多环芳烃作为持久性有机污染物，其来源广泛，易在生物体内富集而难以降解。水产品因能够为人体提供大量的蛋白质、脂肪和矿物质等营养物质而备受青睐，但由于受到水域环境污染的影响，其体内含有不同程度的多环芳烃污染物(PAHs)。而水生生物体内的PAHs通过食物链传递，在人体内蓄积，进而威胁人体健康。本文就PAHs的来源、分布迁移、在水产品中检测方法及污染特征等方面进行综述。

Brain neuropathy target esterase (NTE), associated with organophosphorus (OP)-induced delayed neuropathy, has the same OP inhibitor sensitivity and specificity profiles assayed in the classical way (paraoxon-resistant, mipafox-sensitive hydrolysis of phenyl valerate) or with lysophosphatidylcholine (LysoPC) as the substrate. Extending our earlier observation with mice, we now examine human erythrocyte, lymphocyte, and brain LysoPC hydrolases as possible sensitive targets for OP delayed neurotoxicants and insecticides. Inhibitor profiling of human erythrocytes and lymphocytes gave the surprising result of essentially the same pattern as with brain. Human erythrocyte LysoPC hydrolases are highly sensitive to OP delayed neurotoxicants, with in vitro IC50 values of 0.13-85 nM for longer alkyl analogs, and poorly sensitive to the current OP insecticides. In agricultural workers, erythrocyte LysoPC hydrolyzing activities are similar for newborn children and their mothers and do not vary with paraoxonase status but have high intersample variation that limits their use as a biomarker. Mouse erythrocyte LysoPC hydrolase activity is also of low sensitivity in vitro and in vivo to the OP insecticides whereas the delayed neurotoxicant ethyl n-octylphosphonyl fluoride inhibits activity in vivo at 1-3 mg/kg. Overall, inhibition of blood LysoPC hydrolases is as good as inhibition of brain NTE as a predictor of OP inducers of delayed neuropathy. NTE and lysophospholipases (LysoPLAs) both hydrolyze LysoPC, yet they are in distinct enzyme families with no sequence homology and very different catalytic sites. The relative contributions of NTE and LysoPLAs to LysoPC hydrolysis and clearance from erythrocytes, lymphocytes, and brain remain to be defined.

Specific organic pollutants (SOPs) such as phenolic compounds, PAHs, organic pesticides, and organic herbicides cause health and environmental problems due to their excessive toxic properties and poor biodegradability. Low-cost biosorbents are considered as a promising alternative for conventional adsorbents to remove SOPs from water. These materials have several advantages such as high sorption capacities, good modifiability and recoverability, insensitivity to toxic substances, simple operation in the treatment processes. However, previous reports on various types of biosorbents for removing SOPs are still moderately fragmented. Hence, this paper provides a comprehensive review on using typical low-cost biosorbents obtained from lignocellulose and chitin/chitosan for SOPs adsorption. Especially, their characteristics, biosorption mechanism together with utilization for eliminating SOPs are presented and discussed. The paper also gives a critical view regarding future applications of low-cost biosorbents in SOPs-contaminated water treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

A biomatrix was prepared from rice husk, a lignocellulosic waste from agro-industry, for the removal of several heavy metals as a function of pH and metal concentrations in single and mixed solutions. The biomatrix was characterized using scanning electron microscope and Fourier transform infrared spectroscopy, which indicated the presence of several functional groups for binding metal ions. Different experimental approaches were applied to show mechanistic aspects, especially the role of calcium and magnesium present in the biomatrix in ion exchange mechanism. The ultimate maximum adsorption capacity obtained from the Langmuir isotherm increases in the order (mmol/g): Ni (0.094), Zn (0.124), Cd (0.149), Mn (0.151), Co (0.162), Cu (0.172), Hg (0.18) and Pb (0.28). The sorption of Cr(III) onto biomatrix at pH 2 was 1.0 mmol/g. Speciation of chromium, cadmium and mercury loaded on the biomatrix was determined by X-ray photoelectron spectroscopy. The biomatrix has adsorption capacity comparable or greater to other reported sorbents.

Chitin and chitosan-derivatives have gained wide attention as effective biosorbents due to low cost and high contents of amino and hydroxyl functional groups which show significant adsorption potential for the removal of various aquatic pollutants. In this review, an extensive list of chitin- and chitosan-derivatives from vast literature has been compiled and their adsorption capacities for various aquatic pollutants as available in the literature are presented. This paper will give an overview of the principal results obtained during the treatment of water and wastewater utilizing chitin and chitosan-derivatives for the removal of: (a) metal cations and metal anions; (b) radionuclides; (c) different classes of dyes; (d) phenol and substituted phenols; (e) different anions and other miscellaneous pollutants. The review provides a summary of recent information obtained using batch studies and deals with the various adsorption mechanisms involved. It is evident from the literature survey that chitin- and chitosan-derivatives have shown good potential for the removal of various aquatic pollutants. However, still there is a need to find out the practical utility of such developed adsorbents on commercial scale.

The objective of this study is to investigate the use of coffee waste (CW) to remove the 4-chloro-2-methyl phenoxy acetic acid (MCPA) from aqueous solutions. To prepare CW, it was first washed and boiled to remove color and impurities then it was air dried at room temperature for 48 h. Afterward the particle size distribution and zeta potential of the CW ground were determined. The porous texture of coffee was proved by scanning and transition electron microscopy. Batch adsorption tests were performed at 298 K. The effects of contact time, MCPA concentration, and pH were investigated. It was observed that the adsorption of MCPA by using CW is independent of the solution pH level. The Langmuir isotherm provided the best correlation for MCPA adsorption onto CW, showing that the adsorption was favorable. The Langmuir adsorption capacity was found to be 0.34 g/g. The second-order model provided the best description of MCPA adsorption onto CW when compared with the first order model. Infrared spectral studies revealed that acidic groups carboxyl and hydroxyl, are predominant contributors to MPCA adsorption by coffee. (C) 2013 Production and hosting by Elsevier B.V. on behalf of King Saud University.

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 sorption 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 sorption 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. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

This paper deals with the multiple response optimization for the removal of organophosphorus pesticide quinalphos [QP: O,O-diethyl O-2-quinoxalinyl phosphorothioate] from the aqueous solution onto low-cost material and tried to overcome the drawbacks of univariate optimization. Used tea leaves were used as low-cost adsorbent and batch equilibration method was followed for this study. A Box-Behnken design was used to develop response model and desirability function was then used for simultaneous optimization of all affecting parameters in order to achieve the highest removal% of quinalphos. The optimum conditions of factors predicted for quinalphos removal% were found to be: pH 8.83, concentration 7 mg L(-1) and dose 0.40 g. Under these conditions, maximum removal% of quinalphos was obtained 96.31%. Considering the above optimum conditions, the adsorption isotherms were developed and provided adsorption capacity of 196.07 microg g(-1) by using Langmuir equation, indicating that used tea leaves may be applied as a low-cost material for pesticides removal from aqueous matrices.

Hydrothermal carbonization of urban food waste was carried out to prepare hydrochars for removal of Acridine Orange and Rhodamine 6G dyes from contaminated water. The chemical composition and microstructure properties of the synthesized hydrochars were investigated in details. Batch adsorption experiments revealed that hydrochars with lower degree of carbonization were more efficient in adsorption of dyes. Operational parameters such as pH and temperature had a strong influence on the dye uptake process. The adsorption equilibrium data showed excellent fit to the Langmuir isotherm. The pseudo-second-order kinetic model provided a better correlation for the experimental kinetic data in comparison to the pseudo-first-order kinetic model. Thermodynamic investigations suggested that dye adsorption onto hydrochars was spontaneous and endothermic. The mechanism of dye removal appears to be associated with physisorption. An artificial neural network (ANN)-based modelling was further carried out to predict the dye adsorption capacity of the hydrochars. Copyright © 2014 Elsevier Ltd. All rights reserved.

简述了生物质炭的改性方法（蒸汽活化、酸改性、碱改性、浸渍法），并对改性过程机理进行分析，总结了改性生物质炭对水中重金属、阴离子、有机污染物的去除效果。在此基础上，对未来的研究方向进行展望，认为生物质炭的再生处理是研究重点之一，结合其他功能材料形成新的复合水处理材料也是今后的研究重点。

This study concerns the batch biosorption of paraquat on Ayous (Triplochiton schleroxylon) sawdust; the study centers on the evolution of biosorption parameters during the process. It appears that paraquat forms a monolayer on the sawdust surface as evidenced by the good correlation between the experimental data and the Langmuir model. The biosorption which is rather fast (the equilibrium was reached after ten minutes) follows a pseudo-second-order kinetic model and does not obey to the intra-particle diffusion model. According to the mathematical kinetic modeling, pore and surface mass transfer well describe the phenomenon. NaCl reduces the adsorption capacity of the material but has no significant effect on the kinetics. Alkaline solutions enhance the accumulation of the pollutant, the reverse being observed for acidic media. According to the thermodynamic data, this biosorption is a spontaneous and exothermic process. From these results we concluded that the adsorption of the pollutant is mainly due to cation exchange as indicated by the adsorption energy determined by the Dubinin-Radushkevich model (E=12.0736 kJ mol(-1)); some other interactions resulting from the affinity through organophilic interactions between paraquat and sawdust have also been pointed out. Desorption experiments conducted in HCl and HNO(3) solutions confirmed the proposed mechanism.2010 Elsevier B.V. All rights reserved.

To elucidate biosorption mechanism and removal efficiency of plant residues as a biosorbent to abate polycyclic aromatic hydrocarbons (PAHs) in wastewater, sorption of PAHs onto wood chips (WC), ryegrass roots (RR), orange peels (OP), bamboo leaves (BL), and pine needles (PN) were investigated. The structural characterization of the biosorbents was analyzed by elemental composition, BET-N(2) surface area, and Fourier transform infrared spectroscopy. PAHs sorption to the selected biosorbents were compared and correlated with their structures. Biosorption isotherms fit well with Freundlich equation and the mechanism was dominated by partition process. The magnitude of phenanthrene partition coefficients (K(d)) followed the order of PN > BL > OP > RR > WC, ranged from 2484 ± 24.24 to 5306 ± 92.49 L/kg. Except the WC sample, the K(d) values were negatively correlated with sugar content, polar index [(N+O)/C] of the biosorbents, while the aromatic component exhibited positive effects. For a given biosorbent of bamboo leaves, the carbon-normalized partition coefficients (K(oc)) were linearly correlated with octanol-water partition coefficients (K(ow)) of PAHs, i.e., logK(oc) = 1.16 log K(ow)-1.21. The structure-effect relationship provides a reference to select and modify plant residues as a biosorbent with high efficiency to tackle organic pollutants.Copyright © 2011 Elsevier B.V. All rights reserved.

The aim of this study is to determine the sorption-desorption behavior of a mixture of thirteen aqueous PAHs on cork waste at a particle of size 0.25-0.42 mm obtained from the remains of cork strips. The final purpose is to use this natural adsorbent as an alternative to activated carbon in an innovative approach for the removal of this class of toxic compounds, and significantly reduce the regeneration costs of the process. The chemical composition of the selected cork revealed that suberin (38.5 %) and lignin (31.6 %) were the main structural components of the cell wall. The high efficiency of cork as a biosorbent of PAHs is shown by the fact that just over 80 % of adsorption occurred during the first two minutes of contact time. Both Freundlich's and Langmuir's isotherms gave good fits to the sorption process. The highest adsorption affinities were exhibited for pyrene, anthracene, and phenanthrene. Desorption studies indicate a high degree of irreversibility for all PAHs, and especially so in the case of high molecular PAHs. The correlation with K(F) and low molecular weight PAHs was the most significant. The quantity of cork required to reduce water pollution was estimated to be between 3 and 15 times less than the quantities required in the case of other materials (i.e. aspen wood and leonardite). This study demonstrates for the first time that cork is a potential biosorbent for PAHs and may have relevance in the future treatment of PAH-contaminated waters.

The sorption of hydrophobic organic compounds by natural organic matter is mainly regulated by its aromatic and aliphatic fractions, but it is not clear which fraction is more dominant. In this study, six types of Chinese tea leaves (three varieties of tender and three corresponding mature leaves) and their respective brewed ones were analyzed by elemental analysis, 13C NMR, and Fourier transform infrared attenuated total reflectance. Their sorption of phenanthrene was examined using a batch equilibration technique. The aromatic carbon content of tea leaves reduced while the aliphatic carbon content increased with increasing maturity and brewing. Sorption isotherms by all of the 12 tea sorbents were practically linear, showing a partition type sorption. The phenanthrene KOC (organic carbon-normalized sorption capacity) of the 12 sorbents ranged from 6960 to 32,900 mL/g, which increased with increasing aliphatic carbons and decreasing aromatic carbons in the tea leaves. The dissolved organic matter was released into solution from the sorbents during the sorption process, which could bind phenanthrene in the solution, and thereafter leading to underestimation of sorption capacity of the sorbents, but this did not change the correlation trends between KOC and functional carbon group content. Aliphatic fractions rather than aromatic moieties regulated the phenanthrene sorption of the tea leaf powders used in this study.

Soybean [ (L.) Merr.] stalk-based carbons were prepared by phosphoric acid activation at different carbonization temperatures. Characteristics of the prepared carbon, including specific surface area, iodine number, and amount of methylene blue sorption, were determined. Experiments on phenanthrene, naphthalene, and acenaphthene, as representatives of polycyclic aromatic hydrocarbons (PAHs), removal from aqueous solution by the prepared carbon were conducted at different levels of carbon addition. The results indicated that the specific surface area, iodine number, and amount of methylene blue sorption increased with an increase of carbonization temperature. The maximum values were observed at 700°C and were 287.63 m g, 508.99 mg g, and 90.14 mg g, respectively. The removal efficiencies of phenanthrene, naphthalene, and acenaphthene tended to increase with increasing carbon amounts and carbonization temperature. The optimal removal performance was obtained under the experimental conditions of carbon concentrations of 0.04 g 32 mL and carbonization temperature of 700°C, and the removal efficiencies of phenanthrene, naphthalene, and acenaphthene were 99.89, 100, and 95.64%, respectively. The performance of the prepared carbon was superior to that of commercial activated carbon. Additionally, for the same carbon concentrations, the removal efficiency of PAHs on prepared carbons followed the order: phenanthrene > naphthalene > acenaphthene. Results obtained from this work provide some insight into the reuse of an agricultural residue, and also provide a new application for the treatment of PAHs in contaminated water utilizing activated carbon prepared from agricultural residues.Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Sorptive potential of selected agricultural waste materials i.e. rice (Oryza sativa) bran (RB), bagasse fly ash (BFA) of sugarcane (Saccharum officinarum), Moringa oleifera pods (MOP) and rice husk (RH) for the removal of methyl parathion pesticide (MP) from surface and ground waters has been investigated. Optimization of operating parameters of sorption process, i.e. sorbent dose, agitation time, pH, initial concentration of sorbate, and temperature have been studied. The sorption data fitted to Freundlich, Langmuir and Dubinin-Radushkevich (D-R) sorption isotherms. The maximum capacities of RB, BFA, MOP and RH for MP were calculated to be 3.6+/-0.8, 5.3+/-1.4, 5.2+/-1.5 and 4.7+/-1.0 mmolg(-1) by Freundlich, 0.39+/-0.009, 0.39+/-0.005, 0.36+/-0.004 and 0.35+/-0.008 mmolg(-1) by Langmuir and 0.9+/-0.08, 1.0+/-0.10, 1.0+/-0.10 and 0.9+/-0.07 mmolg(-1) by D-R isotherms respectively, employing 0.1g of each sorbent, at pH 6, 90 min agitation time and at 303 K. Application of first order Lagergren and Morris-Weber equations to the kinetic data yielded correlation coefficients, close to unity. Thermodynamic parameters of sorption process, i.e. DeltaH, DeltaS and DeltaG were computed and their negative values indicated the exothermic and spontaneous nature of sorption process. The pesticide may be stripped by sonication with methanol, making the regeneration and reutilization of sorbents promising. The sorbents investigated exhibited their potential applications in water decontamination, treatment of industrial and agricultural waste waters.

This paper deals with the multiple response optimization for the removal of organophosphorus pesticide quinalphos [QP: O,O-diethyl O-2-quinoxalinyl phosphorothioate] from the aqueous solution onto low-cost material and tried to overcome the drawbacks of univariate optimization. Used tea leaves were used as low-cost adsorbent and batch equilibration method was followed for this study. A Box-Behnken design was used to develop response model and desirability function was then used for simultaneous optimization of all affecting parameters in order to achieve the highest removal% of quinalphos. The optimum conditions of factors predicted for quinalphos removal% were found to be: pH 8.83, concentration 7 mg L(-1) and dose 0.40 g. Under these conditions, maximum removal% of quinalphos was obtained 96.31%. Considering the above optimum conditions, the adsorption isotherms were developed and provided adsorption capacity of 196.07 microg g(-1) by using Langmuir equation, indicating that used tea leaves may be applied as a low-cost material for pesticides removal from aqueous matrices.