The Experts below are selected from a list of 4473 Experts worldwide ranked by ideXlab platform
Chinghua Huang - One of the best experts on this subject based on the ideXlab platform.
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removal of disinfection byproduct dbp precursors in water by two stage Biofiltration treatment
Water Research, 2017Co-Authors: Wanning Lee, Clark Coleman, Jason T Carter, Kirk Nowack, Chinghua HuangAbstract:The removal of precursors of 36 disinfection byproducts (DBPs) in effluents from flocculation/sedimentation process was evaluated across a pilot-scale two-stage Biofiltration process, i.e., a sand/anthracite (SA) biofilter (empty bed contact time (EBCT) of 7.5 min) coupled with a biologically-active granular activated carbon (GAC) contactor (EBCT of 15 min). The Biofiltration process exhibited a good capacity for removal of the total DBP formation potential (DBPFP) (by 25.90 ± 2.63%), and GAC contactors contributed most to the DBPFP removal (accounting for 60.63 ± 16.64% of the total removal). The removal percentage of DBPFPs of different structure types was in the following order: halonitroalkanes (58.50%) > haloaldehydes (33.62%) > haloacetic acids (HAAs, 28.13%) > haloalkanes (20.46%) > haloketones (13.46%) > nitrosamines (10.23%) > halonitriles (-8.82%) > haloalkenes (-9.84%). The precursors of bromo-DBPs (containing only bromine atoms) and maximal halogenated DBPs (containing 3 & 4 halo atoms) were removed largely compared to other DBPs. Among the total DBPFP, trihalomethanes (THMs), HAAs, and chloral hydrate were the dominant DBPs, and they accounted for >92% of the total targeted DBPs by weight. Pearson correlation analysis (CA) and principal components analysis (PCA) indicated a significant association among these dominant DBPs. Canonical correspondence analysis (CCA) revealed specific ultraviolet absorbance (SUVA254) could serve as a good surrogate parameter for DBPFP. Pre-chlorination upstream of the biofilters may not greatly impact the overall removal of DBPFP by SA/GAC Biofiltration. In addition, results showed that SA/GAC Biofiltration was a useful procedure to remove the inorganic DBP chlorite.
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pilot investigation of two stage Biofiltration for removal of natural organic matter in drinking water treatment
Chemosphere, 2017Co-Authors: Wanning Lee, Clark Coleman, Melissa Meyer, Jason T Carter, Kirk Nowack, Chinghua HuangAbstract:A pilot study employing two parallel trains of two-stage Biofiltration, i.e., a sand/anthracite (SA) biofilter followed by a biologically-active granular activated carbon (GAC) contactor, was conducted to test the efficiency, feasibility and stability of Biofiltration for removing natural organic matter (NOM) after coagulation in a drinking water treatment plant. Results showed the Biofiltration process could effectively remove turbidity ( 24% of dissolved organic carbon (DOC), >57% of UV254, and >44% of SUVA254), where the SA biofilters showed a strong capacity for turbidity removal, while the GAC contactors played the dominant role in NOM removal. The vertical profile of water quality in the GAC contactors indicated the middle-upper portion was the critical zone for the removal of NOM, where relatively higher adsorption and enhanced biological removal were afforded. Fluorescence excitation-emission matrix (EEM) analysis of NOM showed that the GAC contactors effectively decreased the content of humic-like component, while protein-like component was refractory for the Biofiltration process. Nutrients (NH4-N and PO4-P) supplementation applied upstream of one of the two-stage Biofiltration trains (called engineered Biofiltration) stimulated the growth of microorganisms, and showed a modest effect on promoting the biological removal of small non-aromatic compositions in NOM. Redundancy analysis (RDA) indicated influent UV254 was the most explanatory water quality parameter for GAC contactors’ treatment performance, and a high load of UV254 would result in significantly reduced removals of UV254 and SUVA254.
Robert C Andrews - One of the best experts on this subject based on the ideXlab platform.
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investigation of ozone and peroxone impacts on natural organic matter character and Biofiltration performance using fluorescence spectroscopy
Chemosphere, 2017Co-Authors: Nicolas M Peleato, Balsher Singh Sidhu, Raymond L Legge, Robert C AndrewsAbstract:Impacts of ozonation alone as well as an advanced oxidation process of ozone plus hydrogen peroxide (H2O2 + O3) on organic matter prior to and following Biofiltration were studied at pilot-scale. Three biofilters were operated in parallel to assess the effects of varying pre-treatment types and dosages. Conventionally treated water (coagulation/flocculation/sedimentation) was fed to one control biofilter, while the remaining two received water with varying applied doses of O3 or H2O2 + O3. Changes in organic matter were characterized using parallel factors analysis (PARAFAC) and fluorescence peak shifts. Intensities of all PARAFAC components were reduced by pre-oxidation, however, individual humic-like components were observed to be impacted to varying degrees upon exposure to O3 or H2O2 + O3. While the control biofilter uniformly reduced fluorescence of all PARAFAC components, three of the humic-like components were produced by Biofiltration only when pre-oxidation was applied. A fluorescence red shift, which occurred with the application of O3 or H2O2 + O3, was attributed to a relative increase in carbonyl-containing components based on previously reported results. A subsequent blue shift in fluorescence caused by Biofiltration which received pre-oxidized water indicated that biological treatment readily utilized organics produced by pre-oxidation. The results provide an understanding as to the impacts of organic matter character and pre-oxidation on Biofiltration efficiency for organic matter removal.
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engineered Biofiltration for the removal of disinfection by product precursors and genotoxicity
Water Research, 2015Co-Authors: Michael J Mckie, Susan A Andrews, Liz Tayloredmonds, Robert C AndrewsAbstract:Disinfection by-products (DBPs) are formed when naturally occurring organic matter reacts with chlorine used in drinking water treatment, and DBPs formed in chlorinated drinking water samples have been shown to cause a genotoxic response. The objective of the current study was to further understand the principles of Biofiltration and the resulting impacts on the formation of DBPs and genotoxicity. Pilot-scale systems were utilized to assess the performance of engineered biofilters enhanced with hydrogen peroxide, in-line coagulants, and nutrients when compared to passively operated biofilters and conventional treatment (coagulation, flocculation, sedimentation, non-biological filtration). Organic fractionation was completed using liquid chromatography-organic carbon detection (LC-OCD). Water samples were chlorinated after collection and examined for the removal of trihalomethane (THM), haloacetic acid (HAA), and adsorbable organic halide (AOX) precursors. Additionally, the formation potential of two halogenated furanones, 3-chloro-4(dichloromethyl)-2(5H)-furanone (MX) and mucochloric acid (MCA), and genotoxicity was determined. Biofiltration was shown to preferentially remove more DBP precursors than dissolved organic carbon (DOC). Formation potential of the unregulated DBPs, including MX and MCA, and genotoxic response was shown to be correlated to THM formation. These results infer that monitoring for THMs and HAAs provide insight to the formation of more mutagenic DBPs such as halogenated furanones, and that Biofiltration may preferentially remove precursors to DBPs at a rate exceeding the removal of DOC.
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engineered Biofiltration for ultrafiltration fouling mitigation and disinfection by product precursor control
Water supply, 2015Co-Authors: Jamal Azzeh, Lizbeth Tayloredmonds, Robert C AndrewsAbstract:A pilot-scale study was conducted to evaluate the impact of several Biofiltration enhancement strategies in terms of organic removal to reduce disinfection by-product (DBP) formation potential and mitigate ultrafiltration (UF) fouling. Strategies included nutrient addition (nitrogen and phosphorus) to optimize metabolic degradation of organics, use of hydrogen peroxide (H2O2, peroxide) to improve filter run times, and the application of in-line aluminum sulphate (alum) for biopolymer removal. The impact of media type on performance was also examined (anthracite versus granular activated carbon (GAC)). Passive Biofiltration (without enhancement) reduced dissolved organic carbon (∼5%), biopolymers (∼20%), and trihalomethane and haloacetic acid precursors (∼20% and ∼12%, respectively) while mitigating UF irreversible fouling (∼60%). Nutrient addition was not observed to enhance biological performance. Addition of 0.5 mg/L hydrogen peroxide decreased head loss by up to 45% without affecting organic removal; however at a dosage of 1 mg/L, it negatively impacted both UF fouling and DBP precursor removal. In-line alum addition prior to Biofiltration (<0.5 mg/L) improved UF fouling control by up to 40%, without sacrificing head loss. Overall, GAC provided superior performance when compared to anthracite.
Wanning Lee - One of the best experts on this subject based on the ideXlab platform.
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removal of disinfection byproduct dbp precursors in water by two stage Biofiltration treatment
Water Research, 2017Co-Authors: Wanning Lee, Clark Coleman, Jason T Carter, Kirk Nowack, Chinghua HuangAbstract:The removal of precursors of 36 disinfection byproducts (DBPs) in effluents from flocculation/sedimentation process was evaluated across a pilot-scale two-stage Biofiltration process, i.e., a sand/anthracite (SA) biofilter (empty bed contact time (EBCT) of 7.5 min) coupled with a biologically-active granular activated carbon (GAC) contactor (EBCT of 15 min). The Biofiltration process exhibited a good capacity for removal of the total DBP formation potential (DBPFP) (by 25.90 ± 2.63%), and GAC contactors contributed most to the DBPFP removal (accounting for 60.63 ± 16.64% of the total removal). The removal percentage of DBPFPs of different structure types was in the following order: halonitroalkanes (58.50%) > haloaldehydes (33.62%) > haloacetic acids (HAAs, 28.13%) > haloalkanes (20.46%) > haloketones (13.46%) > nitrosamines (10.23%) > halonitriles (-8.82%) > haloalkenes (-9.84%). The precursors of bromo-DBPs (containing only bromine atoms) and maximal halogenated DBPs (containing 3 & 4 halo atoms) were removed largely compared to other DBPs. Among the total DBPFP, trihalomethanes (THMs), HAAs, and chloral hydrate were the dominant DBPs, and they accounted for >92% of the total targeted DBPs by weight. Pearson correlation analysis (CA) and principal components analysis (PCA) indicated a significant association among these dominant DBPs. Canonical correspondence analysis (CCA) revealed specific ultraviolet absorbance (SUVA254) could serve as a good surrogate parameter for DBPFP. Pre-chlorination upstream of the biofilters may not greatly impact the overall removal of DBPFP by SA/GAC Biofiltration. In addition, results showed that SA/GAC Biofiltration was a useful procedure to remove the inorganic DBP chlorite.
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pilot investigation of two stage Biofiltration for removal of natural organic matter in drinking water treatment
Chemosphere, 2017Co-Authors: Wanning Lee, Clark Coleman, Melissa Meyer, Jason T Carter, Kirk Nowack, Chinghua HuangAbstract:A pilot study employing two parallel trains of two-stage Biofiltration, i.e., a sand/anthracite (SA) biofilter followed by a biologically-active granular activated carbon (GAC) contactor, was conducted to test the efficiency, feasibility and stability of Biofiltration for removing natural organic matter (NOM) after coagulation in a drinking water treatment plant. Results showed the Biofiltration process could effectively remove turbidity ( 24% of dissolved organic carbon (DOC), >57% of UV254, and >44% of SUVA254), where the SA biofilters showed a strong capacity for turbidity removal, while the GAC contactors played the dominant role in NOM removal. The vertical profile of water quality in the GAC contactors indicated the middle-upper portion was the critical zone for the removal of NOM, where relatively higher adsorption and enhanced biological removal were afforded. Fluorescence excitation-emission matrix (EEM) analysis of NOM showed that the GAC contactors effectively decreased the content of humic-like component, while protein-like component was refractory for the Biofiltration process. Nutrients (NH4-N and PO4-P) supplementation applied upstream of one of the two-stage Biofiltration trains (called engineered Biofiltration) stimulated the growth of microorganisms, and showed a modest effect on promoting the biological removal of small non-aromatic compositions in NOM. Redundancy analysis (RDA) indicated influent UV254 was the most explanatory water quality parameter for GAC contactors’ treatment performance, and a high load of UV254 would result in significantly reduced removals of UV254 and SUVA254.
Jean-louis Fanlo - One of the best experts on this subject based on the ideXlab platform.
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Biofiltration of volatile organic compounds
Applied Microbiology and Biotechnology, 2005Co-Authors: Luc Malhautier, Jean-louis Fanlo, Nadia Khammar, Sandrine BayleAbstract:The removal of volatile organic compounds (VOCs) from contaminated airstreams has become a major air pollution concern. Improvement of the Biofiltration process commonly used for the removal of odorous compounds has led to a better control of key parameters, enabling the application of Biofiltration to be extended also to the removal of VOCs. Moreover, Biofiltration, which is based on the ability of micro-organisms to degrade a large variety of compounds, proves to be economical and environmentally viable. In a biofilter, the waste gas is forced to rise through a layer of packed porous material. Thus, pollutants contained in the gaseous effluent are oxidised or converted into biomass by the action of microorganisms previously fixed on the packing material. The Biofiltration process is then based on two principal phenomena: (1) transfer of contaminants from the air to the water phase or support medium, (2) bioconversion of pollutants to biomass, metabolic end-products, or carbon dioxide and water. The diversity of Biofiltration mechanisms and their interaction with the microflora mean that the biofilter is defined as a complex and structured ecosystem. As a result, in addition to operating conditions, research into the microbial ecology of biofilters is required in order better to optimise the management of such biological treatment systems.
B D Tripathi - One of the best experts on this subject based on the ideXlab platform.
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efficiency of combined process of ozone and bio filtration in the treatment of secondary effluent
Bioresource Technology, 2011Co-Authors: Smriti Tripathi, B D TripathiAbstract:Abstract The present work was aimed at studying the efficiency of the combined process of Biofiltration with ozonation to improve the quality of secondary effluent. The secondary effluent from the Dinapur Sewage Treatment Plant Varanasi, India was used in this work. The process of Biofiltration with the plant species of Eichornia crassipes and Lemna minor , at a flow rate of 262 ml min −1 and plant density of 30 mg L −1 for 48 h, in combination with the process of ozonation with ozone dose of 10 mg L −1 and contact time of 5 min was applied. Results revealed that combined process was statistically most suitable for the highest degradation of physico-chemical and microbial parameters with improving BDOC value. The Biofiltration process is able to remove highest percentage of toxic heavy metals from the secondary effluent without production of toxicity. This technique is highly recommendable for tropical wastewater where sewage is mixed with industrial effluents.