哌嗪氨基二硫代甲酸型螯合树脂的合成及其吸附性能

用哌嗪和二硫化碳反应合成氨基二硫代甲酸中间体，再与二卤代烃反应得到1，4-双(二硫代酯基)哌嗪聚合物，考察了中间体和螯合树脂对Ag^ ，Cu^2 ，Zn^2 ，Ni^2 ，CO^2 ，Pb^2 ，Pd^2 ，Cr^3 的静态吸附性能，结果表明，两者均可以吸附金属离子，缩聚后的螯合树脂具有更强的吸附能力。     

Determination trace amounts of copper, nickel, cobalt and manganese ions in water samples after simultaneous separation and preconcentration

In the present article, a simple, rapid, sensitive and economical method has been developed for the simultaneous separation and preconcentration of the trace amounts of copper, nickel, cobalt and manganese in water samples by using modified XAD-4 resins. The sorption was quantitative in the pH range 6.0–9.0, whereas quantitative desorption occurred instantaneously with 5.0 mL of 2 M HNO₃, and selected elements have been determined by using flame atomic absorption spectrometry. Dynamic ranges were 0.04–3.5, 0.1–6.0, 0.04–4.5 and 0.04–4.0 μg/mL for copper, nickel, cobalt and manganese, respectively. The detection limits were 9.2, 28.6, 12.3 and 5.7 ng/mL for Cu(II), Ni(II), Co(II) and Mn(II), respectively. The effects of the experimental parameters, including the sample pH, eluent type, interference ions and breakthrough volume, were studied for separation and preconcentration of Cu(II), Ni(II), Co(II) and Mn(II) ions. Determination of these ions in standard samples confirmed that the proposed method has good accuracy. The proposed method was used for the determination of these ions in water samples.     

Some characteristics of the distribution of heavy metals in urban topsoil of Xuzhou,China

An assessment is presented of distribution characteristics of heavy metals in the urban topsoil from the city of Xuzhou. The concentrations of Ag, Al, As, Au, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, Hg, Li, Mn, Mo, Ni, Pb, Pd, Pt, Sb, Sc, Se, Sn, V and Zn have been determined from 21 soil samples. Examination of lognormal distribution plots indicates that the diagrams of Al, Be, Fe, Ga, Li, and V are almost linear suggesting that these metals are almost unaffected by anthropogenic activities while the plots for As, Cd, Cu, Pb, Pd, Pt, Se, Zn and others are not linear probably due to anthropogenic activities from which these metals are delivered to the soils. Al is used for mineralogical normalization of these data. An evaluation of background values for topsoil is also carried out by means of lognormal distribution plots. The results show our background values obtained from the lognormal distribution plots are comparable to those values of uncontaminated soils of Xuzhou obtained by previous work except for Cd and Hg. At present, no explanation for the exceptions Cd and Hg can be given.     

Relationship between total concentration and dilute HCl extraction of heavy metals in sediments of harbors and coastal areas in Korea

Total concentrations of Cr, Ni, Cu, Zn, Cd and Pb in surface sediments were determined to investigate the regional trends of heavy metal contamination in 11 coastal areas in Korea. Enrichment factor (EF) of heavy metals was calculated by comparing the level of their regional background. The averages of EF values in study areas were 0.99 for Cr, 1.05 for Ni, 4.23 for Cu, 1.80 for Zn, 3.92 for Cd and 1.54 for Pb, respectively. Dilute HCl extractions were useful to deduce the anthropogenic sources of heavy metals and the 1 M HCl extractable fractions of each metal varied from 0.3 to 37.3% for Cr, 1.9 to 66.3% for Ni, 4.2 to 92.9% for Cu, 7.1 to 99.7% for Zn, 10.9 to 98.9% for Cd and 15.0 to 99.1% for Pb. Comparing 1 M HCl extractable fraction to total concentration, large portions of Cu, Zn, Cd and Pb were present as potentially bioavailable fractions from anthropogenic input and were significantly correlated with their EF values showing r > 0.68.     

Relative extraction ratio (RER) for arsenic and heavy metals in soils and tailings from various metal mines,Korea

This study focused on the evaluation of leaching behaviours for arsenic and heavy metals (Cd, Cu, Ni, Pb and Zn) in soils and tailings contaminated by mining activities. Ten representative mine soils were taken at four representative metal mines in Korea. To evaluate the leaching characteristics of the samples, eight extraction methods were adapted namely 0.1 M HCl, 0.5 M HCl, 1.0 M HCl, 3.0 M HCl, Korean Standard Leaching Procedure for waste materials (KSLP), Synthetic Precipitation Leaching Procedure (SPLP), Toxicity Characteristic Leaching Procedure (TCLP) and aqua regia extraction (AR) methods. In order to compare element concentrations as extraction methods, relative extraction ratios (RERs, %), defined as element concentration extracted by the individual leaching method divided by that extracted by aqua regia based on USEPA method 3050B, were calculated. Although the RER values can vary upon sample types and elements, they increase with increasing ionic strength of each extracting solution. Thus, the RER for arsenic and heavy metals in the samples increased in the order of KSLP < SPLP < TCLP < 0.1 M HCl < 0.5 M HCl < 1.0 M HCl < 3.0 M HCl. In the same extraction method, the RER values for Cd and Zn were relatively higher than those for As, Cu, Ni and Pb. This may be due to differences in geochemical behaviour of each element, namely high solubility of Cd and Zn and low solubility of As, Cu, Ni and Pb in surface environment. Thus, the extraction results can give important information on the degree and extent of arsenic and heavy metal dispersion in the surface environment.     

Effective and selective separation of perrhenate from acidic wastewater by super-stable,superhydrophobic, and recyclable biosorbent

• A ZnO-biochar hybrid composite was prepared by solvothermal-pyrolysis synthesis. • The superhydrophobic composite is suitable for selective recovery of Re(VII). • The adsorption mechanism is elucidated by experiments and material characterization. The recovery of scattered metal ions such as perrhenate (Re(VII)) from industrial effluents has enormous economic benefits and promotes resource reuse. Nanoscale-metal/biochar hybrid biosorbents are attractive for recovery but are limited by their insufficient stability and low selectivity in harsh environments. Herein, a superstable biochar-based biosorbent composed of ZnO nanoparticles with remarkable superhydrophobic features is fabricated, and its adsorption/desorption capabilities toward Re(VII) in strongly acidic aqueous solutions are investigated. The ZnO nanoparticle/biochar hybrid composite (ZBC) exhibits strong acid resistance and high chemical stability, which are attributable to strong C-O-Zn interactions between the biochar and ZnO nanoparticles. Due to the advantages of its hydrolytic stability, superhydrophobicity, and abundance of Zn-O sites, the ZBC proves suitable for the effective and selective separation of Re(VII) from single, binary and multiple ion systems (pH= 1), with a maximum sorption capacity of 29.41 mg/g. More importantly, this material also shows good recyclability and reusability, with high adsorption efficiency after six adsorption-desorption cycles. The findings in this work demonstrate that a metal/biochar hybrid composite is a promising sorbent for Re(VII) separation.     

Amberlite XAD-7 impregnated with morpholine dithiocarbamate as trace metal extractant

Application of Amberlite XAD-7 impregnated with morpholine dithiocarbamate (MDTC) for separation and preconcentration of trace amounts of lead, copper, cobalt, iron, nickel, cadmium and zinc and determination by ICP-AES has been described. The optimum experimental parameters, such as pH, sample flow rate, eluent and effect of matrix ions on the preconcentration were investigated. Simultaneous enrichment of the seven metals was accomplished. The t _1/2 values for sorption are 2.9, 3.3, 3.7, 3.6, 2.8, 4.1 and 2.8 respectively for Pb(II), Cu(II), Co(II), Fe(III), Ni(II), Cd(II) and Zn(II). The method was applied for the determination of trace metal ions in seawater and natural water samples. The results have been compared with extraction GFAAS method.     

Relative extraction ratio (RER) for arsenic and heavy metals in soils and tailings from various metal mines, Korea

This study focused on the evaluation of leaching behaviours for arsenic and heavy metals (Cd, Cu, Ni, Pb and Zn) in soils and tailings contaminated by mining activities. Ten representative mine soils were taken at four representative metal mines in Korea. To evaluate the leaching characteristics of the samples, eight extraction methods were adapted namely 0.1?M HCl, 0.5?M HCl, 1.0?M HCl, 3.0?M HCl, Korean Standard Leaching Procedure for waste materials (KSLP), Synthetic Precipitation Leaching Procedure (SPLP), Toxicity Characteristic Leaching Procedure (TCLP) and aqua regia extraction (AR) methods. In order to compare element concentrations as extraction methods, relative extraction ratios (RERs, %), defined as element concentration extracted by the individual leaching method divided by that extracted by aqua regia based on USEPA method 3050B, were calculated. Although the RER values can vary upon sample types and elements, they increase with increasing ionic strength of each extracting solution. Thus, the RER for arsenic and heavy metals in the samples increased in the order of KSLP?相似文献   

Bioavailability of trace metals in brownfield soils in an urban area in the UK

Thirty-two brownfield sites from the city of Wolverhampton were selected from those with a former industrial use, wasteland or areas adjacent to industrial processes. Samples (<2 mm powdered soil fraction) were analysed, using inductively coupled plasma–atomic emission spectrometry (ICP–AES) for 20 elements. Loss on ignition and pH were also determined. A five-step chemical sequential extraction technique was carried out. Single leach extraction with 0.12 M hydrochloric acid of Pb, Cu and Zn in soil was determined as a first approximation of the bioavailability in the human stomach. Some of the sites were found to have high concentrations of the potentially toxic elements Pb, Zn, Cu and Ni. The partitioning of metals showed a high variability, however a number of trends were determined. The majority of Zn was partitioned into the least chemically stable phases (steps 1, 2 and 3). The majority of Cu was associated with the organic phase (step 4) and the majority of Ni was fractionated into the residue phase (step 5). The majority of Pb was associated with the residue fraction (step 5) followed by Fe–Mn oxide fraction (step 3). The variability reflects the heterogeneous and complex nature of metal speciation in urban soils with varied historic histories. There was a strong inverse linear relationship between the metals Ni, Zn and Pb in the readily exchangeable phase (step 1) and soil pH, significant at P < 0.01 level. There was a significant increase (P < 0.05) in the partitioning of Cu, Ni and Zn into step 4 (the organic phase) in soils with a higher organic carbon content (estimated by loss on ignition). Copper was highly partitioned into step 4 as it has a strong association with organics in soil but this phase was not important for the partitioning of Ni or Zn. The fractionation of Ni, Cu and Zn increased significantly in step 3 when the total metal concentration increases (P < 0.01). The Fe–Mn oxide fraction becomes more important in soils elevated in these metals, possibly due to the scavenging of metals by oxides. Cu and Pb extracted by HCl was statistically similar to the sum of the metals in steps 1 to 4 (P < 0.01) and HCl available Zn was statistically similar to the sum of Zn in steps 1 to 3 (P < 0.01). Step 4 (the organic phase) was not an important phase for Zn, so it was concluded that any Cu, Zn and Pb present in soil in a nonresidue phase would be potentially available for uptake into the human system once soil has been ingested.     

Effect of long-term irrigation with sewage effluent on the metal content of soils, Berlin, Germany

This study aimed to determine whether >110 years of sewage application has led to recognizable changes in the metal chemistry of soils from former sewage farms, Berlin, Germany. Background concentrations of soils and element enrichment factors were used for the evaluation of possible perturbations of natural element abundances in sewage farm soils. Calculations verify that precious metals (Ag, Au) as well as P, C_org, and heavy metals (Cd, Cu, Ni, Pb, Sn, and Zn) are invariably enriched in sewage farm topsoils (0–0.1 m depth) compared to local and regional background soils. Long-term irrigation of soils with municipal wastewater has caused significant heavy metal contamination as well as a pronounced enrichment in precious metals. Leaching of metals including Ag into underlying aquifers may impact on the quality of drinking water supplies.     

Oxidisability of environmental sulphur under different catalytic conditions

The oxidation of elemental sulphur in the catalytic presence of selected metal ions [Cr(III), Ce(III), Cu(II), Hg(II), Ni(II), Co(II), Mo(VI), Cd(II), Zn(II), Ti(IV), and V(V)], and hydrocarbons (benzene, gasoline, and kerosene) was studied in an alkaline medium buffered by marble powder. The catalytic efficiencies of metal ions were: Cr(III) > Ce(III) > Cu(II) > Hg(II) > Ni(II). The oxidation process was inhibited in the presence of other ions, and the inhibitive effect was in the following order: Co(II) < Mo(VI) < Cd(II) < Zn(II) < Ti(IV) < V(V). In the case of hydrocarbons, the efficiencies were as follows: gasoline > benzene > kerosene. The oxidation of sulphur in sulphur-loaded soils obtained from near a textile mill and a distillery were also carried out in the c both cases was significantly enhanced.To whom all correspondence should be addressed.     

Synthesis of 2,3-dihydroxynaphthalene-functionalized Amberlite XAD-4 resin: Applications for the separation and preconcentration of trace metal ions prior to their determination by inductively coupled plasma atomic emission spectrometry

A simple, sensitive column solid-phase extraction procedure for separation and preconcentration of Cu(II), Ni(II), Co(II), and Cd(II) in spiked and natural water samples using 2,3-dihydroxynaphthalene-functionalized Amberlite XAD-4 (XAD-4-DHN) chelating resin prior to their determination by inductively coupled plasma atomic emission spectrometry was discussed. The optimum experimental parameters such as pH, volume of sample and eluent, flow-rates of uptake and stripping, and sorption capacity of the chelating resin, were evaluated. The effect of the electrolytes and the cations on the preconcentration of metal ions was also investigated. The chelating resin could be reused for more than 20 cycles of sorption–desorption without any significant change (<1.0%). Recoveries obtained from this method range from 96 to 102% with R.S.D of 2.50 (n = 4). The detection limits for Cu(II), Ni(II), Co(II), and Cd(II) were found to be 1.9, 0.9, 1.2 µg, and 1.4 µg L^?1, respectively. The proposed method was applied for the determination of Cu(II), Ni(II), Co(II), and Cd(II) in spiked, tap water, and river water samples.     

Efficient removal of heavy metals from electroplating wastewater using polymer ligands

Poly(hydroxamic acid)-poly(amidoxime) chelating ligands were synthesized from poly(methyl acrylate-co-acrylonitrile) grafted acacia cellulose for removing toxic metal ions from industrial wastewaters. These ligands showed higher adsorption capacity to copper (2.80 mmol?g⁻¹) at pH 6. In addition, sorption capacities to other metal ions such as iron, zinc, chromium, and nickel were also found high at pH 6. The metal ions sorption rate (t_1/2) was very fast. The rate of adsorption of copper, iron, zinc, chromium, nickel, cobalt, cadmium and lead were 4, 5, 7, 5, 5, 8, 9 and 11 min, respectively. Therefore, these ligands have an advantage to the metal ions removal using the column technique. We have successfully investigated the known concentration of metal ions using various parameters, which is essential for designing a fixed bed column with ligands. The wastewater from electroplating plants used in this study, having chromium, zinc, nickel, copper and iron, etc. For chromium wastewater, ICP analysis showed that the Cr removal was 99.8% and other metal ions such as Cu, Ni, Fe, Zn, Cd, Pb, Co and Mn removal were 94.7%, 99.2%, 99.9%, 99.9%, 99.5%, 99.9%, 95.6% and 97.6%, respectively. In case of cyanide wastewater, the metal removal, especially Ni and Zn removal were 96.5 and 95.2% at higher initial concentration. For acid/alkali wastewater, metal ions removing for Cd, Cr and Fe were 99.2%, 99.5% and 99.9%, respectively. Overall, these ligands are useful for metal removal by column method from industrial wastewater especially plating wastewater.     

Concentrations of some elements in the sediments of a river in Anhui Province,China

A total of 49 sediment samples from New Bian River near the city of Suzhou in northern Anhui Province, China, were analyzed by inductively coupled plasma-mass spectrometry for As, Cr, Pb, Cu, Fe, Zn, Mn, and Ni. Geoaccumulation indices (I_geo) were used to assess the influence of human activities. Correlation analysis and principal component analysis were also performed. The geoaccumulation indices were in the order of As > Cu > Cr > Ni > Mn > Zn > Pb > Fe, the first four of which had values above 0.5. We considered New Bian River to be moderately contaminated with As, Cr, Cu, and Ni. Correlation analysis and principal component analysis indicated that the presence of Fe, Cu, Ni, Mn, Zn, and Pb in New Bian River was caused by soil or rock weathering, whereas the elevated levels of As and Cr depended upon urban, agricultural, and industrial factors. The sampling stations around the towns were dominated by Component 2 (As and Cr), and the sampling stations that distributed along New Bian River were dominated by Component 1 (Fe, Cu, Ni, Mn, Zn, and Pb).     

Heavy Metals in Superficial Sediments from the Ligurian Sea,Italy

In this paper we are presenting the concentrations and the distributions of trace metals (Fe, Ni, Cr, Cu, Pb and Zn) in the coastal area of the Ligurian Sea between Capo Noli and Capo Mele. Fifty-six samples were subjected to textural, organic carbon and chemical analyses. Three different extraction methods were used: 1N NH₂OH.HCl plus 25% CH₃COOH, nitric acid solution, and total attack with HClO₄-HF mixture. The solutions were analysed by atomic absorption spectrophotometry. The results obtained confirm that the extraction methods which are most informative for environmental purposes are the cold or the easily extractable metal techniques. The results also show that for the study area the concentrations of Fe, Ni, Cr, Cu, Pb, and Zn do not indicate traces of anthropogenic inputs.     

Status,source identification,and health risks of potentially toxic element concentrations in road dust in a medium-sized city in a developing country

This study aims to determine the status of potentially toxic element concentrations of road dust in a medium-sized city (Rawang, Malaysia). This study adopts source identification via enrichment factor, Pearson correlation analysis, and Fourier spectral analysis to identify sources of potentially toxic element concentrations in road dust in Rawang City, Malaysia. Health risk assessment was conducted to determine potential health risks (carcinogenic and non-carcinogenic risks) among adults and children via multiple pathways (i.e., ingestion, dermal contact, and inhalation). Mean of potentially toxic element concentrations were found in the order of Pb > Zn > Cr(IV) > Cu > Ni > Cd > As > Co. Source identification revealed that Cu, Cd, Pb, Zn, Ni, and Cr(IV) are associated with anthropogenic sources in industrial and highly populated areas in northern and southern Rawang, cement factories in southern Rawang, as well as the rapid development and population growth in northwestern Rawang, which have resulted in high traffic congestion. Cobalt, Fe, and As are related to geological background and lithologies in Rawang. Pathway orders for both carcinogenic and non-carcinogenic risks are ingestion, dermal contact, and inhalation, involving adults and children. Non-carcinogenic health risks in adults were attributed to Cr(IV), Pb, and Cd, whereas Cu, Cd, Cr(IV), Pb, and Zn were found to have non-carcinogenic health risks for children. Cd, Cr(IV), Pb, and As may induce carcinogenic risks in adults and children, and the total lifetime cancer risk values exceeded incremental lifetime.     

Watershed land use as a determinant of metal concentrations in freshwater systems

Concentrations of Fe, Mn, Cu, dissolved organic matter (DOM), and pH were synthesized from 30 publications to determine the factors regulating concentrations and behavior of metals in freshwater systems. Results from the review suggest that contrasting watershed land use can directly (erosion and runoff) and indirectly (in-lake processes including metal–DOM–pH interactions) affect the metal concentrations in freshwater systems. Among the watershed land uses considered here, concentrations of Fe, Mn, and Cu were observed in the following order: arctic lakes < forested < agricultural < urbanized < mined. A drastic difference in mean metal concentrations has been observed when undisturbed or low impact watersheds (arctic and forested) were changed by agricultural, urban, and mining developments. Relationships between metal concentrations and pH revealed that metals precipitate at high pH (pH > 5). Additionally, at pH < 5, metal concentrations were significantly correlated with DOM due to metal–DOM complexation. High ratios of metal: DOM occur only at low DOM concentrations. Collectively, two general conclusions can be drawn from this review. First, lakes, rivers, and streams with urbanized watersheds are the most susceptible to increased concentrations of metals. Secondly, these results also suggest that regardless of high or low DOM in the water column, pH would affect metal concentrations in freshwater systems. Nonetheless, free metal ions would be higher in freshwater systems with acidic water and low DOM.     

High level of nickel tolerance and metal exclusion identified in silver maple (Acer saccharinum)

Nickel (Ni) and copper (Cu) are the most prevalent metals found in the Greater Sudbury Region ecosystems. The main objectives of this study are to (1) assess silver maple (Acer saccharinum) tolerance to different doses of Ni and (2) determine the translocation pattern of metals in A. sacharinum. This study revealed that A. sacharinum is highly tolerant to high doses of NI (1600 and 9200?mg/kg). Growth chamber screening trials revealed that Ni is stored in roots and does not translocate to other plant parts. Analysis of samples from A. sacharinum growing for >30 years in soil contaminated with metals also showed that the levels of iron (Fe), manganese (Mn), Ni, and zinc (Zn) were significantly higher in roots compared with soils and aerial parts. On the other hand, the amount of Cu was higher in soil compared with roots and other plant parts. In fact, the bioaccumulation factors (BFs) were 0.29, 2.00, 3.6, 1.9, and 4.0 for Cu, Fe, Mn, Ni, and Zn, respectively. The translocation from roots to aerial parts showed an insignificant level of movement of Cu, Fe, and Ni. Hence, A. saccharinum is classified as excluder for Fe, Mn, Ni, and Zn, and avoider for Cu.     

Ecotoxicity assessment of soil irrigated with domestic wastewater using different extractions

The toxicity of soil irrigated with treated domestic wastewater (site A) and untreated gray wastewater (site B) were investigated. Soil extracts were prepared using distilled water, acid solvent (0.1 mol·L^-1 HCl), and organic solvent (acetone:petroleum ether:cyclohexane= 1:1:1) to understand the type of pollutants responsible for the ecotoxicity associated with wastewater irrigation. The soil toxicity was assessed using a luminescence inhibition assay with Vibrio fischeri for acute toxicity, a micronucleus assay with Vicia faba root tips and a single cell gel electrophoresis assay of mice lymphocytes for genotoxicity. The physicochemical properties and the heavy metal (HM) contents of the irrigated soil were also analyzed. The results indicated that the wastewater irrigation at site A had no effects on the soil properties. With the exception of Pb, Zn, Fe, and Mn, the accumulation of HMs (Cu, Ni, and Cr) occurred. However, the irrigation at site A did not result in obvious acute toxicity or genotoxicity in the soil. The soil properties changed greatly, and HMs (Cu, Ni, and Cr) accumulated in site B. There were significant increases in the acute toxic and genotoxic effects in the soils from site B. The ecotoxicity in site B came primarily from organic-extractable pollutants.