studies. By correlating calculated metal loads to the land use of the catchment areas (describing urban and natural land use), the influences of the local urban status on the metal load could be evaluated. Copper was most influenced by the urban status and less by the regional background. The opposite pattern was shown for cadmium, nickel and zinc (and mercury). Lead and chromium were in-between these groups. It was shown that the metal load from the City of Stockholm is considerable. There is a 5-fold increase in sediment deposition of cadmium, copper, mercury and lead in the central areas of Stockholm compared to surrounding areas. The results also include a model for the lake characteristic concentration of suspended particulate matter (SPM), and new methods for empirical model testing. The results indicate that the traditional distribution (or partition) coefficient Kd (L kg-1) is unsuitable to use in modelling of the particle association of metals. Instead the particulate fraction, PF (-), defined as the ratio of the particulate associated concentration to the total concentration, is recommended. Kd is affected by spurious correlations due to the definition of Kd as a ratio including SPM and also secondary spurious correlations with many variables correlated to SPM. It was also shown that Kd has a larger inherent within-system variability than PF. This is important in modelling.

As the environmental regulations and technical progress have forced the factories’ old “end of pipe” solutions to improve, the metal emissions from point sources have decreased. Instead, the diffuse consumption emissions from goods in use now are in focus. The increased awareness of traffic as a major diffuse metal emission source emphasizes the need for more detailed information on the various traffic related sources. The main scope of this thesis is to study specific parts of metal emissions from some road traffic related sub sources such as brake lining and tyres. The metals in focus are antimony (Sb), cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), nickel(Ni) and zinc (Zn), and the research quantifies emissions from the different sub sources, trace changes over time as well as dispersal patterns and metal mobility in the roadside environment. The results show that even if the road traffic associated metal stocks are small compared to total in use stocks, their emissions are of major importance. The updated figures show that despite material developments during the last 10 years, tyres still are one of the main sources of Zn and Cd, while it can be excluded as a source of concern for the other metals studied. Brake linings are shown to be an especially pronounced source for Cu and Sb. The Pb and Cd emissions from brake linings and tyres have decreased as a result of decreasing material concentrations in these sources, most likely a result of EU regulations. Further the results reveals galvanized goods to be a major road traffic related source for Zn. The results show that the total metal concentrations in roadside soils have increased 3-16 times compared to regional background during the last decades. Each metal has a limited dispersal distance from the roads as well as down in the soil profile. Most metals are found within 10 m from the road in the uppermost 10 cm of the topsoil. However, the sequential extractions show that a large part of the metals found in the soil are rather easily mobilized and can be redistributed if the roadside soils become disturbed. Metals emitted due to decelerating activities are not correlated to elevated concentrations near road junctions. Instead the metals appear to be more evenly spread along the whole driven distance. The study points out Sb as an element that might be problematic to analyse. For Sb, which is sparsely studied as a roadside contaminant, there is a need of more general knowledge as it has a high accumulation rate in roadside soils. / I takt med ökade regleringar inom miljöområdet och en snabb teknikutveckling har fabrikerna allt mer spelat ut sin roll som emissionskällor till miljön. Istället har den diffusa emissionen som kommer från produktanvändning fått en större betydelse. En ökad medvetenhet om transporter och trafikens betydelse för samhällets konsumtionsemissioner understryker det ökade kunskapsbehovet för de trafikrelaterade emissionskällorna. Avhandlingens huvudsyfte är att studera specifika delar av metallemissionen från vissa trafikrelaterade källor så som bromsbelägg och däck. Metallerna som är i fokus är antimon (Sb), bly (Pb), kadmium (Cd), koppar (Cu), krom (Cr), nickel (Ni) och zink (Zn) och forskningen strävar efter att kvantifiera emissionerna från de olika källorna, spåra förändringar i emissioner över tid, kartlägga utsläppsmönster och metallrörlighet i vägnära jord. Resultaten pekar på att även om de trafikrelaterade källorna kvantitativt är små i jämförelse med de totala källorna så är deras emissioner av stor betydelse. De nya siffrorna visar att trots en materialutveckling inom området under det senaste årtiondet så är fortfarande däck en av de största källorna för Cd och Zn i stadsmiljö, medan de kan avfärdas som källa för de övriga studerade metallerna. Studien visar att bromsbelägg fortfarande är en viktig källa för Cu och Sb. Bly- och Cd-emissionerna från däck och bromsbelägg har däremot minskat drastiskt under samma period. Denna minskning beror troligen på en reglering på EU-nivå. Dessutom visar resultaten att galvaniserade ytor är den viktigaste källan till Zn i stadsmiljö. Metallkoncentrationerna i vägnära jord har ökat med 3 – 16 ggr jämfört med bakgrundshalterna i de undersökta områdena. Metallerna uppvisar endast en begränsad spridning från vägen och ner i jordprofilen. Den största metallpåverkan återfinns inom 10 m från vägen och i de översta 10 cm av jorden. Trots den begränsade spridningen så uppvisar de flesta metallerna en förhållandevis hög rörlighet, vilket innebär att de kan bli mobila vid störning av jorden. De bromsrelaterade metallerna uppvisar ingen korrelation till förhöjda halter nära korsningar utan är mer jämnt spridda över hela körsträckan. Studien pekar ut Sb som ett element som kan vara problematiskt att analysera på grund av dess flyktighet. Trots att Sb för närvarande har en snabb ackumulationstakt i trafikmiljö så är den endast sparsamt studerad. Mer generell kunskap om Sb är därför önskvärd.

Bed filters using reactive materials are an emerging technology for on-site wastewater treatment. Chemical reactions transfer contaminants from the aqueous to the solid phase. Phosphorus is removed from domestic wastewater by sorption to filter materials, which can then be recycled to agriculture as fertilisers and soil amendments. This thesis presents long-term column and field-scale studies of nine filter materials, particularly the novel product Polonite®. Phosphorus, nitro-gen and metals were removed by the mineral-based materials to varying degrees. Polonite and Nordkalk Filtra P demonstrated the largest phosphorus removal capacity, maintaining a PO4-P removal efficiency of &gt;95%. Analysis of filter bed layers in columns with downward wastewater flow, showed that phosphorus, carbon and nitrogen content was vertically distributed, with de-creasing values from surface to base layer. Polonite and Filtra P accumulated 1.9-19 g P kg-1. Nitrogen in wastewater was scarcely removed by the alkaline filter materials, but transformation from NH4-N to NO3-N was &gt;90%. Pot experiments with barley (Hordeum vulgare L.) revealed that after wastewater treatment, slags and Polonite could increase plant production. Batch experi-ments and ATR-FTIR investigations indicated that amorphous tricalcium phosphate (ATCP) was formed in the materials, so some of the accumulated PO4-P was readily available to plants. Low heavy metal contents occurred in the materials, showing that they can be applied as soil amend-ments in agriculture without contamination risks. A full-scale treatment system using Polonite as filter material showed an average PO4-P removal efficiency of 89% for a 92-week period, indicat-ing the robustness of the filter bed technology. / QC 20100907

No description available.

X-ray fluorescence (XRF) detection of heavy metals is a cost- and time-effective method for investigation of polluted areas. Compared to laboratory analysis, XRF analysis is limited by high detection limits and uncertainties in some situations. Preparation of samples is known to affect the results of measurements. The purpose of this thesis is to bring a deeper understanding of how different factors affect the results of XRF-analysis. A large number of measurements have been made with the instruments Niton XLt 700 and Niton Xli 700. Results from measurements of lead, zinc and copper have been analysed. This study has shown that a greater moisture content will give a lower measured concentration for the same sample. If the moisture content is known, it is possible to make good approximations of concentrations in dry samples. No obvious differences were found between different metals. Proper homogenisation of samples was found to be one of the most critical issues. It should be noted that laboratories do not usually homogenise samples prior to analysis, so samples sent for laboratory verification should therefore be homogenised before sending. Sample preparation, including drying, sieving to finer grain-sizes and analysing in a special sample cup was found to increase the measured concentrations and decrease the variation between measurements. The concentrations differed with different sample matrices and with sample preparation. Because of the differences, measurements should always be correlated with laboratory analysis before any conclusions can be made. In situations when metals are well within detection range of the XRF instrument, the only preparation needed is in most cases homogenisation. If metal levels are just at the limit, or just below the detection limit, further preparations of samples should be made. When drying samples makes detection possible, more preparation is usually not worth the effort. If detection limits still are a problem after drying, the samples should be sieved and analysed in sample cups. In situations where concentrations still are below the detection limit when analysing in sample cups, or if the measurements are disturbed for other reasons, another method than XRF-analysis must be used. When XRF analysis is possible, the method is preferable compared to only laboratory analysis. This cost- and time effective method makes a larger number of measurements possible, and gives a more complete overview of a polluted area. / Analys med röntgenfluorescensdetektor (XRF) är en snabb och kostnadseffektiv fältmetod för detektion av tungmetaller i mark. Nackdelen är att mätningarna inte är tillförlitliga i alla sammanhang och att detektionsgränsen för många ämnen är förhållandevis hög. Det är sedan tidigare känt att olika former av provbearbetning påverkar mätresultaten. I detta examensarbete har undersökts hur olika faktorer påverkar mätresultaten vid analys av jordprover med XRF instrument. Faktorerna som undersökts är inverkan av vattenkvot, kornstorlek, provpåsar och olika provbearbetningsmetoder. Vid provbearbetningsförsöken skickades prover även in till externt laboratorium för jämförande analys. Metaller som undersökts är bly, zink och koppar. Vid undersökningen konstaterades att en ökad vattenkvot ger upphov till lägre mätvärden. Vid kännedom om vattenkvot kan halt per torrsubstans med god överensstämmelse uppskattas utifrån mätningar på fuktiga prov. Är precisionskraven stora och vattenkvoten varierande och okänd bör dock proverna torkas innan mätningar görs. Ingen avsevärd skillnad sågs mellan de olika metaller som undersöktes. Vid undersökningen om provbearbetningens betydelse visade det sig att homogeniseringen av proverna är mycket viktig, inte minst av prover som skickas till laboratorieanalys. Ökad provbearbetning med torkning och siktning till mindre kornstorlek tenderar att ge högre mätvärden med XRF instrument. Storleksmässigt är mätvärden vid obearbetade prov mest överensstämmande med laboratorieanalys. Mest skiljer sig analys på finsiktade prover i provkopp. Korrelationsmässigt finns i en del fall en tendens till bättre överensstämmelse med mer bearbetade prov. Den största vinsten med ökad bearbetning av prover konstaterades i detta arbete vara att mark med lägre metallkoncentrationer då kan analyseras. I de fall där halterna av metaller ligger väl inom XRF instrumentets detektionsområde visade det sig att det oftast är tillräckligt att endast homogenisera proverna innan analys görs. I de fall där koncentrationen av metaller är på gränsen till vad XRF instrumentet kan detektera rekommenderas att proverna torkas, eller om nödvändigt torkas, siktas och analyseras i provkopp. Där nivåerna av metaller ligger under detektionsgränsen för XRF instrument trots provbearbetning, eller där andra ämnen till exempel järn stör mätningarna, måste en annan analysmetod väljas.

Use of anaerobically digested sludge (ADS) in heavy metal removal, was researched. The raw and dewatered ADS samples collected from the effluent of anaerobic digesters and mechanical dewatering units of Ankara City Wastewater Treatment Plant were used. Sorption kinetic and equilibrium tests were conducted using raw ADS at initial pH of 2.0, 4.0 and without adjusting the initial pH. The highest Pb(II) removal capacity was observed as, 8.5 mmol (or 1760 mg) Pb(II) per g of biomass, when the initial pH was not controlled. When dewatered ADS was used Pb(II) removal capacity of ADS was found to drastically decrease to 2.5 mmol (or 518 mg) Pb(II) per g of biomass. Both biomass samples resulted in an increase in the solution pH from an initial value of 4 &ndash / 5 to an equilibrium value of 7 &ndash / 8. Large floc particles settling rapidly were formed after the ADS samples contacted with Pb(II) solution. The high Pb(II) removal capacities, and visual observations during the experiments indicated that precipitation is a dominant mechanism especially at low initial Pb(II) concentrations. FTIR studies showed that carboxyl groups present in the biomass surface of raw ADS were major functional groups in biosorption of Pb(II). The low capacity values attained at initial pH 2.0 indicated that there was a competition between Pb(II) species and hydrogen ions for carboxyl groups. Single and 3-stage fed-batch reactor systems were operated using raw ADS at different initial Pb(II) concentrations. The efficiency of reactor systems increased when 3-stage fed-batch configuration was used and an effluent Pb(II) concentration below 2 mg/L was reached from an initial value of about 200 mg/L.

Four different kinds of filter-materials with reactive surfaces have been studied concerning their capacity to absorb heavy metals in leachate from a municipal waste deposit. The heavy metals studied were: lead, cadmium, copper, mercury, chromium, nickel and zinc. The leachate contains high levels of dissolved organic carbon (DOC) and has a high pH-value along with a high buffer capacity. These characteristics of the leachate make it difficult to remove pollutants and require efficient filters. The filters that were examined in the report are blast-furnace slag with CaO, sand covered with iron oxides, olivine and nepheline. The experiment was carried out in two sets, starting with batch experiments followed by a column study. The objective of the batch experiments was to find out how variations in pH affected the sorption capacity of the materials. The interval used during the test was from pH 5 to pH 10. The computer program VisualMinteq was used to evaluate the dominating sorption processes when the materials interacted with the solutions. Two different kinds of solutions were used in the batch experiment. One of them was the leachate, to which known concentrations of heavy metals were added (about 1 μM) and the other consisted of sodium nitrate, a solution without organic compounds, which was used as a reference. The sodium nitrate solution was also spiked with the same concentration of heavy metals as the leachate. The results from the batch experiment showed that the sorption of heavy metals was lowered if the DOC level was high. No relation between pH and sorption ability could be found for the leachate, but for some metals in the sodium solution a higher pH improved the removal of heavy metals. The two materials that showed best results in the batch experiment were the blast-furnace slag and the sand with iron oxides. These materials were used in the column study. The olivine material was somewhat better than the nepheline in the batch experiment. Four columns were used in the column study, two for each material. Leachate with heavy metals was pumped into the columns with a specific flow rate; at first a low flow rate was used and when half the experiment time had passed the flow rate was increased. The flow rates used were 0.12 m/24 h and 0.62 m/24 h. The outcome of the column experiment showed that the slag had the highest ability to adsorb metals. The metal sorption was over 60 percent for lead, cadmium and zinc, where the highest sorption was obtained for lead. No affects were noticed when the flow rate was increased. / I detta examensarbete har fyra olika reaktiva filtermaterials kapaciteter att ur deponilakvatten avskilja tungmetallerna bly, kadmium, koppar, kvicksilver, krom, nickel och zink testats. Deponilakvatten är ett avloppsvatten med höga halter organiskt material (DOC), högt pH och en hög buffertkapacitet. Dess sammansättning ställer stora krav på ett filter och närvaron av ligander påverkar sorptionprocesserna. Filtren som ingått i studien är kalciumoxiddopad masugnsslagg, järnoxidtäckt sand, olivin och nefelin. Försöken utfördes i två delar, med inledande skakförsök och därefter kolonnförsök. I båda försöken användes lakvatten med en extra tillsats av tungmetaller. I skakförsöken användes även natriumnitrat; ett referensvatten utan organiska ligander, även det spikat med tungmetaller. I skakförsöken studerades avskiljningens pH-beroende för de olika filtren, med ett pH-intervall på ca 5 – 10. Därefter modellerades resultaten i jämviktsprogrammet VisualMinteq för att fastställa vilka processer som styr avskiljningen. Skakförsöken och kolonnförsöken utfördes båda i klimatrum vid 8 ºC, för att efterlikna markens naturliga temperatur. Resultaten från skakförsöken visade att masugnsslagg och järnoxidsand gav bäst avskiljning för de flesta tungmetaller. Olivin och nefelin var sämre metallsorbenter, där olivin uppvisade något bättre resultat än nefelin. Inget tydligt pH-beroende för lakvattnet kunde utläsas, men för natriumnitratlösningen gav en pH-höjning en ökad sorption för vissa metaller. Den kemiska jämviktsmodelleringen visade att den dominerande processen i filtermaterialen var sorption på filterytorna. De två filtermaterialen som visade bäst resultat i skakförsöken (slagg och järnoxid) studerades vidare i kolonnförsök, där ett bestämt lakvattenflöde pumpades genom kolonner packade med materialen. Två olika flödeshastigheter testades (0,12 m/dygn och 0,62 m/dygn) och sorptionen av metaller analyserades. Slaggen uppvisade högst avskiljningskapacitet av de studerade filtren. De metaller som sorberades bäst var bly, kadmium och zink (över 60 % avskiljning), där den högsta sorptionen erhölls för bly. Gemensamt för både skak- och kolonnförsöken var att sorptionen försvårades då halten organiskt material (DOC) ökade, vilket beror på att DOC konkurrerar med de reaktiva ytorna på filtren om att binda den fria metalljonen. Ingen minskande avskiljningseffekt av en flödesökning kunde utläsas.

In order to avoid harmful substances ending up at the municipal sewage treatment plants, it is important to purify the wastewater at the source. One such source is the wheel washers available in many tire garages which are used to wash the wheels on our vehicles when we change between summer and winter tires. It is important to wash the wheels before storage, to extend the tires lifetime. The purpose of this study is to find a green innovative solution for reduction of emissions of heavy metals at the source, so that the sludge from the sewage treatment plants can be used as fertilizer. The target is to find a wheel wash method which leads to compliance with the guidelines for car washers, and that also provides a better washing result than with the existing method. Chemical analyzes of water samples have been performed and the cleanliness of the wheels has been checked visually. As there are no specific emission requirements for wheel washes, the results have mainly been compared with current guidelines for vehicle washes. A new washing and flocculation method have been developed during the study. The proposed new method is suitable as pretreatment of the water before discharging it, as it reduces metal emissions and provides better washing results compared to the old method. Significantly larger number of wheels may be washed in one session, which leads to a reduction of water- and energy consumption since the machine can be emptied and cleaned less often. For many years there has been an environmental adaption to eco-friendly car washers, so the opportunities should be good for wheel washers to win goodwill and market advantages by being profiled with an environmentally adapted washing method. / För att undvika att miljöskadliga ämnen hamnar i de kommunala reningsverken är det viktigt att rena avloppsvattnet vid källan. En sådan källa är de hjultvättmaskiner som finns på många verkstäder och som används för att tvätta hjulen på våra fordon i samband med skifte mellan sommar- och vinterdäck. Det är viktigt att tvätta hjulen före förvaring, för att förlänga däckens livslängd. Syftet med denna undersökning är att hitta en grön innovativ lösning för att främja uppströmsarbetet, dvs att rena utsläppen av tungmetaller vid källan, så att slammet från våra reningsverk kan användas som gödningsmedel. Målet är att finna en metod för hjultvätt som medför att riktlinjerna för fordonstvättar uppfylls, och som samtidigt ger ett bättre tvättresultat än befintlig metod. Kemiska analyser av vattenprover har utförts och renheten har kontrollerats visuellt. Eftersom det saknas specifika utsläppskrav för hjultvättar, har resultaten i första hand jämförts med gällande riktlinjer för fordonstvättar. En ny tvätt- och flockningsmetod har utvecklats under studiens gång. Den föreslagna nya metoden är lämplig som förbehandling av vattnet innan utsläpp, eftersom den sänker metallutsläppen samt ger ett bättre tvättresultat jämfört med den gamla metoden. Betydligt fler hjul kan tvättas per tvättomgång vilket innebär en minskning av vatten- och energiförbrukningen eftersom maskinen behöver tömmas och rengöras mer sällan. Under många år har det skett en miljöanpassning av fordonstvättar, så möjligheterna borde vara goda för att även hjultvättar ska kunna vinna goodwill och marknadsmässiga fördelar genom att profilera sig med en miljöanpassad tvättmetod.

Extractants and extraction methodologies play a vital role in many industrial processes, from the concentration of precious metals from ores to the separation of longlived nuclei from radioactive waste as well as the removal of heavy metals from soils and water for remediation. The vast majority of extractants rely on the use of nitrogen, oxygen, sulfur or selenium as Lewis base donor atoms to form coordination complexes with the metal ions of interest. These extractants often make use of the chelate effect and/or the macrocyclic effect in order to form stable complexes. Some of the best known types of chelate extractants include polyaminopolycarboxylic acids (N and O donors), polyamines (N donors), dithiocarbamate (S donors) and aminopolythias (N and S donors). The most extensively investigated types of macrocycles include crown ethers (O donors), thia crowns (S donors), aza crowns (N donors) and thiacrown ethers (S and O donors). A conspicuous omission from the list of donor atoms is phosphorus. It is noted that phosphorus has been employed as a backbone atom in the development of extractants, primarily in phosphonates, phosphates and phosphine oxides. The omission of phosphorus is interesting from two points. First, many of the precious and heavy metal ions of interest (Pd2+, Ag+, Pt2+, Pb2+, Cd2+and Hg2+) can be classified as soft Lewis acids, according to Pearson’s HSAB theory. The relative softness of phosphorus as a Lewis base as compared to oxygen and nitrogen indicates that phosphorus would be a very good donor atom toward these soft metal cations. Secondly, chelating agents containing phosphorus donors form stable complexes with transition metal cations in a variety of oxidation states due to their versatile bonding capability. The !-donor characteristics of the phosphine donor coupled with the ability to " accept from filled or partially filled d orbitals of the metal cations result in strong phosphine-metal bonds.