Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018. / Wastewater treatment methods have always gravitated towards the use of biological methods for the treatment of domestic grey water. This has been proven to offer a series of advantages such as the reduction of pollution attributed to the use of synthetic chemicals; therefore, this decreases the requirement of further costly post primary treatment methods. Although such biological methods have been used for decades, their efficiency and sustainability has always been challenged by inhibitory toxicants which renders the systems redundant when these toxins are prevalent in high concentrations, culminating in the deactivation of biomass which facilitates the treatment. In most instances, this biomass is anaerobic sludge. Hence, the proposal to utilize biofilms which are ubiquitous and selfsustaining in nature. The use of engineered biofilms in wastewater treatment and their behaviour has been studied extensively, with current research studies focusing on reducing plant footprint, energy intensity and minimal usage of supplementary synthetic chemicals. An example of such processes include traditional nitrification and denitrification systems, which are currently developed as simultaneous nitrification and aerobic denitrification systems, i.e. in a single stage system, from the historical two stage systems. However, there is limited literature on biofilm robustness against a potpourri of toxicants commonly found in wastewater; particularly for total nitrogen removal systems such as simultaneous nitrification and denitrification (SND). This study was undertaken (aim) to assess the ability of biosurfactant producing biofilms in the removal of total nitrogen in the presence of toxicants, i.e. heavy metals and phenol, as biosurfactants have been proven to facilitate better mass transfer for pollutant mitigation. Unlike in conventional studies, the assessment of biosurfactant producers in total nitrogen removal was assessed in both planktonic and biofilm state. Since biofilms are known to have increased tolerance to toxic environmental conditions, they were developed thus engineered using microorganisms isolated from various sources, mainly waste material including wastewater as suggested in literature reviewed, to harness microorganisms’ possessing specified traits that can be developed when organisms are growing under strenuous environments whereby they are tolerant to toxic compounds. The assessment of these engineered biofilms involved the development from individual microorganisms to form biofilms in 1L batch reactors where the isolated microorganisms were grown in basal media containing immobilisation surfaces. The assessment of the total nitrogen efficiency was conducted using Erlenmeyer flasks (500mL) in a shaker incubator, with the biofilm TN removal efficiency being assessed in batch systems to ascertain simultaneous nitrification and denitrification rates even in the presence of heavy metals (Cu2+, Zn2+) and C6H5OH. Ambient temperature and dissolved oxygen conditions were kept constant throughout the duration of biofilm development with microorganisms (initially n = 20) being isolated for the initiation of biosurfactant studies which included screening. Results indicated that the engineered biofilms, constituted by biosurfactant producing organisms (n = 9), were consisiting of bacteria (97.19%), Protozoa (2.81%) and Archaea (0.1%) as identified using metagenomics methods. Some of the biosurfactant produced had the following functional group characteristics as determined by FTIR: -CH3-CH2, deformed NH, -CH3 amide bond, C-O, C=O, O-C-O of carboxylic acids, and C-O-C of polysaccharides. Other selected microorganisms (n = 5) tolerated maximum concentrations of the selected toxicants (Cu2+, Zn2+ and C6H5OH) of 2400 mg/L, 1800 mg/L and 850 mg/L, respectively. Enzyme analysis of the total nitrogen removal experiments indicated a higher nitrogen removal rate to be the Alcanigene sp. at 180 mg/L/h.

Typescript, etc. / Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

by Li Ka Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 221-242). / Text in English; abstracts in English and Chinese. / by Li Ka Ling. / Acknowledgements --- p.i / Abstract --- p.ii / Contents --- p.vi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Literature review --- p.1 / Chapter 1.1.1 --- Heavy metals in our environment --- p.1 / Chapter 1.1.2 --- Major source of metal pollution in Hong Kong --- p.2 / Chapter 1.1.3 --- Chemistry and toxicity of copper ion --- p.9 / Chapter 1.1.4 --- Removal of metal ions from effluents by precipitation --- p.12 / Chapter 1.1.4.1 --- Metal ions in solution --- p.12 / Chapter 1.1.4.2 --- Precipitation of metal ions --- p.13 / Chapter 1.1.4.3 --- pH adjustment reagents --- p.15 / Chapter 1.1.4.4 --- Precipitation of complexed metal ions --- p.19 / Chapter 1.1.5 --- Other physico-chemical methods for the removal of metal ions --- p.21 / Chapter 1.1.6 --- Removal of metal ions by microorganisms --- p.24 / Chapter 1.1.6.1 --- Biosorption --- p.24 / Chapter 1.1.6.2 --- Other mechanisms for the accumulation of metal ions --- p.28 / Chapter 1.1.6.3 --- An attractive alternative for the removal and recovery of metal ions:biosorption --- p.30 / Chapter 1.1.7 --- Factors affecting biosorption --- p.37 / Chapter 1.1.7.1 --- Culture conditions --- p.38 / Chapter 1.1.7.2 --- pH of solution --- p.39 / Chapter 1.1.7.3 --- Concentration of biosorbent --- p.41 / Chapter 1.1.7.4 --- Initial metal ion concentration --- p.42 / Chapter 1.1.7.5 --- Presence of other cations --- p.43 / Chapter 1.1.7.6 --- Presence of anions --- p.45 / Chapter 1.1.8 --- Properties and uses of magnetite --- p.46 / Chapter 1.1.8.1 --- Physical and chemical properties of magnetite --- p.46 / Chapter 1.1.8.2 --- Use of magnetite for wastewater treatment --- p.48 / Chapter 1.1.8.3 --- Immobilization of cells on magnetite for metal ion removal --- p.49 / Chapter 1.2 --- Objectives of the present study --- p.54 / Chapter 2. --- Materials and methods --- p.57 / Chapter 2.1 --- Effects of physico-chemical factors on the precipitation of Cu2+ --- p.57 / Chapter 2.1.1 --- Reagents and chemicals --- p.57 / Chapter 2.1.2 --- Effects of equilibrium time --- p.59 / Chapter 2.1.3 --- Effects of pH --- p.60 / Chapter 2.1.4 --- Presence of anions and other cations --- p.61 / Chapter 2.1.5 --- "Presence of chelating agent, EDTA" --- p.61 / Chapter 2.2 --- Dissolution of metal sludge --- p.63 / Chapter 2.2.1 --- Dewatering and drying of metal sludge --- p.63 / Chapter 2.2.2 --- Dissolving of metal sludge by sulfuric acid --- p.63 / Chapter 2.3 --- Culture of biomass --- p.65 / Chapter 2.3.1 --- Subculturing of the biomass --- p.65 / Chapter 2.3.2 --- Culture media --- p.66 / Chapter 2.3.3 --- Growth and preparation of the cell suspension --- p.66 / Chapter 2.4 --- Immobilization of the bacterial cells on magnetites --- p.66 / Chapter 2.5 --- Metal ion removal studies --- p.71 / Chapter 2.5.1 --- Preparation of concentrated Cu2+ solutions --- p.71 / Chapter 2.5.2 --- Removal of Cu2+ in the concentrated Cu2+ solutions by magnetite- immobilized cells --- p.74 / Chapter 2.5.3 --- Effects of EDTA --- p.76 / Chapter 2.5.4 --- Effects of anions --- p.77 / Chapter 2.5.5 --- Effects of other cations --- p.78 / Chapter 2.6 --- Maximum removal efficiency of Cu2+ by magnetite-immobilized cells --- p.79 / Chapter 2.7 --- Recovery of adsorbed Cu2+ from magnetite-immobilized cell --- p.79 / Chapter 2.7.1 --- Desorption of Cu2+ from the immobilized cells using sulfuric acid --- p.79 / Chapter 2.7.2 --- Multiple adsorption-desorption cycles --- p.80 / Chapter 2.8 --- Treatment of electroplating effluent by magnetite-immobilized cells --- p.80 / Chapter 2.8.1 --- Removal and recovery of Cu2+ from electroplating effluent collected from rinsing baths --- p.80 / Chapter 2.8.2 --- Removal and recovery of Cu2+ from electroplating effluent collected from final collecting tank --- p.83 / Chapter 2.9 --- Data analysis --- p.84 / Chapter 3. --- Results --- p.86 / Chapter 3.1 --- Effects of physical-chemical factors on the precipitation of Cu2+ --- p.86 / Chapter 3.1.1 --- Effects of equilibrium time --- p.86 / Chapter 3.1.2 --- Effects of pH --- p.86 / Chapter 3.1.3 --- Presence of anions --- p.89 / Chapter 3.1.3.1 --- Cu2+-S042- systems --- p.89 / Chapter 3.1.3.2 --- Cu2+-Cl- systems --- p.89 / Chapter 3.1.3.3 --- Cu2+-Cr2072- systems --- p.89 / Chapter 3.1.3.4 --- Cu2+-mixed anions systems --- p.93 / Chapter 3.1.4 --- Presence of other cations --- p.93 / Chapter 3.1.4.1 --- Cu2+-Ni2+ systems --- p.93 / Chapter 3.1.4.2 --- Cu2+-Zn2+ systems --- p.96 / Chapter 3.1.4.3 --- Cu2+-Cr6+ systems --- p.96 / Chapter 3.1.4.4 --- Cu2+-mixed cations systems --- p.99 / Chapter 3.1.5 --- "Presence of chelating agent, EDTA" --- p.99 / Chapter 3.1.5.1 --- Cu2+-EDTA4 -mixed anions systems --- p.102 / Chapter 3.1.5.2 --- Cu2+-EDTA4--mixed cations systems --- p.102 / Chapter 3.2 --- Dissolution of metal sludge --- p.105 / Chapter 3.2.1 --- Dewatering and drying of metal sludge --- p.105 / Chapter 3.2.2 --- Dissolving of metal sludge by sulfuric acid --- p.105 / Chapter 3.3 --- Removal of Cu2+ in the concentrated Cu2+ solution by magnetite- immobilized cells --- p.109 / Chapter 3.4 --- Effects of EDTA on removal and recovery of Cu2+ by magnetite- immobilized cells --- p.109 / Chapter 3.4.1 --- Effects of EDTA --- p.109 / Chapter 3.4.2 --- Effects of EDTA after precipitation --- p.112 / Chapter 3.5 --- Effects of anions on removal and recovery of Cu2+ by magnetite- immobilized cells --- p.120 / Chapter 3.5.1 --- Effects of anions --- p.120 / Chapter 3.5.2 --- Effects of anions after precipitation --- p.120 / Chapter 3.5.3 --- Effects of anions in the presence of EDTA after precipitation --- p.124 / Chapter 3.6 --- Effects of other cations on removal and recovery of Cu2+ by magnetite-immobilized cells --- p.129 / Chapter 3.6.1 --- Effects of other cations --- p.129 / Chapter 3.6.2 --- Effects of other cations after precipitation --- p.137 / Chapter 3.6.3 --- Effects of other cations in the presence of EDTA after precipitation --- p.137 / Chapter 3.7 --- Maximum removal efficiency of Cu2+ by magnetite-immobilized cells --- p.142 / Chapter 3.8 --- Multiple adsorption-desorption cycle --- p.148 / Chapter 3.9 --- Treatment of electroplating effluent by magnetite-immobilized cells --- p.148 / Chapter 3.9.1 --- Removal and recovery of Cu2+ from electroplating effluent collected from rinsing baths --- p.148 / Chapter 3.9.2 --- Removal and recovery of Cu2+ from electroplating effluent collected from final collecting tank --- p.158 / Chapter 4. --- Discussion --- p.167 / Chapter 4.1 --- Effects of physical-chemical factors on the precipitation of Cu2+ --- p.167 / Chapter 4.1.1 --- Effects of equilibrium time --- p.167 / Chapter 4.1.2 --- Effects of pH --- p.168 / Chapter 4.1.3 --- Presence of anions --- p.169 / Chapter 4.1.4 --- Presence of other cations --- p.170 / Chapter 4.1.5 --- "Presence of chelating agent, EDTA" --- p.171 / Chapter 4.1.5.1 --- Presence of EDTA with anions --- p.174 / Chapter 4.1.5.2 --- Presence of EDTA with other cations --- p.174 / Chapter 4.2 --- Dissolution of metal sludge --- p.175 / Chapter 4.2.1 --- Dewatering and drying of metal sludge --- p.175 / Chapter 4.2.2 --- Dissolving of metal sludge by sulfuric acid --- p.175 / Chapter 4.3 --- Metal ion removal studies --- p.176 / Chapter 4.3.1 --- Selection of biomass --- p.176 / Chapter 4.3.2 --- Removal of Cu2+ in the concentrated Cu2+ solution by magnetite- immobilized cells --- p.178 / Chapter 4.4 --- Effects of EDTA on removal and recovery of Cu2+ by magnetite- immobilized cells --- p.182 / Chapter 4.4.1 --- Effects of EDTA --- p.182 / Chapter 4.4.2 --- Effects of EDTA after precipitation --- p.184 / Chapter 4.5 --- Effects of anions on removal and recovery of Cu2+ by magnetite- immobilized cells --- p.185 / Chapter 4.5.1 --- Effects of anions --- p.185 / Chapter 4.5.2 --- Effects of anions after precipitation --- p.188 / Chapter 4.5.3 --- Effects of anions in the presence of EDTA after precipitation --- p.190 / Chapter 4.6 --- Effects of other cations on removal and recovery of Cu2+ by magnetite-immobilized cells --- p.192 / Chapter 4.6.1 --- Effects of other cations --- p.192 / Chapter 4.6.2 --- Effects of other cations after precipitation --- p.195 / Chapter 4.6.3 --- Effects of other cations in the presence of EDTA after precipitation --- p.197 / Chapter 4.7 --- Maximum removal efficiency of Cu2+ by magnetite-immobilized cells --- p.198 / Chapter 4.8 --- Multiple adsorption-desorption cycles --- p.199 / Chapter 4.9 --- Treatment of electroplating effluent by magnetite-immobilized cells --- p.202 / Chapter 4.9.1 --- Removal and recovery of Cu2+ from electroplating effluent collected from rinsing baths --- p.202 / Chapter 4.9.2 --- Removal and recovery of Cu2+ from electroplating effluent collected from final collecting tank --- p.205 / Chapter 5. --- Conclusion --- p.213 / Chapter 6. --- Summary --- p.215 / Chapter 7. --- Recommendations --- p.219 / Chapter 8. --- References --- p.221

Improved process design and operation of systems engineered for the biological removal and recovery of carbon, nitrogen, and phosphorus from waste streams requires an understanding of the mixed microbial communities employed. While traditional microbiology techniques have been used to characterize the metabolic capability and activity of some organisms responsible for nutrient cycling, the metabolism of novel organisms and dynamics of complex microbial communities have been insufficiently revealed. The development and increased commercial availability of next-generation sequencing technology over the last 5-7 years has led to immense data-gathering capabilities from biological systems at the DNA ((meta)genomics), RNA ((meta)transcriptomics), and protein ((meta)proteomics) levels. However, the application of next-generation sequencing and bioinformatics to engineered biological processes remains rare, and major gaps still exist in the reference databases and metabolic understanding of single organisms (genomics) and mixed communities (metagenomics) driving biological nutrient removal and recovery in wastewater and food waste. This dissertation therefore had several major objectives: (1) Improving understanding of microbial conversion of food waste to volatile fatty acids; (2) Surveying pilot- and full-scale global biological nitrogen removal communities; (3) Application of mainstream deammonification; and (4) Adding to the sparse genomic reference database related to enhanced biological phosphorus removal (EBPR). The model of acidogenesis and acetogenesis from food waste was significantly expanded, and used to link shifts in microbial community structure and functional potential, caused by varying reactor operating conditions, to the production and speciation of volatile fatty acids for a variety of endpoint uses. Unexpected trends in the microbial ecology and functional potential of global full-scale systems were also uncovered, indicating opportunity for further enhancement of nitrogen removal through microbial community selection as a response to increasingly stringent nitrogen discharge permit levels. At the lab-scale, energy- and cost-saving anaerobic ammonia oxidation (anammox) was successfully applied as an alternative to conventional biological nitrogen removal under suboptimal mainstream wastewater conditions without constant bioaugmentation. Lastly, the annotation of PAO and GAO metagenomes from highly enriched cultures for which long-term morphological, physiological, and performance data were available allowed for increased confidence in the resulting genetic insights into the anaerobic metabolism and denitrification capabilities of these organisms. A systems biology approach to the analysis of engineered bioprocesses provided insights on microbial community structure and functional capabilities which were previously unavailable and unattainable. Ultimately, the work reported here will lead to better diagnoses of underlying issues in problematic bioreactors and smarter design of new wastewater and food waste treatment options.

No description available.

The phosphorus removal characteristics of several gravel-based constructed wetland systems (CWSs) in the treatment of secondary sewage effluent was studied.Investigations were conducted on water quality parameters (redox potential, pH, dissolved oxygen and temperature) which affect phosphorus adsorption to substrata.Laboratory phosphorus adsorption experiments on Richmond CWS gravel substrata, a gravel used in Griffith CWS trials and a locally available soil, Hawkesbury sandstone, involved ion-exchange experiments and calculation of Langmuir and Freundlich adsorption isotherms and column adsorption/desorption trials.Six steelworks by-products were investigated in laboratory studies, to determine their potential for use as phosphorus adsorbers in a CWS: granulated blast furnace slag(GBF), blast furnace slag(BF), steel slag(SS), fly ash(FA), bottom ash(BA) and coal wash(CW).The ability to adsorb phosphorus was then correlated to the chemical attributes of each substratum.Of the six steelworks by-products screened in laboratory-based studies as substrata for P removal in a CWS, BF and SS slags showed the most potential due to their high phosphorus adsorption capacity and useable matrix size.Further research is recommended to evaluate the sustainability of using slags for P removal (as well as other contaminants present in wastewater), using full scale CWSs, which should include an evaluation of any likely environmental impacts using leachability and toxicity studies. / Doctor of Philosophy (PhD)(Environmental Science)

Five unique but related studies were conducted at the Oregon State University Dairy Wetland Treatment System (OSUDWTS), Corvallis, OR. The research site consisted of six parallel wetland cells, which were built in 1992 and began receiving concentrated dairy wastewater in the fall of 1993. Hydrologic, hydraulic, and water quality data were collected at the site for three years. The five resulting studies were: 1. the prediction of evapotranspiration (ET) from wetlands; 2. the development of a hydrologic model and water budget for the OSUDWTS; 3. a preliminary investigation of the hydraulics of the OSUDWTS; 4. an overall evaluation of the treatment performance of the OSUDWTS and applicability of current constructed wetland design methods to livestock wastewater wetlands; and 5. the development of a conceptual model for nitrogen removal in constructed wetlands. Average ET rates for the wetland cells were found to be 1.6 times as great as the Penman- Monteith alfalfa reference ET. Specific crop coefficients were 1.72, 2.32, and 0.57 for bulrush, cattails, and floating grass mats. The detailed hydrology model predicted daily water levels very accurately (R��=0.95) and showed seasonal rainfall and ET could increase or decrease the average detention time by as much as 18%. Tracer studies indicated that non ideal flow existed in the wetlands. Actual detention times were found to be an average of 43% shorter than theoretical detention times. Tank-in-series and plug flow modified by dispersion models were inadequate at describing the observed tracer response. Constructed wetlands were shown to be able to reduce a high percentage of most waste constituents in concentrated livestock wastewaters. Average reductions for COD, BOD, TS, TSS, TP, TKN, NH��� and fecal coliforms were 45, 52, 27, 55, 42, 41, 37 and 80%, respectively. Rate constants for volumetric and areal first-order plug flow models were found for each wastewater constituent. Overall, both models were fair at predicting wastewater reduction at the OSUDWTS. A conceptual model of nitrogen cycling showed denitrification to be the most important process for nitrogen removal in constructed wetlands. However, low dissolved oxygen in constructed wetlands limits nitrification, which in turn limits denitrification. / Graduation date: 1997