Bioremediation of trichloroethene (TCE) using Dehalococcoides mccartyi-containing microbial cultures is a recognized and successful remediation technology. Our work with an upflow anaerobic sludge blanket (UASB) reactor has shown that high-performance, fast-rate dechlorination of TCE can be achieved by promoting bioflocculation of Dehalococcoides mccartyi-containing cultures. The bioreactor achieved high maximum conversion rates of 1.63 ± 0.012 mmol Cl- Lculture-1 h-1 at an HRT of 3.6 hours and >97% dechlorination of TCE to ethene while continuously fed 2 mM TCE. The UASB generated bioflocs from a microbially heterogeneous dechlorinating culture and produced Dehalococcoides mccartyi densities of 1.73x10-13 cells Lculture-1 indicating that bioflocculation of Dehalococcoides mccartyi-containing cultures can lead to high density inocula and high-performance, fast-rate bioaugmentation culture for in situ treatment. The successful operation of our pilot scale bioreactor led to the assessment of the technology as an onsite ex-situ treatment system. The bioreactor was then fed TCE-contaminated groundwater from the Motorola Inc. 52nd Street Plant Superfund site in Phoenix, AZ augmented with the lactate and methanol. The bioreactor maintained >99% dechlorination of TCE to ethene during continuous operation at an HRT of 3.2 hours. Microbial community analysis under both experimental conditions reveals shifts in the community structure although maintaining high rate dechlorination. High density dechlorinating cultures containing bioflocs can provide new ways to 1) produce dense bioaugmentation cultures, 2) perform ex-situ bioremediation of TCE, and 3) increase our understanding of Dehalococcoides mccartyi critical microbial interactions that can be exploited at contaminated sites in order to improve long-term bioremediation schemes.

Hexavalant chromium (Cr(VI)) poses an emerging concern in drinking water treatment with stricter regulations on the horizon. Photocatalytic reduction of Cr(VI) was investigated as an engineering scale option to remove hexavalent chromium from drinking or industrial waters via a UV/titanium dioxide (TiO2) process. Using an integrated UV lamp/ceramic membrane system to recirculate TiO2, both hexavalent and total chromium levels were reduced through photocatalytic processes without additional chemicals. Cr(VI) removal increased as a function of higher energy input and TiO2 dosage, achieving above 90% removal for a 1g/L dose of TiO2. Surface analysis of effluent TiO2 confirmed the presence of chromium species.

An eco-industrial park (EIP) is an industrial ecosystem in which a group of co-located firms are involved in collective resource optimization with each other and with the local community through physical exchanges of energy, water, materials, byproducts and services - referenced in the industrial ecology literature as "industrial symbiosis". EIPs, when compared with standard industrial resource sharing networks, prove to be of greater public advantage as they offer improved environmental and economic benefits, and higher operational efficiencies both upstream and downstream in their supply chain.

Although there have been many attempts to adapt EIP methodology to existing industrial sharing networks, most of them have failed for various factors: geographic restrictions by governmental organizations on use of technology, cost of technology, the inability of industries to effectively communicate their upstream and downstream resource usage, and to diminishing natural resources such as water, land and non-renewable energy (NRE) sources for energy production.

This paper presents a feasibility study conducted to evaluate the comparative environmental, economic, and geographic impacts arising from the use of renewable energy (RE) and NRE to power EIPs. Life Cycle Assessment (LCA) methodology, which is used in a variety of sectors to evaluate the environmental merits and demerits of different kinds of products and processes, was employed for comparison between these two energy production methods based on factors such as greenhouse gas emission, acidification potential, eutrophication potential, human toxicity potential, fresh water usage and land usage. To complement the environmental LCA analysis, levelized cost of electricity was used to evaluate the economic impact. This model was analyzed for two different geographic locations; United States and Europe, for 12 different energy production technologies.

The outcome of this study points out the environmental, economic and geographic superiority of one energy source over the other, including the total carbon dioxide equivalent emissions, which can then be related to the total number of carbon credits that can be earned or used to mitigate the overall carbon emission and move closer towards a net zero carbon footprint goal thus making the EIPs truly sustainable.

Advanced oxidation processes (AOP’s) are water/wastewater treatment processes simultaneously providing disinfection and potential oxidation of contaminants that may cause long-term adverse health effects in humans. One AOP involves injecting peracetic acid (PAA) upstream of an ultraviolet (UV) irradiation reactor. Two studies were conducted, one in pilot-scale field conditions and another under laboratory conditions. A pilot-scale NeoTech UV reactor (rated for 375 GPM) was used in the pilot study, where a smaller version of this unit was used in the laboratory study (20 to 35 GPM). The pilot study analyzed coliform disinfection and also monitored water quality parameters including UV transmittance (UVT), pH and chlorine residual. Pilot study UV experiments indicate the unit is effectively treating flow streams (>6 logs total coliforms) twice the 95% UVT unit capacity (750 GPM or 17 mJ/cm2 UV Dose). The results were inconclusive on PAA/UV inactivation due to high data variability and field operation conditions creating low inlet concentrations.Escherichia coli (E. coli) bacteria and the enterobacteria phage P22—a surrogate for enteric viruses—were analyzed. UV inactivated >7.9 and 4 logs of E. coli and P22 respectively at a 16.8 mJ/cm2 UV dose in test water containing a significant organics concentration. When PAA doses of 0.25 and 0.5 mg/L were injected upstream of UV at approximately the same UV Dose, the average E.coli log inactivation increased to >8.9 and >9 logs respectively, but P22 inactivation decreased to 2.9 and 3.0 logs, respectively. A bench-scale study with PAA was also conducted for 5, 10 and 30 minutes of contact time, where 0.25 and 0.5 mg/L had <1 log inactivation of E. coli and P22 after 30 minutes of contact time. In addition, degradation of the chemical N-Nitrosodimethylamine (NDMA) in tap water was analyzed, where UV degraded NDMA by 48 to 97% for 4 and 0.5 GPM flowrates, respectively. Adding 0.5 mg/L PAA upstream of UV did not significantly improve NDMA degradation.

The results under laboratory conditions indicate that PAA/UV have synergy in the inactivation of bacteria, but decrease virus inactivation. In addition, the pilot study demonstrates the applicability of the technology for full scale operation.

Reverse osmosis (RO) membranes are considered the most effective treatment to remove salt from water. Specifically, thin film composite (TFC) membranes are considered the gold standard for RO. Despite TFC membranes good performance, there are drawbacks to consider including: permeability-selectivity tradeoff, chlorine damage, and biofouling potential. In order to counter these drawbacks, polyamide matrixes were embedded with various nanomaterials called mixed matrix membranes (MMMs) or thin film nanocomposites (TFNs). This research investigates the use of graphene oxide (GO) and reduced graphene oxide (RGO) into the polyamide matrix of a TFC membrane. GO and RGO have the potential to alter the permeability-selectivity trade off by offering nanochannels for water molecules to sieve through, protect polyamide from trace amounts of chlorine, as well as increase the hydrophilicity of the membrane thereby reducing biofouling potential. This project focuses on the impacts of GO on the permeability selectivity tradeoff. The hypothesis of this work is that the permeability and selectivity of GO can be tuned by controlling the oxidation level of the material. To test this hypothesis, a range of GO materials were produced in the lab using different graphite oxidation methods. The synthesized GOs were characterized by X-ray diffraction and X-ray photoelectron microscopy to show that the spacing is a function of the GO oxygen content. From these materials, two were selected due to their optimal sheet spacing between 3.4 and 7 angstroms and embedded into desalination MMM. This work reveals that the water permeability coefficient of MMM embedded with GO and RGO increased significantly; however, that the salt permeability coefficient of the membrane also increased. Future research directions are proposed to overcome this limitation.

Bacteriophage provide high specificity to bacteria; receiving interest in various applications and have been used as target recognition tools in designing bioactive surfaces. Several current immobilization strategies to detect and capture bacteriophage require non-deliverable bioactive substrates or modifying the chemistry of the phage, procedures that are labor intensive and can damage the integrity of the virus. The aim of this research was to develop the framework to physisorb and chemisorb T4 coliphage on varied sized functionalized silica particles while retaining its infectivity. First, silica surface modification, silanization, altered pristine silica colloids to positively, amine coated silica. The phages remain infective to their host bacteria while adsorbed on the surface of the silica particles. It is reported that the number of infective phage bound to the silica is enhanced by the immobilization method. It was determined that covalent attachment yielded 106 PFU/ml while electrostatic attachment resulted in 105 PFU/ml.

Microplastics are emerging to be major problem when it comes to water pollution and they pose a great threat to marine life. These materials have the potential to affect a wide range of human population since humans are the major consumers of marine organisms. Microplastics are less than 5 mm in diameter, and can escape from traditional wastewater treatment plant (WWTP) processes and end up in our water sources. Due to their small size, they have a large surface area and can react with chlorine, which it encounters in the final stages of WWTP. After the microplastics accumulate in various bodies of water, they are exposed to sunlight, which contains oxidative ultraviolet (UV) light. Since the microplastics are exposed to oxidants during and after the treatment, there is a strong chance that they will undergo chemical and/or physical changes. The WWTP conditions were replicated in the lab by varying the concentrations of chlorine from 70 to 100 mg/L in increments of 10 mg/L and incubating the samples in chlorine baths for 1–9 days. The chlorinated samples were tested for any structural changes using Raman spectroscopy. High density polyethylene (HDPE), polystyrene (PS), and polypropylene (PP) were treated in chlorine baths and observed for Raman intensity variations, Raman peak shifts, and the formation of new peaks over different exposure times. HDPE responded with a lot of oxidation peaks and shifts of peaks after just one day. For the degradation of semi-crystalline polymers, there was a reduction in crystallinity, as verified by thermal analysis. There was a decrease in the enthalpy of melting as well as the melting temperature with an increase in the exposure time or chlorine concentration, which pointed at the degradation of plastics and bond cleavages. To test the plastic response to

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UV, the samples were exposed to sunlight for up to 210 days and analyzed under Raman spectroscopy. Overall the physical and chemical changes with the polymers are evident and makes a way for the wastewater treatment plant to take necessary steps to capture the microplastics to avoid the release of any kind of degraded microplastics that could affect marine life and the environment.

Drinking water filtration using reverse osmosis (RO) membranes effectively removes salts and most other inorganic, organic, and microbial pollutants. RO technologies are utilized at both the municipal and residential scale. The formation of biofilms on RO membranes reduces water flux and increases energy consumption. The research conducted for this thesis involves In-Situ coating of silver, a known biocide, on the surface of RO membranes. This research was adapted from a protocol developed for coating flat sheet membranes with silver nanoparticles, and scaled up into spiral-wound membranes that are commonly used at the residential scale in point-of-use (POU) filtration systems. Performance analyses of the silver-coated spiral-wound were conducted in a mobile drinking water treatment system fitted with two POU units for comparison. Five month-long analyses were performed, including a deployment of the mobile system. In addition to flux, salt rejection, and other water quality analyses, additional membrane characterization tests were conducted on pristine and silver-coated membranes.

For flat sheet membranes coated with silver, the surface charge remained negative and contact angle remained below 90. Scaling up to spiral-wound RO membrane configuration was successful, with an average silver-loading of 1.93 g-Ag/cm2. Results showed the flux of water through the membrane ranged from 8 to 13 liters/m2*hr. (LMH) operating at 25% recovery during long-term of operation. The flux was initially decreased due to the silver coating, but no statistically significant differences were observed after 14 days of operation (P < 0.05). The salt rejection was also not effected due to the silver coating (P < 0.05). While 98% of silver was released during long-term studies, the silver release from the spiral-wound membrane was consistently below the secondary MCL of 100 ppb established by the EPA, and was consistently below 5 ppb after two hours of operation. Microbial assays in the form of heterotrophic plate counts suggested there was no statistically significant difference in the prevention of biofouling formation due to the silver coating (P < 0.05). In addition to performance tests and membrane characterizations, a remote data acquisition system was configured to remotely monitor performance and water quality parameters in the mobile system.

Adenoviruses cause gastrointestinal illnesses and have been listed on the U.S. EPA’s Contaminant Candidate Lists (CCL). They are highly resistant to ultraviolet (UV) inactivation. Advanced oxidation processes (AOPs) are known to improve inactivation of microorganisms and simultaneously oxidize organics. The bacteriophage P22 was selected as a surrogate for adenoviruses due to their physical and genetic similarities.

The main objective of this study was to compare the synergic disinfection potential of titanium dioxide (TiO2) or peracetic acid (PAA) with UV for viruses and bacteria in water.

Both bench-scale and pilot-scale evaluation was done. A bench-scale collimated beam was included to evaluate the inactivation of P22 and E. coli by UV with and without TiO2 or PAA. A Purifics Photo-Cat system which is an integrated UV/ceramic membrane reactor was used for the pilot-scale TiO2-UV AOP experiments. For pilot-scale PAA-UV AOP experiments, an in-line D222 UV reactor unit provided by NeoTech Aqua Solutions, Inc. was used.

TiO2 doses of 1, 10, and 40 mg/L were applied in the collimated beam and the Photo-Cat system. Higher TiO2 doses resulted in a higher inactivation in the Photo-Cat and lower inactivation in the collimated beam apparatus. Adding 40 mg/L of TiO2 in the photo-Cat system improved P22 inactivation by 25% while it slightly decreased P22 inactivation in collimated beam apparatus.

PAA doses of 0.25 or 0.5 ppm were continuously injected upstream of the UV light and a 53% or 90% increase in inactivation was observed for E. coli, respectively, as compared to UV alone. However, P22 required higher dose with PAA-UV AOP and PAA concentrations of 1 or 10 ppm resulted in an 18% and 70% increase in the inactivation respectively, as compared to UV alone. Interestingly, when the same condition was applied to water with more organics (UVT 79%), E. coli exhibited the same level of susceptibility to PAA-UV AOP while P22 inactivation decreased.

The results provide new insight on the effectiveness and applicability of adding AOP to UV for microbial inactivation in water. PAA-UV AOP can potentially enhance existing UV disinfection systems with minimal chemical addition, and a simple retrofit to existing UV units.

With the application of reverse osmosis (RO) membranes in the wastewater treatment and seawater desalination, the limitation of flux and fouling problems of RO have gained more attention from researchers. Because of the tunable structure and physicochemical properties of nanomaterials, it is a suitable material that can be used to incorporate with RO to change the membrane performances. Silver is biocidal, which has been used in a variety of consumer products. Recent studies showed that fabricating silver nanoparticles (AgNPs) on membrane surfaces can mitigate the biofouling problem on the membrane. Studies have shown that Ag released from the membrane in the form of either Ag ions or AgNP will accelerate the antimicrobial activity of the membrane. However, the silver release from the membrane will lower the silver loading on the membrane, which will eventually shorten the antimicrobial activity lifetime of the membrane. Therefore, the silver leaching amount is a crucial parameter that needs to be determined for every type of Ag composite membrane.

This study is attempting to compare four different silver leaching test methods, to study the silver leaching potential of the silver impregnated membranes, conducting the advantages and disadvantages of the leaching methods. An In-situ reduction Ag loaded RO membrane was examined in this study. A custom waterjet test was established to create a high-velocity water flow to test the silver leaching from the nanocomposite membrane in a relative extreme environment. The batch leaching test was examined as the most common leaching test method for the silver composite membrane. The cross-flow filtration and dead-end test were also examined to compare the silver leaching amounts.

The silver coated membrane used in this experiment has an initial silver loading of 2.0± 0.51 ug/cm2. The mass balance was conducted for all of the leaching tests. For the batch test, water jet test, and dead-end filtration, the mass balances are all within 100±25%, which is acceptable in this experiment because of the variance of the initial silver loading on the membranes. A bad silver mass balance was observed at cross-flow filtration. Both of AgNP and Ag ions leached in the solution was examined in this experiment. The concentration of total silver leaching into solutions from the four leaching tests are all below the Secondary Drinking Water Standard for silver which is 100 ppb. The cross-flow test is the most aggressive leaching method, which has more than 80% of silver leached from the membrane after 50 hours of the test. The water jet (54 ± 6.9% of silver remaining) can cause higher silver leaching than batch test (85 ± 1.2% of silver remaining) in one-hour, and it can also cause both AgNP and Ag ions leaching from the membrane, which is closer to the leaching condition in the cross-flow test.