The transformation behaviors of Pb fractions during composting of Pb-polluted waste without inoculants and with the inoculants of Phanerochaete chrysosporium were studied.Results show that the active Pb ions with high...The transformation behaviors of Pb fractions during composting of Pb-polluted waste without inoculants and with the inoculants of Phanerochaete chrysosporium were studied.Results show that the active Pb ions with high toxicity and transferability are transformed into the inactive Pb with low toxicity and transferability,confirming that Pb ions can be efficiently immobilized during composting without or with the inoculants.The soluble-exchangeable Pb in composting without inoculants reaches 49.0 mg/kg at day 60,while that with the inoculants is reduced to 0 mg/kg dry mass compost.The higher contents of organic-bound Pb (59.0 mg/kg)and residual Pb(69.2 mg/kg)with low toxicity are found after 60-day composting with inoculants,compared with those without inoculants.The above data indicate the better immobilization effect of Pb and the greater alleviation of Pb hazards in composting with the inoculants of Phanerochaete chrysosporium than without inoculants,which may be due to the more microbial biomass and the higher pH value in composting of Pb-polluted waste with inoculants.展开更多
Understanding the effects of oxalic acid（OA） on the immobilization of Pb（Ⅱ） in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A s...Understanding the effects of oxalic acid（OA） on the immobilization of Pb（Ⅱ） in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb（Ⅱ） by KH2PO4, phosphate rock（PR）, activated phosphate rock（APR） and synthetic hydroxyapatite（HAP） at different phosphate：Pb（P：Pb） molar ratios（0, 0.6, 2.0 and 4.0） in the presence/absence of 50 mmol oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or Ca Cl2, Community Bureau of Reference（BCR） sequential extraction and toxicity characteristic leaching procedure（TCLP）methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after120 days was reduced by 100% when soils were amended with APR, HAP and HAP ＋ OA, and the TCLP-Pb was 〈5 mg/L for the red soil at P：Pb molar ratio 4.0. Water-soluble Pb could not be detected and the TCLP-Pb was 〈5 mg/L at all treatments applied to the yellow-brown soil. BCR results indicated that APR was most effective, although a slight enhancement of water-soluble phosphate was detected at the P：Pb molar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability.展开更多
A field demonstration of reduction of lead availability in a soil and cabbage (Brassica Chinensis L.) contaminated by mining tailings, located in Shaoxing, China was carried out to evaluate the effects of applications...A field demonstration of reduction of lead availability in a soil and cabbage (Brassica Chinensis L.) contaminated by mining tailings, located in Shaoxing, China was carried out to evaluate the effects of applications of phosphorus fertilizers on Pb fractionation and Pb phytoavailability in the soil. It was found that the addition of all three P fertilizers including single super phosphate (SSP), phosphate rock (PR), and calcium magnesium phosphate (CMP) significantly decreased the percentage of water-soluble and exchangeable (WE) soil Pb and then reduced the uptake of Pb, Cd, and Zn by the cabbage compared to the control (CK). The results showed that the level of 300 g P/m2 soil was the most cost-effective application rate of P fertilizers for reducing Pb availability at the first stage of remediation, and that at this P level, the effect of WE fraction of Pb in the soil de- creased by three phosphorus fertilizers followed the order: CMP (79%)>SSP (41%)>PR (23%); Effectiveness on the reduction of Pb uptake by cabbage was in the order: CMP (53%)>SSP (41%)>PR (30%). Therefore our field trial demonstrated that it was effective and feasible to reduce Pb availability in soil and cabbage contaminated by mining tailings using P fertilizers in China and PR would be a most cost-effective amendment.展开更多
Soil samples from 4 defined city zones of Nanjing were randomly collected at 0-5 cm and 5-20 cm intervals and size fractions of soil particles were separated from undisturbed bulk soils by low energy dispersion proced...Soil samples from 4 defined city zones of Nanjing were randomly collected at 0-5 cm and 5-20 cm intervals and size fractions of soil particles were separated from undisturbed bulk soils by low energy dispersion procedure. The total contents of Cu and Pb in the different particle size fractions of the urban soils were analyzed by HNO3-HF-HClO4 digestion and flame atomic absorption spectrophotometer determination. The total content of Cu and Pb in soil particle size fractions varied with their size and with city zones as well. Both the content and variation with the size fractions of Pb was bigger than of Cu supporting our previous finding that there was Pb pollution to different degrees in the urban soils although the two elements were generally enriched in clay-sized fraction. Contaminated Pb tended to be preferentially enriched in the size fraction of 2000-250 μm and clay-sized fraction. While the size fractions of the soils from newly developed and preserved area contained smaller amount of Cu and Pb, the partitioning of them in coarse and fine particle size fractions were insignificant compared to that from inner residence and commercial area. The very high Pb level over 150 mg/kg of the fine particle fractions from the soils of the inner city could be a cause of high blood Pb level reported of children from the city as acute exposure to Pb of fine particles of the urban soil might occur by soil ingestion and inhalation by young children. Thus, much attention should be paid to the partitioning of toxic metals in fine soil particles of the urban soils and countermeasures against high health risk of Pb exposure by soil ingestion and dust inhalation should be practiced against the health problem of blood Pb for young children from the cities.展开更多
Sources of Pb pollution in the local atmosphere together with Pb species, major ions, and heavy metal concentrations in a size-fractionated aerosol sample from Higashi-Hiroshima （Japan） have been determined by X-ray...Sources of Pb pollution in the local atmosphere together with Pb species, major ions, and heavy metal concentrations in a size-fractionated aerosol sample from Higashi-Hiroshima （Japan） have been determined by X-ray absorption near-edge structure （XANES） spectroscopy, ion chromatography, and ICP-MS/AES, respectively. About 80% of total Pb was concentrated in fine aerosol particles. Lead species in the coarse aerosol particles were PbC204, 2PbCO3-Pb（OH）2, and Pb（NO3）2, whereas Pb species in the fine aerosol particles were PbC204, PbSO4, and Pb（NO3）2. Chemical speciation and abundance data suggested that the source of Pb in the fine aerosol particles was different from that of the coarse ones. The dominant sources of Pb in the fine aerosol particles were judged to be fly ash from a municipal solid waste incinerator and heavy oil combustion. For the coarse aerosol particles, road dust was considered to be the main Pb source. In addition to Pb species, elemental concentrations in the aerosols were also determined. The results suggested that Pb species in size-fractionated aerosols can be used to identify the origin of aerosol particles in the atmosphere as an alternative to Pb isotope ratio measurement.展开更多
基金Project(50808073)supported by the National Natural Science Foundation of ChinaProject(2005CB724203)supported by the National Basic Research Program of China+1 种基金Project(2007)supported by the Program for Changjiang Scholars and Innovative Research Team in University,ChinaProject(2007185)supported by the Environmental Protection Technology Research Program of Hunan Province,China
文摘The transformation behaviors of Pb fractions during composting of Pb-polluted waste without inoculants and with the inoculants of Phanerochaete chrysosporium were studied.Results show that the active Pb ions with high toxicity and transferability are transformed into the inactive Pb with low toxicity and transferability,confirming that Pb ions can be efficiently immobilized during composting without or with the inoculants.The soluble-exchangeable Pb in composting without inoculants reaches 49.0 mg/kg at day 60,while that with the inoculants is reduced to 0 mg/kg dry mass compost.The higher contents of organic-bound Pb (59.0 mg/kg)and residual Pb(69.2 mg/kg)with low toxicity are found after 60-day composting with inoculants,compared with those without inoculants.The above data indicate the better immobilization effect of Pb and the greater alleviation of Pb hazards in composting with the inoculants of Phanerochaete chrysosporium than without inoculants,which may be due to the more microbial biomass and the higher pH value in composting of Pb-polluted waste with inoculants.
基金supported by the National High Technology Research and Development Program (863) of China (No. 2012AA101402)the National Natural Science Foundation of China (No. 41071165)
文摘Understanding the effects of oxalic acid（OA） on the immobilization of Pb（Ⅱ） in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb（Ⅱ） by KH2PO4, phosphate rock（PR）, activated phosphate rock（APR） and synthetic hydroxyapatite（HAP） at different phosphate：Pb（P：Pb） molar ratios（0, 0.6, 2.0 and 4.0） in the presence/absence of 50 mmol oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or Ca Cl2, Community Bureau of Reference（BCR） sequential extraction and toxicity characteristic leaching procedure（TCLP）methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after120 days was reduced by 100% when soils were amended with APR, HAP and HAP ＋ OA, and the TCLP-Pb was 〈5 mg/L for the red soil at P：Pb molar ratio 4.0. Water-soluble Pb could not be detected and the TCLP-Pb was 〈5 mg/L at all treatments applied to the yellow-brown soil. BCR results indicated that APR was most effective, although a slight enhancement of water-soluble phosphate was detected at the P：Pb molar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability.
基金Project (No. 40432004) supported by the National Natural ScienceFoundation of China and the Science & Technology Foundation(2004) of Zhejiang Province, China
文摘A field demonstration of reduction of lead availability in a soil and cabbage (Brassica Chinensis L.) contaminated by mining tailings, located in Shaoxing, China was carried out to evaluate the effects of applications of phosphorus fertilizers on Pb fractionation and Pb phytoavailability in the soil. It was found that the addition of all three P fertilizers including single super phosphate (SSP), phosphate rock (PR), and calcium magnesium phosphate (CMP) significantly decreased the percentage of water-soluble and exchangeable (WE) soil Pb and then reduced the uptake of Pb, Cd, and Zn by the cabbage compared to the control (CK). The results showed that the level of 300 g P/m2 soil was the most cost-effective application rate of P fertilizers for reducing Pb availability at the first stage of remediation, and that at this P level, the effect of WE fraction of Pb in the soil de- creased by three phosphorus fertilizers followed the order: CMP (79%)>SSP (41%)>PR (23%); Effectiveness on the reduction of Pb uptake by cabbage was in the order: CMP (53%)>SSP (41%)>PR (30%). Therefore our field trial demonstrated that it was effective and feasible to reduce Pb availability in soil and cabbage contaminated by mining tailings using P fertilizers in China and PR would be a most cost-effective amendment.
基金The Key Research Project of Ministry of Education of China(No. 2002012)
文摘Soil samples from 4 defined city zones of Nanjing were randomly collected at 0-5 cm and 5-20 cm intervals and size fractions of soil particles were separated from undisturbed bulk soils by low energy dispersion procedure. The total contents of Cu and Pb in the different particle size fractions of the urban soils were analyzed by HNO3-HF-HClO4 digestion and flame atomic absorption spectrophotometer determination. The total content of Cu and Pb in soil particle size fractions varied with their size and with city zones as well. Both the content and variation with the size fractions of Pb was bigger than of Cu supporting our previous finding that there was Pb pollution to different degrees in the urban soils although the two elements were generally enriched in clay-sized fraction. Contaminated Pb tended to be preferentially enriched in the size fraction of 2000-250 μm and clay-sized fraction. While the size fractions of the soils from newly developed and preserved area contained smaller amount of Cu and Pb, the partitioning of them in coarse and fine particle size fractions were insignificant compared to that from inner residence and commercial area. The very high Pb level over 150 mg/kg of the fine particle fractions from the soils of the inner city could be a cause of high blood Pb level reported of children from the city as acute exposure to Pb of fine particles of the urban soil might occur by soil ingestion and inhalation by young children. Thus, much attention should be paid to the partitioning of toxic metals in fine soil particles of the urban soils and countermeasures against high health risk of Pb exposure by soil ingestion and dust inhalation should be practiced against the health problem of blood Pb for young children from the cities.
基金performed with the approval of KEK-PF (2011G644 and 2012G111)SPring-8 (2012A1299, 2012B1428, and 2012B1564)
文摘Sources of Pb pollution in the local atmosphere together with Pb species, major ions, and heavy metal concentrations in a size-fractionated aerosol sample from Higashi-Hiroshima （Japan） have been determined by X-ray absorption near-edge structure （XANES） spectroscopy, ion chromatography, and ICP-MS/AES, respectively. About 80% of total Pb was concentrated in fine aerosol particles. Lead species in the coarse aerosol particles were PbC204, 2PbCO3-Pb（OH）2, and Pb（NO3）2, whereas Pb species in the fine aerosol particles were PbC204, PbSO4, and Pb（NO3）2. Chemical speciation and abundance data suggested that the source of Pb in the fine aerosol particles was different from that of the coarse ones. The dominant sources of Pb in the fine aerosol particles were judged to be fly ash from a municipal solid waste incinerator and heavy oil combustion. For the coarse aerosol particles, road dust was considered to be the main Pb source. In addition to Pb species, elemental concentrations in the aerosols were also determined. The results suggested that Pb species in size-fractionated aerosols can be used to identify the origin of aerosol particles in the atmosphere as an alternative to Pb isotope ratio measurement.
