abstract: Managing water resources has become one of the most pressing concerns of scientists both in academia and industry. The reverse osmosis (RO) water treatment process is a well-researched technology among the pressure driven processes to produce potable water. RO is an energy intensive process and often RO membranes are susceptible to fouling and scaling that drives up operational cost and hinder the efficiency. To increase the performance of RO membranes the feed water is pretreated to remove pollutants before desalination. This work aims to fabricate pretreatment membranes to prevent the effects of fouling and scaling by introducing hydrophilic character to membrane. This work explores electrospinning, a cost-effective and scalable technique, to blend two polymers into a nonwoven membrane comprised of fibers ~100 nm - 10 µm in diameter. A rotary drum collector holding the mat was used to simultaneously collect the electrospun hydrophobic poly(vinyl chloride) (PVC) and hydrophilic poly(vinyl alcohol) (PVA) fibers from two separate solutions. The hydrophilicity of the resulting membrane was tuned by controlling the relative deposition rate of PVA onto the co-spun mat. Fiber diameter and morphologies were characterized by scanning electron microscopy, and Fourier-transform infrared spectroscopy and Confocal fluorescence microscopy further confirmed the presence of both polymers. Moreover, a rigorous analysis to map the PVA/PVC concentration was established to accurately report the relative concentrations of the two polymers on the co-spun mat. After electrospinning, the PVA in the co-spun mats were cross-linked with poly(ethylene glycol) diacid to impart mechanical strength and tune the porosity. EDS analysis revealed inconsistencies in the mass deposition of both polymers suggesting an improvement in the current experimental design to establish a meaningful relationship between PVA concentration and hydrophilicity. However, tensile test revealed that co-spun mats with high mass flow ratios of PVA possessed high mechanical strength showing a significant improvement in the Young’s Modulus. Furthermore, the co-spun mats were challenged with filtration experiments expecting a positive correlation of flux with PVA concentration. But it was found that with increased concentration, crosslinked PVA constricted PVC fibers minimizing the pores causing a lower flux and a dense membrane structure suitable for filtration. / Dissertation/Thesis / Masters Thesis Chemical Engineering 2020

Family therapy, similar to other mental health services, has focused on ways to make therapy brief or short term . One model of family therapy, the brief/solutions therapeutic orientation, claims that certain techniques can reduce the number of sessions. This therapeutic model focuses on the solutions clients bring with them to therapy. By focusing on clients' solutions and not their problems, the brief/solutions orientation claims that clients reach their goals more quickly, finish therapy more quickly, and are more satisfied with the services they receive . However, there is little empirical evidence to support these claims. This research specifically looked at the brief/solutions concept of pretreatment changes (changes clients make before the first therapy session) and the impact that noticing pretreatment changes as a therapeutic intervention had on therapeutic outcome variables of relationship functioning, goal attainment, problem solving, and communication. No evidence was found that noticing pretreatment changes influences therapeutic outcome. Evidence was found that pretreatment changes do not disappear when noticed. Ideas for future research are included.

The objectives of this research were to develop the best methods for cellulose nanowhiskers (CNWs) preparation from raw biomass materials and the feasibility to perform CNWs as Fe3+ catalyst support in converting syngas to biofuels. Raw kenaf bast and switchgrass were initially pretreated with dilute NaOH followed by dilute H2SO4. High yields of alpha-cellulose were obtained. Hemicellulose, ash, and most lignin were removed during pretreatment. Preparation of CNWs after pretreatment was then conducted via H2SO4 hydrolysis. The most efficient hydrolysis condition was determined as H2SO4 concentration through orthogonal experiments. In contrast with pure cellulose fibers, CNWs supported Fe3+ catalyst applied in converting syngas to biofuels showed shorter stabilization time and higher C4+ product selectivity. With the increase of reaction temperature to 310°C, CO and H2 could reach their peak conversion rates of 83.4% and 72.1%, while the maximum selectivity of CO2 was 41.1%.

No description available.

No description available.

The production of biofuels and biobased products from low-cost abundant renewable non-food lignocellulosic biomass will be vital to sustainable development because it will bring benefits to the environment, the economy, and the national security. The largest technical and economic challenge for emerging biorefineries is cost-effective release of fermentable sugars from recalcitrant structure of lignocellulosic biomass. Cellulose- and organic-solvent-based lignocelluloses fractionation (COSLIF) technology was employed to overcome biomass recalcitrance. Surface response methodology (SRM) showed that optimal COSLIF pretreatment conditions were 85% (w/v) H₃PO₄ and ~50 °C, regardless of moisture contents in biomass from 5-15% (w/w) for common reed. Under these conditions, the pretreated biomass was hydrolyzed fast with high glucan digestibilities at low enzyme loadings (i.e., one FPU of cellulase per gram of glucan). Crystallinity index (CrI) measurements by X-ray diffraction (XRD) and cross polarization/magic angle spinning (CP/MAS) ¹³C nuclear magnetic resonance (NMR), and cellulose accessibility to cellulase (CAC) determinations of COSLIF-pretreated biomass confirmed that highly ordered hydrogen-bonding networks in cellulose fibers of biomass were disrupted through cellulose dissolution in a cellulose solvent. This disruption of hydrogen bonding networks among cellulose chains resulted in a drastic increase in CAC values. Fourier transform infrared (FTIR) analyses on COSLIF-pretreated biomass revealed conformational changes in specific hydrogen bonding among cellulose chains due to COSLIF. While CrI is believed to be a key substrate characteristic that impacts enzymatic cellulose hydrolysis, studies in this thesis showed CrI values varied greatly depending on measurement techniques, calculation approaches, and sample preparation conditions. A correlation between CAC values and glucan digestibility of pretreated biomass showed that substrate accessibility is a key substrate characteristic impacting enzymatic cellulose hydrolysis. In summary, COSLIF can effectively overcome biomass recalcitrance. The resulting pretreated biomass has high CAC values, resulting in fast hydrolysis rates and high enzymatic glucan digestibilities of COSLIF-pretreated biomass at low enzyme usage. / Ph. D.

Waste activated sludge (WAS) pretreatment technologies are typically evaluated in terms of the associated improvement in biogas and sludge production during digestion and post-digestion dewaterability. However, WAS properties, and hence the impact of pretreatment on WAS properties, are dependent upon the raw wastewater composition and configuration of the wastewater treatment plant (WWTP). A generally accepted means of characterizing and comparing all pretreatment processes does not exist. The motivation for this project was to evaluate the impact of pretreatment on WAS properties in terms of changes in COD fractionation. The first objective of this study was to fractionate the COD of the WAS before and after pretreatment to show how pretreatment may increase the rate and extent of aerobic digestion. The second objective was to develop a COD-based stoichiometric pretreatment model that may be integrated into WWTP simulations. A bench-scale biological reactor (BR) with a solids retention time (SRT) of 5 days was started up with WAS from the Waterloo WWTP. The BR was fed daily with a completely biodegradable synthetic substrate so that the BR WAS contained only biomass and decay products after 3 SRTs of operation. In the first phase of the study, an aerobic digester (AD) with a SRT of 10 d was fed daily with BR WAS. The BR-AD system was operated at steady state for one month. A range of physical and biochemical properties were regularly measured in each process stream. Offline respirometric tests were regularly conducted to determine the aerobic degradability and fractionate the COD of the BR and AD WAS. The oxygen uptake rate (OUR) associated with the daily addition of BR WAS to the AD was determined as an additional measurement of the aerobic degradability of the BR WAS. In the second phase of the study, the BR WAS was pretreated prior to being fed daily to the AD. High pressure thermal hydrolysis (HPTH) pretreatment was selected for this project since it is one of the most popular and promising pretreatment techniques. A sealed volume of BR WAS was heated to 150°C at 3 bars for 30 minutes. The same physical, biochemical and biological tests used to characterize the process streams in Phase 1 were employed to characterize those in Phase 2. The Phase 2 system was operated for two months at steady-state. The results of several independent tests showed that the COD of the BR WAS was comprised of storage products (XSTO) in addition to active heterotrophs (Zbh) and decay products (Ze). However, it was shown that the AD WAS only contained Zbh and Ze as XSTO was depleted in the AD. HPTH pretreatment did not reduce the TCOD concentration of the WAS however it did solubilize 56 ± 7% of COD, 49% ± 11% of organic nitrogen, 56 ± 10% of VSS and did not solubilize ISS. Furthermore, pretreatment did not generate soluble non-biodegradable COD. These findings were consistent with prior research on HPTH WAS pretreatment. Pretreatment increased the rate at which the BR WAS was aerobically degraded. The offline respirometric tests showed that the pretreated BR WAS contained a substantial amount of readily biodegradable COD (Sbsc). However, pretreatment did not increase the extent of biodegradation. The results of several independent tests showed that the non-biodegradable COD component of the BR WAS, i.e. Ze, was not converted to biodegradable COD by pretreatment. A COD-based stoichiometric pretreatment model was developed for the dose of HPTH pretreatment employed in this study. When this model was integrated into BioWin®, it was able to accurately simulate both the steady state performance of the overall system employed in this study as well as dynamic respirometry results. The experimental results showed that the TCOD of the BR WAS consisted of 51% Zbh, 12% Ze and 37% XSTO and the pretreated BR WAS consisted of 12% Ze and a negligible amount of Zbh. The pretreatment model verified these fractions and predicted that the pretreated BR WAS also contained 54% Sbsc and 32% slowly biodegradable COD (Xsp). The approach described in this study may be followed to determine the impacts of pretreatment on Zbh, Ze and XSTO when other doses of HPTH pretreatment and other pretreatment techniques are employed.

The significant increase in the sewage sludge production in treatment plants makes anaerobic digestion more important as a stabilization process. However hydrolysis is the rate-limiting step of anaerobic digestion because of the semirigid structure of the microbial cells. Pretreatment of waste activated sludge (WAS) leads to disruption of cell walls and release of extracellular and intracellular materials. Therefore biodegradability of sludge will be improved in terms of more biogas production and sludge minimization. Among the pretreatment methods, alkaline, thermal and thermochemical pretreatments are effectual ones. Considering the effect of thermal pretreatment, microwave technology in which the sample reaches to elevated temperatures very rapidly is a very new pretreatment method. However no previous research has been conducted to test the effectiveness of microwave (MW) irradiation combined with alkaline pretreatment. Since both of these techniques seem to be highly effective, their combination can act synergistically and even more efficient method can be obtained. Therefore the main objective of this study was to investigate the effect of combination of a chemical method (alkaline pretreatment) and a physical method (microwave irradiation) in improving anaerobic digestion of WAS. In the first part of the study, alkaline and MW pretreatment methods were examined separately, then their combinations were investigated for the first time in the literature in terms of COD solubilization, turbidity and CST. Highest SCOD was achieved with the combined method of MW+pH-12. In the second part, based on the results obtained in the first part, alkaline pretreatments of pH-10 and pH-12 / MW pretreatment alone and combined pretreatments of MW+pH-10 and MW+pH-12 pretreated WAS samples were anaerobically digested in small scale batch anaerobic reactors. In correlation with the highest protein and carbohydrate releases with MW+pH-12, highest total gas and methane productions were achieved with MW+pH-12 pretreatment reactor with 16.3% and 18.9% improvements over control reactor, respectively. Finally the performance of MW+pH-12 pretreatment was examined with 2L anaerobic semi-continuous reactors. 43.5% and 53.2% improvements were obtained in daily total gas and methane productions. TS, VS and TCOD reductions were improved by 24.9%, 35.4% and 30.3%, respectively. Pretreated digested sludge had 22% improved dewaterability than non-pretreated digested sludge. Higher SCOD and NH3-N concentrations were measured in the effluent of pretreated digested sludge / however, PO4-P concentration did not vary so much. Heavy metal concentrations of all digested sludges met Soil Pollution Control Regulation Standards. Finally a simple cost calculation was done for a MW+pH-12 pretreatment of WAS for a fictitious WWTP. Results showed that, WWTP can move into profit in 5.5 years.

Sludge management is one of the most difficult and expensive problems in wastewater treatment plant operation. Consequently, &amp / #8216 / sludge minimization&amp / #8217 / concept arose to solve the excess sludge production by sludge pretreatment. Sludge pretreatment converts the waste sludge into a more bioavailable substrate for anaerobic digestion and leads to an enhanced degradation. The enhanced degradation results in more organic reduction and more biogas production. Therefore, sludge pretreatment is a means of improving sludge management in a treatment plant. Among pretreatment methods, acidic pretreatment has been subject of limited successful studies reported in the literature. On the contrary / ultrasonic pretreatment was reported as an effective pretreatment method. Main objective of this study was to investigate the effects of these two pretreatment methods and their combination in order to achieve a synergistic effect and improve the success of both pretreatment methods. Experimental investigation of pretreatment methods consists of preliminary studies for deciding the most appropriate pretreatment method. Anaerobic batch tests were conducted for optimization of the parameters of selected method. Finally, operation of semi-continuous anaerobic reactors was to investigate the effect of pretreatment on anaerobic digestion in details. Preliminary studies indicated that, more effective pretreatment method in terms of solubilization of organics is ultrasonic pretreatment. Fifteen minutes of sonication enhanced 50 mg/L initial soluble COD concentration up to a value of 2500 mg/L. Biochemical methane potential tests indicated that the increased soluble substrate improved anaerobic biodegradability concurrently. Finally, semi-continuous anaerobic reactors were used to investigate the efficiency of pretreatment under different operating conditions. Results indicate that at SRT 15 days and OLR 0.5 kg/m3d ultrasonic pretreatment improved the daily biogas production of anaerobic digester by 49% and methane percentage by 16% and 24% more volatile solids were removed after pretreatment. Moreover, even after pushing reactors into worse operating conditions such as shorter solids retention time (7.5 days) and low strength influent, pretreatment worked efficiently and improved the anaerobic digestion. Finally cost calculations were performed. Considering the gatherings from enhancement of biogas amount, higher methane percentage and smaller amounts of volatile solid disposal from a treatment plant / installation and operation costs of ultrasound were calculated. The payback period of the installation was found to be 4.7 years.

Waste activated sludge (WAS) pretreatment technologies are typically evaluated in terms of the associated improvement in biogas and sludge production during digestion and post-digestion dewaterability. However, WAS properties, and hence the impact of pretreatment on WAS properties, are dependent upon the raw wastewater composition and configuration of the wastewater treatment plant (WWTP). A generally accepted means of characterizing and comparing all pretreatment processes does not exist. The motivation for this project was to evaluate the impact of pretreatment on WAS properties in terms of changes in COD fractionation. The first objective of this study was to fractionate the COD of the WAS before and after pretreatment to show how pretreatment may increase the rate and extent of aerobic digestion. The second objective was to develop a COD-based stoichiometric pretreatment model that may be integrated into WWTP simulations. A bench-scale biological reactor (BR) with a solids retention time (SRT) of 5 days was started up with WAS from the Waterloo WWTP. The BR was fed daily with a completely biodegradable synthetic substrate so that the BR WAS contained only biomass and decay products after 3 SRTs of operation. In the first phase of the study, an aerobic digester (AD) with a SRT of 10 d was fed daily with BR WAS. The BR-AD system was operated at steady state for one month. A range of physical and biochemical properties were regularly measured in each process stream. Offline respirometric tests were regularly conducted to determine the aerobic degradability and fractionate the COD of the BR and AD WAS. The oxygen uptake rate (OUR) associated with the daily addition of BR WAS to the AD was determined as an additional measurement of the aerobic degradability of the BR WAS. In the second phase of the study, the BR WAS was pretreated prior to being fed daily to the AD. High pressure thermal hydrolysis (HPTH) pretreatment was selected for this project since it is one of the most popular and promising pretreatment techniques. A sealed volume of BR WAS was heated to 150°C at 3 bars for 30 minutes. The same physical, biochemical and biological tests used to characterize the process streams in Phase 1 were employed to characterize those in Phase 2. The Phase 2 system was operated for two months at steady-state. The results of several independent tests showed that the COD of the BR WAS was comprised of storage products (XSTO) in addition to active heterotrophs (Zbh) and decay products (Ze). However, it was shown that the AD WAS only contained Zbh and Ze as XSTO was depleted in the AD. HPTH pretreatment did not reduce the TCOD concentration of the WAS however it did solubilize 56 ± 7% of COD, 49% ± 11% of organic nitrogen, 56 ± 10% of VSS and did not solubilize ISS. Furthermore, pretreatment did not generate soluble non-biodegradable COD. These findings were consistent with prior research on HPTH WAS pretreatment. Pretreatment increased the rate at which the BR WAS was aerobically degraded. The offline respirometric tests showed that the pretreated BR WAS contained a substantial amount of readily biodegradable COD (Sbsc). However, pretreatment did not increase the extent of biodegradation. The results of several independent tests showed that the non-biodegradable COD component of the BR WAS, i.e. Ze, was not converted to biodegradable COD by pretreatment. A COD-based stoichiometric pretreatment model was developed for the dose of HPTH pretreatment employed in this study. When this model was integrated into BioWin®, it was able to accurately simulate both the steady state performance of the overall system employed in this study as well as dynamic respirometry results. The experimental results showed that the TCOD of the BR WAS consisted of 51% Zbh, 12% Ze and 37% XSTO and the pretreated BR WAS consisted of 12% Ze and a negligible amount of Zbh. The pretreatment model verified these fractions and predicted that the pretreated BR WAS also contained 54% Sbsc and 32% slowly biodegradable COD (Xsp). The approach described in this study may be followed to determine the impacts of pretreatment on Zbh, Ze and XSTO when other doses of HPTH pretreatment and other pretreatment techniques are employed.