- Donald C. Phillip Professor and Francis Alison Professor at the University of Delaware. Has been in teaching and res... moreDonald C. Phillip Professor and Francis Alison Professor at the University of Delaware. Has been in teaching and research in the general field of environmental engineering and science for over 50 years.His research interests are 1) chemistry at the solid-water interfacesedit
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... In this case, the inactivation reaction may not be defined totally in pure chemical terms. Rather, a combined hydroxyl oxidation and microbubble attack may play the most important role in inactivating the oocysts. ... Chemical... more
... In this case, the inactivation reaction may not be defined totally in pure chemical terms. Rather, a combined hydroxyl oxidation and microbubble attack may play the most important role in inactivating the oocysts. ... Chemical effects of ultrasound on aqueous solutions. ...
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The effectiveness of pretreating an activated carbon with iron-salt solution to improve its arsenic removal capacity was studied. Various factors such as type and concentration of salt, pH, and treating time were thoroughly investigated... more
The effectiveness of pretreating an activated carbon with iron-salt solution to improve its arsenic removal capacity was studied. Various factors such as type and concentration of salt, pH, and treating time were thoroughly investigated for their effects on the improvement of removal capacity. An effort was made to identify the optimal pretreatment conditions. A ten-fold increase, over the untreated activated
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Both metam sodium and copper/zinc-containing compounds are widely used as fungicides. They therefore may co-occur in the biosphere. Despite certain studies of individual toxicity for either metam or copper (II)/zinc (II), their... more
Both metam sodium and copper/zinc-containing compounds are widely used as fungicides. They therefore may co-occur in the biosphere. Despite certain studies of individual toxicity for either metam or copper (II)/zinc (II), their synergistic toxicity has not been examined. In this paper, a remarkable synergistic toxicity was observed in HepG2 cells when metam and copper (II)/zinc (II) at non-toxic and sub-toxic levels were combined. Unexpectedly, cell death modes between metam/copper (II) and metam/zinc (II) were different: For metam/copper (II), apoptosis was evident from morphological characteristics including cytoplasm-chromatin condensation, phosphatidylserine (PS) exposure, SubG0 /G1 DNA fragmentation, mitochondrial membrane potential decrease, pro/anti-apoptotic protein activation, and cytochrome c release; for metam/zinc (II), necrosis was evident from organelle swelling and uncontrolled collapse. To our knowledge, this work first not only demonstrates the synergistic toxicitie...
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The fouling phenomenon and associated fouling mechanisms of the cross-flow type nanofiltration membrane were investigated using the modified Hermia empirical model and the resistance-in-series model. The effects of pH on membrane permeate... more
The fouling phenomenon and associated fouling mechanisms of the cross-flow type nanofiltration membrane were investigated using the modified Hermia empirical model and the resistance-in-series model. The effects of pH on membrane permeate flux and the rejection of natural organic matter (NOM) were also studied. Natural water and the effluent of a rapid sand filter (SF) were used as the source
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Response Surface Methodology (RSM) was employed to investigate the effect of TOC ratio of high molecular weight organic matter (HMWOM) to low molecular weight organic matter (LMWOM), the LMWOM concentration and hydrogen peroxide to... more
Response Surface Methodology (RSM) was employed to investigate the effect of TOC ratio of high molecular weight organic matter (HMWOM) to low molecular weight organic matter (LMWOM), the LMWOM concentration and hydrogen peroxide to ferrous ion molar ratio on COD removal during the treatment of sanitary landfill leachate with Fenton reagents. The high and low levels of HMWOM/LMWOM, the LMWOM concentration and H2O2/Fe2+ were from 14 to 38, 975 to 3000 mg/L, and 1.75 to 4.00 respectively. Using the software of Design--Expert 5, a response surface quadratic model in terms of actual factors was obtained based on the experimental data, and COD removal contour plots were derived from the model accordingly. It showed that COD removal increased with the increase of HMWOM to LMWOM ratio, but decreased with increasing LMWOM concentration. There existed an optimal hydrogen peroxide to ferrous ion molar ratio so that the highest COD removal efficiency could be achieved.