Objective To examine the effects of chlorogenic acid （CGA） on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α （PPAR-α...Objective To examine the effects of chlorogenic acid （CGA） on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α （PPAR-α） in these effects. Methods Twenty male golden hamsters were randomly divided into CGA treatment group （n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily）, and control group （n=10, given PBS i.p. at the average volume of the treatment group）. Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-α were determined. Results Eight weeks after treatment with CGA, the levels of fasting serum triglyceride （TG）, free fatty acid （FFA）, total cholesterol （TC）, low density lipoprotein cholesterol （LDL-C）, high density lipoprotein cholesterol （HDL-C）, glucose （FSG）, and insulin （FSI） were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase （HL） lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase （LPL） in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-α. Conclusion CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-α facilitated lipid clearance in liver and improved insulin sensitivity.展开更多
Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleachin...Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice. It is worthwhile tonote that in this study, Zn, Mn, Fe, As and Ni in the first leachate exceeded the total amount of eachcorresponding water-extractable (1:5, soil:water) metal contained in the minespoil sample. This appears tosuggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of theabove heavy metals. This work has implications for the management of sulfidic minespoils. Acid drainageof great environmental concerns is likely to occur only during heavy rainfall events after substantial solubleand readily exchangeable acid and metals are accumulated in the minespoils. The slow-reacting fractionsother than water-soluble and readily exchangeable fractions may pose little environmental hazards. This isparticularly true for Pb, As and Ni.展开更多
Mine tailings, waste rock piles, acid mine drainage, industrial wastewater, and sewage sludge have contaminated a vast area of cultivable and fallow lands, with a consequence of deterioration of soil and water quality...Mine tailings, waste rock piles, acid mine drainage, industrial wastewater, and sewage sludge have contaminated a vast area of cultivable and fallow lands, with a consequence of deterioration of soil and water quality and watercourses due to the erosion of contaminated soils for absence of vegetative cover. High concentrations of toxic elements, organic contaminants, acidic soils, and harsh climatic conditions have made it difficult to re-establish vegetation and produce crops there. Recently, a significant body of work has focussed on the suitability and potentiality of biochar as a soil remediation tool that increases seed emergence, soil and crop productivity, above ground biomass, and vegetation cover on mine tailings, waste rock piles, and industrial and sewage waste- contaminated soils by increasing soil nutrients and water-holding capacity, amelioration of soil acidity, and stimulation of microbial diversity and functions. This review addresses： i） the functional properties of biochar, and microbial cycling of nutrients in soil; ii） bioremediation, especially phytoremediation of mine railings, industrial waste, sewage sludge, and contaminated soil using biochar; iii） impact of biochar on reduction of acid production, acid mine drainage treatment, and geochemical dynamics in mine railings; and iv） treatment of metal and organic contaminants in soils using biochar, and restoration of degraded land.展开更多
Formation of acid mine drainage(AMD)is a widespread environmental issue that has not subsided throughout decades of continuing research.Highly acidic and highly concentrated metallic streams are characteristics of suc...Formation of acid mine drainage(AMD)is a widespread environmental issue that has not subsided throughout decades of continuing research.Highly acidic and highly concentrated metallic streams are characteristics of such streams.Humans,plants and surrounding ecosystems that are in proximity to AMD producing sites face immediate threats.Remediation options include active and passive biological treatments which are markedly different in many aspects.Sulfate reducing bacteria(SRB)remove sulfate and heavy metals to generate non-toxic streams.Passive systems are inexpensive to operate but entail fundamental drawbacks such as large land requirements and prolonged treatment period.Active bioreactors offer greater operational predictability and quicker treatment time but require higher investment costs and wide scale usage is limited by lack of expertise.Recent advancements include the use of renewable raw materials for AMD clean up purposes,which will likely achieve much greener mitigation solutions.展开更多
AIM: To investigate the effect of biliary drainage on inducible nitric oxide synthase (iNOS), CD14 and TGR5 expression in rats with obstructive jaundice (OJ). METHODS: Male adult Sprague-Dawley rats were randomly assi...AIM: To investigate the effect of biliary drainage on inducible nitric oxide synthase (iNOS), CD14 and TGR5 expression in rats with obstructive jaundice (OJ). METHODS: Male adult Sprague-Dawley rats were randomly assigned to four groups: OJ, sham operation (SH), internal biliary drainage (ID) and external biliary drainage (ED). Rat models were successfully established by two operations and succumbed for extraction of Kupffer cells (KCs) and liver tissue collection on the 8 th and 15 th day. KCs were isolated by in situ hepatic perfusion and digested with collagen Ⅳ, density gradient centrifuged by percoll reagent and purified by cell culture attachment. The isolated KCs were cultured with the endotoxin lipopolysaccharide (LPS) with and without the addition of ursodeoxycholic acid (UDCA). The expression of iNOS, CD14 and bile acid receptor-TGR5 protein in rat liver tissues was determined by immunohistochemistry. The expression of iNOS and CD14 messenger RNA (mRNA) on the isolated KCs was detected by reverse transcription polymerase chain reaction (PCR) and the TGR5 mRNA level in KCs was measured by real-time quantitative PCR. RESULTS: The iNOS protein was markedly expressed in the liver of OJ rats, but rare expressed in SH rats. After relief of OJ, the iNOS expression was decidedly suppressed in the ID group (ID vs OJ, P < 0.01), but obviously increased in rats of ED (ED vs OJ, P=0.004). When interfered only with LPS, the expression of iNOS mRNA by KCs was increased in the OJ group compared with the SH group (P=0.004). After relief of biliary obstruction, the iNOS mRNA expression showed slight changes in the ED group (ED vs OJ, P=0.71), but dropped in the ID group (ID vs OJ, P=0.001). Compared with the simple intervention with LPS, the expressions of iNOS mRNA were significantly inhibited in all four groups after interfered with both LPS and UDCA (P < 0.01, respectively). After bile duct ligation, the CD14 protein expression in rat liver was significantly strengthened (OJ vs SH, P < 0.01), but the CD14 mRNA leve展开更多
The issues of acid mine drainage （AMD） and heavy metals contamination in the metal sulfide mine in the add district were explored, through studying the acidification and the heavy metals distribution and evolution o...The issues of acid mine drainage （AMD） and heavy metals contamination in the metal sulfide mine in the add district were explored, through studying the acidification and the heavy metals distribution and evolution of groundwater in the black swan （BS） nickel sulfide mine （Western Australia）. The groundwater samples were collected from the drilling holes situated in the vicinity of tailings storage facility （TSF） and in the background of the mine （away from TSF）, respectively, and the pH and electric conductivity （Ec） were measured in site and the metal contents were analysed by ICP-MS and ICP-AES, quarterly in one hydrological year. The results disclose that the TSF groundwater is remarkably acidified （.pHmean=5, pHmin=3）, and the average contents of heavy metals （Co, Cu, Zn, Cd） and Al, Mn are of 1-2 orders of magnitude higher in TSF groundwater than in background groundwater. It may be due to the percolation of tailings waste water from miU process, which leads the tailings to oxidize and the deep groundwater to acidify and contaminate with heavy metals. Besides, the heavy metals concentration in groundwater may be controlled by pH mainly.展开更多
Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact betwe...Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact between microbial cells and growth substrates, having a pivotal role in organic film formation and bacterium-substratum interactions. The production and chemical composition of EPS produced by seven bioleaching strains grown with different substrates were studied. Analysis of the EPS extracted from these strains indicated that the EPS consisted of carbohydrates, proteins and galacturonic acid. The contents of EPS, carbohydrates, proteins and galacturonic acid of EPS were largely related to the kind of strain used and culture condition. The results show that EPS productions of microbes grown with pyrite were significantly higher than those of microbes grown with sulfur or FeSO4·7H2O. The highest EPS production of the seven acidiphilic strains was （159.43±3.93） mg/g, which was produced by Leptospirillum ferriphilum CBCBSUCSU208015 when cultivated with pyrite.展开更多
背景:人工膝关节置换是治疗终末期膝关节骨性关节炎的有效方法,可以明显缓解疼痛,改善功能。但术后大量失血是其较为严重的并发症之一,如何减少术后失血一直困扰着关节外科医生。目的:探讨不同剂量氨甲环酸关节内局部应用结合不放置引...背景:人工膝关节置换是治疗终末期膝关节骨性关节炎的有效方法,可以明显缓解疼痛,改善功能。但术后大量失血是其较为严重的并发症之一,如何减少术后失血一直困扰着关节外科医生。目的:探讨不同剂量氨甲环酸关节内局部应用结合不放置引流减少全膝关节置换后失血的效果。方法:选择行全膝关节置换的150例骨关节炎患者,随机分成3组,每组50例。A组为关节腔注射氨甲环酸2 g加生理盐水稀释至50 m L;B组为关节腔注射氨甲环酸1 g加生理盐水稀释至50 m L;C组为对照组,关节内注射生理盐水50 m L,均不放置引流。记录和比较3组患者术后不同时间点的血红蛋白值、输血人数、术中失血量、术后显性失血量、术后隐性失血量、术后总失血量和术后3 h相关凝血指标,观察有无切口感染、下肢深静脉血栓形成等并发症发生。结果与结论:(1)3组患者相比,术后第1,3,5天血红蛋白值差异均有显著性意义(F=7.218-7.516,P=0.000);(2)术后A,B,C组患者输血人数分别为2,5和9例,差异亦有显著性意义(χ~2=5.753,P=0.000);(3)3组患者之间术中失血量差异无显著性意义(F=1.206,P=5.283),术后显性失血量比较差异有显著性意义(F=14.389,P=0.000),术后隐性失血量差异有显著性意义(F=7.158,P=0.009),术后总失血量差异亦有显著性意义(F=6.752,P=0.012),且止血效果与氨甲环酸呈剂量依赖效应;(4)3组患者术后3 h凝血指标比较差异无显著性意义(P>0.05);(5)术后1周复查下肢血管彩超,未见明显下肢深静脉血栓形成;术后3个月内观察3组患者未见症状性深静脉血栓和肺栓塞发生;(6)综上,全膝关节置换术中关节内注射氨甲环酸且不放置引流,可以有效减少围手术期失血和输血,不增加并发症,且止血效果与氨甲环酸呈剂量依赖关系。展开更多
Arsenic(As)speciation transformation in acid mine drainage(AMD)is comprehensively affected by biological and abiotic factors,such as microbially mediated Fe/S redox reactions and changes in environmental conditions(pH...Arsenic(As)speciation transformation in acid mine drainage(AMD)is comprehensively affected by biological and abiotic factors,such as microbially mediated Fe/S redox reactions and changes in environmental conditions(pH and oxidation-reduction potential).However,their combined impacts on arsenic speciation transformation remain poorly studied.Therefore,we explored arsenic transformation and immobilization during pyrite dissolution mediated by AMD enrichment culture under different acidic pH conditions.The results for incubation and mineralogical transformation of solid residues show that in the presence of AMD enrichment culture,pH 2.0,2.5,and 3.0 are more conducive to the formation of jarosites and ferric arsenate,which could immobilize high quantities of dissolved arsenic by adsorption and coprecipitation.The pH conditions significantly affect the initial adsorption of microbial cells to the minerals and the evolution of microbial community structure,further infuencing the biodissolution of pyrite and the release and oxidation process of Fe/S.The results of Fe/S/As speciation transformation of the solid residues show that the transformation of Fe,S,and As in solution is mainly regulated by pH and potential values,which imposed significantly different effects on the formation of secondary minerals and thus arsenic oxidation and immobilization.The above results indicated that arsenic transformation is closely related to the Fe/S oxidation associated with pyrite bio-oxidation,and this correlation is critically regulated by the pH conditions of the system.展开更多
基金supported by 2003 Nutrition Research Fund of Chinese Nutrition Society
文摘Objective To examine the effects of chlorogenic acid （CGA） on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α （PPAR-α） in these effects. Methods Twenty male golden hamsters were randomly divided into CGA treatment group （n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily）, and control group （n=10, given PBS i.p. at the average volume of the treatment group）. Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-α were determined. Results Eight weeks after treatment with CGA, the levels of fasting serum triglyceride （TG）, free fatty acid （FFA）, total cholesterol （TC）, low density lipoprotein cholesterol （LDL-C）, high density lipoprotein cholesterol （HDL-C）, glucose （FSG）, and insulin （FSI） were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase （HL） lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase （LPL） in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-α. Conclusion CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-α facilitated lipid clearance in liver and improved insulin sensitivity.
基金Project partly supported by an internal grant of Southern Cross University,Australia(Project No.305093).
文摘Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice. It is worthwhile tonote that in this study, Zn, Mn, Fe, As and Ni in the first leachate exceeded the total amount of eachcorresponding water-extractable (1:5, soil:water) metal contained in the minespoil sample. This appears tosuggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of theabove heavy metals. This work has implications for the management of sulfidic minespoils. Acid drainageof great environmental concerns is likely to occur only during heavy rainfall events after substantial solubleand readily exchangeable acid and metals are accumulated in the minespoils. The slow-reacting fractionsother than water-soluble and readily exchangeable fractions may pose little environmental hazards. This isparticularly true for Pb, As and Ni.
文摘Mine tailings, waste rock piles, acid mine drainage, industrial wastewater, and sewage sludge have contaminated a vast area of cultivable and fallow lands, with a consequence of deterioration of soil and water quality and watercourses due to the erosion of contaminated soils for absence of vegetative cover. High concentrations of toxic elements, organic contaminants, acidic soils, and harsh climatic conditions have made it difficult to re-establish vegetation and produce crops there. Recently, a significant body of work has focussed on the suitability and potentiality of biochar as a soil remediation tool that increases seed emergence, soil and crop productivity, above ground biomass, and vegetation cover on mine tailings, waste rock piles, and industrial and sewage waste- contaminated soils by increasing soil nutrients and water-holding capacity, amelioration of soil acidity, and stimulation of microbial diversity and functions. This review addresses： i） the functional properties of biochar, and microbial cycling of nutrients in soil; ii） bioremediation, especially phytoremediation of mine railings, industrial waste, sewage sludge, and contaminated soil using biochar; iii） impact of biochar on reduction of acid production, acid mine drainage treatment, and geochemical dynamics in mine railings; and iv） treatment of metal and organic contaminants in soils using biochar, and restoration of degraded land.
基金supported by the Fundamental Research Grant Scheme,Malaysia[FRGS/1/2019/STG05/UNIM/02/2].
文摘Formation of acid mine drainage(AMD)is a widespread environmental issue that has not subsided throughout decades of continuing research.Highly acidic and highly concentrated metallic streams are characteristics of such streams.Humans,plants and surrounding ecosystems that are in proximity to AMD producing sites face immediate threats.Remediation options include active and passive biological treatments which are markedly different in many aspects.Sulfate reducing bacteria(SRB)remove sulfate and heavy metals to generate non-toxic streams.Passive systems are inexpensive to operate but entail fundamental drawbacks such as large land requirements and prolonged treatment period.Active bioreactors offer greater operational predictability and quicker treatment time but require higher investment costs and wide scale usage is limited by lack of expertise.Recent advancements include the use of renewable raw materials for AMD clean up purposes,which will likely achieve much greener mitigation solutions.
基金Supported by National Natural Science Foundation of China,No. 30470790 and 30971355
文摘AIM: To investigate the effect of biliary drainage on inducible nitric oxide synthase (iNOS), CD14 and TGR5 expression in rats with obstructive jaundice (OJ). METHODS: Male adult Sprague-Dawley rats were randomly assigned to four groups: OJ, sham operation (SH), internal biliary drainage (ID) and external biliary drainage (ED). Rat models were successfully established by two operations and succumbed for extraction of Kupffer cells (KCs) and liver tissue collection on the 8 th and 15 th day. KCs were isolated by in situ hepatic perfusion and digested with collagen Ⅳ, density gradient centrifuged by percoll reagent and purified by cell culture attachment. The isolated KCs were cultured with the endotoxin lipopolysaccharide (LPS) with and without the addition of ursodeoxycholic acid (UDCA). The expression of iNOS, CD14 and bile acid receptor-TGR5 protein in rat liver tissues was determined by immunohistochemistry. The expression of iNOS and CD14 messenger RNA (mRNA) on the isolated KCs was detected by reverse transcription polymerase chain reaction (PCR) and the TGR5 mRNA level in KCs was measured by real-time quantitative PCR. RESULTS: The iNOS protein was markedly expressed in the liver of OJ rats, but rare expressed in SH rats. After relief of OJ, the iNOS expression was decidedly suppressed in the ID group (ID vs OJ, P < 0.01), but obviously increased in rats of ED (ED vs OJ, P=0.004). When interfered only with LPS, the expression of iNOS mRNA by KCs was increased in the OJ group compared with the SH group (P=0.004). After relief of biliary obstruction, the iNOS mRNA expression showed slight changes in the ED group (ED vs OJ, P=0.71), but dropped in the ID group (ID vs OJ, P=0.001). Compared with the simple intervention with LPS, the expressions of iNOS mRNA were significantly inhibited in all four groups after interfered with both LPS and UDCA (P < 0.01, respectively). After bile duct ligation, the CD14 protein expression in rat liver was significantly strengthened (OJ vs SH, P < 0.01), but the CD14 mRNA leve
基金Projects(40972220,40873030) supported by the National Natural Science Foundation of ChinaProject(0991024) supported by the Special Project for Applied Basic Research of Guangxi,China
文摘The issues of acid mine drainage （AMD） and heavy metals contamination in the metal sulfide mine in the add district were explored, through studying the acidification and the heavy metals distribution and evolution of groundwater in the black swan （BS） nickel sulfide mine （Western Australia）. The groundwater samples were collected from the drilling holes situated in the vicinity of tailings storage facility （TSF） and in the background of the mine （away from TSF）, respectively, and the pH and electric conductivity （Ec） were measured in site and the metal contents were analysed by ICP-MS and ICP-AES, quarterly in one hydrological year. The results disclose that the TSF groundwater is remarkably acidified （.pHmean=5, pHmin=3）, and the average contents of heavy metals （Co, Cu, Zn, Cd） and Al, Mn are of 1-2 orders of magnitude higher in TSF groundwater than in background groundwater. It may be due to the percolation of tailings waste water from miU process, which leads the tailings to oxidize and the deep groundwater to acidify and contaminate with heavy metals. Besides, the heavy metals concentration in groundwater may be controlled by pH mainly.
文摘Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact between microbial cells and growth substrates, having a pivotal role in organic film formation and bacterium-substratum interactions. The production and chemical composition of EPS produced by seven bioleaching strains grown with different substrates were studied. Analysis of the EPS extracted from these strains indicated that the EPS consisted of carbohydrates, proteins and galacturonic acid. The contents of EPS, carbohydrates, proteins and galacturonic acid of EPS were largely related to the kind of strain used and culture condition. The results show that EPS productions of microbes grown with pyrite were significantly higher than those of microbes grown with sulfur or FeSO4·7H2O. The highest EPS production of the seven acidiphilic strains was （159.43±3.93） mg/g, which was produced by Leptospirillum ferriphilum CBCBSUCSU208015 when cultivated with pyrite.
文摘背景:人工膝关节置换是治疗终末期膝关节骨性关节炎的有效方法,可以明显缓解疼痛,改善功能。但术后大量失血是其较为严重的并发症之一,如何减少术后失血一直困扰着关节外科医生。目的:探讨不同剂量氨甲环酸关节内局部应用结合不放置引流减少全膝关节置换后失血的效果。方法:选择行全膝关节置换的150例骨关节炎患者,随机分成3组,每组50例。A组为关节腔注射氨甲环酸2 g加生理盐水稀释至50 m L;B组为关节腔注射氨甲环酸1 g加生理盐水稀释至50 m L;C组为对照组,关节内注射生理盐水50 m L,均不放置引流。记录和比较3组患者术后不同时间点的血红蛋白值、输血人数、术中失血量、术后显性失血量、术后隐性失血量、术后总失血量和术后3 h相关凝血指标,观察有无切口感染、下肢深静脉血栓形成等并发症发生。结果与结论:(1)3组患者相比,术后第1,3,5天血红蛋白值差异均有显著性意义(F=7.218-7.516,P=0.000);(2)术后A,B,C组患者输血人数分别为2,5和9例,差异亦有显著性意义(χ~2=5.753,P=0.000);(3)3组患者之间术中失血量差异无显著性意义(F=1.206,P=5.283),术后显性失血量比较差异有显著性意义(F=14.389,P=0.000),术后隐性失血量差异有显著性意义(F=7.158,P=0.009),术后总失血量差异亦有显著性意义(F=6.752,P=0.012),且止血效果与氨甲环酸呈剂量依赖效应;(4)3组患者术后3 h凝血指标比较差异无显著性意义(P>0.05);(5)术后1周复查下肢血管彩超,未见明显下肢深静脉血栓形成;术后3个月内观察3组患者未见症状性深静脉血栓和肺栓塞发生;(6)综上,全膝关节置换术中关节内注射氨甲环酸且不放置引流,可以有效减少围手术期失血和输血,不增加并发症,且止血效果与氨甲环酸呈剂量依赖关系。
基金supported by the National Natural Science Foundation of China (NSFC) (No.41830318)the Joint Funds of the NSFC-DFG (No.51861135305)。
文摘Arsenic(As)speciation transformation in acid mine drainage(AMD)is comprehensively affected by biological and abiotic factors,such as microbially mediated Fe/S redox reactions and changes in environmental conditions(pH and oxidation-reduction potential).However,their combined impacts on arsenic speciation transformation remain poorly studied.Therefore,we explored arsenic transformation and immobilization during pyrite dissolution mediated by AMD enrichment culture under different acidic pH conditions.The results for incubation and mineralogical transformation of solid residues show that in the presence of AMD enrichment culture,pH 2.0,2.5,and 3.0 are more conducive to the formation of jarosites and ferric arsenate,which could immobilize high quantities of dissolved arsenic by adsorption and coprecipitation.The pH conditions significantly affect the initial adsorption of microbial cells to the minerals and the evolution of microbial community structure,further infuencing the biodissolution of pyrite and the release and oxidation process of Fe/S.The results of Fe/S/As speciation transformation of the solid residues show that the transformation of Fe,S,and As in solution is mainly regulated by pH and potential values,which imposed significantly different effects on the formation of secondary minerals and thus arsenic oxidation and immobilization.The above results indicated that arsenic transformation is closely related to the Fe/S oxidation associated with pyrite bio-oxidation,and this correlation is critically regulated by the pH conditions of the system.
