Cheng-Fang Lin

National Taiwan University, T’ai-pei, Taipei, Taiwan

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Publications (77)222.48 Total impact

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    ABSTRACT: Methamphetamine (MAT) is a prescription drug and often a substance of abuse. It is found in WWTP influents and effluents as well as surface waters in many regions, elevating concerns about their potential impact. MAT is not effectively removed by conventional processes of domestic wastewater treatment plants (WWTPs). To contemplate advanced treatment, this study evaluates the feasibility of eliminating MAT by UV-illuminated TiO2, a potential retrofit to existing UV disinfection units. The degradation kinetics and mechanism of MAT by TiO2 under low-wattage UV illumination (9 W with maximum output at 365 nm) were investigated. Experimental parameters were varied including the TiO2 loading, MAT concentration, and pH. During treatment, MAT and its intermediates were tracked by HPLC-MS/MS, along with TOC and IC measurements to determine the mineralization extent. In contact with 0.1 g/L of TiO2 under illumination at pH 7, an entire spike amount of 100 μg/L of MAT was removed from deionized water after 3 min and 76 μg/L of MAT was removed from the secondary wastewater effluent after 30 min. The degradation of MAT followed an apparent first-order kinetics. Near complete mineralization of MAT from 10 mg/L was achieved in 180 min with 0.1 g/L of TiO2 at pH 5, by which the organic nitrogen was converted to NH4(+) and NO3(-). Based on identified intermediates, two degradation pathways were deduced that involved cleavage of the side chain as well as hydroxylation of the MAT compound. The photocatalytic UV/TiO2 process shows promise in arresting the release of MAT and its intermediate derivatives into the water environment. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Water Research 02/2015; 74. DOI:10.1016/j.watres.2015.01.043 · 5.32 Impact Factor
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    ABSTRACT: Methamphetamine (MAT) is a prescription drug and a substance of abuse; it cannot be effectively removed in wastewater treatment plants (WWTPs). As a result, MAT has been found at 61-405 ng/L in hospital effluents, WWTP influents and effluents, as well as surface waters in Taiwan. Even at trace level, MAT can pose risks of long-term exposure, bioaccumulation, and biomagnification on aquatic organisms. This project evaluates the effectiveness of eliminating MAT from waters using existent UV disinfection process in WWTPs in the presence of TiO2 photocatalyst. We tested the use of TiO2 (Degussa P25) under UV illumination (9 W at 365 nm) for the photocatalytic degradation of MAT to define the removal kinetics. Removal was investigated under varied experimental parameters including TiO2 loading, MAT concentration, and pH; MAT and its intermediates throughout treatment were monitored by HPLC-MS/MS, along with TOC and IC analyses to determine the extent of mineralization. The results showed elimination of 100 ppb of MAT within 30 min of irradiation of TiO2 at 0.03 g/L at pH 7. The degradation of MAT followed pseudo-first order kinetics conforming to the Langmuir-Hinshelwood model. Complete mineralization of 10 ppm of MAT was achieved in 180 min with 0.1 g/L of TiO2 at pH 5, whereas the organic nitrogen was converted predominantly to NH4+. Photocatalytic process with UV/TiO2 shows promise in arresting the release of MAT and its intermediates into the water environment.
    14 AIChE Annual Meeting; 11/2014
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    ABSTRACT: This study presented a method to upgrade existing aeration tanks to remove total nitrogen (TN). Bioplates carrying entrapped biomass were installed in an aeration basin to create anoxic/anaerobic zones where denitrification can proceed. In a reactor that coupled bioplates containing entrapped biomass (equivalent to as high as 7,500 mg/L of biomass) and an activated sludge suspension (at mixed liquor suspended solids of 1,300-2,400 mg/L), nitrification efficiency exceeded 95% for an influent wastewater containing 21-54 mg/L of NH3-N. In all cases amended with alkalinity and with or without added methanol as an electron source, TN removal was between 60 and 70%. The results demonstrated anoxic/oxic or anaerobic/anoxic/oxic processes could be incorporated in a conventional aeration basin, requiring no substantial modifications of the vessel and operation, and thus providing improved treatment in terms of nitrogen removal in the conventional suspended-growth process.
    Water Science & Technology 04/2014; 69(7):1558-64. DOI:10.2166/wst.2014.053 · 1.21 Impact Factor
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    ABSTRACT: The aim of present study was to treat municipal wastewater in two-stage anaerobic fluidized membrane bioreactor (AFMBR) (anaerobic fluidized bed reactor (AFBR) followed by AFMBR) using granular activated carbon (GAC) as carrier medium in both stages. Approximately 95% COD removal efficiency could be obtained when the two-stage AFMBR was operated at total HRT of 5h (2h for AFBR and 3h for AFMBR) and influent COD concentration of 250mg/L. About 67% COD and 99% TSS removal efficiency could be achieved by the system treating the effluent from primary clarifier of municipal wastewater treatment plant, at HRT of 1.28h and OLR of 5.65kg COD/m(3)d. The system could also effectively remove twenty detected pharmaceuticals in raw wastewaters with removal efficiency in the range of 86-100% except for diclofenac (78%). No other membrane fouling control was required except scouring effect of GAC for flux of 16LMH.
    Bioresource Technology 03/2014; 165. DOI:10.1016/j.biortech.2014.03.054 · 5.04 Impact Factor
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    ABSTRACT: This study employed entrapped biomass technology to augment the conventional activated sludge process with anoxic-oxic (AO)/anaerobic-anoxic-oxic (A20) functions for the removal of total nitrogen (TN) from wastewater of a science and industrial park in Taiwan. The entrapped biomass unit was fabricated in the format of carrier plates on which microbial cells were entrapped. Due to mass transport limitations, anoxic and anaerobic conditions were created within the bioplates that enabled denitrification to occur. The treatment basin incorporated an equivalent amount of 1300-2400mg MLSS/L of activated sludge on the bioplates at packing ratios of 10-30% (volume ratio ofbioplates to basin) operating with the addition of sodium carbonate for alkalinity and methanol for the electron donor. The results showed nearly 90% of ammonia nitrogen being converted to nitrate and 63% of TN removal, in comparison with typically 10% of TN removal in traditional activated sludge process of domestic wastewater plants.
    Environmental Technology 01/2014; 35(9-12):1401-8. DOI:10.1080/09593330.2013.869610 · 1.20 Impact Factor
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    ABSTRACT: Methamphetamine, ketamine, and morphine, found in the influent and effluent of domestic treatment plants as well as in rivers, were selected as parent compounds in this study. This investigation examined the photocatalytic removal of methamphetamine, ketamine, and morphine, from municipal wastewater effluents using illuminated TiO2 and ZnO. HPLC–MS/MS was used to measure the concentration of these drugs during reactions. UV light of 254 nm alone is capable of destroying the drugs to some extent without the TiO2 or ZnO photocatalyst, while UV light of 365 nm must be coupled with the photocatalysts to be effective. UV light of 254 nm in the presence of 0.04 g/L of TiO2 was most effective, eliminating all three drugs within 5 min; ten times as much of ZnO were required to demonstrate comparable removal. Among the three tested drugs, morphine is most readily removed by the photocatalytic treatment.
    Reaction Kinetics, Mechanisms and Catalysis 12/2013; 110(2). DOI:10.1007/s11144-013-0621-y · 0.98 Impact Factor
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    ABSTRACT: Entrapped mixed microbial cell (EMMC) process offers good capability to remove organics and nitrogen compounds from wastewater in a single aerobic chamber. This research modeled quantitatively the hydraulic characteristics and biochemical process of immobilized activated sludge process (ASP) for the removal of COD and [Inline formula], providing insights to mass and oxygen transfer limitation in EMMC spherical carriers. Based on the conceptual kinetic model and previous experimental results, hydraulic and reaction rate constants were determined for both COD degradation and [Inline formula] nitrification with the EMMC carrier. The dissolved oxygen (DO) distribution profile along the radius of EMMC carriers was also simulated. The depletion of DO in the EMMC carrier was very rapid resulting from COD removal and ammonia nitrification given the mass transport condition of DO. The anoxic/anaerobic zone developed in the EMMC carrier within 1 cm from its external surface in contact with the bulk water phase. Beyond this anoxic/anaerobic boundary, denitrification of nitrate occurred utilizing the residual COD. The efficiency of organics biodegradation and nitrification was not influenced by the thickness or diameter of the EMMC carriers. EMMC carriers of 1 cm in thickness supported removal of organics by biodegradation and nitrogen compounds via nitrification and denitrification processes. The EMMC carrier enabled combined nitrification and denitrification in the aerobic chamber, which signified the enhancement of a traditional ASP to an anoxic/oxic (AO) or anaerobic/anoxic/oxic reactor system via the EMMC carrier in an aeration tank.
    Desalination and water treatment 07/2013; 52. DOI:10.1080/19443994.2013.808407 · 0.99 Impact Factor
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    ABSTRACT: This work investigated the concurrent removal of organics and nitrogen from wastewater as it passed through a slab of immobilized activated sludge of different thickness. Removals of chemical oxygen demand (COD) by 90% from feed of 300 mg/L and of ammonia nitrogen (NH3-N) by 30-50% from feed of 27 mg/L in the synthetic wastewater were achieved. Wastewater exited the entrapped mixed microbial cells (EMMC) bed of 0.01 m in depth after a hydraulic retention time of 8 h through the bed. Increasing the bed thickness by up to 5 folds resulted in no enhancement, indicating aerobic processes ceased within the bed depth. The removal of COD was by aerobic respiration and the removal of nitrogen by oxidation via nitrification, both occurring in the aerobic zone of the EMMC bed near the entrance surface. Denitrification occurred deeper into the anaerobic zone of the bed that removed nitrate leaving behind <0.75 mg/L of nitrate in the emerging effluent. Apparent first-order rate constants were >0.29 L/h and >0.045 L/h for COD and NH3-N removal, respectively. 􀀡􀀓􀀑􀀓􀀗􀀘􀀃􀀒􀁋􀀃􀁉􀁒􀁕􀀃􀀦􀀲􀀧􀀃􀁄􀁑􀁇􀀃􀀱􀀫3-N removal, respectively.
    Journal of Environmental Science and Management 06/2013; 16(1):29-35. · 0.10 Impact Factor
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    ABSTRACT: It is easy to measure energy consumption with a power meter. However, energy savings cannot be directly computed by the powers measured using existing power meter technologies, since the power consumption only reflects parts of the real energy flows. The International Performance Measurement and Verification Protocol (IPMVP) was proposed by the Efficiency Valuation Organization (EVO) to quantify energy savings using four different methodologies of A, B, C and D. Although energy savings can be estimated following the IPMVP, there are limitations on its practical implementation. Moreover, the data processing methods of the four IPMVP alternatives use multiple sensors (thermometer, hygrometer, Occupant information) and power meter readings to simulate all facilities, in order to determine an energy usage benchmark and the energy savings. This study proposes a simple sensor platform to measure energy savings. Using usually the Electronic Product Code (EPC) global standard, an architecture framework for an information system is constructed that integrates sensors data, power meter readings and occupancy conditions. The proposed sensor platform is used to monitor a building with a newly built vertical garden system (VGS). A VGS shields solar radiation and saves on energy that would be expended on air-conditioning. With this platform, the amount of energy saved in the whole facility is measured and reported in real-time. The data are compared with those obtained from detailed measurement and verification (M&V) processes. The discrepancy is less than 1.565%. Using measurements from the proposed sensor platform, the energy savings for the entire facility are quantified, with a resolution of ±1.2%. The VGS gives an 8.483% daily electricity saving for the building. Thus, the results show that the simple sensor platform proposed by this study is more widely applicable than the four complicated IPMVP alternatives and the VGS is an effective tool in reducing the carbon footprint of a building.
    Sensors 05/2013; 13(5):6811-6831. DOI:10.3390/s130506811 · 2.05 Impact Factor
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    ABSTRACT: The abundance of perfluorooctanoic acid (PFOA) in the aquatic environment makes it important to understand the influence of important parameters affecting the partition of PFOA onto sediment. With a focus on the influence by dissolved organic matter (DOM), we investigated the sorption of PFOA to river sediment downstream of a semiconductor and optoelectronic industrial complex that discharged wastewater with a considerable amount of PFOA in it. The dominant components of the sediment were silica oxide (∼14%) and iron oxide (∼2%). The sorption density of PFOA was not significantly affected by solution pH and ionic strength. The combinations of low pH-high ionic strength and high pH-low ionic strength favored partitioning of PFOA to the sediment. The sorption density of PFOA to sediment ranged from 0.41 to 1.43 µg/m2, with the presence of DOM in the aqueous phase reducing the affinity of PFOA toward the sediment. The sorption of PFOA seemed to be facilitated not by electrostatic but by hydrophobic interactions. The PFOA-sediment sorption equilibration required a duration exceeding 12 d. This study revealed DOM as an important solution-specific parameter in sorption studies. The influence of DOM on PFOA sorption provides a useful reference to understand PFOA partition in the aqueous environment. Supplemental materials are available for this article. Go to the publisher's online edition of Separation Science & Technology to view the free supplemental file.
    Separation Science and Technology 05/2013; 48(10). DOI:10.1080/01496395.2012.737887 · 1.20 Impact Factor
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    ABSTRACT: The immobilized membrane bioreactor (IMBR) was investigated for the removal of organic matter and its membrane fouling condition in treating food processing wastewater. The IMBR contains 5,000mg/L mixed liquor suspended solids with hydraulic retention time of 24h. The advantages of IMBR include high sludge retention time, improved removal of COD, ammonia nitrogen, and reduced membrane fouling frequency with much less production of soluble microbial products (SMPs). The results showed that the IMBR was an effective organic matter removal system because it achieved 96–97% removal of COD consistently. The concentration of total SMP in the IMBR was measured at 46.4mg/L which included 24.8mg/L of protein and 21.6mg/L of carbohydrate. Steadily, approxi- mately 33% of carbohydrate and 11% of protein were rejected by the microfiltration (MF) membrane. For this reason, it was concluded that carbohydrate poses a more significant impact on membrane fouling through formation of cake/gel layer than protein. Further, various operating conditions during membrane filtration were experimented which included continuous and intermittent filtration, aeration and non-aeration, and with fiber filter (FF) as pretreatment. It was discovered that while adding an additional FF filtration before MF might improve suspended solid retention, SMP was instead discovered to be the major cause of membrane fouling. In addition, aeration in the membrane tank could significantly improve membrane performance by scouring lightly attached particles from the membrane surface.
    Desalination and water treatment 02/2013; 51(13-15):3090-3096. DOI:10.1080/19443994.2013.776726 · 0.99 Impact Factor
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    ABSTRACT: The impact of ultrasound (US) on membrane filtration and cleaning were studied and compared at various operating parameters of nominal pore sizes of 10 and 100 kDa membrane, trans-membrane pressure (TMP) of 100 and 140 kPa, and US frequencies of 20 kHz and 40 kHz. An average of 15%–20% increase of permeability was observed when US (20 kHz) was applied to assist membrane filtration on 10 kDa membrane and 100 kPa trans-membrane pressure (TMP). However, an insignificant improvement was observed in the case of larger pore size membrane at higher TMP (140 kPa). US also augmented the membrane cleaning process effectively. Lower frequency 20 kHz US exhibited a higher flux recovery (>90%) than the high frequency 40 kHz (59%) using the 10 kDa pore size membrane with US-assisted membrane cleaning. Important factors influencing optimization of US effectiveness lie heavily on its configuration and operation. The experimental results as supported with SEM images demonstrate that US-assisted filtration and cleaning are most effective when membrane pore size, US frequency, and TMP are lower.
    Separation Science and Technology 12/2012; 48(2). DOI:10.1080/01496395.2012.682289 · 1.20 Impact Factor
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    ABSTRACT: Reservoirs in Taiwan are inundated with nutrients that result in algal growth, and thus also reservoir eutrophication. Controlling the phosphorus load has always been the most crucial issue for maintaining reservoir water quality. Numerous agricultural activities, especially the production of tea in riparian areas, are conducted in watersheds in Taiwan. Nutrients from such activities, including phosphorus, are typically flushed into rivers during flooding, when over 90 % of the yearly total amount of phosphorous enters reservoirs. Excessive or enhanced soil erosion from rainstorms can dramatically increase the river sediment load and the amount of particulate phosphorus flushed into rivers. When flow rates are high, particulate phosphorus is the dominant form of phosphorus, but sediment and discharge measurements are difficult during flooding, which makes estimating phosphorus flux in rivers difficult. This study determines total amounts of phosphorus transport by measuring flood discharge and phosphorous levels during flooding. Changes in particulate phosphorus, dissolved phosphorus, and their adsorption behavior during a 24-h period are analyzed owing to the fact that the time for particulate phosphorus adsorption and desorption approaching equilibrium is about 16 h. Erosion of the reservoir watershed was caused by adsorption and desorption of suspended solids in the river, a process which can be summarily described using the Lagmuir isotherm. A method for estimating the phosphorus flux in the Daiyujay Creek during Typhoon Bilis in 2006 is presented in this study. Both sediment and phosphorus are affected by the drastic discharge during flooding. Water quality data were collected during two flood events, flood in June 9, 2006 and Typhoon Bilis, to show the concentrations of suspended solids and total phosphorus during floods are much higher than normal stages. Therefore, the drastic changes of total phosphorus, particulate phosphorus, and dissolved phosphorus in rivers during flooding should be monitored to evaluate the loading of phosphorus more precisely. The results show that monitoring and controlling phosphorus transport during flooding can help prevent the eutrophication of a reservoir.
    Environmental Monitoring and Assessment 11/2012; 185(7). DOI:10.1007/s10661-012-2974-5 · 1.68 Impact Factor
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    ABSTRACT: The sorption and biodegradation of three sulfonamide antibiotics, namely sulfamethoxazole (SMX), sulfadimethoxine (SDM), and sulfamonomethoxine (SMM), in an activated sludge system were investigated. Experiments were carried out by contacting 100 μg/L of each sulfonamide compound individually with 2.56 g/L of MLSS at 25±0.5 °C, pH 7.0, and dissolved oxygen of 3.0±0.1 mg/L in a batch reactor over different periods of 2 d and 14 d. All sulfonamides were removed completely over 11-13 d. Sorptive equilibrium was established well within the first few hours, followed by a lag period of 1-3 days before biodegradation was to deplete the antibiotic compounds linearly in the ensuing 10 days. Apparent zeroth-order rate constants were obtained by regression analysis of measured aqueous concentration vs. time profiles to a kinetic model accounting for sorption and biodegradation; they were 8.1, 7.9, and 7.7 μg/L/d for SDM, SMX, and SMM, respectively, at activated sludge concentration of 2.56 g/L. The measured kinetics implied that with typical hydraulic retention time (e.g. 6 h) provided by WWTP the removal of sulfonamide compounds from the wastewater during the activated sludge process would approximate 2 μg/L.
    Water Research 03/2012; 46(4):1301-8. DOI:10.1016/j.watres.2011.12.035 · 5.32 Impact Factor
  • Chia-Jung Cheng, P K Andy Hong, Cheng-Fang Lin
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    ABSTRACT: The generation of a large volume of activated sludge (AS) from wastewater treatment has increasingly become a great burden on the environment. Anaerobic digestion is routinely practiced for excess waste sludge; however, the process retention time is long because of kinetic limitation in the hydrolysis step. We tested the feasibility of applying ozone in pressure cycles to enhance the disintegration and solubilization of AS with the goal to prepare them for digestion using reduced ozone dose and contact time. The AS was subjected to repetitive pressure cycles in a closed vessel in which an ozone gas mixture was compressed into the slurry to reach 1040 kPa in the headspace to be followed by rapid venting. For a returned AS with total COD (tCOD) of 8200 mg L(-1), a dose of 0.01 gO(3)g(-1) total suspended solids (TSS) delivered via 20 pressure cycles within 16 min resulted in a 37-fold increase of the sCOD/tCOD ratio (due to increased soluble COD, i.e. sCOD) and a 25% reduction of TSS, in comparison to a dose of 0.08 gO(3)g(-1) TSS via bubbling contact over 15 min that resulted in a 15-fold increase of the sCOD/tCOD ratio and a 12% reduction of TSS. Sludge solubilization was evidenced by increased dissolved contents of total phosphorous (from 10 to 64 mg L(-1)), total nitrogen (from 14 to 120 mg L(-1)), and protein (from <15 to 39 mg L(-1)) in the sludge suspension after treatment, indicating significant solubilization of AS.
    Chemosphere 02/2012; 87(6):637-43. DOI:10.1016/j.chemosphere.2012.02.001 · 3.50 Impact Factor
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    ABSTRACT: This study investigated the performance of a novel bio-entrapped membrane reactor (BEMR) in removal of organic matter and its membrane fouling condition in treating food processing wastewater. Three different hydraulic retention times (HRTs) with 6, 12 and 18 h, continuous aeration and intermittent aerations (1 h aeration and 1 h non-aeration; 1 h aeration and 2 h non-aeration) were studied. The results show that the HRT and aeration have significant impacts on the BEMR performance. The chemical oxygen demand and ammonia (NH4 –N) removal efficiencies increased as the HRT increased with the continuous aeration condition. Results of this study indicated that the membrane fouling was severe at lower HRTs and intermittent aeration modes in the BEMR with a constant flux of 20L/m2 h. Conventional membrane bioreactor (CMBR) took 57 min to reach 55 kPa of trans-membrane pressure at HRT of 12 h while the BEMR could operate 215 min before reaching 55 kPa, which was 3.8 times longer than the CMBR. This may be attributed to the higher yield of biomass and production of soluble microbial products in the CMBR, because the CMBR produced 17% more of carbohydrate and 33% more of protein than the BEMR. Better performance of the BEMR was found at the longer HRTs (18 h > 12 h > 6 h) and continuous aeration was better than intermittent aeration.
    Desalination and water treatment 01/2012; 50(1-3):59-66. DOI:10.1080/19443994.2012.708538 · 0.99 Impact Factor
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    ABSTRACT: The sorption and biodegradation of three sulfonamide antibiotics, namely sulfamethoxazole (SMX), sulfadimethoxine (SDM), and sulfamonomethoxine (SMM), in an activated sludge system were investigated. Experiments were carried out by contacting 100 mg/L of each sulfonamide compound individually with 2.56 g/L of MLSS at 25 � 0.5 �C, pH 7.0, and dissolved oxygen of 3.0 � 0.1 mg/L in a batch reactor over different periods of 2 d and 14 d. All sulfonamides were removed completely over 11e13 d. Sorptive equilibrium was established well within the first few hours, followed by a lag period of 1e3 days before biodegradation was to deplete the antibiotic compounds linearly in the ensuing 10 days. Apparent zeroth-order rate constants were obtained by regression analysis of measured aqueous concentration vs. time profiles to a kinetic model accounting for sorption and biodegradation; they were 8.1, 7.9, and 7.7 mg/L/d for SDM, SMX, and SMM, respectively, at activated sludge concentration of 2.56 g/L. The measured kinetics implied that with typical hydraulic retention time (e.g. 6 h) provided by WWTP the removal of sulfonamide compounds from the wastewater during the activated sludge process would approximate 2 mg/L.
    Water Research 01/2012; 46:1301-1308. · 5.32 Impact Factor
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    ABSTRACT: The immobilized bioprocess (IBP) was investigated for the removal of organic carbon and ammonia nitrogen from wastewater. Two wastewaters (a food industry wastewater and a composite industrial wastewater) were investigated, one containing high concentration (820–1300 mg/l) and the other medium concentration (250–450 mg/l) of chemical oxygen demand (COD). Three mixed liquor suspended solids (MLSS) (3000, 5000, and 9000 mg/l) and two hydraulic retention times (HRT) (12 h and 24 h) were employed representing different surface loading and volume loading factors. IBP provides high sludge retention time (SRT), enabling improved removal of COD and ammonia nitrogen. The results showed 78–93% and 83–96% removals of soluble COD (SCOD) and ammonia (NH4 –N), respectively, from the food industry wastewater, when the surficial removal rate and volumetric removal rate in the IBP were 0.011–0.056 kg COD/m-d and 2.3–12 kg COD/m-d, respectively. For the composite industrial wastewater, removal of SCOD and NH4 –N were 53–80% and 38–69%, respectively, when the surficial removal rate and volumetric removal rate were 0.0048–0.016 kg COD/m-d and 1.0–3.4 kg COD/m-d, respectively. The results further show stable removals of COD and NH4 –N, albeit decreasing with decreasing HRTs and MLSS. IBP facilitates simple operation and good effluent quality without requiring sludge recycling.
    Desalination and water treatment 01/2012; 37(1-3):296-301. DOI:10.1080/19443994.2012.661284 · 0.99 Impact Factor
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    ABSTRACT: Valence copper was recovered from wastewater by chemical reduction and use of a high gradient magnetic separation (HGMS) system. Ammonia (NH3) and sodium dithionate (Na2S2O4) at a molar ratio of [Cu]:[NH3]:[Na2S2O4] = 1:4:3 at pH = 9.5 were used first to chemically reduce copper ion to metallic copper; the resultant metal solids were captured in an upflowing reactor space equipped with a permalloy matrix net under a high gradient magnetic field. The captured solids were predominantly 6-20 microm in diameter, with Cu2O and CuO present among the solids. Four treatment configurations with and without the use of magnetic field and metal alloy as the matrix net were tested and their effects evaluated: (1) no magnetic field or matrix, (2) no magnetic field but with matrix, (3) with magnetic field but no matrix, (4) with both magnetic field and matrix. At flow rates of 40, 60, 80 and 100 cm3/min, capture efficiencies for metallic copper in the absence of magnetic field were 87%, 86%, 63%, and 39%, respectively, and in the presence of magnetic field were 99%, 98%, 95%, and 93%, respectively. The HGMS was critical for a high capture efficiency, whereas a matrix net only marginally enhanced it. Additional tests with a larger reactor confirmed similarly high efficiencies of > 85%. The use of an alloy matrix appeared to be important when high flow rates are most likely to be employed in practical applications.
    Environmental Technology 10/2011; 32(13-14):1427-33. DOI:10.1080/09593330.2010.538439 · 1.20 Impact Factor