I recently retired as a faculty member from the Department of Civil and Environmental Engineering at the University of California, Davis. Majority of my research activities during the past 26 years was related to conversion of biodegradable waste into energy and surface water quality. In my post-retirement I am devoting more time of water reuse
... ANAEROBIC DIGESTION OF MUNICIPAL SOLID WASTE FOR FUEL GAS PRODUCTION ... Biogas production in... more ... ANAEROBIC DIGESTION OF MUNICIPAL SOLID WASTE FOR FUEL GAS PRODUCTION ... Biogas production increased with an increase of organic loading rate up to a rate of 7.5 g BVS kg-1 active reactor mass d. Organic overload occurred at 7.6 g kg-1 and continued up to ...
World Environmental and Water Resources Congress 2011, May 19, 2011
ABSTRACT Urban and non-urban stormwater runoff is considered as a source of pollution to many rec... more ABSTRACT Urban and non-urban stormwater runoff is considered as a source of pollution to many receiving water bodies. To reduce the impact of pollution on receiving waters, knowledge of input runoff concentration and hydrograph is needed in order to design and optimize best management practices (BMPs). Also, to include the first flush impact on BMP design and risk assessment, it is essential to measure the pollutograph (pollutant concentration vs. storm duration) of desired chemical constituents. Since monitoring of ...
A Bayesian chemical mass balance (CMB) source apportionment method is developed using the Markov ... more A Bayesian chemical mass balance (CMB) source apportionment method is developed using the Markov Chain Monte Carlo (MCMC) approach. Compared with deterministic approaches, the Bayesian method is capable to account for the measurement errors as well as the impact of variability of the source elemental compositions due to the heterogeneities and estimate the uncertainties associated with the estimated source contributions. The method estimates the joint probability densities and consequently the credible intervals ...
Journal of Chemical Technology & Biotechnology, Apr 1, 1994
Ammonia is produced during anaerobic digestion of protein‐containing materials. While ammonia can... more Ammonia is produced during anaerobic digestion of protein‐containing materials. While ammonia can be utilized by some members of the anaerobic population, excess ammonia can inhibit methanogenesis. High‐solids anaerobic digestion may be especially sensitive to the effects of ammonia overproduction. This study explored the performance of a pilot scale high‐solids anaerobic digestion process under various total ammonia nitrogen (TAN) concentrations. In general the high‐solids digester could operate up to 1000 mg dm−3 without any inhibitory effect. The digester performed best when it was operated at TAN concentrations in the narrow range of 600 to 800 mg dm−3.
Abstract Urban and non-urban stormwater are important sources of pollution in various water bodie... more Abstract Urban and non-urban stormwater are important sources of pollution in various water bodies including rivers, streams, estuaries, lakes and coastal areas as well as groundwater. One step in testing the effectiveness of best management practices in removing or reducing the pollutions in stormwater in a quantitative way is to predict the concentration of pollutions in the influent water. In this research a stepwise approach is utilized, along with a hybrid genetic algorithm optimization technique, to identify optimal ...
... ANAEROBIC DIGESTION OF MUNICIPAL SOLID WASTE FOR FUEL GAS PRODUCTION ... Biogas production in... more ... ANAEROBIC DIGESTION OF MUNICIPAL SOLID WASTE FOR FUEL GAS PRODUCTION ... Biogas production increased with an increase of organic loading rate up to a rate of 7.5 g BVS kg-1 active reactor mass d. Organic overload occurred at 7.6 g kg-1 and continued up to ...
World Environmental and Water Resources Congress 2011, May 19, 2011
ABSTRACT Urban and non-urban stormwater runoff is considered as a source of pollution to many rec... more ABSTRACT Urban and non-urban stormwater runoff is considered as a source of pollution to many receiving water bodies. To reduce the impact of pollution on receiving waters, knowledge of input runoff concentration and hydrograph is needed in order to design and optimize best management practices (BMPs). Also, to include the first flush impact on BMP design and risk assessment, it is essential to measure the pollutograph (pollutant concentration vs. storm duration) of desired chemical constituents. Since monitoring of ...
A Bayesian chemical mass balance (CMB) source apportionment method is developed using the Markov ... more A Bayesian chemical mass balance (CMB) source apportionment method is developed using the Markov Chain Monte Carlo (MCMC) approach. Compared with deterministic approaches, the Bayesian method is capable to account for the measurement errors as well as the impact of variability of the source elemental compositions due to the heterogeneities and estimate the uncertainties associated with the estimated source contributions. The method estimates the joint probability densities and consequently the credible intervals ...
Journal of Chemical Technology & Biotechnology, Apr 1, 1994
Ammonia is produced during anaerobic digestion of protein‐containing materials. While ammonia can... more Ammonia is produced during anaerobic digestion of protein‐containing materials. While ammonia can be utilized by some members of the anaerobic population, excess ammonia can inhibit methanogenesis. High‐solids anaerobic digestion may be especially sensitive to the effects of ammonia overproduction. This study explored the performance of a pilot scale high‐solids anaerobic digestion process under various total ammonia nitrogen (TAN) concentrations. In general the high‐solids digester could operate up to 1000 mg dm−3 without any inhibitory effect. The digester performed best when it was operated at TAN concentrations in the narrow range of 600 to 800 mg dm−3.
Abstract Urban and non-urban stormwater are important sources of pollution in various water bodie... more Abstract Urban and non-urban stormwater are important sources of pollution in various water bodies including rivers, streams, estuaries, lakes and coastal areas as well as groundwater. One step in testing the effectiveness of best management practices in removing or reducing the pollutions in stormwater in a quantitative way is to predict the concentration of pollutions in the influent water. In this research a stepwise approach is utilized, along with a hybrid genetic algorithm optimization technique, to identify optimal ...
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