The current work determined whether there is a constant tissue residue associated with narcotic compounds. In this investigation, the cladoceran, Daphnia magna was exposed to lethal levels (48h LC50) of ten, $ sp{14}$C-labelled, narcotic organic chemicals in a closed system. Exposure times, ambient concentrations, and body sizes were varied to evaluate their effects. The $ sp{14}$C-method developed in current work can detect chemicals in single D. magna in concentrations ranging from 0.02 to 6310 mmol/kg. Moreover, the technique detected phobic and lipophilic chemicals equally well. The technique's sensitivity (nmol/kg) allowed for detection of differences in the internal concentrations of pollutants among the unaffected, immobilized, and dead D. magna. Immobilized D. magna contained between 0.14 mmol/kg and 200 mmol/kg of narcotics. On the average, however, the internal residues were 3.1 mmol/kg (95%CL = 3.1 $ pm$ 2.0). This agreed with literature values. The effects of time of exposure, ambient concentration, and body size on the tissue residues of narcotics varied with the chemical compound.

Discharge of colored effluents without decoloration originated from textile industries may cause serious problems in the receiving environments. In this study, natural materials that are basaltic tephra and clinoptilolite were used to remove various dyestuffs used in the textile industry. Those materials are cheap and available in large quantities in Turkey. The investigation of adsorption of basic, acidic and reactive dyes on these materials is the objective of this study. During preliminary experiments it was seen that adsorption equilibrium was reached in about 2 days. In adsorption experiments, in order to obtain adsorption isotherms, a fixed amount of adsorbent and 100 mL dye solutions of different concentrations were placed in glass bottles which were shaken at 200 rpm and 25&plusmn / 2oC for 2 days. Then, samples were filtered and the equilibrium concentrations of dyestuffs in the solutions were determined by using spectrophotometer at appropriate wavelength corresponding to the maximum absorbency. After equilibrium concentrations of the solutions were obtained, Langmuir and Freundlich adsorption isotherm constants were calculated for the adsorbents used in this study. The removal efficiencies for cationic basic dyes are higher than those for anionic acidic and reactive dyes with the natural materials. Therefore, modification of surface properties of natural materials with a cationic surfactant was considered to increase the removal efficiencies of those for anionic dyes. After modification of the surface properties, adsorption capacities of adsorbents for anionic dyes were higher than those of natural materials. Finally, the adsorption capacity of activated carbon for the same dyes was determined to compare with that of natural and modified materials. The results showed that the adsorption of dyes on adsorbents used in this study fitted nicely the Langmuir Isotherm Equations.

Chlorine is still the most commonly used disinfectant in many water treatment plants all over the World. However, studies conducted demonstrated that the chlorine reacts with the natural organic matter (NOM) in source waters, and leads to the formation of a variety of chlorinated organic compounds, disinfection by-products (DBPs). Among these, the most common are the trihalomethanes (THMs). In this study, kinetics of the THM formation was investigated. Kinetic experiments were carried out with the raw waters from Devege&ccedil / idi and Atat&uuml / rk Reservoirs as well as with water containing a model compound, humic acid. THM and Chlorine concentrations were measured for 6 weeks on a seasonal basis. The simulation model developed by USEPA was used for predicting THM concentrations. The results of this study have shown that THM formation increases with increasing time and higher chlorine doses result in higher THM formation. Also, higher organic matter concentrations resulted in higher chlorine demands and both these parameters increased the TTHM concentrations. But, on the contrary to the standard THMFP testing, THM formation did not complete in seven days. In addition, THM formation and chlorine consumption were very rapid during the first 24 hr followed by a more gradual formation and decay after 24 hr. THM formation rates ranged between 35-66 &micro / g/L.day for Atat&uuml / rk Reservoir, between 80-167 &micro / g/L.day for Devege&ccedil / idi Reservoir and between 85-248 &micro / g/L.day for humic acid during the first 24 hr, and ranged between 2-6 &micro / g/L.day for Atat&uuml / rk Reservoir, between 7-16 &micro / g/L.day for Devege&ccedil / idi Reservoir and between 3-14 &micro / g/L.day for humic acid after 24 hr.

The objective of this study is to develop a calibration and verification tool for the QUAL2E Model by using Genetic Algorithms. In the developed optimization model, an objective function that is formulated on the basis of the sum-of-least squares approach aiming at minimizing the difference between the observed and simulated quantities was used. In order to perform simultaneous calibration and verification, verification of the calibrated results was treated as a constraint and inserted into the objective function as a penalty function. The performance of the optimization model was tested for different observation data qualities represented by the synthetic perfect and biased data sets. Although it was not possible to obtain the exact values of the kinetic coefficients for any of the tests performed, the coefficient estimates were successful in reflecting the water quality variable profiles in the river. The results of the tests showed that the performance of the optimization model is generally sensitive to the error in the observed data sets, to the number and location of sampling points, and to the objective function formulation. For the problems that involve multiple water quality variables, a weighting approach used in the objective function formulation resulted in better performances. The optimization model was also applied for a case study. For the same input data, calibration obtained with the genetic algorithm optimization &ndash / simulation was better compared to the trial-and-error approach.

This study was carried out to develop combined cultures which were composed of anaerobic and aerobic cultures, and could survive and operate under alternating aerobic and/or microaerobic / anaerobic conditions in semi-continuous and Upflow Sludge Blanket (USB) reactors. Granular combined cultures with median diameter of 1.28-1.86 mm and 0.8 mm were developed from suspended anaerobic and aerobic cultures in semi-continuous and USB reactors, respectively. Significant specific methanogenic activity (SMA, 14-42 mL CH4/g VSS.hr) and specific oxygen uptake rate (SOUR, 6-47 mg DO/g VSS.hr) values of combined granules in semi-continuous reactors were comparable to those of anaerobic and aerobic granules. Similarly, combined granules in USB reactors exhibited noteworthy SMA and SOUR values of 11-77 mL CH4/g VSS.hr and 10-75 mg DO/g VSS.hr, respectively. Combined granules developed in semi-continuous reactors were found to overcome the drawbacks of both anaerobic and aerobic granules such as the need for long start-up and low stability, respectively. Combined cultures were also developed from anaerobic granular and suspended aerobic cultures in three USB reactors aerated at 10 mL air/min for 4 hours/day (R2), every other day (R3) and 24 hours/day (R4). The use of combined cultures was found to be advantageous compared to the anaerobic granules for the treatment of low strength wastewaters. During municipal wastewater treatment at influent 5-day biochemical oxygen demand (BOD5) concentration of 53-118 mg/L (Hydraulic retention time, HRT: 0.75 day), combined cultures in R2, R3 and R4 exhibited average BOD5 removal efficiencies of 52, 75 and 76%, respectively. Combined granules developed in USB reactor also displayed significant BOD5 removal efficiencies (66-68%) during municipal wastewater application (HRT: 0.75 day). Combined cultures/granules developed in USB reactors might be proposed as an alternative for municipal wastewater treatment due to their advantages such as achievement of required discharge standards, prevention of biomass loss / settleability problems unlike activated sludge systems and possible methanogenic activity as well as high settling characteristics comparable to those of anaerobic granules.

Natural zeolites, especially clinoptilolite, have the ability of removing certain cations from wastewater by utilizing ion exchange and adsorption. In this study, clinoptilolite originated from Bigadi&ccedil / , Balikesir deposit was investigated in its natural and conditioned form for its effectiveness in removing Zn2+ and Pb2+ ions from aqueous solutions. In addition, relevant mechanisms involved in heavy metal removal by clinoptilolite were examined in this study. Throughout this work, equilibrium and kinetic studies were performed with as-received and conditioned clinoptilolite, having particle size of 0.15 &ndash / 0.80 mm. Conditioning aimed to replace exchangeable cations (Na+, K+, Ca2+, Mg2+) on clinoptilolite with a cation that is more willing to undergo ion exchange. The results of equilibrium studies revealed that clinoptilolite had different capacities for Zn2+ and Pb2+ ions. Clinoptilolite had high capacity for Pb2+ ions, whereas lower capacities were attained for Zn2+. Conditioning with concentrated NaCl solution increased the removal capacity for both metals. Maximum capacities attained were 0.14 meq/g (as-received) and 0.39 meq/g (conditioned) for Zn2+, and 0.51 meq/g (as-received) and 1.10 meq/g (conditioned) for Pb2+. Furthermore, kinetic studies performed under pH-uncontrolled and pH-controlled conditions revealed that heavy metal removal can not only be explained by ion exchange. These studies also indicated that Zn2+ ions were weakly bound to clinoptilolite structure, whereas there was a strong bonding between Pb2+ ions and clinoptilolite structure. To examine possible removal mechanisms, relationship between exchangeable ions released from clinoptilolite structure and Zn2+ and Pb2+ ions removed from aqueous solutions were investigated during equilibrium and kinetic studies. For equilibrium studies, it was observed that the higher the heavy metal equilibrium concentration, the higher is the amount of exchangeable ions released. However, the results indicated that the release of exchangeable ions were not only due to ion exchange. Examination of Si4+, the main central metal ion of clinoptilolite, during kinetic studies showed that destruction of clinoptilolite framework was partly responsible for the release of exchangeable ions. Release of Si4+ was more pronounced in Pb2+ removal studies, indicating dependency of framework destruction on the type of heavy metal species.

Heavy metals are well known toxic priority pollutants. Hence, wastewaters containing these species must be treated prior to discharge into receiving bodies. In this study, the potential of Bigadi&ccedil / clinoptilolite for Cu2+ and Ni2+ removal from wastewaters was investigated in batch and continuous reactors. Results of the preliminary experiments revealed the optimum operating conditions, namely, initial solution pH of 5 and 4 for Cu2+ and Ni2+, respectively and contact time of 48 hours. Additionally, conditioning of clinoptilolite with 2M NaCl solution for 24 hours was found to considerably improve the capacity utilized at breakthrough. Maximum removal capacities and prevailing mechanisms in the system were investigated via equilibrium studies under preliminary determined optimum operating conditions. Langmuir and Freundlich models were fitted to the experimental data and Langmuir model was found to be better in describing the system behavior. Maximum removal capacities obtained from non-linear regression of Langmuir model are almost the same for Cu2+ and Ni2+ removal using as received clinoptilolite samples (0.31 and 0.32 meq/g respectively). However, conditioned clinoptilolite samples exhibit higher capacity for Cu2+ over Ni2+ (0.5 and 0.43 meq/g, respectively). Analyses of exchangeable cations in the aqueous phase were carried out to examine the prevailing mechanisms in the system. As a result, adsorption, dissolution of clinoptilolite and surface precipitation (particularly in the case of Cu2+ removal) are considered to accompany ion exchange. Finally, fixed-bed column studies were conducted with conditioned clinoptilolite samples for Cu2+ removal. An improvement in Cu2+ uptake was observed with decreasing volumetric flow rate (from 8 BV/h to 2-4 BV/h) and decreasing particle size (from 1.180-1.400 mm to 0.833-1.180 mm). Analyses of exchangeable cations as well as Si4+, Fe(total) and Al3+ were also carried out to examine the prevailing mechanisms. Ion exchange was discussed as the predominant mechanism in the system with minor contributions from adsorption and dissolution of clinoptilolite to the total amount of Cu2+ uptake and to the total amount of exchangeable cations release, respectively.

The Lesotho Highlands Development Authority routinely uses the South African Scoring System version 4 (SASS4) in conjunction with water chemistry to monitor water quality of rivers in the Lesotho Highlands Water Project areas. The objective of this study was to test the efficiency of SASS4 in these areas.

The relationships between metal exposure, dose and response were investigated in two sediment dwelling marine bivalves: a deposit feeder Tellina deltoidalis and a filter feeder Anadara trapezia. The bivalves were exposed in the laboratory to individual metal spiked sediments: Cadmium 10 and 50 Ag/g; lead 100 and 300 Ag/g; selenium 5 and 20 Ag/g dry mass, T. deltoidalis for 28 days A. trapezia for 56 days. A. trapezia was also exposed in the laboratory for 56 days to sediments from three sites along a metal contamination gradient of cadmium, lead, selenium, zinc and copper from Lake Macquarie, NSW. Metal total tissue dose was measured in whole tissue of T. deltoidalis over 28 days and in gill, hepatopancreas and haemolymph tissues in A. trapezia over 56 days. Subcellular metal distribution, biologically active metal (BAM) versus biologically detoxified metal (BDM) was measured in whole tissues of T. deltoidalis at day 28 and in gill and hepatopancreas tissues of A. trapezia at day 56. Biomarkers of response measured in spiked sediment exposed, at day 28 T. deltoidalis and day 56 A. trapezia were: total antioxidant capacity (TAOC); glutathione peroxidase enzyme activity (GPx); total glutathione concentration (GSH+2GSSG); reduced to oxidised glutathione ratio (GSH:GSSG); lipid peroxidation (TBARS); lysosomal membrane stability and micronuclei frequency. Response indices measured in A. trapezia exposed to Lake Macquarie sediments were: TAOC, TBARS, lysosomal membrane stability, micronucleus frequency and condition index. Native A. trapezia and sediments were also collected from Lake Macquarie and measured for sediment and tissue metal concentrations, TAOC, TBARS, lysosomal membrane stability and condition index to allow comparison between chronically exposed and previously unexposed organisms. T. deltoidalis and A. trapezia accumulated metal over time in all sediment metal exposures with most reaching equilibrium tissue metal concentrations by the end of the exposure period. T. deltoidalis generally reached equilibrium with the exposure concentration for cadmium and lead but had significantly higher selenium tissue concentrations than the sediment metal at the 5 Ag/g exposure. A. trapezia tissue lead was below the sediment concentration for all exposures including in the native organisms. A high proportion of accumulated lead and copper in A. trapezia was in the haemolymph, probably associated with haemoglobin which has a high affinity for these metals`. A. trapezia cadmium tissue concentrations were higher than the sediment metal in the 10 Ag/g spiked sediment exposure and between half and one eighth the sediment concentrations in other treatments, including in native organisms. A. trapezia including the native organisms exposed to selenium sediment concentrations at or below 5 Ag/g in the Lake Macquarie mixed metal sediments accumulated significantly higher than ambient selenium tissue concentrations while those exposed to 5 and 20 Ag/g selenium spiked sediments had lower than ambient selenium tissue concentrations. The majority of accumulated cadmium, selenium and zinc was associated with the gill/mantle tissues. A. trapezia hepatopancreas contributed significant selenium concentrations in the later part of the exposure period indicating and increased contribution from dietary derived selenium. Native A. trapezia had significantly lower tissue concentrations of selenium, copper and zinc, higher cadmium and approximately equal lead compared to organisms exposed to similar sediment metal concentrations in the laboratory. T. deltoidalis detoxified around 50 % of accumulated cadmium and 70 % of lead while A. trapezia detoxified around 70 % of accumulated cadmium and 60 % of lead. Much of T. deltoidalis BDM cadmium was converted to metal rich granules (MRG), while A. trapezia had most in the metallothionein like proteins (MTLP) fraction. The conversion of lead to MRG was 75 % of the total BDM in T. deltoidalis while A. trapezia had an even distribution between MRG and MTLP. The majority of recovered selenium in both species was associated with the nuclei+cellular debris fraction, probably as protein bound selenium associated with plasma and selenium bound directly to cell walls. Selenium exposed organisms had increased BDM selenium burdens which were associated with both MRG and MTLP fractions, indicating selenium detoxification. The majority of BAM cadmium, lead and selenium was associated with the mitochondrial fraction in both species with increases in cadmium burden in this organelle of T. deltoidalis up to 7200 fold; lead 154 fold; and selenium 7 fold and in A. trapezia up to 84 fold cadmium, 50 fold lead and selenium 7 fold in exposed organisms compared to controls. The subcellular distribution of all three metals in T. deltoidalis and A. trapezia indicates active metal detoxification processes which at these exposure concentrations were unable to prevent significant metal burdens from accumulating in sensitive organelles. A contamination gradient of zinc, lead, copper, cadmium and selenium was established in Lake Macquarie sediments which emanated from the same source. A. trapezia accumulated all metals in each sediment exposure. Accumulation and tissue distribution patterns of cadmium, lead and selenium were similar to those of the single metal spiked sediment exposures. Cadmium and lead BAM burdens increased at all exposures while selenium, zinc and copper did not. T. deltoidalis and A. trapezia in the spiked sediment metal exposures generally had reduced GPx activity. This resulted in an increase in total glutathione concentrations which the reduced GSH:GSSG ratios indicated was due to a build up of oxidised glutathione. T. deltoidalis and A. trapezia had reduced TAOC in all laboratory sediment metal exposures which corresponded with increased TBARS concentrations, lysosomal destabilisation and micronucleus frequency. A. trapezia exposed to Lake Macquarie metal contaminated sediments also had a reduction in physiological condition, indicated by the reduced condition index, after 56 days at the higher metal exposures. Clear exposure - dose - response relationships have been demonstrated for T. deltoidalis and A. trapezia exposed to single cadmium, lead and selenium spiked sediments and for A. trapezia exposed to Lake Macquarie mixed metal contaminated sediments. Detoxification of all metals was evident in both T. deltoidalis and A. trapezia but detoxification capacity was exceeded for cadmium, lead and selenium leading to significant accumulation of these metals in sensitive organelles. The significant relationships, in the laboratory exposed T. deltoidalis and A. trapezia, between TAOC reduction with increased TBARS, lysosomal destabilisation and micronuclei frequency and between increased TBARS with lysosomal destabilisation and micronuclei frequency indicates that increased tissue metal dose and BAM burdens caused significant impairment of the antioxidant reduction capacity which resulted in a cascade of effects from lipid peroxidation to cellular perturbation and genotoxic damage. The reduction in physiological condition in the organisms with the highest tissue metal doses suggests the response goes beyond subcellular perturbations to whole organism and potentially population effects. Chronically metal exposed native Lake Macquarie A. trapezia did not show a clear metal exposure - dose - response relationship. Accumulation of the essential elements zinc, copper and selenium appeared to be regulated while cadmium and lead were not. TAOC was significantly reduced and TBARS significantly increased compared to reference organisms but lysosomal stability and condition were not significantly affected. The suite of interrelated biomarkers used offers a weight of evidence approach for demonstrating adverse effects of metal tissue accumulation in T. deltoidalis and A. trapezia

The ever-increasing detection of harmful organic and inorganic compounds in habitable areas throughout the world has led to mounting research into applications and techniques for the treatment of contaminated soils, surface and groundwaters, and chemical and industrial wastewaters. Chemical oxidation technologies, in particular Fenton-based remediation systems, have exhibited considerable potential for the effective treatment and remediation of such contaminated waters and soils. The use of Fenton-based oxidation systems for the treatment of contaminated waters and wastewaters warrants the development of kinetic models capable of accurately simulating system behaviour. In this thesis, the kinetics of Fenton-mediated oxidation systems and kinetic models based on its governing reaction mechanism are investigated in order to highlight those parameters and conditions that effect Fenton chemistry and oxidation performance, and to demonstrate the application of such kinetic models to design and improve treatment systems. Experimental and simulated data describing the oxidation of formic acid by Fenton's reagent at low pH (3 to 4) and under a variety of initial conditions, operating regimes, and solution environments supports a proposed reaction mechanism that nominates the hydroxyl radical (OH) as the active oxidizing intermediate in Fenton-based oxidation systems. Laboratory experiments demonstrate that formic acid oxidation is inhibited in the presence of oxygen, and model simulations of these systems reveals that such behaviour is due to the effect organic radical intermediates and/or by-products have in assisting or hindering the redox cycling of the catalytic iron species. The critical role that iron redox cycling plays in affecting oxidation performance is further highlighted by experimental and simulated studies at alternate pHs and using different target organics, including those that react directly with iron in a redox capacity. Experiments at pH 4 reveal an increase in the redox cycling of iron and improved oxidation performance compared to pH 3 as the higher pH favours the superoxide radical, a stronger reductant than the hydroperoxyl radical that predominates at pH 3. Other laboratory and modelling studies on the Fenton-mediated oxidation of certain aromatic compounds highlight the manner in which quinone and quinone-like compounds, being added directly or generated as oxidation by-products, can improve oxidation performance via redox reactions with iron. Further simulations reveal the type of practical design and operating information kinetic models can provide for treatment processes, though it is noted an appropriate understanding of the oxidation mechanism of the target species is necessary for the accurate application of the model.