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Sutton P.M.,P.M. Sutton and Associates Inc. | Melcer H.,Brown and Caldwell | Schraa O.J.,Hydromantis Inc. | Togna A.P.,Envirogen Technologies Inc.
Water Science and Technology | Year: 2011

A new municipal wastewater treatment flowsheet was developed with the objectives of energy sustainability, and water and nutrient recovery. Energy is derived by shunting a large fraction of the organic carbon in the wastewater to an anaerobic digestion system. Aerobic and anaerobic membrane bioreactors play a key role in energy recovery. Phosphorus and nitrogen are removed from the wastewater and recovered through physical-chemical processes. Computer modeling and simulation results together with energy balance calculations, imply the new flowsheet will result in a dramatic reduction in energy usage at lower treatment plant capital costs in comparison to conventional methods. © IWA Publishing 2010. Source


Hatzinger P.B.,Chicago Bridge And Iron Company | Condee C.,Chicago Bridge And Iron Company | McClay K.R.,Chicago Bridge And Iron Company | Paul Togna A.,Envirogen Technologies Inc.
Water Research | Year: 2011

N-Nitrosodimethylamine (NDMA) is a suspected human carcinogen that has recently been detected in wastewater, groundwater and drinking water. Treatment of this compound to low part-per-trillion (ng/L) concentrations is required to mitigate cancer risk. Current treatment generally entails UV irradiation, which while effective, is also expensive. The objective of this research was to explore potential bioremediation strategies as alternatives for treating NDMA to ng/L concentrations. Batch studies revealed that the propanotroph Rhodococcus ruber ENV425 was capable of metabolizing NDMA from 8 μg/L to <2 ng/L after growth on propane, and that the strain produced metabolites that do not pose a significant risk at the concentrations generated (Fournier et al., 2009). A laboratory-scale membrane bioreactor (MBR) was subsequently constructed to evaluate the potential for long-term ex situ treatment of NDMA. The MBR was seeded with ENV425 and received propane as the primary growth substrate and oxygen as an electron acceptor. At an average influent NDMA concentration of 7.4 μg/L and a 28.5 h hydraulic residence time, the reactor effluent concentration was 3.0 ± 2.3 ng/L (>99.95% removal) over more than 70 days of operation. The addition of trichloroethene (TCE) to the reactor resulted in a significant increase in effluent NDMA concentrations, most likely due to cell toxicity from TCE-epoxide produced during its cometabolic oxidation by ENV425. The data suggest that an MBR system can be a viable treatment option for NDMA in groundwater provided that high concentrations of TCE are not present. © 2010 Elsevier Ltd. Source


Sutton P.M.,P.M. Sutton and Associates Inc. | Rittmann B.E.,Arizona State University | Schraa O.J.,Hydromantis Inc. | Banaszak J.E.,OpenCEL | Togna A.P.,Envirogen Technologies Inc.
Water Science and Technology | Year: 2011

A wastewater-treatment flowsheet was developed to integrate uniquely designed biological processes with physical-chemical unit processes, allowing conversion of the organic carbon in the wastewater to methane, the removal and recovery of phosphorus and nitrogen from the wastewater, and the production of water suitable for reuse. In the flowsheet, energy is derived from the wastewater by first shunting a large fraction of the organic carbon in the wastewater to a solids slurry which is treated via anaerobic digestion. The anaerobic digestion system consists of focused pulsed (FP) pretreatment coupled to anaerobic membrane bioreactors (MBRs). Computer modelling and simulation results are used to optimize design of the system. Energy generation from the system is maximized and costs are reduced by using modest levels of recycle flow from the anaerobic MBRs to the FP pretreatment step. © IWA Publishing 2011. Source


Patent
Envirogen Technologies Inc. | Date: 2012-03-08

A system is provided for treating contaminated water. The system includes a bioreactor having an outlet for treated water and a filter coupled to receive treated water from the outlet of the bioreactor. The filter is configured to operate in an anoxic mode. The filter has: (a) a vessel configured to receive the treated water, (b) a membrane associated with the vessel and positioned to extract permeate from the received water, (c) a fluid outlet positioned to direct fluid toward the membrane to inhibit film build up on the membrane, (d) a fluid recirculator positioned to recirculate fluid between the vessel and the fluid outlet, and (e) an oxidant supply positioned to introduce an oxidant into the vessel, the oxidant supply being adjustable to control the oxidation-reduction potential of the received water in the vessel within a predetermined range.


Patent
Envirogen Technologies Inc. | Date: 2015-11-09

A system is provided for treating contaminated water. The system includes a bioreactor having an outlet for treated water and a filter coupled to receive treated water from the outlet of the bioreactor. The filter is configured to operate in an anoxic mode. The filter has: (a) a vessel configured to receive the treated water, (b) a membrane associated with the vessel and positioned to extract permeate from the received water, (c) a fluid outlet positioned to direct fluid toward the membrane to inhibit film build up on the membrane, (d) a fluid recirculator positioned to recirculate fluid between the vessel and the fluid outlet, and (e) an oxidant supply positioned to introduce an oxidant into the vessel, the oxidant supply being adjustable to control the oxidation-reduction potential of the received water in the vessel within a predetermined range.

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