Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/dieoff- rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates.

Abstract Centro Universitaire UNIVATES is located in the town Lajeado that is situated in the most southerly state, Rio Grande Do Sul, in Brazil. The university has 5000 students, teachers and others staff. UNIVATES is not satisfied with their present wastewater situation and wants to improve it by eliminate the smell caused by the wastewater. They would also like to remove the oil that the storm water brings into the wetland. The high amount of particles in the storm water gives rise to a lot of sediments that eventually will fill up the wetland, and something has to be done about this, if the wetland should continue to be in use. Another aspect to consider is the wish of some people at UNIVATES, for the wetland to be a beautiful and recreational place. All these factors had to be considered, which led to the main question: How can the use of the wetland for wastewater treatment be combined with the request for the wetland to be a beautiful place with the wildlife preserved? During the course Wetland Technology that we took before our departure to Brazil, we got introduced to the situation at UNIVATES by Professor André Jasper and Odorico Konrad who visited the course several times. They pointed out that the main issue is the smell from the wastewater and later during the field study at UNIVATES, more information were obtained through discussions, meetings and conversations with the people involved. Several visual inspections were carried out by walking around the wetland. We could determine where and how the inlets and outlets to the wetland were and when it was clear which inlets that brought wastewater and which that brought storm water, the water flow of the wastewater was estimated. Water samples from the wetland were collected at five different sites and analyses of pH, BOD, COD, N-Tot, phosphorus and metals were done by the accredited laboratory at UNIVATES. To test some of our theories, we did a smaller practical experiment that got the name Superficial Filtration Bed. The results from the water samples showed the highest BOD, COD, N-Tot and Phosphorus levels in the samples from site 2 and 4 and this reveals that it is wastewater. This was also confirmed by the smell that we felt at these sites during the visual inspections. The results also showed that there is no wastewater coming from site 1, 3 and 5. Our final proposal is to create a multifunctional wetland with the purpose to take care of both storm water and wastewater and at the same time work as a research and recreational area. The wetland, which would be divided into two parts, will constitute of all the fundamental functions; storm water buffering, sedimentation basin and biological oil separation and treatment. There will also be research sites and hybrid system for wastewater treatment. The hybrid system will consist of two steps where the first is aerobic and the second both aerobic and anaerobic. The first step is a Superficial Filtration Bed (SFB) and the second a FWS wetland. The conclusion of this thesis is that more detailed research is needed to be able to dimension the specific functions correctly. With some further investigations the proposal presented is possible to carry through and our feeling when we left UNIVATES was that the people responsible really liked our ideas. They made it clear that they want to make a change and improve the situation and with the help they have gotten from us, they are a few steps closer to solving the problem.

A microwave enhanced advanced oxidation process using hydrogen peroxide (MW/H₂O₂-AOP) was used for the release of nutrients and the destruction of solids from secondary municipal sewage sludge. The significant factors affecting the MW/H₂O₂-AOP that would yield maximum soluble substrates were studied. Using a computer statistical software package for experimental design and data analysis, four factors including microwave heating temperature, heating time, hydrogen peroxide dosage, and sludge solids content, were selected and examined. The initial sludge TS content and hydrogen peroxide dosage were the most significant factors for the solubilization of COD and nutrients release under the experimental conditions selected in this study. Overall, the maximum solubilization of nutrients was obtained at 2.5 % of total solids content, 2% of hydrogen peroxide by weight, 5 min. of microwave heating and 120 ºC. The effects of combination of microwave treatment and oxidative reagents on solids destruction and nutrients release were also investigated. Microwave enhanced advanced oxidation processes (MW-AOP), such as MW/O₃, MW/H₂O₂ and MW/H₂O₂/O₃, were conducted at 100 °C. In terms of nutrients release and solids reduction, the MW/H₂O₂/O₃-AOP yielded the best result. Subsequently, three factors including microwave heating temperature, hydrogen peroxide dosage, and ozone dosage, were investigated. The best result, in terms of the release of phosphate and ammonia, and solids reduction, was obtained with additions of 2 % hydrogen peroxide by weight and ozone dosage of 5.09 mg/ml, and operating at 120ºC. About 95%, 32% and 78% of TP, TKN and COD were released into the solution, respectively. The microwave enhanced advanced oxidation processes, with and without an addition of ferrous sulfate (MW/H₂O₂-AOP and MW/H₂O₂/Fe+²-AOP), were also studied for reducing solids, and solubilizing nutrients from the secondary sewage sludge. For the MW/H₂O₂/Fe+²-AOP, the best results of solubilization, in terms of orthophosphate, ammonia and soluble chemical oxygen demand, were obtained at treatment temperatures of 40 ºC, the yields decreased as the temperature was increased. The highest yields of solubilization were obtained at 60 ºC for orthophosphate, and at 80 ºC for both ammonia and soluble chemical oxygen demand.

Wastewaters from rural sewage lagoons in Manitoba contain pharmaceuticals that are potentially harmful to non-target organisms and reduce overall water quality when released. An option for reducing exposure to wastewater contaminants and potential toxicity is surface flow treatment wetlands. However, little is known of the fate of pharmaceuticals in these types of systems. The fate and effects of six pharmaceuticals (carbamazepine, clofibric acid, fluoxetine, naproxen, sulfamethoxazole, sulfapyridine) were assessed in mesocosms simulating treatment wetlands in two separate 28-day experiments in the summer and fall of 2011, respectively: with and without significant aquatic plant communities, and with additional nutrients and harvesting of biomass. The removal of pharmaceuticals had half-lives that ranged from 0.23 to 9.4 days and 1.4 to 18 days during the summer and fall, respectively, and were predicted to occur primarily through photolysis and sorption. No overt toxicity from pharmaceuticals was observed for the common wetland macrophytes Myriophyllum sibiricum and Typha spp., but there was partitioning and bioaccumulation into macrophyte biomass. Treatment wetlands appeared to reduce pharmaceuticals and nutrients adequately, and may be a cost-effective means of treating rural wastewater.

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Wastewaters from rural sewage lagoons in Manitoba contain pharmaceuticals that are potentially harmful to non-target organisms and reduce overall water quality when released. An option for reducing exposure to wastewater contaminants and potential toxicity is surface flow treatment wetlands. However, little is known of the fate of pharmaceuticals in these types of systems. The fate and effects of six pharmaceuticals (carbamazepine, clofibric acid, fluoxetine, naproxen, sulfamethoxazole, sulfapyridine) were assessed in mesocosms simulating treatment wetlands in two separate 28-day experiments in the summer and fall of 2011, respectively: with and without significant aquatic plant communities, and with additional nutrients and harvesting of biomass. The removal of pharmaceuticals had half-lives that ranged from 0.23 to 9.4 days and 1.4 to 18 days during the summer and fall, respectively, and were predicted to occur primarily through photolysis and sorption. No overt toxicity from pharmaceuticals was observed for the common wetland macrophytes Myriophyllum sibiricum and Typha spp., but there was partitioning and bioaccumulation into macrophyte biomass. Treatment wetlands appeared to reduce pharmaceuticals and nutrients adequately, and may be a cost-effective means of treating rural wastewater.

Facultative aerated lagoons are aerated lagoons operated at low power levels and are wastewater stabilization ponds with artificial aeration. These lagoons are used more commonly than aerobic aerated lagoons because a satisfactory effluent can be produced with a lower power input. The power level applied to facultative aerated lagoons is sufficient only to satisfy the oxygen demand but not adequate to keep all the solids in suspension and settled solids will decompose aerobically and anaerobically. In the study reported, laboratory-model facultative aerated lagoons of 81 litres volume, aerated with diffused air, were used to study the performance of such lagoons in the treatment of municipal wastewater. Different combinations of four power levels, 0.25,0.5,1 and 2.0 W/m3, three different organic loadings, 20,33 and 62 g BOD5/m3d. , and two temperature levels, 20°C and 30°C, were applied in twenty four experimental runs. Influent and effluent were sampled on a regular basis and their characteristics were determined. The effluent from the model facultative aerated lagoons was always of reasonable quality, with respect to BOD5, COD and suspended solids. This was achieved with no provision for effluent settling or additional treatment. Removals of 91 percent BOD5 and 67 percent COD could be achieved for unfiltered samples. Effluent BOD5 of 13 mg/l in the filtered samples and 31 mg/l in the unfiltered samples was attainable in these lagoons. Effluent suspended solids levels as low as 41 mg/i were also obtained. Thus facultative aerated lagoons will provide both biological and physical treatment operations in a single earthen tank. Because suspended solids in the effluent from facultative aerated lagoons are low, no sludge disposal or processing is needed on a continuous basis. Other performance criteria; nitrogen, phosphorus, iii chlorophyll "a", Escherichia. coli and faecal streptococci, are reported on in the thesis. It was observed that the level of power introduced into the facultative aerated lagoon had positive and significant effects on some performance parameters, including BOD5 and COD filtered removal rate coefficients, removal efficiencies for BOD5 and COD (except for COD removal in facultative aerated lagoons operated at high temperature, 30°C) and effluent suspended solids and negative and significant effects for others, such as suspended solids removal efficiency. The effect of power was insignificant for other parameters, especially BOD5 and COD unfiltered removal rate coefficients. The effect of power level on filtered removal efficiencies was higher than on unfiltered ones. BOD5 and COD removal efficiencies were negatively affected by organic loading (or positively by retention time) and the effect was found to be significant. The organic loading effect was significant and positive on filtered BOD5 and both filtered and unfiltered COD removal rate coefficients whereas it was negative on unfiltered BOD5 removal rate coefficients. Temperature had significant and positive effects on some parameters, including removal rate coefficients both filtered BOD5 and COD as well as unfiltered BOD5 and BOD5 and COD removal efficiencies, and insignificant effects on others, such as unfiltered COD removal rate coefficient. The effect of temperature on the removal rate coefficients, except the unfiltered COD removal rate coefficient, was higher at higher organic loadings (shorter retention times) whereas its effect on BOD5 and COD removals efficiencies was higher at lower power levels. The temperature correction coefficient for BOD5 at low power levels was higher than at higher levels of power. iv The effect of power level on the temperature correction coefficient was significant whereas the organic loading (or retention time) effect was insignificant. Relationships between the individual operating parameters and performance parameters are presented in the form of empirical equations and the combined effects of these operating parameters and performance parameters were also modelled. High organic loading (short retention time) in facultative aerated lagoons operated at low power levels proved to remove more organic material per day per unit of power introduced into the lagoon. Therefore, the optimum conditions of organic loading and power level at which a single facultative aerated lagoon used as a sole treatment process for treating settled sewage should be operated are 0.25 W/m3 for power level and 62 g BOD5 /m3. d for organic loading (3 to 4 days retentiom time). The effect of mixing, represented by the parameters in a simulation model, on performance was also modelled in the form of empirical equations. Nitrogen, phosphorus, Escherichia coli and faecal streptococci removals were considerable. Variations of their removal performance as well as algal concentration variations with the operating parameters were also studied and discussed. A mathematical equation was developed for the determination of the mean solids retention time (SRT) in facultative aerated lagoons. The relationship between SRT and power level and organic loading was determined and represented by an empirical equation. A power level of around 0.5 W/m3 was the threshold for settleable solids suspension below which no significant decrease in effluent or mixed liquor suspended solids concentration would take place.