[Objectives]To study the content and antidepressant effects of the flavonoids in the Zanthoxylum Pericarpium Residue(ZPR)and to provide a basis for the full utilization of ZPR.[Methods]The method for the assay of tota...[Objectives]To study the content and antidepressant effects of the flavonoids in the Zanthoxylum Pericarpium Residue(ZPR)and to provide a basis for the full utilization of ZPR.[Methods]The method for the assay of total flavonoids in ZPR by UV spectrophotometry was developed with rutin as reference.The total flavonoids were extracted and separated from ZPR.The contents of total flavonoids were quantified in ZPR and its extract.The autonomous activity test,tail suspension test and forced swimming test were conducted in mice,and the levels of malondialdehyde(MDA),superoxide dismutase(SOD)and total antioxidation were detected to evaluate the antidepressant effects of total flavonoids.[Results]The recovery rate of UV spectrophotometry was 98.88%(n=6).The contents of flavonoids in ZPR and its extract were 11.07%and 78.42%,respectively.In the autonomous activity test,compared with the control group,the standing times of mice in the positive drug group was significantly increased(P<0.05),but there was not significant difference among the low-,medium-and high-dose groups of total flavonoids extract(P>0.05),as well as there was no significant difference of the activity times among all groups(P>0.05).In the tail suspension and forced swimming tests,compared with the control group,the immobility time of the high-dose group of total flavonoids extract was significantly reduced(P>0.05),and the serum SOD levels of the low-,medium-and high-dose groups were significantly increased(P<0.05).The MDA levels of the middle-and high-dose groups of total flavonoids were significantly decreased(P<0.05),and the total antioxidant capacity was increased significantly(P<0.05).[Conclusions]The developed UV spectrophotometry can accurately detect the level of total flavonoids in ZPR.ZPR is rich in flavonoids,and has significant antidepressant effects,which may be related to eliminating internal free radicals and inhibiting lipid peroxidation.展开更多
[Objectives] The infrared fingerprint spectra of Gastrodia elata Blume of different origins and different varieties were studied.[Methods]One-dimensional infrared spectroscopy was used to analyze G. elata of different...[Objectives] The infrared fingerprint spectra of Gastrodia elata Blume of different origins and different varieties were studied.[Methods]One-dimensional infrared spectroscopy was used to analyze G. elata of different origins and different varieties. Based on the infrared spectra of 14 batches of G. elata,the common peak ratio and variant peak ratio were calculated,the double index sequences of common peak ratio and variant peak ratio were established to compare the similarities between the samples of G. elata. [Results] Infrared fingerprint spectra of G. elata of different origins and different varieties were obtained,and a total of 14 common peaks were calibrated. The maximum and minimum common peak ratios among the G. elata samples were 100. 00% and 73. 68%,respectively; and the maximum and minimum variant peak ratios were 21. 43% and 0%,respectively. [Conclusions]The combination of Fourier transform infrared spectroscopy and common peak ratio-variant peak ratio double-index analysis can provide scientific basis for the quality standard research of G. elata.展开更多
[Objectives] To carry out infrared spectroscopic study of different growth years and different parts of the traditional Chinese medicine Radix Chuanmingshinis Violacei. [Methods]Using potassium bromide squash method a...[Objectives] To carry out infrared spectroscopic study of different growth years and different parts of the traditional Chinese medicine Radix Chuanmingshinis Violacei. [Methods]Using potassium bromide squash method and Fourier transform infrared spectroscopy on the different growth years and different parts of Radix Chuanmingshinis Violacei for infrared spectrum and second derivative spectrum. [Results]With the increasing growth time,Radix Chuanmingshinis Violacei accumulated in the secondary metabolism substances gradually increased,the characteristic absorption peak appeared in the position such as 3 366,2 927,1 634,1 416,1 516,1 080,1 020,and 928 cm^(-1),the main chemicals as polysaccharide,coumarin,saponins and steroids. The difference of chemical position between root tuber and cauline leaf is obvious. [Conclusions]Infrared spectroscopy was applied in studying different growing periods and different parts of Radix Chuanmingshinis Violacei,of obvious characteristics,identification and quality evaluation method,is simple and suitable for Radix Chuanmingshinis Violacei.展开更多
The presence of trace organic pollutants in the effluent of wastewater treatment plants(WWTPs)poses considerable risks to aquatic organisms and human health.A large-scale survey of 302 trace organic pollutants in the ...The presence of trace organic pollutants in the effluent of wastewater treatment plants(WWTPs)poses considerable risks to aquatic organisms and human health.A large-scale survey of 302 trace organic pollutants in the effluent of 46 Chinese WWTPs was conducted to gain an improved understanding of their occurrence and ecological risks.The survey data showed that 216 compounds in 11 chemical classes had been detected in effluents.The sum concentrations of the trace contaminants in effluent ranged from 1,392 ng/L to 35,453 ng/L,with the maximum concentration of perfluoroalkyl substances(PFASs)recorded as the highest(30,573 ng/L),which was markedly less than the reported 185,000 ng/L for the 38 American WWTPs.The concentration of bisphenol analogs(BPs)was up to 4,422 ng/L,significantly higher than those reported in France,Germany,Japan,Korea,and the U.S.PFASs and BPs were the major pollutants,accounting for 59%of the total pollution.Additionally,a total of 119 contaminants were found to have ecological risks(RQ>0.01).Among these,23 contaminants(RQ>1.0)warrant higher attention and should be prioritized for removal.This study lists valuable information for controlling contaminants with higher priority in WWTP effluent in China.展开更多
Bisphenol compounds(BPs)are commonly used in industry and agriculture.However,BPs pollution has already raised global concerns due to their ecological risks.This study investigated nine types of BPs in agricultural so...Bisphenol compounds(BPs)are commonly used in industry and agriculture.However,BPs pollution has already raised global concerns due to their ecological risks.This study investigated nine types of BPs in agricultural soil and irrigation rivers,and evaluated the occurrence,source apportionment,and ecological risks for BPs in soils of agricultural environment by using principal component analysis-multivariate linear regression(PCA-MLR)and risk quotients(RQ).The average concentration of BPs in soil,irrigation water and sediments were 29.19 ng/g,30.21 ng/L and 610.09 ng/g dw,respectively.BPA was the most highly detected contaminant in all media.In soil,the primary BPA substitutes were bisphenol S(BPS)and bisphenol F(BPF),contributing about 50%to the pollution in total.PCA-MLR analysis indicated that the release of solid waste was the primary cause of BPs pollution in the agricultural soils,following by waste water discharge.The evaluation of RQ revealed that BPs presented a low to medium risk to algae,daphnia,and fish in irrigation rivers,while more than 90% of soil sampling sites faced medium or high risk,with BPA and BPS as the main contributors to the risk.The research findings offer evidence to support the assessment of contaminants concentration,source pathways,and risk management strategies pertaining to BPs in the agricultural system.With ongoing BPA substitute occurrence,addressing risks to agricultural soil ecosystems remains crucial.展开更多
The active biomonitoring (ABM) approach was investigated using species of indigenous (from a pristine site) and transplanted (to a polluted area) fish Carassius auratus as an indicator organism of water/sediment...The active biomonitoring (ABM) approach was investigated using species of indigenous (from a pristine site) and transplanted (to a polluted area) fish Carassius auratus as an indicator organism of water/sediment pollution in Taihu Lake, a highly urbanized and industrialized area. The biotransformation enzymes 7-ethoxyresorufin-O-deethylase (EROD), reduced glutathione (GSH) content, catalase activities (CAT) and lipoperoxidation (as MDA) in liver were determined as stress-related biomarkers during the field exposure period. At the same time, the contents of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and heavy metals in the surface sediments of biomonitoring sites were also determined. The results indicate that the in situ exposed organisms were stressed. The marked increases of EROD, GSH, CAT and MDA in transplanted animals, suggested their potential application as biomarkers in pollution monitoring. Integrated biomarker response (IBR) was used to evaluate an integrated impact of toxicants from different polluted sites.展开更多
Effects of river water from the Yangtze River (Nanjing section) on fish development, vitellogenin (VTG) induction, gonado-somatic index (GSI) and sex ratio were investigated by exposing goldfish (Carassius aura...Effects of river water from the Yangtze River (Nanjing section) on fish development, vitellogenin (VTG) induction, gonado-somatic index (GSI) and sex ratio were investigated by exposing goldfish (Carassius auratus) in the early life stage (from fertilization to 28 days post-hatch) to water samples (25%, 50% and 100%) collected from three representative sections. The results showed that there was no significant effect on hatching success for any of the exposure groups, but survival was significantly reduced when compared with the control (P 0.05). Body lengths, weights of all treated fish did not differ significantly from those of the control. Condition factors (CF) of larval fish exposed to 50% and 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section were significantly lower than that of the control (P 0.05). VTG inductions were significant in larval fish exposed to all the dilution series of river water. No significant difference in CF value was observed in any exposure group after 150 days of depuration. VTG was fully eliminated after 75 days of depuration. For both female and male, GSI did not significantly differ between exposure groups and the control after 150 days of convalescence. The highest female:male ratios were observed in response to the treatment with 50% or 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section (53:47, 56:44 and 54:46, respectively), but no significant difference in sex ratio was observed in any treated group when compared to the control. The results showed that early life stage exposure of river water from the Yangtze River (Nanjing section) had adverse effects on goldfish development and reproductive health, and the effects on CF and VTG were reversible after depuration in clean water.展开更多
Numerous studies have evaluated the toxicity and endocrine disrupting properties of organic UV filters for aquatic organisms,but little is known about their biodegradation in river sediments and their impact on microo...Numerous studies have evaluated the toxicity and endocrine disrupting properties of organic UV filters for aquatic organisms,but little is known about their biodegradation in river sediments and their impact on microorganisms.We have set up the sterile and microbiological systems in the laboratory,adding 2-ethylhexyl-4-methoxycinnamate(EHMC),one of organic UV filters included in the list of high yield chemicals,at concentrations of 2,20 and 200μg/L,and characterized the microbial community composition and diversity in sediments.Monitoring of EHMC degradation within 30 days revealed that the half-life in the microbial system(3.49 days)was much shorter than that in the sterile system(7.55 days).Two potential degradation products,4-mercaptobenzoic acid and 3-methoxyphenol were identified in the microbial system.Furthermore,high-throughput 16s and 18s rRNA gene sequencing showed that Proteobacteria dominated the sediment bacterial assemblages followed by Chloroflexi,Acidobacteria,Bacteroidetes and Nitrospirae;Eukaryota_uncultured fungus dominated the sediment fungal assemblages.Correlation analysis demonstrated that two bacterium genera(Anaerolineaceae_uncultured and Burkholderiaceae_uncultured)were significantly correlated with the biodegradation of EHMC.These results illustrate the biodegradability of EHMC in river sediments and its potential impact on microbial communities,which can provide useful information for eliminating the pollution of organic UV filters in natural river systems and assessing their potential ecological risks.展开更多
Clean and efficient treatment of high-mercury leachate produced from remediation of mercury-polluted soil has become a huge challenge for environmental scientists. In this work, cement solidification was firstly adopt...Clean and efficient treatment of high-mercury leachate produced from remediation of mercury-polluted soil has become a huge challenge for environmental scientists. In this work, cement solidification was firstly adopted to treat the high-concentration mercury leachate, which had high alkalinity. Different mercury concentrations, namely 3.120 mg/L Hg mercury leachate and 9.243 mg/L Hg mercury concentrated leachate, were separately solidified by Portland cement. The results indicated that simply using the cement can properly solidify both the leachates to meet the waste landfill standard, with liquid (mL)/solid (g) ratio (US ratio) of 4:10-6:10. In order to make full use of mercury in the leachates, a Hg extraction method was subsequently carried out under different experimental parameters, such as temperature and pH value. It was shown that the Hg extraction ratio could reach as high as 99.84% and almost all the mercury in the leachate could be transformed to HgS precipitate; moreover, the Hg concentration in the treated leachate was reduced from 3.120 to 0.005 mg/L at pH 2.98 and 30℃, which was much less than the limit of the national standard, indicating that the leachate had been completely cleaned and could be discharged freely. Hence, simple cement solidification renders high-mercury leachate nontoxic, and the Hg extraction method can successfully recover the Hg and enable the residual leachate to be discharged safely.展开更多
基金the Construction Plan of Scientific Research and Innovation Team of Colleges and Universities in Sichuan Province(18TD0017)Xinglin Scholar Research Promotion Project of Chengdu University of TCM(CXTD2018018)。
文摘[Objectives]To study the content and antidepressant effects of the flavonoids in the Zanthoxylum Pericarpium Residue(ZPR)and to provide a basis for the full utilization of ZPR.[Methods]The method for the assay of total flavonoids in ZPR by UV spectrophotometry was developed with rutin as reference.The total flavonoids were extracted and separated from ZPR.The contents of total flavonoids were quantified in ZPR and its extract.The autonomous activity test,tail suspension test and forced swimming test were conducted in mice,and the levels of malondialdehyde(MDA),superoxide dismutase(SOD)and total antioxidation were detected to evaluate the antidepressant effects of total flavonoids.[Results]The recovery rate of UV spectrophotometry was 98.88%(n=6).The contents of flavonoids in ZPR and its extract were 11.07%and 78.42%,respectively.In the autonomous activity test,compared with the control group,the standing times of mice in the positive drug group was significantly increased(P<0.05),but there was not significant difference among the low-,medium-and high-dose groups of total flavonoids extract(P>0.05),as well as there was no significant difference of the activity times among all groups(P>0.05).In the tail suspension and forced swimming tests,compared with the control group,the immobility time of the high-dose group of total flavonoids extract was significantly reduced(P>0.05),and the serum SOD levels of the low-,medium-and high-dose groups were significantly increased(P<0.05).The MDA levels of the middle-and high-dose groups of total flavonoids were significantly decreased(P<0.05),and the total antioxidant capacity was increased significantly(P<0.05).[Conclusions]The developed UV spectrophotometry can accurately detect the level of total flavonoids in ZPR.ZPR is rich in flavonoids,and has significant antidepressant effects,which may be related to eliminating internal free radicals and inhibiting lipid peroxidation.
基金Supported by Science and Technology Support Program of Sichuan Province of China(2016NYZ0036,2014SZ0131)
文摘[Objectives] The infrared fingerprint spectra of Gastrodia elata Blume of different origins and different varieties were studied.[Methods]One-dimensional infrared spectroscopy was used to analyze G. elata of different origins and different varieties. Based on the infrared spectra of 14 batches of G. elata,the common peak ratio and variant peak ratio were calculated,the double index sequences of common peak ratio and variant peak ratio were established to compare the similarities between the samples of G. elata. [Results] Infrared fingerprint spectra of G. elata of different origins and different varieties were obtained,and a total of 14 common peaks were calibrated. The maximum and minimum common peak ratios among the G. elata samples were 100. 00% and 73. 68%,respectively; and the maximum and minimum variant peak ratios were 21. 43% and 0%,respectively. [Conclusions]The combination of Fourier transform infrared spectroscopy and common peak ratio-variant peak ratio double-index analysis can provide scientific basis for the quality standard research of G. elata.
基金Supported by Sichuan Science and Technology Support Program Funding(No.2014SZ0132)
文摘[Objectives] To carry out infrared spectroscopic study of different growth years and different parts of the traditional Chinese medicine Radix Chuanmingshinis Violacei. [Methods]Using potassium bromide squash method and Fourier transform infrared spectroscopy on the different growth years and different parts of Radix Chuanmingshinis Violacei for infrared spectrum and second derivative spectrum. [Results]With the increasing growth time,Radix Chuanmingshinis Violacei accumulated in the secondary metabolism substances gradually increased,the characteristic absorption peak appeared in the position such as 3 366,2 927,1 634,1 416,1 516,1 080,1 020,and 928 cm^(-1),the main chemicals as polysaccharide,coumarin,saponins and steroids. The difference of chemical position between root tuber and cauline leaf is obvious. [Conclusions]Infrared spectroscopy was applied in studying different growing periods and different parts of Radix Chuanmingshinis Violacei,of obvious characteristics,identification and quality evaluation method,is simple and suitable for Radix Chuanmingshinis Violacei.
基金supported by the National Natural Science Foundation of China(Grant 52179063 and 42177353)the Natural Science Foundation of Jiangsu Province(BK20221505)the key program of National Natural Science Foundation of China(Grant 52039003).
文摘The presence of trace organic pollutants in the effluent of wastewater treatment plants(WWTPs)poses considerable risks to aquatic organisms and human health.A large-scale survey of 302 trace organic pollutants in the effluent of 46 Chinese WWTPs was conducted to gain an improved understanding of their occurrence and ecological risks.The survey data showed that 216 compounds in 11 chemical classes had been detected in effluents.The sum concentrations of the trace contaminants in effluent ranged from 1,392 ng/L to 35,453 ng/L,with the maximum concentration of perfluoroalkyl substances(PFASs)recorded as the highest(30,573 ng/L),which was markedly less than the reported 185,000 ng/L for the 38 American WWTPs.The concentration of bisphenol analogs(BPs)was up to 4,422 ng/L,significantly higher than those reported in France,Germany,Japan,Korea,and the U.S.PFASs and BPs were the major pollutants,accounting for 59%of the total pollution.Additionally,a total of 119 contaminants were found to have ecological risks(RQ>0.01).Among these,23 contaminants(RQ>1.0)warrant higher attention and should be prioritized for removal.This study lists valuable information for controlling contaminants with higher priority in WWTP effluent in China.
基金This study was supported by the Fundamental Research Funds for The Central Universities(No.B230201058)the National Natural Science Foundation of China(Grant 52179063 and 42177353)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20221505)the key program of National Natural Science Foundation of China(Grant 52039003).
文摘Bisphenol compounds(BPs)are commonly used in industry and agriculture.However,BPs pollution has already raised global concerns due to their ecological risks.This study investigated nine types of BPs in agricultural soil and irrigation rivers,and evaluated the occurrence,source apportionment,and ecological risks for BPs in soils of agricultural environment by using principal component analysis-multivariate linear regression(PCA-MLR)and risk quotients(RQ).The average concentration of BPs in soil,irrigation water and sediments were 29.19 ng/g,30.21 ng/L and 610.09 ng/g dw,respectively.BPA was the most highly detected contaminant in all media.In soil,the primary BPA substitutes were bisphenol S(BPS)and bisphenol F(BPF),contributing about 50%to the pollution in total.PCA-MLR analysis indicated that the release of solid waste was the primary cause of BPs pollution in the agricultural soils,following by waste water discharge.The evaluation of RQ revealed that BPs presented a low to medium risk to algae,daphnia,and fish in irrigation rivers,while more than 90% of soil sampling sites faced medium or high risk,with BPA and BPS as the main contributors to the risk.The research findings offer evidence to support the assessment of contaminants concentration,source pathways,and risk management strategies pertaining to BPs in the agricultural system.With ongoing BPA substitute occurrence,addressing risks to agricultural soil ecosystems remains crucial.
基金supported by the Project of Ministry of Education Key Laboratory of Integrated Regulationand Resource Development on Shallow Lakes,HohaiUniversity(No.2008KJ001)the National Basic Research Program(973) of China(No.2008CB418203)+1 种基金the Key Project of Chinese Ministry of Education(No.109076)the State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering under Project No.2008490811
文摘The active biomonitoring (ABM) approach was investigated using species of indigenous (from a pristine site) and transplanted (to a polluted area) fish Carassius auratus as an indicator organism of water/sediment pollution in Taihu Lake, a highly urbanized and industrialized area. The biotransformation enzymes 7-ethoxyresorufin-O-deethylase (EROD), reduced glutathione (GSH) content, catalase activities (CAT) and lipoperoxidation (as MDA) in liver were determined as stress-related biomarkers during the field exposure period. At the same time, the contents of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and heavy metals in the surface sediments of biomonitoring sites were also determined. The results indicate that the in situ exposed organisms were stressed. The marked increases of EROD, GSH, CAT and MDA in transplanted animals, suggested their potential application as biomarkers in pollution monitoring. Integrated biomarker response (IBR) was used to evaluate an integrated impact of toxicants from different polluted sites.
基金supported by the National Natural Science Foundation of China (No. 51079049)the National Basic Research Program (973) of China (No. 2010CB429006)
文摘Effects of river water from the Yangtze River (Nanjing section) on fish development, vitellogenin (VTG) induction, gonado-somatic index (GSI) and sex ratio were investigated by exposing goldfish (Carassius auratus) in the early life stage (from fertilization to 28 days post-hatch) to water samples (25%, 50% and 100%) collected from three representative sections. The results showed that there was no significant effect on hatching success for any of the exposure groups, but survival was significantly reduced when compared with the control (P 0.05). Body lengths, weights of all treated fish did not differ significantly from those of the control. Condition factors (CF) of larval fish exposed to 50% and 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section were significantly lower than that of the control (P 0.05). VTG inductions were significant in larval fish exposed to all the dilution series of river water. No significant difference in CF value was observed in any exposure group after 150 days of depuration. VTG was fully eliminated after 75 days of depuration. For both female and male, GSI did not significantly differ between exposure groups and the control after 150 days of convalescence. The highest female:male ratios were observed in response to the treatment with 50% or 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section (53:47, 56:44 and 54:46, respectively), but no significant difference in sex ratio was observed in any treated group when compared to the control. The results showed that early life stage exposure of river water from the Yangtze River (Nanjing section) had adverse effects on goldfish development and reproductive health, and the effects on CF and VTG were reversible after depuration in clean water.
基金supported by the National Natural Science Foundation of China(Nos.51879228,51769034)the National Science Funds for Creative Research Groups of China(No.51421006)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Numerous studies have evaluated the toxicity and endocrine disrupting properties of organic UV filters for aquatic organisms,but little is known about their biodegradation in river sediments and their impact on microorganisms.We have set up the sterile and microbiological systems in the laboratory,adding 2-ethylhexyl-4-methoxycinnamate(EHMC),one of organic UV filters included in the list of high yield chemicals,at concentrations of 2,20 and 200μg/L,and characterized the microbial community composition and diversity in sediments.Monitoring of EHMC degradation within 30 days revealed that the half-life in the microbial system(3.49 days)was much shorter than that in the sterile system(7.55 days).Two potential degradation products,4-mercaptobenzoic acid and 3-methoxyphenol were identified in the microbial system.Furthermore,high-throughput 16s and 18s rRNA gene sequencing showed that Proteobacteria dominated the sediment bacterial assemblages followed by Chloroflexi,Acidobacteria,Bacteroidetes and Nitrospirae;Eukaryota_uncultured fungus dominated the sediment fungal assemblages.Correlation analysis demonstrated that two bacterium genera(Anaerolineaceae_uncultured and Burkholderiaceae_uncultured)were significantly correlated with the biodegradation of EHMC.These results illustrate the biodegradability of EHMC in river sediments and its potential impact on microbial communities,which can provide useful information for eliminating the pollution of organic UV filters in natural river systems and assessing their potential ecological risks.
基金supported by the National Natural Science Foundation of China(Nos.51672025,51572020,51372019)Major Projects of Science and Technology in Shanxi Province(No.MC2016-03)
文摘Clean and efficient treatment of high-mercury leachate produced from remediation of mercury-polluted soil has become a huge challenge for environmental scientists. In this work, cement solidification was firstly adopted to treat the high-concentration mercury leachate, which had high alkalinity. Different mercury concentrations, namely 3.120 mg/L Hg mercury leachate and 9.243 mg/L Hg mercury concentrated leachate, were separately solidified by Portland cement. The results indicated that simply using the cement can properly solidify both the leachates to meet the waste landfill standard, with liquid (mL)/solid (g) ratio (US ratio) of 4:10-6:10. In order to make full use of mercury in the leachates, a Hg extraction method was subsequently carried out under different experimental parameters, such as temperature and pH value. It was shown that the Hg extraction ratio could reach as high as 99.84% and almost all the mercury in the leachate could be transformed to HgS precipitate; moreover, the Hg concentration in the treated leachate was reduced from 3.120 to 0.005 mg/L at pH 2.98 and 30℃, which was much less than the limit of the national standard, indicating that the leachate had been completely cleaned and could be discharged freely. Hence, simple cement solidification renders high-mercury leachate nontoxic, and the Hg extraction method can successfully recover the Hg and enable the residual leachate to be discharged safely.