@article{ma_chang_chiang_sung_chao_2008, title={Photocatalytic degradation of lignin using Pt/TiO2 as the catalyst}, volume={71}, ISSN={["0045-6535"]}, DOI={10.1016/j.chemosphere.2007.10.061}, abstractNote={Photocatalytic degradation of lignin was studied with the use of catalysts TiO2 and Pt/TiO2. The influence of several experimental parameters, i.e. pH, catalyst dosage and illumination on lignin degradation was investigated. The results showed that application of UV irradiation alone has almost no effect on the reduction of dissolved organic carbon (DOC) and American Dye Manufacture Institute value (ADMI). However, the addition of TiO2 and Pt/TiO2 reduced the original DOC (251 mg l−1) by more than 40% within 30 min of treatment and the reaction can be simulated with pseudo-first order kinetics. Rapid degradation of lignin was observed in acidic solution using either TiO2 or Pt/TiO2 as the catalyst compared to high pH cases. The content of Pt in the Pt/TiO2 catalyst is 1%. In addition, too much catalyst addition has not increased the DOC and ADMI reduction proportionally. The investigation also indicated that the photocatalytic degradation rates could be enhanced 1–6 times faster after doping TiO2 with Pt in different pH cases. A modified Nernst type model was adopted to simulate the decoloring process using TiO2 and Pt/TiO2 based on the profiles of oxidation reduction potential during the photocatalytic reaction. The developed equation can be used to predict the color removal efficiency of lignin wastewater by the photocatalytic process.}, number={5}, journal={CHEMOSPHERE}, author={Ma, Ying-Shih and Chang, Cheng-Nan and Chiang, Yen-Pei and Sung, Hsiao-Fan and Chao, Allen C.}, year={2008}, month={Mar}, pages={998–1004} }
 @misc{chiu_lee_chang_chao_2007, title={Control of carbon and ammonium ratio for simultaneous nitrification and denitrification in a sequencing batch bioreactor}, volume={59}, ISSN={["1879-0208"]}, DOI={10.1016/j.ibiod.2006.08.001}, abstractNote={This study shows how the carbon and nitrogen (C/N) ratio controls the simultaneous occurrence of nitrification and denitrification in a sequencing batch reactor (SBR). Data demonstrated that a low C/N ratio resulted in a rapid carbon deficit, causing an unbalanced simultaneous nitrification–denitrification (SND) process in SBR. When the initial COD/NH4+-N ratio was adjusted to 11.1, the SND-based SBR achieved complete removal of NH4-N and COD without leaving any NO2−-N in the effluent. The nitrogen removal efficiency decreases gradually with increasing ammonium-loading rate to the SND–SBR system. Altogether, data showed that appropriate controls of carbon and nitrogen input are required to achieve an efficient SND–SBR. An established SND technology can save operation time and energy, and might replace the traditional two-stage biological nitrification and denitrification process.}, number={1}, journal={INTERNATIONAL BIODETERIORATION & BIODEGRADATION}, author={Chiu, Ying-Chih and Lee, Li-Ling and Chang, Cheng-Nan and Chao, Allen C.}, year={2007}, month={Jan}, pages={1–7} }
 @article{chen_kao_yeh_chien_chao_2006, title={Application of a constructed wetland for industrial wastewater treatment: A pilot-scale study}, volume={64}, ISSN={["1879-1298"]}, DOI={10.1016/j.chemosphere.2005.11.069}, abstractNote={The main objective of this study was to examine the efficacy and capacity of using constructed wetlands on industrial pollutant removal. Four parallel pilot-scale modified free water surface (FWS) constructed wetland systems [dimension for each system: 4-m (L) × 1-m (W) × 1-m (D)] were installed inside an industrial park for conducting the proposed treatability study. The averaged influent contains approximately 170 mg l−1 chemical oxygen demand (COD), 80 mg l−1 biochemical oxygen demand (BOD), 90 mg l−1 suspend solid (SS), and 32 mg l−1 NH3–N. In the plant-selection study, four different wetland plant species including floating plants [Pistia stratiotes L. (P. stratiotes) and Ipomoea aquatica (I. aquatica)] and emergent plants [Phragmites communis L. (P. communis) and Typha orientalis Presl. (T. orientalis)] were evaluated. Results show that only the emergent plant (P. communis) could survive and reproduce with a continuous feed of 0.4 m3 d−1 of the raw wastewater. Thus, P. communis was used in the subsequent treatment study. Two different control parameters including hydraulic retention time (HRT) (3, 5, and 7 d) and media [vesicles ceramic bioballs and small gravels, 1 cm in diameter] were examined in the treatment study. Results indicate that the system with a 5-d HRT (feed rate of 0.4 m3 d−1) and vesicles ceramic bioballs as the media had the acceptable and optimal pollutant removal efficiency. If operated under conditions of the above parameters, the pilot-plant wetland system can achieve removal of 61% COD, 89% BOD, 81% SS, 35% TP, and 56% NH3–N. The treated wastewater meets the current industrial wastewater discharge standards in Taiwan.}, number={3}, journal={CHEMOSPHERE}, author={Chen, T. Y. and Kao, C. M. and Yeh, T. Y. and Chien, H. Y. and Chao, C.}, year={2006}, month={Jun}, pages={497–502} }
 @article{chiang_liang_chang_chao_2006, title={Differentiating ozone direct and indirect reactions on decomposition of humic substances}, volume={65}, ISSN={["1879-1298"]}, DOI={10.1016/j.chemosphere.2006.04.080}, abstractNote={The ozonation reaction is accomplished into two pathways: direct ozone oxidation and indirect free hydroxyl radical oxidation. Both reactions are proceeding simultaneously, thus, it is difficult to separate them and study their respective reaction mechanisms. Carbonate and bicarbonate react with free radicals that will effectively inhibit the indirect free radical oxidation without affecting the direct oxidation reaction. The feasibility of using these chemicals as scavengers to inhibit the hydroxyl radicals so that the direct ozone oxidation reaction and indirect free hydroxyl radical oxidation reaction can be differentiated is presented in this paper. The results will assist in achieving a better understanding of the ozone reaction mechanism in oxidizing organic substances. In this study, synthetic samples made of commercially available humic substance are used to carry out the inhibited and non-inhibited ozone oxidation experiments. The intersecting point of the ORP (oxidation reduction potential) time series curves of the inhibited and un-inhibited reactions, occurring at 120 s after the onset of the oxidation reaction, marks the turning point at which all added scavenger chemicals have been completely exhausted. Based on the measured A254 values, percentage distributions of direct ozone oxidation and indirect hydroxyl radical oxidation are estimated. The results indicate that the contribution of indirect reaction decreases with increasing amounts of inhibiting scavengers. The on-line ORP measurement results are simulated using a modified form of the Nernst equation expressed as ORP = 11 852 − 1196 pH + 130 ln [(A254,0 − A254,t)(A254,t)−1] with R2 value of 0.99. In this equation, A254 is the absorbance at 254 nm used to index the humic substance concentration while subscript 0 and t denote the initial and the final time, respectively.}, number={11}, journal={CHEMOSPHERE}, author={Chiang, Yen-Pei and Liang, Yung-Ying and Chang, Cheng-Nan and Chao, Allen C.}, year={2006}, month={Dec}, pages={2395–2400} }
 @article{chang_cheng_chao_2004, title={Applying the nernst equation to simulate redox potential variations for biological nitrification and denitrification processes}, volume={38}, ISSN={["1520-5851"]}, DOI={10.1021/es021088e}, abstractNote={In this paper, various forms of Nernst equations have been developed based on the real stoichiometric relationship of biological nitrification and denitrification reactions. Instead of using the Nernst equation based on a one-to-one stoichiometric relation for the oxidizing and the reducing species, the basic Nernst equation is modified into slightly different forms. Each is suitable for simulating the redox potential (ORP) variation of a specific biological nitrification or denitrification process. Using the data published in the literature, the validity of these developed Nernst equations has been verified by close fits of the measured ORP data with the calculated ORP curve. The simulation results also indicate that if the biological process is simulated using an incorrect form of Nernst equation, the calculated ORP curve will not fit the measured data. Using these Nernst equations, the ORP value that corresponds to a predetermined degree of completion for the biochemical reaction can be calculated. Thus, these Nernst equations will enable a more efficient on-line control of the biological process.}, number={6}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Chang, CN and Cheng, HB and Chao, AC}, year={2004}, month={Mar}, pages={1807–1812} }
 @article{chang_ma_fang_chao_tsai_sung_2004, title={Corrigendum to "Decolorizing of lignin wastewater using the photochemical UV/TiO2 process" (vol 56, pg 1011, 2004)}, volume={57}, ISSN={["0045-6535"]}, DOI={10.1016/j.chemosphere.2004.08.002}, number={6}, journal={CHEMOSPHERE}, author={Chang, CN and Ma, YS and Fang, GC and Chao, AC and Tsai, MC and Sung, HF}, year={2004}, month={Nov}, pages={529–529} }
 @article{chang_ma_fang_chao_tsai_sung_2004, title={Decolorizing of lignin wastewater using the photochemical UV/TiO2 process}, volume={56}, ISSN={["1879-1298"]}, DOI={10.1016/j.chemosphere.2004.04.021}, abstractNote={Studies on applying the photochemical UV/TiO2 oxidation process to treat the lignin-containing wastewater for dissolved organic carbon (DOC), color and reducing A254 (the absorption at the wavelength of 254 nm) have been carried out. The data obtained in this study demonstrate that the UV/TiO2 process is effective in oxidizing the lignin thus reducing the color and DOC of the wastewater treated. The combined UV/TiO2 treatment can achieve better removal of DOC and color than the UV treatment alone. Color removal, based on American Dye Manufacture Index (ADMI) measurement, is greater than 99% if the pH is maintained at 3.0 with the addition of 1 g l(-1) TiO2. When 10 g l(-1) TiO2 is applied, the oxidation reduction potential (ORP) value is reached to result in an 88% removal of both DOC and color. A model was developed based on the variation of ORP during the photochemical reaction to simulate the decoloring process. The proposed model can be used to predict the color removal efficiency of the UV/TiO2 process.}, number={10}, journal={CHEMOSPHERE}, author={Chang, CN and Ma, YS and Fang, GC and Chao, AC and Tsai, MC and Sung, HF}, year={2004}, month={Sep}, pages={1011–1017} }
 @article{zheng_chao_ji_2004, title={Transient analysis of linear birth-death processes with immigration and emigration}, volume={18}, DOI={10.1017/s0269964804182016}, abstractNote={Linear birth–death processes with immigration 
and emigration are major models in the study of population processes of 
biological and ecological systems, and their transient analysis is 
important in the understanding of the structural behavior of such 
systems. The spectral method has been widely used for solving these 
processes; see, for example, Karlin and McGregor [11]. In this article, we provide an 
alternative approach: the method of characteristics. This method yields 
a Volterra-type integral equation for the chance of extinction and an 
explicit formula for the z-transform of the transient 
distribution. These results allow us to obtain closed-form solutions 
for the transient behavior of several cases that have not been 
previously explicitly presented in the literature.}, number={2}, journal={Probability in the Engineering and Informational Sciences}, author={Zheng, Y. X. and Chao, X. L. and Ji, X. M.}, year={2004}, pages={141–159} }
 @article{wu_langley_chao_2001, title={Reaction kinetics of immobilized-cell denitrification. II: Experimental study}, volume={127}, DOI={10.1061/(asce)0733-9372(2001)127:8(689)}, abstractNote={Laboratory experiments were conducted to characterize the performance of an immobilized-cell denitrification process treating nitrate-contaminated groundwater and to provide supporting data for the validation of a quasi-steady state model based on half-order reaction kinetics. The treatment process consists of laboratory-scale, plug-flow reactors packed with biocatalyst particles. Pseudomonas denitrificans (American Type Culture Collection 13867), a heterotrophic denitrifier, was cultured and immobilized in calcium alginate particles. Ethanol was used as the source of organic carbon. Thirty concentration profiles were obtained at four levels of nitrate concentration and at three ranges of flow rate. An analysis of the nitrate and nitrite concentration profiles suggested that a half-order reaction rate model could be used to describe the reduction of both nitrate and nitrite. The half-order reaction rate constants for nitrate and nitrite reduction were dependent on the age of the biocatalyst particles and ...}, number={8}, journal={Journal of Environmental Engineering (New York, N.Y.)}, author={Wu, J. S. and Langley, W. G. and Chao, A. C.}, year={2001}, pages={689–697} }
 @article{xu_sheldon_carawan_larick_chao_2001, title={Recovery and characterization of by-products from egg processing plant wastewater using coagulants}, volume={80}, DOI={10.1093/ps/80.1.57}, abstractNote={The effectiveness of precipitation or coagulation technology to treat commercial egg processing plant wastewater, using such coagulants as lignosulfonate, bentonite, carboxymethylcellulose, and ferric chloride, was evaluated. For simulated and industrial waste-water, chemical oxygen demand, turbidity, and total solids were reduced over 90, 97, and 95%, respectively, for all coagulants tested. Protein and fat recoveries were over 95% for all coagulants. The optimal coagulant concentration for maximum by-product recovery depended on initial wastewater concentrations of protein, total solids, and fat. The dried by-products contained high concentrations of protein (30 to 50%) and fat (30 to 40%) and had similar essential amino acid profiles as standard proteins from the United Nations Food and Agricultural Organization (FAO). The relative protein digestibilities of each recovered solid (carboxymethycellulose, lignosulfonate, bentonite, and ferric chloride) and corn meal relative to a liquid whole egg standard were approximately 80, 90, 60, 30, and 56%, respectively. These compositional and in vitro digestibility studies suggest that the recovered by-products could be useful as livestock feed ingredients or for other applications.}, number={1}, journal={Poultry Science}, author={Xu, L. J. and Sheldon, B. W. and Carawan, R. E. and Larick, D. K. and Chao, A. C.}, year={2001}, pages={57–65} }
 @article{chang_chao_lee_zing_2000, title={Influence of molecular weight distribution of organic substances on the removal efficiency of DBPS in a conventional water treatment plant}, volume={41}, ISSN={["0273-1223"]}, DOI={10.2166/wst.2000.0604}, abstractNote={The objective of this study is to investigate how the molecular weight distribution of the organic substances affects their treatment efficiencies and the reduction of disinfection by-products (DBPs) in the various unit operations of a full-scale water treatment plant. The results indicate that the membrane with a smaller molecular weight cut-off is more effective for removing the organic substances and its associated water quality parameters from the raw water. For example, using the membrane with a molecular weight cut-off of 0.5 K (500 daltons), the removal efficiency of DOC from the raw water sample can be as high as 88%. Removal efficiencies of other water quality parameters such as UV254 absorbance, THMFP and AOXFP are generally between 65–69%. When undergoing the various unit operations in the conventional water treatment plant, most organic substances are removed in the coagulation process followed by sedimentation.}, number={10-11}, journal={WATER SCIENCE AND TECHNOLOGY}, author={Chang, CN and Chao, A and Lee, FS and Zing, FF}, year={2000}, pages={43–49} }
 @article{chang_chen_huang_chao_2000, title={Using sequencing batch biofilm reactor (SBBR) to treat ABS wastewater}, volume={41}, ISSN={["0273-1223"]}, DOI={10.2166/wst.2000.0476}, abstractNote={Ratio of total Kjeldahl Nitrogen to COD for ABS (acrylnitrile, butadiene and styrene) wastewater is in a range of 0.12–0.17, which is significantly higher than that needed for optimal growth of an activated sludge. In this work, an automated Sequencing Batch Biofilm Reactor (SBBR) system at lab-scale is applied to reduce the amount of ABS; this system is controlled by an on-line monitoring of oxidation-reduction potential (ORP). A comparison of the operation efficiency for the lab-scale SBBR operated with the control of fix-time method and ORP-based real-time automatic method is presented. The results show that the system ORP can be used as an available parameter for achieving a real-time operation and control of the lab-scale SBBR. It is found that the reaction time is reduced of 11.1–55.2% if an ORP-based real-time control is used, instead of the fixed-time control. Also, the SBBR system is made more efficient and cost-effective.}, number={4-5}, journal={WATER SCIENCE AND TECHNOLOGY}, author={Chang, CN and Chen, HR and Huang, CH and Chao, A}, year={2000}, pages={433–440} }
 @article{lin_ma_chao_huang_1999, title={BMP test on chemically pretreated sludge}, volume={68}, ISSN={["0960-8524"]}, DOI={10.1016/S0960-8524(98)00126-6}, abstractNote={Municipal waste activated sludge (WAS) was treated with NaOH to solubilize the particulate organic matter in order to improve its digestibility when the sludge was stabilized in an anaerobic digestion process. For the WAS of 1% TS treated with 20 and 40 meq/l NaOH at ambient temperature for 24 h, the SCOD/TCOD values increased from 3.5 to 39 and 55%, respectively. Results of the BMP (biochemical methane potential) test showed that recoveries of carbon and nitrogen reached 94–105% and the methane produced was 349 ml (at 1 atm and 35°C) for 1 g of COD removed. The improvement in VS removal for sludge treated with 40 meq/l of NaOH was as high as 41% over the control sludge sample, with COD removal and gas production improved by 30 and 34%, respectively, over the control. Results of the cumulative COD removal appeared to follow first-order reaction kinetics. Parameters of the first-order model such as ultimate biodegradable COD (Lu), reaction rate coefficient (k) and ultimate biodegradability (μ), were calculated using the Thomas method. The BMP test can be used as a valuable tool to study the kinetics and efficiency of anaerobic digestion processes.}, number={2}, journal={BIORESOURCE TECHNOLOGY}, author={Lin, JG and Ma, YS and Chao, AC and Huang, CL}, year={1999}, month={May}, pages={187–192} }
 @article{neale_bricka_chao_1997, title={Evaluating acids and chelating agents for removing heavy metals from contaminated soils}, volume={16}, ISSN={["0278-4491"]}, DOI={10.1002/ep.3300160416}, abstractNote={Abstract}, number={4}, journal={ENVIRONMENTAL PROGRESS}, author={Neale, CN and Bricka, RM and Chao, AC}, year={1997}, pages={274–280} }
 @article{chang_lin_chao_cho_yu_1997, title={The pretreatment of acrylonitrile and styrene with the ozonation process}, volume={36}, ISSN={["0273-1223"]}, DOI={10.1016/S0273-1223(97)00396-X}, abstractNote={Acrylonitrile and styrene are used as the raw materials for manufacturing acrylic fiber, thus they are often found as pollutants in the petrochemical wastewater. This study utilizes ozone to decompose the organic nitrogen contained in acrylonitrile and styrene, and the oxidation process was monitored using on-line measurements of oxidation-reduction potential (ORP) and pH. The efficiency of organic nitrogen decomposition was also estimated based on the COD, organic nitrogen, TOC, ammonia-N, nitrite, and nitrate measurements. Both the initial pH and alkalinity are observed to affect the degradation rate of organic nitrogen. The acrylonitrile sample with the lowest initial pH value (i.e., 4.0) has a shorter t1/2 of 18.9 min and that for samples of the highest initial pH (i.e., 11) was 34 min. The alkalinity of one acrylonitrile sample was boosted by adding 500 mg/l CaCO3, to simulate the field ABS (Acrylonltrde-Butadiene-Styrene) wastewater effluent. It was observed that within a short ozone contact time, the acrylonitrile sample spiked with 500 mg/l CaCO3 had the highest COD decomposition rate of 0.411 mm−1, or 1.3 times more than that for samples without addition of CaCO3. Results of the ozonation process can be fitted with a modified Nernst equation for the various pH conditions. Additionally, the ozone treated synthetic ABS sample shows a faster COD removal rate in the subsequent biological process than those samples without ozone treatment.}, number={2-3}, journal={WATER SCIENCE AND TECHNOLOGY}, author={Chang, CN and Lin, JG and Chao, AC and Cho, BC and Yu, RF}, year={1997}, pages={263–270} }
 @inproceedings{chao_liu_rasdorf_1988, title={Spreadsheet approach for the design of air stripping of volatile organic contaminants (VOCs) from water}, ISBN={0872626350}, booktitle={Computing in civil engineering: Microcomputers to supercomputers: Proceedings of the fifth conference, Radisson Mark Plaza Hotel, Alexandria, Virginia, March 29-31, 1988}, publisher={Alexandria, VA: American Society of Civil Engineers}, author={Chao, A. C. and Liu, Y. and Rasdorf, W. J.}, year={1988}, pages={731–741} }
 @inproceedings{chao_rasdorf_paige_1987, title={Classifying industrial sludge using a knowledge-based expert system}, ISBN={087371136X}, booktitle={Proceedings of the 42nd Industrial Waste Conference: May 12, 13, 14, 1987, Purdue University, West Lafayette, Indiana}, publisher={West Lafayette, IN: School of Civil Engineering, Purdue University}, author={Chao, A. C. and Rasdorf, W. J. and Paige, W.}, year={1987}, pages={399–405} }