Wayne J Parker

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The requirements for pH buffer addition for hydrogen production and acidogenesis in batch acidogenic digestion of a food waste (FW) feedstock with limited alkalinity was studied at various initial pH conditions (6.0-8.0). The results showed that, without buffer addition, hydrogen production from this feedstock was insignificant regardless of the initial pH.(More)
It is known that the presence of volatile fatty acids may play a role in the inactivation of pathogens for systems that employ an acid phase reactor. This study was conducted to investigate the influence of volatile fatty acids on the inactivation of Salmonella spp. over a range of digestion temperatures. In this study, digesters that were treating(More)
Municipal wastewater treatment plants (WWTPs) dispose of numerous trace organic contaminants in the receiving waters that can impact biological function in aquatic organisms. However, the complex nature of WWTP effluent mixtures and a wide variety of potential mechanisms that can alter physiological and reproductive development of aquatic organisms make it(More)
A modified oxygen uptake rate (OUR) test for characterizing the performance of integrated fixed-film activated sludge (IFAS) processes was developed while monitoring the startup of a full-scale demonstration facility. Data on total biofilm solids, in-basin nitrification rates, and batch nitrification rates were compared to the OUR test. The data was used to(More)
Waste activated sludge (WAS) samples that were generated over a range of solids residence times (SRTs) were employed in bench scale ozonation tests to evaluate the impact of ozonation, on physical, chemical and biochemical properties of WAS and digestibility. Solubilization responses suggested that the types of solubilized materials were affected by the(More)
Laboratory scale two-stage anaerobic digestion process model was operated for 280 days to investigate the feasibility to produce both hydrogen and methane from a mixture feedstock (1:1 (v/v)) of municipal food waste and sewage sludge. The maximum hydrogen and methane yields obtained in the two stages were 0.93 and 9.5 mL/mL feedstock. To eliminate(More)
Due to the high costs associated with laboratory analysis, load estimation of pharmaceuticals is necessary to identify compounds that may have high influent and effluent concentrations in wastewater treatment plants (WWTPs). The load estimation model presented in this paper was developed to estimate the influent concentration of prescription and(More)
Endocrine disruption and high occurrences of intersex have been observed in wild fish associated with municipal wastewater treatment plant (WWTP) effluents in urbanized reaches of rivers around the globe. These reproductive effects have often been attributed to the presence of estrogen receptor agonists in effluents. However, recent studies have isolated a(More)
Improved endocrine disrupting compound (EDC) removal is desirable in municipal wastewater treatment plants (MWWTPs) although increased removal does not always translate into reduced biological activity. Suitable methods for determining reduction in biological activity of effluents are needed. In order to determine which MWWTPs are the most effective at(More)
Phased anaerobic digestion is a promising technology and may be a potential source of bio-energy production. Anaerobic digesters are widely used for sewage sludge stabilization and thus a better understanding of the microbial process and kinetics may allow increased volatile solids reduction and methane production through robust process operation. In this(More)