The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the ...The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.展开更多
Some enzymatic activities were determined in the areas polluted by tailings from Tiantai Pb-Zn-Ag Mine in Zhejiang Province of China. The results indicated the soil enzymatic activities decreased significantly with in...Some enzymatic activities were determined in the areas polluted by tailings from Tiantai Pb-Zn-Ag Mine in Zhejiang Province of China. The results indicated the soil enzymatic activities decreased significantly with increase of concentrations of heavy metals or the distance away from mining tailing center, especially dehydrogenase and urease activities. Multivariate regression analysis between heavy metal contents and soil enzymatic activities indicated that single dehydrogenase activity was very significantly correlated to combined effect of soil heavy metals in mine area. Moreover, single urease, protease and acid phosphatase activities were significantly related to the combined effect of heavy metals. The results suggest it is feasible to use soil enzymatic activities to indicate the pollution situation by combined heavy metals in the soil of mine area.展开更多
Two new d;metal-based metal-organic frameworks,{[Zn;（btc）;（bib）;（H;O）;]·2H;O};（1）and{[Cd;（btc）;（bib）;（H;O）;]·6H;O};（2）(btc=1,3,5-benzenetricarboxylate anion,bib=1,4-bis（1-imidazolyl）benzene...Two new d;metal-based metal-organic frameworks,{[Zn;（btc）;（bib）;（H;O）;]·2H;O};（1）and{[Cd;（btc）;（bib）;（H;O）;]·6H;O};（2）(btc=1,3,5-benzenetricarboxylate anion,bib=1,4-bis（1-imidazolyl）benzene)have been prepared under hydrothermal conditions by the reactions of d;metal oxides of ZnO and CdO with the aromatic polycarboxylic H;btc and the N-heterocyclic bib.The two products were characterized by single-crystal X-ray diffraction analysis,elemental analysis,thermogravimetric analysis（TGA）,and IR spectroscopy.Complexes 1 and 2 crystallize in monoclinic C2/c and triclinic P 1 space groups,respectively.1 shows a 3D framework,and the potential large voids of the 3D network lead to a 3-fold interpenetrating architecture.2 displays a 2D framework,and the adjacent 2D layers expand into a 3D supramulecular network via rich hydrogen bonds.Moreover,the luminescent properties of the two complexes are investigated in solid state.展开更多
A field experiment was conducted to compare the growth and metal accumulation of Vetiveria zizanioides, Paspalum notatum, Cynodon dactylon and Imperata cylindraca var. major on the tailings, amended with 10 cm domesti...A field experiment was conducted to compare the growth and metal accumulation of Vetiveria zizanioides, Paspalum notatum, Cynodon dactylon and Imperata cylindraca var. major on the tailings, amended with 10 cm domestic refuse + complex NPK fertilizer(Treatment A), 10 cm domestic refuse(Treatment B) and complex NPK fertilizer(Treatment C) respectively, and without any amendment used as control(Treatment D). The results indicated that V. zizanioides was a typical heavy metal excluder, because the concentrations in shoots of the plants were the lowest among the four plants tested. The most of metal accumulated in V. zizanioides distributed in its root, and transportation of metal in this plant from root to shoot was restricted. Therefore, V. zizanioides was more suitable for phytostabilization of toxic mined lands than P. notatum and C. dactylon, which accumulated a relatively high level of metals in their shoots and roots. It was also found that I. cylindraca var. major accumulated lower amounts of Pb, Zn and Cu than C. dactylon and P. notatum, and could also be considered for phytostalilisaton of tailings. Although the metal(Pb, Zn and Cu) concentrations in shoots and roots of V. zizanioides were the lowest, the total amounts of heavy metals accumulated in shoots of V. zizanioides were the highest among the four tested plants due to the highest dry weight yield of it. The results indicated that V. zizanioides was the best choice among the four species used for phytoremediation(for both phytostabilization and phytoextraction) of metal contaminated soils.展开更多
A new metal-organic framework(MOF) with the chemical formula of [Ni_(2) F_2(4,4'-Bipy)_(2)(H_(2) O)_(2)](VO_(3))_(2)·8 H_(2) O was introduced to adsorb Pb(Ⅱ) with the highest capacity.The sorbent was charact...A new metal-organic framework(MOF) with the chemical formula of [Ni_(2) F_2(4,4'-Bipy)_(2)(H_(2) O)_(2)](VO_(3))_(2)·8 H_(2) O was introduced to adsorb Pb(Ⅱ) with the highest capacity.The sorbent was characterized by thermogravimetric analysis(TGA),infrared spectroscopy(FT-IR),field-emission scanning electron microscopy(FESEM),energy-dispersive Xray(EDX),and elemental analysis.The optimum conditions were obtained by a face-centered central composite design(FCCD) as follows:adsorbent dosage(m)=1.2 mg, initial concentration of Pb(Ⅱ)(C)=390 mg·L^(-1),and pH=5.According to the Langmuir model(R~2=0.9999),the maximum monolayer uptake capacity of lead(Ⅱ) is 2400.7 mg·g^(-1),which is the highe st observed amount for lead(Ⅱ) adsorption.Neither of the old adsorbents for lead(Ⅱ)has the uptake capacity over 2000 mg·g^(-1).The model of pseudo-second-order describes well the process kinetics.The adsorption process of lead(Ⅱ) is independent of temperature changes.This compound can adsorb lead(Ⅱ) from tap water.In addition to introducing a new MOF with the highest uptake capacity for removal of Pb(Ⅱ) that is the outright novelty of this study,the concurrent modeling of both the removal percent(R) and the uptake capacity(q) is another important advantage.Because it achieves the more economical and favorable optimum conditions in comparison with the single optimization of each response.展开更多
A bstract Cadmium(Cd) is one of the most common and widespread heavy metals in the environment. Cd has adverse effects on photosynthesis that are countered by photosystem I(PSI) and photosystem II(PSII); however, the ...A bstract Cadmium(Cd) is one of the most common and widespread heavy metals in the environment. Cd has adverse effects on photosynthesis that are countered by photosystem I(PSI) and photosystem II(PSII); however, the protective responses of these photosystems to heavy metal stress remain unclear. Using the model diatom P haeodactylum tricornutum, a biological indicator that is widely used to assess the impact of environmental toxins, we simultaneously measured the effects of Cd on PSI and PSII and examined the levels of pigments in response to high light treatments before and after Cd exposure. Cd significantly reduced the quantum yield and electron transport rates of PSI and PSII. The quantum yield of non-photochemical energy dissipation in PSI due to donor side limitation increased faster than the quantum yield due to acceptor side limitation. The Cd treatment activated the P. tricornutum xanthophyll cycle under artificial light conditions, as indicated by an increased diatoxanthin content. Xanthophyll is important for photoprotection; therefore, the accumulation of diatoxanthin may down-regulate PSII activities to reduce oxidative damage. Together, our results suggest that the rapid reduction in PSII activities following Cd exposure is an adaptive response to heavy metal stress that reflects the variable exposure to external stressors in the native P. tricornutum environment.展开更多
基金supported by the project of China Geology Survey(12120115032801,DD20190340)。
文摘The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.
文摘Some enzymatic activities were determined in the areas polluted by tailings from Tiantai Pb-Zn-Ag Mine in Zhejiang Province of China. The results indicated the soil enzymatic activities decreased significantly with increase of concentrations of heavy metals or the distance away from mining tailing center, especially dehydrogenase and urease activities. Multivariate regression analysis between heavy metal contents and soil enzymatic activities indicated that single dehydrogenase activity was very significantly correlated to combined effect of soil heavy metals in mine area. Moreover, single urease, protease and acid phosphatase activities were significantly related to the combined effect of heavy metals. The results suggest it is feasible to use soil enzymatic activities to indicate the pollution situation by combined heavy metals in the soil of mine area.
基金Supported by the National Natural Science Foundation of China(No.21373178,21663031 and 21503183)the Scientific Research Foundation of Shaanxi Provincial Education Department(No.16JK1857)the Natural Scientific Research Foundation of Yan’an City Technology Division of China(No.2016kg-01)
文摘Two new d;metal-based metal-organic frameworks,{[Zn;（btc）;（bib）;（H;O）;]·2H;O};（1）and{[Cd;（btc）;（bib）;（H;O）;]·6H;O};（2）(btc=1,3,5-benzenetricarboxylate anion,bib=1,4-bis（1-imidazolyl）benzene)have been prepared under hydrothermal conditions by the reactions of d;metal oxides of ZnO and CdO with the aromatic polycarboxylic H;btc and the N-heterocyclic bib.The two products were characterized by single-crystal X-ray diffraction analysis,elemental analysis,thermogravimetric analysis（TGA）,and IR spectroscopy.Complexes 1 and 2 crystallize in monoclinic C2/c and triclinic P 1 space groups,respectively.1 shows a 3D framework,and the potential large voids of the 3D network lead to a 3-fold interpenetrating architecture.2 displays a 2D framework,and the adjacent 2D layers expand into a 3D supramulecular network via rich hydrogen bonds.Moreover,the luminescent properties of the two complexes are investigated in solid state.
文摘A field experiment was conducted to compare the growth and metal accumulation of Vetiveria zizanioides, Paspalum notatum, Cynodon dactylon and Imperata cylindraca var. major on the tailings, amended with 10 cm domestic refuse + complex NPK fertilizer(Treatment A), 10 cm domestic refuse(Treatment B) and complex NPK fertilizer(Treatment C) respectively, and without any amendment used as control(Treatment D). The results indicated that V. zizanioides was a typical heavy metal excluder, because the concentrations in shoots of the plants were the lowest among the four plants tested. The most of metal accumulated in V. zizanioides distributed in its root, and transportation of metal in this plant from root to shoot was restricted. Therefore, V. zizanioides was more suitable for phytostabilization of toxic mined lands than P. notatum and C. dactylon, which accumulated a relatively high level of metals in their shoots and roots. It was also found that I. cylindraca var. major accumulated lower amounts of Pb, Zn and Cu than C. dactylon and P. notatum, and could also be considered for phytostalilisaton of tailings. Although the metal(Pb, Zn and Cu) concentrations in shoots and roots of V. zizanioides were the lowest, the total amounts of heavy metals accumulated in shoots of V. zizanioides were the highest among the four tested plants due to the highest dry weight yield of it. The results indicated that V. zizanioides was the best choice among the four species used for phytoremediation(for both phytostabilization and phytoextraction) of metal contaminated soils.
基金Fundamental Research Fund for the Heilongjiang Provincial Universities(1355ZD001,1353MSYQN004)Mudanjiang Normal University Key Project(GP2018002)Mudanjiang Normal University Graduate Science and Technology Innovation Project(kjcx2020-79mdjnu)。
文摘A new metal-organic framework(MOF) with the chemical formula of [Ni_(2) F_2(4,4'-Bipy)_(2)(H_(2) O)_(2)](VO_(3))_(2)·8 H_(2) O was introduced to adsorb Pb(Ⅱ) with the highest capacity.The sorbent was characterized by thermogravimetric analysis(TGA),infrared spectroscopy(FT-IR),field-emission scanning electron microscopy(FESEM),energy-dispersive Xray(EDX),and elemental analysis.The optimum conditions were obtained by a face-centered central composite design(FCCD) as follows:adsorbent dosage(m)=1.2 mg, initial concentration of Pb(Ⅱ)(C)=390 mg·L^(-1),and pH=5.According to the Langmuir model(R~2=0.9999),the maximum monolayer uptake capacity of lead(Ⅱ) is 2400.7 mg·g^(-1),which is the highe st observed amount for lead(Ⅱ) adsorption.Neither of the old adsorbents for lead(Ⅱ)has the uptake capacity over 2000 mg·g^(-1).The model of pseudo-second-order describes well the process kinetics.The adsorption process of lead(Ⅱ) is independent of temperature changes.This compound can adsorb lead(Ⅱ) from tap water.In addition to introducing a new MOF with the highest uptake capacity for removal of Pb(Ⅱ) that is the outright novelty of this study,the concurrent modeling of both the removal percent(R) and the uptake capacity(q) is another important advantage.Because it achieves the more economical and favorable optimum conditions in comparison with the single optimization of each response.
基金Supported by the National Natural Science Foundation of China(No.41506172)the International S&T Cooperation Program of China(No.2015DFG32160)
文摘A bstract Cadmium(Cd) is one of the most common and widespread heavy metals in the environment. Cd has adverse effects on photosynthesis that are countered by photosystem I(PSI) and photosystem II(PSII); however, the protective responses of these photosystems to heavy metal stress remain unclear. Using the model diatom P haeodactylum tricornutum, a biological indicator that is widely used to assess the impact of environmental toxins, we simultaneously measured the effects of Cd on PSI and PSII and examined the levels of pigments in response to high light treatments before and after Cd exposure. Cd significantly reduced the quantum yield and electron transport rates of PSI and PSII. The quantum yield of non-photochemical energy dissipation in PSI due to donor side limitation increased faster than the quantum yield due to acceptor side limitation. The Cd treatment activated the P. tricornutum xanthophyll cycle under artificial light conditions, as indicated by an increased diatoxanthin content. Xanthophyll is important for photoprotection; therefore, the accumulation of diatoxanthin may down-regulate PSII activities to reduce oxidative damage. Together, our results suggest that the rapid reduction in PSII activities following Cd exposure is an adaptive response to heavy metal stress that reflects the variable exposure to external stressors in the native P. tricornutum environment.
