Increased attention has been given to the fate of pollutants such as polycyclic aromatic hydrocarbons (PAHs) introduced to the wastewater treatment plants.Dissolved and adsorbed PAHs were detected in the centralized w...Increased attention has been given to the fate of pollutants such as polycyclic aromatic hydrocarbons (PAHs) introduced to the wastewater treatment plants.Dissolved and adsorbed PAHs were detected in the centralized wastewater treatment plant of a chemical industry zone in Zhejiang Province,China.The most abundant PAHs were the low molecular weight PAHs (e.g.,Acy,Ace,Flu and Phe),accounting for more than 80% of the total 16 PAHs in each treatment stage.Phase partitioning suggested that the removal of PAHs in every treatment stage was influenced greater by the sorption of particles or microorganisms.The removal efficiencies of individual PAHs ranged between 4% and 87% in the primary sedimentation stage,between 1% and 42% in anaerobic hydrolysis stage,between <1% and 70% in aerobic bio-process stage,between 1.5% and 80% in high-density clarifier stage,and between 44% and 97% in the whole treatment process.Mass balance calculations in primary stage showed significant losses for low molecular weight PAHs and relatively good agreements for high molecular weight PAHs as well as in anaerobic hydrolysis,high-density clarifier stage and sludge stream for most PAHs.Great gains of 60%-150% were obtained for high molecular weight PAHs in aerobic bio-process stage due to biosorption and bioaccumulation.Our investigations found that PAHs entering the wastewater treatment plant (WWTP) could be derived from the dyeing chemical processes as the byproducts,and the contribution supported by the largest dyeing chemical group was up to 48%.展开更多
In order to investigate the transfer and migration behavior of polycyclic aromatic hydrocarbons(PAHs)in soil with long-term wastewater irrigation,Groundwater Ubiquity Score(GUS)and fugacity method were respectively us...In order to investigate the transfer and migration behavior of polycyclic aromatic hydrocarbons(PAHs)in soil with long-term wastewater irrigation,Groundwater Ubiquity Score(GUS)and fugacity method were respectively used to assess the potential entry into the groundwater and transfer capacity of PAHs.The results of assessment using GUS show that there is significant correlation between the GUS and organic carbon sorption coefficient(KOC)for PAHs and a simple assessment method with KOC was referred to evaluate contamination of groundwater.Applying fugacity method,evaluation results of transfer and migration of PAHs in soil suggest that the PAHs accumulation in the soil through long-term wastewater irrigation could be re-volatilized as secondary emission sources to atmosphere for the Low Molecular Weight(LMW)PAHs,in contrast to High Molecular Weight(HMW)PAHs for which the soil remains a sink that could absorb more PAHs.The net volatilisation flux was 0.39 g/d in upland and 0.32 g/d in paddy for LMW Nap(Naphthalene),and 0.97×10^(-3)g/d in upland and 0.37×10^(-3)g/d in paddy for LMW Phe(Phenanthrene).The net deposition was 0.72×10^(-4)g/d in upland and 0.10×10^(-3)g/d in paddy for HMW Fla(Fluoranthene),and 0.22×10^(-4)g/d in upland and 0.20×10^(-4)g/d in paddy for HMW Bap(Benzo[a]pyrene).Sensitivities of the model estimates to input parameters were tested,and the sensitivity coefficient was defined for the test.The most influential parameters were the volumes of the air,water,and organic carbon fractions in soil and the thickness of the soil.展开更多
Removal of polycyclic aromatic hydrocarbons （PAHs）, e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents...Removal of polycyclic aromatic hydrocarbons （PAHs）, e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents for organic pollutant abatement. Bamboo wood, pine wood, pine needles and pine bark were selected as plant residues, and acid hydrolysis was used as an easily modification method. The raw and modified biosorbents were characterized by elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorption isotherms of PAHs to raw biosorbents were apparently linear, and were dominated by a partitioning process. In comparison, the isotherms of the hydrolyzed biosorbents displayed nonlinearity, which was controlled by partitioning and the specific interaction mechanism. The sorpfion kinetic curves of PAHs to the raw and modified plant residues fit well with the pseudo second-order kinetics model. The sorption rates were faster for the raw biosorbents than the corresponding hydrolyzed biosorbents, which was attributed to the latter having more condensed domains （i.e., exposed aromatic core）. By the consumption of the amorphous cellulose component under acid hydrolysis, the sorption capability of the hydrolyzed biosorbents was notably enhanced, i.e., 6-18 fold for phenanthrene, 6-8 fold for naphthalene and pyrene and 5-8 fold for acenaphthene. The sorpfion coefficients （Kd） were negatively correlated with the polarity index [（O＋N）/C], and positively correlated with the aromaticity of the biosorbents. For a given biosorbent, a positive linear correlation between logKoc and logKow for different PAHs was observed. Interestingly, the linear plots of logKoc-logKow were parallel for different biosorbents. These observations suggest that the raw and modified plant residues have great potential as biosorbents to remove PAHs from wastewater.展开更多
基金support to this study provided by National Key Technology R&D Program of China (2008BAC32B06)the National Natural Science Foundation of China (21076188,20836008, 20976158,20990221 & 21076189)the Key Innovation Team for Science and Technology of Zhejiang Province of China (2009R50047)
文摘Increased attention has been given to the fate of pollutants such as polycyclic aromatic hydrocarbons (PAHs) introduced to the wastewater treatment plants.Dissolved and adsorbed PAHs were detected in the centralized wastewater treatment plant of a chemical industry zone in Zhejiang Province,China.The most abundant PAHs were the low molecular weight PAHs (e.g.,Acy,Ace,Flu and Phe),accounting for more than 80% of the total 16 PAHs in each treatment stage.Phase partitioning suggested that the removal of PAHs in every treatment stage was influenced greater by the sorption of particles or microorganisms.The removal efficiencies of individual PAHs ranged between 4% and 87% in the primary sedimentation stage,between 1% and 42% in anaerobic hydrolysis stage,between <1% and 70% in aerobic bio-process stage,between 1.5% and 80% in high-density clarifier stage,and between 44% and 97% in the whole treatment process.Mass balance calculations in primary stage showed significant losses for low molecular weight PAHs and relatively good agreements for high molecular weight PAHs as well as in anaerobic hydrolysis,high-density clarifier stage and sludge stream for most PAHs.Great gains of 60%-150% were obtained for high molecular weight PAHs in aerobic bio-process stage due to biosorption and bioaccumulation.Our investigations found that PAHs entering the wastewater treatment plant (WWTP) could be derived from the dyeing chemical processes as the byproducts,and the contribution supported by the largest dyeing chemical group was up to 48%.
基金the National Natural Science Foundation of China(No.41401550)the Humanity and Social Science Youth Foundation of Ministry of Education of China(No.14YJCZH017)+4 种基金the Heilongjiang Post-Doctoral Financial Assistance of China(No.LBH-Z13029)the Scientific Research Fund of Heilongjiang Provincial Education Department(No.12541123)the Young Talents Project of Northeast Agricultural University(No.14QC49)the Natural Science Foundation of Heilongjiang Province(No.QC2016054)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(UNPYSCT-2016001).
文摘In order to investigate the transfer and migration behavior of polycyclic aromatic hydrocarbons(PAHs)in soil with long-term wastewater irrigation,Groundwater Ubiquity Score(GUS)and fugacity method were respectively used to assess the potential entry into the groundwater and transfer capacity of PAHs.The results of assessment using GUS show that there is significant correlation between the GUS and organic carbon sorption coefficient(KOC)for PAHs and a simple assessment method with KOC was referred to evaluate contamination of groundwater.Applying fugacity method,evaluation results of transfer and migration of PAHs in soil suggest that the PAHs accumulation in the soil through long-term wastewater irrigation could be re-volatilized as secondary emission sources to atmosphere for the Low Molecular Weight(LMW)PAHs,in contrast to High Molecular Weight(HMW)PAHs for which the soil remains a sink that could absorb more PAHs.The net volatilisation flux was 0.39 g/d in upland and 0.32 g/d in paddy for LMW Nap(Naphthalene),and 0.97×10^(-3)g/d in upland and 0.37×10^(-3)g/d in paddy for LMW Phe(Phenanthrene).The net deposition was 0.72×10^(-4)g/d in upland and 0.10×10^(-3)g/d in paddy for HMW Fla(Fluoranthene),and 0.22×10^(-4)g/d in upland and 0.20×10^(-4)g/d in paddy for HMW Bap(Benzo[a]pyrene).Sensitivities of the model estimates to input parameters were tested,and the sensitivity coefficient was defined for the test.The most influential parameters were the volumes of the air,water,and organic carbon fractions in soil and the thickness of the soil.
基金supported by the National Natural Sci-ence Foundation of China(No.41071210)the Zhejiang Provincial Natural Science Foundation of China(No.R5100105)+1 种基金the National High-Tech Research and Development Program of China(No.2012AA06A203)the Doctoral Fund of Ministry of Education of China(No.J20091588)
文摘Removal of polycyclic aromatic hydrocarbons （PAHs）, e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents for organic pollutant abatement. Bamboo wood, pine wood, pine needles and pine bark were selected as plant residues, and acid hydrolysis was used as an easily modification method. The raw and modified biosorbents were characterized by elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorption isotherms of PAHs to raw biosorbents were apparently linear, and were dominated by a partitioning process. In comparison, the isotherms of the hydrolyzed biosorbents displayed nonlinearity, which was controlled by partitioning and the specific interaction mechanism. The sorpfion kinetic curves of PAHs to the raw and modified plant residues fit well with the pseudo second-order kinetics model. The sorption rates were faster for the raw biosorbents than the corresponding hydrolyzed biosorbents, which was attributed to the latter having more condensed domains （i.e., exposed aromatic core）. By the consumption of the amorphous cellulose component under acid hydrolysis, the sorption capability of the hydrolyzed biosorbents was notably enhanced, i.e., 6-18 fold for phenanthrene, 6-8 fold for naphthalene and pyrene and 5-8 fold for acenaphthene. The sorpfion coefficients （Kd） were negatively correlated with the polarity index [（O＋N）/C], and positively correlated with the aromaticity of the biosorbents. For a given biosorbent, a positive linear correlation between logKoc and logKow for different PAHs was observed. Interestingly, the linear plots of logKoc-logKow were parallel for different biosorbents. These observations suggest that the raw and modified plant residues have great potential as biosorbents to remove PAHs from wastewater.
