Slow sand filtration is a proven and sustainable technology for drinking water treatment in small communities. The process, however, is sensitive to lower water temperatures that can lead to decreased biological treatment, and high raw water turbidity levels that can lead to premature clogging of the filter and frequent cleaning requirements, resulting in increased risk of pathogen breakthrough. Multistage filtration, consisting of roughing filtration followed by slow sand filtration, can overcome these treatment limitations and provide a robust treatment alternative for surface water sources of variable water quality in northern climates, which typically experience water temperatures ranging down to 2&deg;C. Prior to this study, however, multistage filtration had yet to be systematically challenged in colder climates, including testing of its performance under increased hydraulic loadings and elevated influent turbidity together with cold water conditions. The primary goal of this research was to demonstrate the reliability of multistage filtration for small communities in northern climates with reference to the Ontario Safe Drinking Water Act. In this research, testing was conducted on two different pilot multistage filtration systems and fed with water from the Grand River, a municipally and agriculturally impacted river in Southern Ontario. One system featured pre-ozonation and post-granular activated carbon (GAC) stages, and shallower bed depths in the roughing filter and slow sand filter. The other system featured deeper bed depths in the roughing filter and slow sand filter, two parallel roughing filters of different design for comparison, and a second stage of slow sand filtration for increased robustness. Removal of turbidity, total coliforms, and fecal coliforms under a range of influent turbidities (1 to >100 NTU), water temperatures (~2 to 20&deg;C), and hydraulic loading rates (0. 2 to 0. 8 m/h) were investigated. In addition, the slow sand filters in each pilot system were challenged with high concentrations (~10⁶ oocyst/L) of inactivated <i>Cryptosporidium parvum</i> oocysts. The performance of both pilot multistage filtration systems was highly dependent on the biological maturity of the system and its hydraulic loading rate. In a less mature system operating in cold water conditions (<5&deg;C), effluent turbidity was mostly below 0. 5 NTU during periods of stable influent turbidity (no runoff events) and a hydraulic loading of 0. 4 m/h, however, runoff events of high influent turbidity (>50 NTU), increased hydraulic loadings (0. 6 m/h), and filter cleaning occasionally resulted in effluent turbidity above 1 NTU. Furthermore, in a less mature system operating during runoff events of high turbidity, reducing the hydraulic loading rate to 0. 2 m/h was important for achieving effluent turbidity below 1 NTU. However, in a more mature system operating in warm water conditions (19-22&deg;C), effluent turbidity was consistently below 0. 3 NTU at a hydraulic loading rate of 0. 4 m/h, and below 0. 5 NTU at 0. 8 m/h, despite numerous events of high influent turbidity (>25 NTU). It remains to be seen whether this performance could be sustained in colder water temperatures with a fully mature filter. Removal of coliform bacteria was occasionally incomplete in a less mature multistage system, whereas, in a more mature system operating in warm water conditions (>9&deg;C), removal was complete in all measurements. Furthermore, the average removal of <i>Cryptosporidium</i> was greater than 2. 5 logs in both systems (with hydraulic loading rates ranging from 0. 4 to 0. 8 m/h) and improved with increased filter maturity. Each individual stage of the multistage system was an important treatment barrier in the overall process of turbidity and pathogen removal. The roughing filter was not only important for protecting the slow sand filter from solids loading and increasing its run length, but was also a significant contributor to coliform removal when the system was less mature. Removal of turbidity was significantly improved when the roughing filter was more mature, suggesting that biological treatment was an important treatment mechanism in the roughing filter. Although pre-ozonation was used mainly for the removal of organic carbon and colour, it achieved complete removal of coliform bacteria and was also suspected to be important for enhanced removal of turbidity. The second slow sand filter in series provided additional robustness to the process by reducing effluent turbidity to below 1 NTU during cold water runoff events of high turbidity and increased hydraulic loadings (0. 6 m/h), while achieving effluent below 0. 3 NTU during normal periods of operation. It also provided additional removals of coliforms under challenging operating conditions, and contributed an additional average removal of <i>Cryptosporidium</i> of 0. 8 logs, which resulted in cumulative removal of 3. 7 logs, approximately 1 log greater than all the other challenge tests. Collectively, the entire multistage system performed well with water temperatures ranging down to 2&deg;C, limited filter maturity, elevated raw water turbidities, and increased hydraulic loading rates. Its ability to meet the current Ontario turbidity regulations and greater than 2 log removal of <i>Cryptosporidium</i> over a range of operating conditions, with little or no process adjustment, is a testament to the robustness and minimal maintenance requirements of the process, which are desirable attributes for small water systems that are often located in rural areas. While this research demonstrated the performance of multistage filtration using pilot scale testing, it is important to note that full-scale plants tend to produce significantly better results than pilot facilities, due to long term biological maturation of the system. Overall, multistage filtration is a sustainable and cost-effective technology that, through this research, appears to be a safe, reliable, and robust treatment alternative for small and non-municipal water systems in North America and the developing world. Further, based on its performance with challenging influent water quality and cold water conditions, multistage filtration holds particular promise for small communities in northern climates that are required to meet safe drinking water regulations, but are dependent on surface water sources of variable water quality and temperatures.

Chromium is a common groundwater pollutant originating from industrial processes such as metal plating, leather tanning and pigment manufacturing. Permeable reactive barriers (PRBs) have proven to be viable and cost-effective systems for remediation of chromium contaminated groundwater at many sites. The purpose of this research presented in this thesis is to focus on two parameters that affect the performance of PRB on chromium removal, namely the concentration of reactive media and groundwater flux by analyzing the data obtained from laboratory column studies. Laboratory scale columns packed with different amounts of iron powder and quartz sand mixtures were fed with 20 mg/l chromium influent solution under different fluxes. When chromium treatment efficiencies of the columns were compared with respect to iron powder/quartz sand ratio, the amount of iron powder was found to be an important parameter for treatment efficiency of PRBs. The formation of H2 gas and the reddish-brown precipitates throughout the column matrix were observed, suggesting the reductive precipitation reactions. SEM-EDX analysis of the iron surface after the breakthrough illustrated chromium precipitation. In addition to chromium / calcium and significant amount of iron-oxides or -hydroxides was also detected on the iron surfaces. When the same experiments were conducted at higher fluxes, an increase was observed in the treatment efficiency in the column containing 50% iron. This suggested that the precipitates may not be accumulating at higher fluxes which, in turn, create available surface area for reduction. Extraction experiments were also performed to determine the fraction of chromium that adsorbed to ironhydroxides. The analysis showed that chromium was not removed by adsorption to oxyhydroxides and that reduction is the only removal mechanism in the laboratory experiments. The observed rate of Cr(VI) removal was calculated for each reactive mixture which ranged from 48.86 hour-1 to 3804.13 hour-1. These rate constants and complete removal efficiency values were thought to be important design parameters in the field scale permeable reactive barrier applications.

Clinoptilolite samples obtained from two deposits in Turkey were tested for their potential in removing cadmium from aqueous solutions. Preliminary experiments in batch mode revealed inferior cadmium uptake at low pH. Particle size was found to have no effect on cadmium removal efficiency suggesting the use of exchangeable cations found in the internal/available sites. Increasing temperature yielded positive, whereas prewashing had no effect on cadmium removal using both clinoptilolite samples. The Langmuir model fitted the equilibrium data for both samples better than the Freundlich model. The capacity reached after conditioning represents about 4 and 3 fold increase for G&ouml / rdes and Bigadi&ccedil / samples, respectively. The relatively poor performance of Bigadi&ccedil / clinoptilolite was due to low clinoptilolite/high impurity contents. Further studies were carried out only with G&ouml / rdes clinoptilolite. The performance of the G&ouml / rdes samples conditioned with various chemicals were NaCl&gt / KCl&gt / As-received&gt / CaCl2&gt / HCl. 20BV of NaCl solution was found to be sufficient with no pH adjustment or water quality requirement during column conditioning. In column experiments, among the tested flowrates 5, 10 and 15 BV/hr, highest flowrate indicated inferior utilization of the removal capacity. No significant difference by decreasing particle size indicated pore diffusion resistance not to be a limiting factor. In five conditioning and regeneration cycles, clinoptilolite exhibited 36% increase in operating capacity. Cadmium removed by clinoptilolite in progressing cycles was concentrated by about 7 times. Overall, this study shows that Manisa-G&ouml / rdes clinoptilolite is advantageous for the removal of cadmium ions from aqueous solutions and hold great potential to be used in practical applications.

In the present study, the recovery of the indigo dyeing rinsing wastewater originating from a denim textile mill to the degree of reuse quality, which generally requires nanofiltration (NF), was investigated. In order to control flux decline and hence to maintain an efficient NF / coagulation, microfiltration (MF) and sequential MF plus ultrafiltration (UF) pretreatment process alternatives were tested. All pretreatment alternatives were optimized to reduce chemical oxygen demand (COD) and color load to NF. Coagulation process was investigated using the coagulants, aluminum sulfate (Al2(SO4)3.18H2O) and ferric chloride (FeCl3.6H2O) by running a series of jar tests. The results showed that coagulation process did not provide an effective and efficient pretreatment due to high dose of coagulant requirement. MF tests run by using 0.45, 2.5 and, 8 &micro / m membranes indicated that MF through 0.45 &micro / m pore-sized membrane is the best process providing 64% color and 29% COD removals, leading to a color value of 2493 Pt-Co and COD of 892 mg /L in the permeate. Application of sequential MF+UF filtration provided a significant benefit over single MF in terms of rejections and also permeate flux. UF applied after MF provided additional 62% color and 4% COD removals leading to 960 Pt-Co color and 856 mg/L COD. NF tests conducted using pretreated wastewater via single MF and sequential MF+UF indicated that single MF is the best pretreatment to NF and this treatment scheme provided 99% color, 97% COD and 80 % conductivity removals and satisfied reuse criteria.

Rapid urbanization and population growth have represented a great challenge to water resources management, since wastewater generated in urban areas forms a non-conventional source, wastewater reuse is being recognized as a sustainable water management approach. This study focuses on with the potential and practibility of implementing wastewater reuse techniques in Izmir region, especially with the aim to use treated wastewater and nutrient for agriculture. To this end, qualititative and quantitative agricultural water demand were considered. This thesis introduces a wastewater reuse planning model and optimization method with an emphasis on the wastewater treatment technology used as well as the agricultural demand in the area of the study. The model was developed with considerations over water quality, wastewater treatment and discharge. The objective of the model is to upgrade existing wastewater treatment plants or to design new treatment plants in regard to reuse wastewater in agriculture. The model is also capable of comparing treatment technologies from the point of design and cost. Three case studies were represented so as to demonstrate the modeling process and optimization studies for agricultural irrigation.

Numerous organic reagents of diverse structural composition are employed in the froth flotation process for the beneficiation of non-metallic and sulphide ores. Alkyl xanthates are used as collectors for sulphide ores while amines and fatty acids are used for non-metallic ore beneficiation. Although these collector reagents react preferentially with the concerned minerals in the treated ore pulp, excess and unreacted concentration of these organic collectors end up in the mill process effluents. It has been known that even small concentrations of these organic reagents in water streams are toxic to water life, besides their deleterious influence on end stream processes during recycling. Bioremediation has long been recognised as an inexpensive, flexible and environmentally benign technique for waste water treatment. These organic flotation reagents are amenable to biological degradation. The major objective of this work is the degradation of solubilized collector reagents from aqueous solutions using a microbial technique. Bacillus polymyxa, a Gram-positive, neutrophilic, periflagellated heterotroph that occurs indigenously in soils and certain mineral deposits has been used in the bioremediation studies. Organic flotation reagents namely, dodecyl ammonium acetate (DAA), which is used as a collector for oxides and silicates, sodium isopropylxanthate which finds application in sulphide flotation and sodium oleate, mainly used for oxide and salt-type minerals, have been chosen for the degradation studies. Pure minerals of galena, pyrite, magnetite, quartz and calcite have been typically selected for these investigations. The growth of Bacillus polymyxa in the presence of these organic reagents at different concentrations has been assessed and the degradation of these reagents monitored. Attempts have been made to grow the bacterium in the presence of the organic reagents, both in the absence and presence of sucrose, by adaptation technique. Electrokinetic studies on the chosen minerals namely, galena, pyrite, quartz, calcite and magnetite have been carried out both in the presence of the organic reagents and Bacillus polymyxa cells or metabolite. Biological stripping of the adsorbed collector reagents from the mineral surfaces have been examined through FTIR spectroscopy. The progress of bioremoval of the organic reagents along with the generation of newer reaction products has also been monitored through uv-visible spectroscopic technique. The results of this study highlight that Bacillus polymyxa and its metabolic products bring about the degradation of the chosen organic flotation collectors. Further, the bacteria are able to utilise the collector reagents as carbon source for their growth, in the absence of added organic carbon (sucrose). Electrokinetic studies and examination by FTIR spectroscopy reveal that consequent to interaction with Bacillus polymyxa, significant surface modification on the mineral takes place. Probable mechanisms in the biodegradation processes are illustrated. Biological metabolic products responsible for bringing about the bio-deterioration have been analysed and characterised.

Schwerpunkt der vorliegenden Arbeit war die Erstellung, Anpassung und Anwendung einer Methode, die es über die Quantifizierung gebildeter OH-Radikale ermöglicht, sowohl den Einfluss verschiedener Materialmodifikationen (physikalisch dotierte Nanokatalysatoren bzw. Biokompositmaterialien) als auch die Auswirkungen von Matrixbestandteilen oder hydrochemischen Randbedingungen auf die photokatalytische Effizienz der Materialien zu untersuchen. Zudem wurde angestrebt, dass sich die Anwendbarkeit der Methode nicht nur auf die Photokatalyse beschränkt, sondern auch auf andere AOPs ausgeweitet werden kann. Des Weiteren wurde über die Umsetzung der Modellspurenstoffe Carbamazepin und Diclofenac die Wirksamkeit der Katalysatormaterialien untersucht. Anhand von Versuchen im Labormaßstab werden unter Anwendung der entsprechenden Methode zur Quantifizierung der OH-Radikale bisherige zugrundeliegende Hypothesen zur photokatalytischen Erzeugung von OH-Radikalen (Einfluss von pH und Oberfläche) überprüft und modifiziert. Dabei werden neue Ansätze zur Oberflächenabhängigkeit der OH-Radikalbildung in AOPs (EAOP Diamantelektrode, UV/VUV), die Effizienz von UV/VUV im Vergleich zu UVA-Photokatalyse, die Anwendung von S-Layer-Proteinen in photokatalytischen Biokompositmaterialien sowie eine photokatalytische Umsetzung von Carbamazepin unter Nutzung neuartiger Katalysatoren und Sonnenlicht untersucht. Mit Hilfe der gewonnenen Erkenntnisse ist es möglich, photokatalytisch aktive Materialien über die OH-Radikalbildungskapazität, als Basisprozess einer photokatalytischen Eliminierung von pharmazeutischen Wirkstoffen aus Wässern, mit Hinblick auf ihre Effizienz und Haltbarkeit zu untersuchen. Daneben bietet das erstellte Konzept zur analytischen Anwendung der OH-Radikalbestimmung neben der Gelegenheit für interessante Vergleiche diverser AOP-Systeme auch die Möglichkeit einer Charakterisierung und Optimierung der einzelnen AOPs. Zudem konnte gezeigt werden, dass die Anwendung von nano-Biokompositmaterialien unter Verwendung von S-Layer-Protein zur Herstellung multifunktionaler photokatalytischer Beschichtungen vielversprechend ist. Die Ergebnisse der Arbeit unterstreichen, dass die analytische Erfassung von Transformationsprodukten aus photokatalytischen bzw. oxidativen Umsetzungen im Allgemeinen von großer Bedeutung ist, jedoch allein nicht ausreicht, um hinreichend sichere Aussagen über eine mögliche Gefährdung für Mensch bzw. Ökosystem zu erhalten. / The current work was focused on the preparation, adaption and application of an analytical method for the determination of OH radicals for the comparison of the activity of different photocatalytic materials in relation to the material modification (i.e. physically doped nanomaterials or biocomposite materials) and the composition of the water matrix. Furthermore, the application of the OH radical assay should be extended on other AOPs. The degradation of the model compounds carbamazepine and diclofenac was examined to determine the efficiency of the novel photocatalysts. By using appropriate OH radical assays in laboratory scale experiments, present hypotheses in relation to the photocatalytic formation of OH radicals (i.e. influence of pH or surface) were examined and modified. New approaches on the formation of OH radicals with respect to the surface within AOPs (EAOP diamond electrodes or UV/VUV), the efficiency of UV/VUV in relation to photocatalysis using UVA irradiation, the application of S-layer proteins in biocomposite materials and the photocatalytic degradation of carbamazepine applying novel photocatalysts and natural sunlight were examined. Based upon the findings, it was possible to compare photocatalytic materials regarding efficiency and stability by means of the capacity to form OH radicals as the base process for the oxidative degradation of pharmaceutical trace compounds. The analytical concept offers the possibility to compare different AOPs and to characterize or optimize a single AOP. Furthermore, it was shown that the implementation of nanoscale biocomposite materials using S-layer proteins for the preparation of multi-functional coatings for photocatalytic applications is promising. In addition, the current work confirmed that the examination of transformation products of photocatalytic treatment processes or other oxidative reactions is very important. However, the analytical characterization alone is not sufficient to predict potential hazards to human health or the ecosystem with adequate reliability.

The eutrophication in the Baltic Sea is a big issue which threatens marine ecosystems, increases the depletion of oxygen in the water and causes harm to aquatic animals. Human activities such as industries, agriculture, forestry and untreated sewage increase nutrient input (mainly nitrogen and phosphorus) which causes increased levels of plankton and bacteria. Sweden has suggested to prohibit recreational craft owners to discharge their untreated wastewater to the ocean. The aim for this study is to examine and analyze the different types of water treatment systems that exist today and to see what levels of bacteria and nutrients the effluent water has from the systems. This research will help the EU-commission to decide what demands you can put on the discharged effluent water on recreational crafts. The study shows that none of the existing systems is able to decrease the levels of nutrients in the effluent treated wastewater. This makes it hard for the EU-commission to decide on demands for recreational crafts. This may lead to increased use of drainstations of wastewater in harbors for owners.

Traditionally, energy capture by non-concentrating solar collectors is calculated using the Hottel-Whillier Equation (HW): Q(u)=A(c)*F(r)*S-A(c)*F(r)*U(l)*(T(fi)-Tₐ), or its derivative: Q(u)=A(c)*F(r)*S-A(c)*F(r)*U(l)*((T(fi)-T(fo))/2-Tₐ). In these models, the rate of energy capture is based on the collector's aperture area (A(c)), collector heat removal factor (F(r)), absorbed solar radiation (S), collector overall heat loss coefficient (U(l)), inlet fluid temperature (T(fi)) and ambient air temperature (Tₐ). However real-world testing showed that these equations could potentially show significant errors during non-ideal solar and environmental conditions. It also predicts that when T(fi)-Tₐ equals zero, the energy lost convectively is zero. An improved model was tested: Q(u)=A(c)F(r)S-A(c)U(l)((T(fo)-T(fi))/(ln(T(fo)/T(fi)))-Tₐ) where T(fo) is the exit fluid temperature. Individual variables and coefficients were analyzed for all versions of the equation using linear analysis methods, statistical stepwise linear regression, F-Test, and Variance analysis, to determine their importance in the equation, as well as identify alternate methods of calculated collector coefficient modeling.

Visų hidroelektrinių veikimo principas pagrįstas dviem pagrindiniais parametrais, - slėgio aukščiu ir debitais. Lietuvoje iki 2009 metų buvo pastatyta 82 MHE. Šis etapas jau baigiasi, kadangi potencialių vietų mažajai hidroenergetikai plėtoti Lietuvoje beveik neliko ir buvo paskelbtos upės, kuriose draudžiama statyti užtvankas. Šiame tyrime buvo ieškoma alternatyvaus, netradicinio sprendimo – vandentiekos ir vandenvalos tinklų panaudojimui. Tyrimų tikslas – išnagrinėti Kauno nuotėkų tinklų galimybes elektros energijos gamybai. Buvo apžvelgtos galimybės Pabaltijo šalyse panašaus tipo projektams įgyvendinti. Taip pat buvo apžvelgtos Kauno nuotėkos ir ištirta galimybė panaudoti esamą infrastruktūrą elektros energijos gamybai Kauno nuotėkų pirmose ir antrose valymo grotose. Šiame darbe pateikiama metodika, leidžianti apskaičiuoti projektinius hidrografus programa SMADA kurią naudoja JAV universiteto studentai projektuojantys užtvankas, krantines ir kitką. Vadovaujantis sudarytais hidrografais, pasirenkama turbina ir apskaičiuojamas jos galingumas bei komponavimo tipas programa RETScrean. RETScrean sukurta Kanadoje. Ji skirta įvertinti atnaujinamų energijos technologijų projektus. Skaičiuojant šia programa, buvo pasirinkti vidutinio 50 % tikimybės vandeningumo metai. Žinant tai buvo apskaičiuoti instaliuotas galingumas, metinis išdirbis ir turbinos tipas. Vertinant turbinų komponavimo tipus, buvo atliekama daugiakriterinė analizė programine įranga DAM ir pasirinktas optimaliausias... [toliau žr. visą tekstą] / The way of working of all hydroelectric power stations is based on two main parameters: the pressure height and the rate. 82 SHP were built in Kaunas till 2009. This period is coming to the end since there are not many places left for the Small Hydropower development in Lithuania. In addition to this, the list of rivers was announced in which it is forbidden to build dams. Therefore, the untraditional way of producing the electric power in the waste water network was explored. The aim of this research is to analyze the possibilities of Kaunas Waste Water Network for the Electric Power Generation. The opportunities to realize similar types of projects in the Baltic States as well as to adapt them to the existing infrastructure in primary and secondary wastewater grating of Kaunas were discussed in this research. Methodology that is presented in this paper enables to calculate hydrographs by the use of SMADA which influences the choice of the turbine and calculations of its power as well as the type of composition by the use of RETScrean. SMADA is widely used by the students of universities in the USA. The program RETScrean, that is used to evaluate the renewed projects of energetic technologies, was created in Canada. The year with the probability 50 % of wateriness was chosen. This information was used to calculate the installed powerfulness, production per year as well as the type of the turbine with a programme RETScrean. Multicriteria analysis was performed by the use of... [to full text]