[Objective] The aim was to study the correlation between Cr6+ and Mn2+ adsorption in rock-soil medium with combined pollution. [Method] Combining single Cr6+ and Mn2+ adsorption test with combined pollution test, the ...[Objective] The aim was to study the correlation between Cr6+ and Mn2+ adsorption in rock-soil medium with combined pollution. [Method] Combining single Cr6+ and Mn2+ adsorption test with combined pollution test, the adsorption laws of Cr6+ and Mn2+ were studied, and the correlation between Cr6+ and Mn2+ adsorption was analysed by using correlation analysis and regression analysis. [Result] According to the comparative analysis on adsorption tests, the adsorption time, adsorption amount and adsorption speed of Cr6+ and Mn2+ were obviously distinct in single adsorption test and combined adsorption test. Correlation analysis revealed that there was a significantly positive correlation between Cr6+ and Mn2+, and there existed addition effects between Cr6+ and Mn2+ in regression analysis, that is, the adsorption of Cr6+ by the soil tested would be enhanced by Mn2+. [Conclusion] The research could provide scientific references for environmental control and environmental management.展开更多
Due to the mining,smelting,sewage irriga-tion,agricultural runoff,and development ofrural enterprises,combined pollution of Cd andZn in soil-rice systems has frequently oc-curred.This problem was studied by using thep...Due to the mining,smelting,sewage irriga-tion,agricultural runoff,and development ofrural enterprises,combined pollution of Cd andZn in soil-rice systems has frequently oc-curred.This problem was studied by using thepot-culture imitative method combined withhemical analysis and mathematical models.展开更多
The DNA-damaging effects of the combined pollution of heavy metal and organic contamination on earthworms were evaluated by single cell gel electrophoresis (SCGE) assay. Earthworms Eisenia andrei were exposed to sin...The DNA-damaging effects of the combined pollution of heavy metal and organic contamination on earthworms were evaluated by single cell gel electrophoresis (SCGE) assay. Earthworms Eisenia andrei were exposed to single or combined test compounds in different doses of cadmium (Cd) 5, 10, 50 mg/kg and phenanthrene (Phe) 0.5, 2.5, 12.5 mg/kg with a treatment of 14 d. In SCGE assay, isolated coelomcytes and electrophoresis were employed to determine DNA damage degree after a 14-d treatment by test compounds. The results showed that there was a significant statistical difference between earthworms treated with Cd combined Phe with them treated alone with Cd or Phe. The Olive tail moment (OTM) of SCGE assay using earthworm coelomcytes appears to be a sensitive biomarker for evaluating exposure to genotoxic compounds. These tests also revealed that the interaction between Cd and Phe to DNA damaging effects was negative, and was strongly dependent on the concentration of pollution. This study corresponds to exploratory phase in order to reveal interaction effects of heavy metal and organic contamination on earthworms and then to set up more in-depth analysis to increase progressively the understanding of the genotoxicity mechanisms involved.展开更多
Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showe...Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showed that the significant zinc factor indicated both the inhibition rate of shoot mass and that of root elongation were affected by zinc(P<0.05 and P<0.01, respectively). The first toxicity canonical variable (TOXI), formed from the toxicity data set, explained 49% of the total variance in the toxicity data set; the first biological canonical variable(BIOL) explained 42% of the total variation in the biological data set. The correlation between the first canonical variables TOXI and BIOL (canonical correlation) was 0.94 (P<0.0001). Therefore, it is reliable and feasible to use the achievement to assess toxicity of heavy metal combined polluted soil using canonical analysis. Toxicity of soil combined polluted by heavy metals to plant community was estimated by comparing the IC 50 values describing the concentration needed to cause 50% decrease with grow rate compared to no metal addition. Environmental quality standard for soils prescribe that all these tested concentration of heavy metals in soil should not cause hazard and pollution ultimately, whereas it indicated that the soils in second grade cause more or less than 50% inhibition rates of wheat growth. So environmental quality standard for soils can be modified to include other features.展开更多
The actions and interactions of acetochlor and As on the soil phosphatase activity were investigated after 1, 3, 6, 10, 15, 30 and 60 d of exposure under control conditions. The soils were exposed to various concentra...The actions and interactions of acetochlor and As on the soil phosphatase activity were investigated after 1, 3, 6, 10, 15, 30 and 60 d of exposure under control conditions. The soils were exposed to various concentrations of acetochlor and As individually and simultaneously. The results showed that acetochlor, As only, and combined pollution all clearly inhibited soil phosphatase activity. The maximum inhibition ratios of soil phosphatase activity by acetochlor, As only and combined pollution were 36.44, 74.12 and 61.29%, respectively. Two kinetic models, ν=c/(1+bi) (model 1) and ν=c(1+ai)/(l+bi) (model 2), were used to describe the relationship between the concentrations of As and acetochlor and the activity of soil phosphatase. The semi-effect dose (ED 50 ) values induced by As and acetochlor stress based on the inhibition of soil phosphatase were 18.1 and 33.11 mg kg-1, respectively, according to calculation by model 1. The interactive effect of acetochlor with As on soil phosphatase primarily consisted of significant antagonism effects at the higher concentrations tested. The step regression results show that the toxicity order was As (III)〉acetochlor〉As (III)×acetochlor throughout the incubation period.展开更多
Biochar-coupled Fe_(3)O_(4)@SiO_(2)/TiO_(2)/g-C_(3)N_(4) composites were successfully constructed through simple sol-gel and calcination methods.The composites efficiently removed high-concentration toxic tetracycline...Biochar-coupled Fe_(3)O_(4)@SiO_(2)/TiO_(2)/g-C_(3)N_(4) composites were successfully constructed through simple sol-gel and calcination methods.The composites efficiently removed high-concentration toxic tetracycline(TC)by means of·OH and·O_(2)^(−),whose removal rate exhibited 91.88%during 3 h,and the degradation rate constant reached up to 0.0068 min^(−1).The excellent performance can be attributed to the high specific surface area,enhanced visible light response,the introduction of magnetic nanoparticles and biochars expediting charge transfer,Z-scheme heterojunction enhancing the spatial separation of photo-generate carriers and,importantly extraordinary adsorption capacity of 147.96 mg g^(−1).Moreover,the composites showed the most excellent efficiency under the calcination temperature of 450℃,and exhibited good stability with tolerance to a wide range of pH and anions.Interestingly,a synergistic photocatalytic effect was discovered in the TC/Cr(Ⅵ)combined pollution systems,resulting in significantly improved removal of Cr(Ⅵ).Besides,the photocatalytic mechanism and degradation path of tetracycline were also elucidated.All these findings suggested the as-synthesized catalyst was an excellent photocatalyst for removal of TC/Cr(Ⅵ)-contaminated water.展开更多
The strength deterioration mechanism of soil polluted by heavy metals plays a crucial role in the research of mine site pollution.In this study,an unconfined compressive strength(UCS)test,a pH test,a scanning electron...The strength deterioration mechanism of soil polluted by heavy metals plays a crucial role in the research of mine site pollution.In this study,an unconfined compressive strength(UCS)test,a pH test,a scanning electron microscopy(SEM)test,a low filed nuclear magnetic resonance(NMR)test,and an X-ray diffraction(XRD)test were conducted on Zn^(2+),Cu^(2+) and the combination of Zn^(2+) and Cu^(2+) polluted soil to investigate the strength deterioration mechanism.The results show that both the UCS and pH value of soil decrease with increasing heavy metal concentration.The UCS of Zn^(2+)-Cu^(2+) combined polluted soil is between Zn^(2+) and Cu^(2+) polluted soil at the same total concentration.However,the deterioration rate of combined heavy metal polluted soil is less than the sum of deterioration rate of the two single polluted soils at the same total concentration.In addition,heavy metal cations in polluted soil cause flocculent gels of cosmids to shrink,the micropores to become smaller and the macropores to become larger.The porosity increases slightly with the increase of heavy metal concentration due to decreased pH value.The results from SEM,low field NMR,and pH could explain the dynamic evolution process of soil structure with different heavy metals and concentrations,which provides an experimental basis for mine-site polluted heavy metal treatment technology and the prediction of clayey soil strength deterioration.展开更多
Abandoned chemical smelting sites containing toxic substances can seriously threaten and pose a risk to the surrounding ecological environment.Soil samples were collected from different depths(0 to 13 m)and analyzed f...Abandoned chemical smelting sites containing toxic substances can seriously threaten and pose a risk to the surrounding ecological environment.Soil samples were collected from different depths(0 to 13 m)and analyzed for metal(loid)s content and fractionation,as well as microbial activities.The potential ecological risk indices for the different soil depths(ordered from high to low)were:1 m(D-1)>surface(S-0)>5 m(D-5)>13 m(D-13)>9 m(D-9),ranging between 1840.65-13,089.62,and representing extremely high environmental risks,of which Cd(and probably not arsenic)contributed to the highest environmental risk.A modified combined pollution risk index(MCR)combining total content and mobile proportion of metal(loid)s,and relative toxicities,was used to evaluate the degree of contamination and potential environmental risks.For the near-surface samples(S-0 and D-1 layers),the MCR considered that As,Cd,Pb,Sb,and Zn achieved high and alarming degrees of contamination,whereas Fe,Mn,and Ti were negligible or low to moderate pollution degrees.Combined microcalorimetry and enzymatic activity measurements of contaminated soil samples were used to assess the microbial metabolic activity characteristics.Correlation analysis elucidated the relationship between metal(loid)s exchangeable fraction or content and microbial activity characteristics(p<0.05).The microbial metabolic activity in the D-1 layer was low presumably due to heavy metal stress.Enzyme activity indicators and microcalorimetric growth rate(k)measurements were considered sensitive indicators to reflect the soil microbial activities in abandoned chemical smelting sites.展开更多
Ecological toxicity of reactive X\|3B red dye and cadmium in both their single form and their combined form on wheat was studied using the experimental method of seed and root exposure. The single factor exposure ind...Ecological toxicity of reactive X\|3B red dye and cadmium in both their single form and their combined form on wheat was studied using the experimental method of seed and root exposure. The single factor exposure indicated that the inhibitory rate of wheat root elongation was significantly increased with the increase in the concentration of the dye in the cultural solution, although seed germination of wheat was not sensitive to the dye. The toxicity of cadmium was greatly higher than that of the dye, but low concentration cadmium (<40 mg/L) could promote the germination of wheat seed. Interactive effects of the dye and cadmium on wheat were complicated. There was no significant correlation between the inhibitory rate of seed germination and the concentrations of the dye and cadmium. Low concentration cadmium could strengthen the toxicity of the dye acting on root elongation. On the contrary, high concentration cadmium could weaken the toxicity of the dye acting on root elongation.展开更多
Acetochlor and methamidophos are two important agrochemicals which are widely applied to agricultural production in northeast China. The investigation on the earthworm Eisenia fetida as an important type of soil anima...Acetochlor and methamidophos are two important agrochemicals which are widely applied to agricultural production in northeast China. The investigation on the earthworm Eisenia fetida as an important type of soil animals exposed to single and binary-combined contamination of acetochlor and methamidophos was thus carried out. The single toxic effect test showed that the two agrochemicals had their toxicity to the earthworms living in phaiozem. Acetochlor had a stronger acute toxic effect on the earthworms than methamidophos. The mortality of the earthworms exposed to individual acetochlor and methamidophos changed with an increase in the exposure time and the exposed concentrations. The LD50 value of acetochlor and methamidophos toxic to the earthworms was 115.6-275,3 and 29.5-228.6 mg/kg, respectively. The weight of the earthworms was a more sensitive index compared to the mortality in indicating toxic effects of acetochlor and methamidophos in phaiozem. When considering both the mortality and the body-weight change, the combined pollution of acetochlor and methamidophos in phaiozem resulted in their synergic toxic effects on the earthworms.展开更多
The influence of two pesticides including chlorimuron-ethyl and furadan and mercury (Hg) on urease activity in 4 soils (meadow burozem and phaeozem) was investigated. The soils were exposed to various concentratio...The influence of two pesticides including chlorimuron-ethyl and furadan and mercury (Hg) on urease activity in 4 soils (meadow burozem and phaeozem) was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase (up to 13%-21%) in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship (P〈0.05) between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose (ED50) values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.展开更多
Using the concentration gradient and combined pollutant exposure method, the single and joint effects of petroleum hydrocarbons (PHCs) and cadmium (Cd) on polychaete Perinereis aibuhitensis Grube, an ecologically ...Using the concentration gradient and combined pollutant exposure method, the single and joint effects of petroleum hydrocarbons (PHCs) and cadmium (Cd) on polychaete Perinereis aibuhitensis Grube, an ecologically keystone species in estuarine and coastal environment, have been investigated. The results indicate that the toxicity of PHCs to P. aibuhitensis is stronger than that of Cd to the organism. There are positive correlations between the mortality of worms and the exposed concentration of single Cd or PHCs in solution. Similarly, the accumulation of Cd or PHCs in worms increased with increasing Cd- or PHC-exposed concentrations. All the correlation relationships can be described using unitary quadratic equations (Y or Z = aX^2 + bX + c). It is calculated, on the basis of these expressions, that the median lethal dose (LC50) ofP aibuhitensis exposed to a single Cd or PHCs is 793.4-13567.3 and 28.0-119.9 μg/L, respectively. The exposed time has some stimulative effect on the two pollutants and on the mortality of the worms. Thus, even a low concentration of a single Cd or PHCs may have strong toxic effects on the worms when the exposed time becomes longer. The accumulation of Cd or PHCs in worms differs with an increase in exposure time at the given exposed concentration of a single Cd or PHCs. Noticeably, the accumulation of PHCs in worms decreases with an increase in exposure time at the given high concentration of PHCs in solution. The joint effect of PHCs and Cd on P. aibuhitensis is very complicated and changes with the exposed concentrations of the two pollutants. At the given concentration of PHCs, the joint toxicity of the two pollutants on the worms changes from synergism to antagonism with an increase in Cd concentration. The accumulation of Cd in the worms significantly decreases with the addition of PHCs to exposure solution.展开更多
Using the exposure simulation experiment, the action of petroleum affecting the accumulation of the trace metals including copper (Cu) and cadmium (Cd) in littoral polychaete Nereis diversicolor collected from the...Using the exposure simulation experiment, the action of petroleum affecting the accumulation of the trace metals including copper (Cu) and cadmium (Cd) in littoral polychaete Nereis diversicolor collected from the Shuangtaizi Estuary in Liaoning Province, China was examined. The results showed that there was a markedly non-linear relationship between the accumulation of Cu in worms and the experimental concentration of Cu in exposure solutions when the concentration of petroleum remained at 0, 100, and 220 μl/L, respectively. However, significantly non-linear relationship for worms exposed to Cd was observed only when the concentration of added petroleum was 0 and 220 μl/L. The accumulation of Cu in worms did not differ significantly among the three different levels of petroleum concentrations combined with various concentrations of Cu. So was the accumulation of Cd in worms (p〉0.05). However, the addition of petroleum in exposure solutions brought about an increase in the accumulation of Cu in Nereis diversicolor, in comparison with single Cu pollution. On the other hand, when the concentration of added petroleum remained at 100 μl/L, the accumulation of Cd in worms was lower than that in worms exposed to various concentrations of only cadmium. However, the worms exposed to Cd and petroleum 220 μl/L did not show obvious and identical increase in the accumulation of Cd, compared with single Cd exposure. The accumulation of both Cu and Cd in worms did not increase significantly with the increases in concentrations of Cu or Cd in exposure solutions combined with petroleum (0, 100, and 220μl/L) under the experimental conditions. Although Nereis diversicolor is exposed to very high Cu and Cd in exposure solutions, accumulation and detoxification mechanisms are sufficient to cope with the extra metal influx in order to survive.展开更多
The main effects of pollutions including acid rain, Cu 2+ ,atrazine and their combined products on the activities of urease, invertin, acid phosphatase and catalase were studied by means of orthogonal test. The re...The main effects of pollutions including acid rain, Cu 2+ ,atrazine and their combined products on the activities of urease, invertin, acid phosphatase and catalase were studied by means of orthogonal test. The results showed that H + and Cu 2+ had significant influence on the activities of four enzymes and the ability of their inhibiting followed the order: H +>Cu 2+ . Al 3+ and atrazine only had litter effects on the activity of urease and phosphatase, respectively. Furthermore, interaction analysis revealed that Cu 2+ -H + affected on the activity of acid phosphatase significantly and antagonism on invertin and urease, Cu 2+ -atrazine only exhibited the synergism on the activity of acid phosphatase. But atrazine-H + had non-interaction within the investigated concentration range. Among four enzymes, acid phosphatase was the most sensitive one to the contaminations.展开更多
This paper discussed current situations of researches about the isolation remediation technology " soil barrier and landfill technology" and " physical isolation remediation technology" for heavy m...This paper discussed current situations of researches about the isolation remediation technology " soil barrier and landfill technology" and " physical isolation remediation technology" for heavy metal contaminated soil in mining areas.In view of defects of current technologies,it introduced a new isolation remediation technology,of which the new isolation materials were mixed by slaked lime,soil,find sand,and clay mineral in certain proportion.The new isolation remediation technology is expected to realize isolation remediation of heavy metal combined pollution of soil through chemical passivation of slaked lime and physical adsorption function of clay minerals or activated carbons.展开更多
The effect of combined antibiotics exposure on nitrogen removal,microbial community assembly and proliferation of antibiotics resistance genes(ARGs)is a hotspot in activated sludge system.However,it is unclear that ho...The effect of combined antibiotics exposure on nitrogen removal,microbial community assembly and proliferation of antibiotics resistance genes(ARGs)is a hotspot in activated sludge system.However,it is unclear that how the historical antibiotic stress affects the subsequent responses of microbes and ARGs to combined antibiotics.In this study,the effects of combined sulfamethoxazole(SMX)and trimethoprim(TMP)pollution on activated sludge under legacy of SMX or TMP stress with different doses(0.005-30 mg/L)were investigated to clarify antibiotic legacy effects.Nitrification activity was inhibited under higher level of combined exposure but a high total nitrogen removal(∼70%)occurred.Based on the full-scale classification,the legacy effect of past antibiotic stress had a marked effect on community composition of conditionally abundant taxa(CAT)and conditionally rare or abundant taxa(CRAT).Rare taxa(RT)were the keystone taxa in the microbial network,and the responses of hub genera were also affected by the legacy of antibiotic stress.Nitrifying bacteria and genes were inhibited by the antibiotics and aerobic denitrifying bacteria(Pseudomonas,Thaurea and Hydrogenophaga)were enriched under legacy of high dose,as were the key denitrifying genes(napA,nirK and norB).Furthermore,the occurrences and co-selection relationship of 94 ARGs were affected by legacy effect.While,some shared hosts(eg.,Citrobacter)and hub ARGs(eg.,mdtD,mdtE and acrD)were identified.Overall,antibiotic legacy could affect responses of activated sludge to combined antibiotic and the legacy effect was stronger at higher exposure levels.展开更多
In situ measurement of multiple pollutants coexisting in sediment porewater is an essential step in comprehensively assessing the bioavailability and risk of pollutants,but to date,this needs to be better developed.In...In situ measurement of multiple pollutants coexisting in sediment porewater is an essential step in comprehensively assessing the bioavailability and risk of pollutants,but to date,this needs to be better developed.In this study,a passive sampler,consisting of an“I-shaped”supporting frame and inorganic/organic sampling units,incorporating equilibrium dialysis theory and kinetic/equilibrium sorption principle,was developed for the synchronous measurement of inorganic(e.g.,phosphorus and metal(loid)s)and organic pollutants(e.g.,parent and substituted PAHs).The equilibrium time and sampling rates were explored in laboratory tests to support in situ application.Profiles of pollutants in porewater within a vertical resolution of centimeters,i.e.,1 cm and 2 cm for inorganic and organic pollutants,respectively,were obtained by field deployment of the sampler for further estimation of diffusive fluxes across the sediment-water interface.The results suggested that the role of sediments for a specific pollutant may change(e.g.,from“sink”to“source”)during the sampling time.This study demonstrated the feasibility of synchronous measurement of inorganic and organic pollutants in sediment porewater by the passive sampler.In addition,it provided new insight for further investigation into the combined pollution effects of various pollutants in sediments.展开更多
The combined pollution of heavy metals is ubiquitous worldwide.Mn/Al-layered double oxide-loaded crab shells biochar (LDO/BC) was prepared,so as to remediate the combined pollution of Cd and Cu in soil and water.The p...The combined pollution of heavy metals is ubiquitous worldwide.Mn/Al-layered double oxide-loaded crab shells biochar (LDO/BC) was prepared,so as to remediate the combined pollution of Cd and Cu in soil and water.The pristine and used LDO/BC were characterized and the results revealed that the layered double oxide was successfully loaded on crab shells biochar (BC) and metal element Ca in crab shells was beneficial to the formation of more regular layered and flake structure.The maximal adsorption capacity (Qm) of LDO/BC for aqueous Cu^(2+)and Cd^(2+)was 66.23 and 73.47 mg/g,respectively.LDO/BC and BC were used to remediate e-waste-contaminated soil for the first time and exhibited highly efficient performance.The extraction amount of Cu and Cd in the contaminated soil by diethylene triamine penta-acetic acid (DTPA) after treating with 5% LDO/BC was significantly reduced from 819.84 to 205.95 mg/kg (with passivation rate 74.8%) and 8.46 to 4.16 mg/kg(with passivation rate 50.8%),respectively,inferring that the bioavailability of heavy metals declined remarkably.The experimental result also suggested that after remediation by LDO/BC the exchangeable and weak acid soluble Cu and Cd in soil translated to reducible,residual and oxidizable fraction which are more stable state.Precipitation,complexation and ion exchange were proposed as the possible mechanisms for Cd and Cu removal.In general,these experiment results indicate that LDO/BC can be a potentially effective reagent for remediation of heavy metal contaminated water and soil.展开更多
The mechanisms of adsorption of pesticides(dimethoate, metalaxyl, atrazine, malathion and prometryn) and heavy metals(Cu, Cd, Pb, Zn and Ni) coexisting in sediments, with pesticides as target pollutants, and the i...The mechanisms of adsorption of pesticides(dimethoate, metalaxyl, atrazine, malathion and prometryn) and heavy metals(Cu, Cd, Pb, Zn and Ni) coexisting in sediments, with pesticides as target pollutants, and the influence of their main effects and double-order interaction effects were studied using the experimental design module in the Minitab software package with a 2^10-3 fractional factorial design method at resolution V. The main, double-order interaction, synergistic and antagonistic effect values of pollutant concentrations influencing the adsorption of pesticides were set as dependent variables, while various quantum chemical parameters of pesticides were set as independent variables, and two-dimensional quantitative structure activity relationship(2D-QSAR) models were established by stepwise regression to reveal the adsorption mechanisms of pesticides in a composite contamination system. The main effects of pollutants concentration played the primary role in the adsorption of dimethoate and malathion(the rates of contributions were 53.54% and 56.46%, respectively), while double-order interaction effects were primarily responsible for metalaxyl, atrazine and prometryn adsorption(the rates of contributions were 79.05%, 60.21% and 57.89%, respectively) in the pesticide/heavy metals coexisting sediment system. The synergistic effects of the main effects and double-order interaction effects of pollutants concentration(synergistic effects) played a leading role in adsorption of malathion and prometryn(the rates of contributions were 70.61% and 69.61%, respectively), while an- tagonistic effects of the main effects and double-order interaction effects of pollutants(antagonistic effects) played a dominant role in the adsorption of dimethoate, metalaxyl and atrazine(the rates of contributions were 58.82%, 56.89% and 58.24%, respectively). Moreover, the correlation coefficient value(R2) ranged from 0.986 to 0.999(〉0.8783) in the 2D-QSAR model, while the standard deviation(SD) ranged from 0.006 to 0.066 and the Ftest values were 22.684-199.544, indicating the model has good predictive ability and fit. The 2D-QSAR model revealed a significant correlation(P=0.05) between the main effects of pollutants concentrations on pesticides adsorption(main effect values) and the most positive hydrogen atomic charge(qa+), the highest occupied molecular orbital energy(EHOMO) and the dipole moment(μ). Furthermore, double-order interaction effect values of pollutant concentrations influenced the adsorption of pesticides(double-order interaction effect values), and the most positive atomic charge(q+), qH+, and the lowest unoccupied molecular orbital energy(ELMO) were significantly correlated. The qw, EHOMO and μ of pesticides were found to be significant factors promoting pesticides adsorption, while the q+ and ELVMO of pesticides were significant inhibiting factors(P=0,05). Overall, this study provides a theoretical basis for further realization of combined pollution control of pesticide pollutants in complex environmental systems.展开更多
Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint st...Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint stress of Cd and As.The results showed that Cd and As had an antagonistic effect on enhancing the growth of Rorippa globosa plants and Cd uptake and accumulation under the low concentration Cd and As treatments.When the concentra-tion of Cd in the soil was 10 mg/kg and the concentration of As was 50 mg/kg,the highest growing height of the plant was up to 35.9 cm and the dry weight of the shoots was up to 2.2 g/pot,respectively.Meanwhile,the accumulation of Cd in the leaves under the joint stress was higher than that at the same level under single Cd pollution.However,there were synergic adverse effects on plant growth and Cd uptake under the combined pollution from a high concentration of Cd and As.Meanwhile,the accumulation of As in the roots was greater than that in the shoots,the translocation factor(TF)was h0.3 and the bioaccumulation factor(BF)was h0.6,thus showing that Rorippa globosa had an excluding effect on As uptake.These results confirmed that Rorippa globosa had a strong tolerant ability to the joint stress of Cd and As,and the potential for phytoremediation of soils contaminated by Cd and As.展开更多
基金Supported by Hydrogeologic Investigation and Karst Water Exploitation Demonstration of Major Karst Basin in Guangxi,China (200710)Project of China Geological Survey (1212010634803)
文摘[Objective] The aim was to study the correlation between Cr6+ and Mn2+ adsorption in rock-soil medium with combined pollution. [Method] Combining single Cr6+ and Mn2+ adsorption test with combined pollution test, the adsorption laws of Cr6+ and Mn2+ were studied, and the correlation between Cr6+ and Mn2+ adsorption was analysed by using correlation analysis and regression analysis. [Result] According to the comparative analysis on adsorption tests, the adsorption time, adsorption amount and adsorption speed of Cr6+ and Mn2+ were obviously distinct in single adsorption test and combined adsorption test. Correlation analysis revealed that there was a significantly positive correlation between Cr6+ and Mn2+, and there existed addition effects between Cr6+ and Mn2+ in regression analysis, that is, the adsorption of Cr6+ by the soil tested would be enhanced by Mn2+. [Conclusion] The research could provide scientific references for environmental control and environmental management.
文摘Due to the mining,smelting,sewage irriga-tion,agricultural runoff,and development ofrural enterprises,combined pollution of Cd andZn in soil-rice systems has frequently oc-curred.This problem was studied by using thepot-culture imitative method combined withhemical analysis and mathematical models.
基金The National Basic Research Program (973) of China (No. 2004CB18503)the National Natural Science Foundation of China (No.20337010) the Key Program of Basic Research of Shanghai City (No. 04JC14051)
文摘The DNA-damaging effects of the combined pollution of heavy metal and organic contamination on earthworms were evaluated by single cell gel electrophoresis (SCGE) assay. Earthworms Eisenia andrei were exposed to single or combined test compounds in different doses of cadmium (Cd) 5, 10, 50 mg/kg and phenanthrene (Phe) 0.5, 2.5, 12.5 mg/kg with a treatment of 14 d. In SCGE assay, isolated coelomcytes and electrophoresis were employed to determine DNA damage degree after a 14-d treatment by test compounds. The results showed that there was a significant statistical difference between earthworms treated with Cd combined Phe with them treated alone with Cd or Phe. The Olive tail moment (OTM) of SCGE assay using earthworm coelomcytes appears to be a sensitive biomarker for evaluating exposure to genotoxic compounds. These tests also revealed that the interaction between Cd and Phe to DNA damaging effects was negative, and was strongly dependent on the concentration of pollution. This study corresponds to exploratory phase in order to reveal interaction effects of heavy metal and organic contamination on earthworms and then to set up more in-depth analysis to increase progressively the understanding of the genotoxicity mechanisms involved.
文摘Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showed that the significant zinc factor indicated both the inhibition rate of shoot mass and that of root elongation were affected by zinc(P<0.05 and P<0.01, respectively). The first toxicity canonical variable (TOXI), formed from the toxicity data set, explained 49% of the total variance in the toxicity data set; the first biological canonical variable(BIOL) explained 42% of the total variation in the biological data set. The correlation between the first canonical variables TOXI and BIOL (canonical correlation) was 0.94 (P<0.0001). Therefore, it is reliable and feasible to use the achievement to assess toxicity of heavy metal combined polluted soil using canonical analysis. Toxicity of soil combined polluted by heavy metals to plant community was estimated by comparing the IC 50 values describing the concentration needed to cause 50% decrease with grow rate compared to no metal addition. Environmental quality standard for soils prescribe that all these tested concentration of heavy metals in soil should not cause hazard and pollution ultimately, whereas it indicated that the soils in second grade cause more or less than 50% inhibition rates of wheat growth. So environmental quality standard for soils can be modified to include other features.
基金supported by the National Natural Science Foundation of China(41101455)
文摘The actions and interactions of acetochlor and As on the soil phosphatase activity were investigated after 1, 3, 6, 10, 15, 30 and 60 d of exposure under control conditions. The soils were exposed to various concentrations of acetochlor and As individually and simultaneously. The results showed that acetochlor, As only, and combined pollution all clearly inhibited soil phosphatase activity. The maximum inhibition ratios of soil phosphatase activity by acetochlor, As only and combined pollution were 36.44, 74.12 and 61.29%, respectively. Two kinetic models, ν=c/(1+bi) (model 1) and ν=c(1+ai)/(l+bi) (model 2), were used to describe the relationship between the concentrations of As and acetochlor and the activity of soil phosphatase. The semi-effect dose (ED 50 ) values induced by As and acetochlor stress based on the inhibition of soil phosphatase were 18.1 and 33.11 mg kg-1, respectively, according to calculation by model 1. The interactive effect of acetochlor with As on soil phosphatase primarily consisted of significant antagonism effects at the higher concentrations tested. The step regression results show that the toxicity order was As (III)〉acetochlor〉As (III)×acetochlor throughout the incubation period.
基金National Natural Science Foundation of China(Grant Numbers[42220104004])National Natural Science Foundation of China(Grant Numbers[41671331])+1 种基金Innovative Approaches Special Project of the Ministry of Science and Technology of China(Grant Numbers[2020IM020300])Beijing-Tianjin-Hebei Collaborative Innovation Promotion Project of China(Grant Numbers[Z201100006720001]).
文摘Biochar-coupled Fe_(3)O_(4)@SiO_(2)/TiO_(2)/g-C_(3)N_(4) composites were successfully constructed through simple sol-gel and calcination methods.The composites efficiently removed high-concentration toxic tetracycline(TC)by means of·OH and·O_(2)^(−),whose removal rate exhibited 91.88%during 3 h,and the degradation rate constant reached up to 0.0068 min^(−1).The excellent performance can be attributed to the high specific surface area,enhanced visible light response,the introduction of magnetic nanoparticles and biochars expediting charge transfer,Z-scheme heterojunction enhancing the spatial separation of photo-generate carriers and,importantly extraordinary adsorption capacity of 147.96 mg g^(−1).Moreover,the composites showed the most excellent efficiency under the calcination temperature of 450℃,and exhibited good stability with tolerance to a wide range of pH and anions.Interestingly,a synergistic photocatalytic effect was discovered in the TC/Cr(Ⅵ)combined pollution systems,resulting in significantly improved removal of Cr(Ⅵ).Besides,the photocatalytic mechanism and degradation path of tetracycline were also elucidated.All these findings suggested the as-synthesized catalyst was an excellent photocatalyst for removal of TC/Cr(Ⅵ)-contaminated water.
基金the financial support of the National Natural Science Foundation of China(No.52078194)the National Young Topnotch Talent of Ten Thousand Talents Program+1 种基金the Young Top-notch Talent Cultivation Program of Hubei Provincefunding from the Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes(2020EJB004)。
文摘The strength deterioration mechanism of soil polluted by heavy metals plays a crucial role in the research of mine site pollution.In this study,an unconfined compressive strength(UCS)test,a pH test,a scanning electron microscopy(SEM)test,a low filed nuclear magnetic resonance(NMR)test,and an X-ray diffraction(XRD)test were conducted on Zn^(2+),Cu^(2+) and the combination of Zn^(2+) and Cu^(2+) polluted soil to investigate the strength deterioration mechanism.The results show that both the UCS and pH value of soil decrease with increasing heavy metal concentration.The UCS of Zn^(2+)-Cu^(2+) combined polluted soil is between Zn^(2+) and Cu^(2+) polluted soil at the same total concentration.However,the deterioration rate of combined heavy metal polluted soil is less than the sum of deterioration rate of the two single polluted soils at the same total concentration.In addition,heavy metal cations in polluted soil cause flocculent gels of cosmids to shrink,the micropores to become smaller and the macropores to become larger.The porosity increases slightly with the increase of heavy metal concentration due to decreased pH value.The results from SEM,low field NMR,and pH could explain the dynamic evolution process of soil structure with different heavy metals and concentrations,which provides an experimental basis for mine-site polluted heavy metal treatment technology and the prediction of clayey soil strength deterioration.
基金supported by the National Key Research and Development Program of China(No.2019YFC1803500)the National Natural Science Foundation of China(No.42230716)+3 种基金the National Natural Science Foundation of China(No.42007289)the 111 Project(No.B21017)the Centre National de la Recherche Scientifique(No.CNRS PRC1416,France)the 1000-Talents Plan project(No.WQ2017110423)。
文摘Abandoned chemical smelting sites containing toxic substances can seriously threaten and pose a risk to the surrounding ecological environment.Soil samples were collected from different depths(0 to 13 m)and analyzed for metal(loid)s content and fractionation,as well as microbial activities.The potential ecological risk indices for the different soil depths(ordered from high to low)were:1 m(D-1)>surface(S-0)>5 m(D-5)>13 m(D-13)>9 m(D-9),ranging between 1840.65-13,089.62,and representing extremely high environmental risks,of which Cd(and probably not arsenic)contributed to the highest environmental risk.A modified combined pollution risk index(MCR)combining total content and mobile proportion of metal(loid)s,and relative toxicities,was used to evaluate the degree of contamination and potential environmental risks.For the near-surface samples(S-0 and D-1 layers),the MCR considered that As,Cd,Pb,Sb,and Zn achieved high and alarming degrees of contamination,whereas Fe,Mn,and Ti were negligible or low to moderate pollution degrees.Combined microcalorimetry and enzymatic activity measurements of contaminated soil samples were used to assess the microbial metabolic activity characteristics.Correlation analysis elucidated the relationship between metal(loid)s exchangeable fraction or content and microbial activity characteristics(p<0.05).The microbial metabolic activity in the D-1 layer was low presumably due to heavy metal stress.Enzyme activity indicators and microcalorimetric growth rate(k)measurements were considered sensitive indicators to reflect the soil microbial activities in abandoned chemical smelting sites.
文摘Ecological toxicity of reactive X\|3B red dye and cadmium in both their single form and their combined form on wheat was studied using the experimental method of seed and root exposure. The single factor exposure indicated that the inhibitory rate of wheat root elongation was significantly increased with the increase in the concentration of the dye in the cultural solution, although seed germination of wheat was not sensitive to the dye. The toxicity of cadmium was greatly higher than that of the dye, but low concentration cadmium (<40 mg/L) could promote the germination of wheat seed. Interactive effects of the dye and cadmium on wheat were complicated. There was no significant correlation between the inhibitory rate of seed germination and the concentrations of the dye and cadmium. Low concentration cadmium could strengthen the toxicity of the dye acting on root elongation. On the contrary, high concentration cadmium could weaken the toxicity of the dye acting on root elongation.
文摘Acetochlor and methamidophos are two important agrochemicals which are widely applied to agricultural production in northeast China. The investigation on the earthworm Eisenia fetida as an important type of soil animals exposed to single and binary-combined contamination of acetochlor and methamidophos was thus carried out. The single toxic effect test showed that the two agrochemicals had their toxicity to the earthworms living in phaiozem. Acetochlor had a stronger acute toxic effect on the earthworms than methamidophos. The mortality of the earthworms exposed to individual acetochlor and methamidophos changed with an increase in the exposure time and the exposed concentrations. The LD50 value of acetochlor and methamidophos toxic to the earthworms was 115.6-275,3 and 29.5-228.6 mg/kg, respectively. The weight of the earthworms was a more sensitive index compared to the mortality in indicating toxic effects of acetochlor and methamidophos in phaiozem. When considering both the mortality and the body-weight change, the combined pollution of acetochlor and methamidophos in phaiozem resulted in their synergic toxic effects on the earthworms.
基金Project supported by the National Basic Research Program (973) of China (No. 2004CB418506)the National Natural Science Foundation of China (No. 20337010+1 种基金40301022)the Key Laboratory of Environmental Engineering Foundation of Shenyang University (No. 04001).
文摘The influence of two pesticides including chlorimuron-ethyl and furadan and mercury (Hg) on urease activity in 4 soils (meadow burozem and phaeozem) was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase (up to 13%-21%) in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship (P〈0.05) between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose (ED50) values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.
基金This work was supported by the National Basic Research Program(973)of China(No.2004CB418503)the National Natural Science Foundation of China(No.20477049).
文摘Using the concentration gradient and combined pollutant exposure method, the single and joint effects of petroleum hydrocarbons (PHCs) and cadmium (Cd) on polychaete Perinereis aibuhitensis Grube, an ecologically keystone species in estuarine and coastal environment, have been investigated. The results indicate that the toxicity of PHCs to P. aibuhitensis is stronger than that of Cd to the organism. There are positive correlations between the mortality of worms and the exposed concentration of single Cd or PHCs in solution. Similarly, the accumulation of Cd or PHCs in worms increased with increasing Cd- or PHC-exposed concentrations. All the correlation relationships can be described using unitary quadratic equations (Y or Z = aX^2 + bX + c). It is calculated, on the basis of these expressions, that the median lethal dose (LC50) ofP aibuhitensis exposed to a single Cd or PHCs is 793.4-13567.3 and 28.0-119.9 μg/L, respectively. The exposed time has some stimulative effect on the two pollutants and on the mortality of the worms. Thus, even a low concentration of a single Cd or PHCs may have strong toxic effects on the worms when the exposed time becomes longer. The accumulation of Cd or PHCs in worms differs with an increase in exposure time at the given exposed concentration of a single Cd or PHCs. Noticeably, the accumulation of PHCs in worms decreases with an increase in exposure time at the given high concentration of PHCs in solution. The joint effect of PHCs and Cd on P. aibuhitensis is very complicated and changes with the exposed concentrations of the two pollutants. At the given concentration of PHCs, the joint toxicity of the two pollutants on the worms changes from synergism to antagonism with an increase in Cd concentration. The accumulation of Cd in the worms significantly decreases with the addition of PHCs to exposure solution.
基金The National Natural Science Foundation of China (No. 20477049) and the Key Basic Research Development and Planning Project (No. 2004CB418503)
文摘Using the exposure simulation experiment, the action of petroleum affecting the accumulation of the trace metals including copper (Cu) and cadmium (Cd) in littoral polychaete Nereis diversicolor collected from the Shuangtaizi Estuary in Liaoning Province, China was examined. The results showed that there was a markedly non-linear relationship between the accumulation of Cu in worms and the experimental concentration of Cu in exposure solutions when the concentration of petroleum remained at 0, 100, and 220 μl/L, respectively. However, significantly non-linear relationship for worms exposed to Cd was observed only when the concentration of added petroleum was 0 and 220 μl/L. The accumulation of Cu in worms did not differ significantly among the three different levels of petroleum concentrations combined with various concentrations of Cu. So was the accumulation of Cd in worms (p〉0.05). However, the addition of petroleum in exposure solutions brought about an increase in the accumulation of Cu in Nereis diversicolor, in comparison with single Cu pollution. On the other hand, when the concentration of added petroleum remained at 100 μl/L, the accumulation of Cd in worms was lower than that in worms exposed to various concentrations of only cadmium. However, the worms exposed to Cd and petroleum 220 μl/L did not show obvious and identical increase in the accumulation of Cd, compared with single Cd exposure. The accumulation of both Cu and Cd in worms did not increase significantly with the increases in concentrations of Cu or Cd in exposure solutions combined with petroleum (0, 100, and 220μl/L) under the experimental conditions. Although Nereis diversicolor is exposed to very high Cu and Cd in exposure solutions, accumulation and detoxification mechanisms are sufficient to cope with the extra metal influx in order to survive.
文摘The main effects of pollutions including acid rain, Cu 2+ ,atrazine and their combined products on the activities of urease, invertin, acid phosphatase and catalase were studied by means of orthogonal test. The results showed that H + and Cu 2+ had significant influence on the activities of four enzymes and the ability of their inhibiting followed the order: H +>Cu 2+ . Al 3+ and atrazine only had litter effects on the activity of urease and phosphatase, respectively. Furthermore, interaction analysis revealed that Cu 2+ -H + affected on the activity of acid phosphatase significantly and antagonism on invertin and urease, Cu 2+ -atrazine only exhibited the synergism on the activity of acid phosphatase. But atrazine-H + had non-interaction within the investigated concentration range. Among four enzymes, acid phosphatase was the most sensitive one to the contaminations.
基金Supported by Scientific Research Project of Shaanxi Province Land Engineering Construction Group(DJNY2017-13)
文摘This paper discussed current situations of researches about the isolation remediation technology " soil barrier and landfill technology" and " physical isolation remediation technology" for heavy metal contaminated soil in mining areas.In view of defects of current technologies,it introduced a new isolation remediation technology,of which the new isolation materials were mixed by slaked lime,soil,find sand,and clay mineral in certain proportion.The new isolation remediation technology is expected to realize isolation remediation of heavy metal combined pollution of soil through chemical passivation of slaked lime and physical adsorption function of clay minerals or activated carbons.
基金supported by the National Natural Science Foundation of China(No.51808013)Connotation Development Quota Project of High-top Talent of BJUT(No.YS20-1006757-056).
文摘The effect of combined antibiotics exposure on nitrogen removal,microbial community assembly and proliferation of antibiotics resistance genes(ARGs)is a hotspot in activated sludge system.However,it is unclear that how the historical antibiotic stress affects the subsequent responses of microbes and ARGs to combined antibiotics.In this study,the effects of combined sulfamethoxazole(SMX)and trimethoprim(TMP)pollution on activated sludge under legacy of SMX or TMP stress with different doses(0.005-30 mg/L)were investigated to clarify antibiotic legacy effects.Nitrification activity was inhibited under higher level of combined exposure but a high total nitrogen removal(∼70%)occurred.Based on the full-scale classification,the legacy effect of past antibiotic stress had a marked effect on community composition of conditionally abundant taxa(CAT)and conditionally rare or abundant taxa(CRAT).Rare taxa(RT)were the keystone taxa in the microbial network,and the responses of hub genera were also affected by the legacy of antibiotic stress.Nitrifying bacteria and genes were inhibited by the antibiotics and aerobic denitrifying bacteria(Pseudomonas,Thaurea and Hydrogenophaga)were enriched under legacy of high dose,as were the key denitrifying genes(napA,nirK and norB).Furthermore,the occurrences and co-selection relationship of 94 ARGs were affected by legacy effect.While,some shared hosts(eg.,Citrobacter)and hub ARGs(eg.,mdtD,mdtE and acrD)were identified.Overall,antibiotic legacy could affect responses of activated sludge to combined antibiotic and the legacy effect was stronger at higher exposure levels.
基金supported by the Natural Science Foundation of Jiangsu Province (No.BK20200322)the special fund from the State Key Joint Laboratory of Environment Simulation and Pollution Control (RCEES,CAS) (No.20K02ESPCR)the Scientific Research Start-up Fund for High-level Talents of Nanjing Normal University (No.184080H202B357)。
文摘In situ measurement of multiple pollutants coexisting in sediment porewater is an essential step in comprehensively assessing the bioavailability and risk of pollutants,but to date,this needs to be better developed.In this study,a passive sampler,consisting of an“I-shaped”supporting frame and inorganic/organic sampling units,incorporating equilibrium dialysis theory and kinetic/equilibrium sorption principle,was developed for the synchronous measurement of inorganic(e.g.,phosphorus and metal(loid)s)and organic pollutants(e.g.,parent and substituted PAHs).The equilibrium time and sampling rates were explored in laboratory tests to support in situ application.Profiles of pollutants in porewater within a vertical resolution of centimeters,i.e.,1 cm and 2 cm for inorganic and organic pollutants,respectively,were obtained by field deployment of the sampler for further estimation of diffusive fluxes across the sediment-water interface.The results suggested that the role of sediments for a specific pollutant may change(e.g.,from“sink”to“source”)during the sampling time.This study demonstrated the feasibility of synchronous measurement of inorganic and organic pollutants in sediment porewater by the passive sampler.In addition,it provided new insight for further investigation into the combined pollution effects of various pollutants in sediments.
基金supported by the National Key Research and Development Program of China (No. 2018YFC1802800)the Local Innovation and Entrepreneurship Team Project of Guangdong Special Support Program (No. 2019BT02L218)+1 种基金the National Natural Science Foundation of China (Nos. 41673091, U1501234)the Guangdong Science and Technology Program (No. 2020B121201003)。
文摘The combined pollution of heavy metals is ubiquitous worldwide.Mn/Al-layered double oxide-loaded crab shells biochar (LDO/BC) was prepared,so as to remediate the combined pollution of Cd and Cu in soil and water.The pristine and used LDO/BC were characterized and the results revealed that the layered double oxide was successfully loaded on crab shells biochar (BC) and metal element Ca in crab shells was beneficial to the formation of more regular layered and flake structure.The maximal adsorption capacity (Qm) of LDO/BC for aqueous Cu^(2+)and Cd^(2+)was 66.23 and 73.47 mg/g,respectively.LDO/BC and BC were used to remediate e-waste-contaminated soil for the first time and exhibited highly efficient performance.The extraction amount of Cu and Cd in the contaminated soil by diethylene triamine penta-acetic acid (DTPA) after treating with 5% LDO/BC was significantly reduced from 819.84 to 205.95 mg/kg (with passivation rate 74.8%) and 8.46 to 4.16 mg/kg(with passivation rate 50.8%),respectively,inferring that the bioavailability of heavy metals declined remarkably.The experimental result also suggested that after remediation by LDO/BC the exchangeable and weak acid soluble Cu and Cd in soil translated to reducible,residual and oxidizable fraction which are more stable state.Precipitation,complexation and ion exchange were proposed as the possible mechanisms for Cd and Cu removal.In general,these experiment results indicate that LDO/BC can be a potentially effective reagent for remediation of heavy metal contaminated water and soil.
文摘The mechanisms of adsorption of pesticides(dimethoate, metalaxyl, atrazine, malathion and prometryn) and heavy metals(Cu, Cd, Pb, Zn and Ni) coexisting in sediments, with pesticides as target pollutants, and the influence of their main effects and double-order interaction effects were studied using the experimental design module in the Minitab software package with a 2^10-3 fractional factorial design method at resolution V. The main, double-order interaction, synergistic and antagonistic effect values of pollutant concentrations influencing the adsorption of pesticides were set as dependent variables, while various quantum chemical parameters of pesticides were set as independent variables, and two-dimensional quantitative structure activity relationship(2D-QSAR) models were established by stepwise regression to reveal the adsorption mechanisms of pesticides in a composite contamination system. The main effects of pollutants concentration played the primary role in the adsorption of dimethoate and malathion(the rates of contributions were 53.54% and 56.46%, respectively), while double-order interaction effects were primarily responsible for metalaxyl, atrazine and prometryn adsorption(the rates of contributions were 79.05%, 60.21% and 57.89%, respectively) in the pesticide/heavy metals coexisting sediment system. The synergistic effects of the main effects and double-order interaction effects of pollutants concentration(synergistic effects) played a leading role in adsorption of malathion and prometryn(the rates of contributions were 70.61% and 69.61%, respectively), while an- tagonistic effects of the main effects and double-order interaction effects of pollutants(antagonistic effects) played a dominant role in the adsorption of dimethoate, metalaxyl and atrazine(the rates of contributions were 58.82%, 56.89% and 58.24%, respectively). Moreover, the correlation coefficient value(R2) ranged from 0.986 to 0.999(〉0.8783) in the 2D-QSAR model, while the standard deviation(SD) ranged from 0.006 to 0.066 and the Ftest values were 22.684-199.544, indicating the model has good predictive ability and fit. The 2D-QSAR model revealed a significant correlation(P=0.05) between the main effects of pollutants concentrations on pesticides adsorption(main effect values) and the most positive hydrogen atomic charge(qa+), the highest occupied molecular orbital energy(EHOMO) and the dipole moment(μ). Furthermore, double-order interaction effect values of pollutant concentrations influenced the adsorption of pesticides(double-order interaction effect values), and the most positive atomic charge(q+), qH+, and the lowest unoccupied molecular orbital energy(ELMO) were significantly correlated. The qw, EHOMO and μ of pesticides were found to be significant factors promoting pesticides adsorption, while the q+ and ELVMO of pesticides were significant inhibiting factors(P=0,05). Overall, this study provides a theoretical basis for further realization of combined pollution control of pesticide pollutants in complex environmental systems.
基金This work was support by the National Natural Science Foundation of China as an overseas distinguished young scholars award(Grant No.20428707)as a key project(Grant No.20337010)by the Sino-Russia Joint Research Center on Natural Resources and Eco-Environmental Sciences.
文摘Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint stress of Cd and As.The results showed that Cd and As had an antagonistic effect on enhancing the growth of Rorippa globosa plants and Cd uptake and accumulation under the low concentration Cd and As treatments.When the concentra-tion of Cd in the soil was 10 mg/kg and the concentration of As was 50 mg/kg,the highest growing height of the plant was up to 35.9 cm and the dry weight of the shoots was up to 2.2 g/pot,respectively.Meanwhile,the accumulation of Cd in the leaves under the joint stress was higher than that at the same level under single Cd pollution.However,there were synergic adverse effects on plant growth and Cd uptake under the combined pollution from a high concentration of Cd and As.Meanwhile,the accumulation of As in the roots was greater than that in the shoots,the translocation factor(TF)was h0.3 and the bioaccumulation factor(BF)was h0.6,thus showing that Rorippa globosa had an excluding effect on As uptake.These results confirmed that Rorippa globosa had a strong tolerant ability to the joint stress of Cd and As,and the potential for phytoremediation of soils contaminated by Cd and As.