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PubMed | Helmholtz Center Dresden, Guangzhou University, National Taiwan University, Guangdong Provincial Academy of Environmental Science and Fujian Normal University
Type: | Journal: Environmental pollution (Barking, Essex : 1987) | Year: 2016

Thallium (Tl) is a non-essential element in humans and it is considered to be highly toxic. In this study, the contents, sources, and dispersal of Tl were investigated in surface sediments from a riverine system (the western Pearl River Basin, China), whose catchment has been contaminated by mining and roasting of Tl-bearing pyrite ores. The isotopic composition of Pb and total contents of Tl and other relevant metals (Pb, Zn, Cd, Co, and Ni) were measured in the pyrite ores, mining and roasting wastes, and the river sediments. Widespread contamination of Tl was observed in the sediments across the river, with the highest concentration of Tl (17.3mg/kg) measured 4km downstream from the pyrite industrial site. Application of a modified Institute for Reference Materials and Measurement (IRMM) sequential extraction scheme in representative sediments unveiled that 60-90% of Tl and Pb were present in the residual fraction of the sediments. The sediments contained generally lower (206)Pb/(207)Pb and higher (208)Pb/(206)Pb ratios compared with the natural Pb isotope signature (1.2008 and 2.0766 for (206)Pb/(207)Pb and (208)Pb/(206)Pb, respectively). These results suggested that a significant fraction of non-indigenous Pb could be attributed to the mining and roasting activities of pyrite ores, with low (206)Pb/(207)Pb (1.1539) and high (208)Pb/(206)Pb (2.1263). Results also showed that approximately 6-88% of Tl contamination in the sediments originated from the pyrite mining and roasting activities. This study highlights that Pb isotopic compositions could be used for quantitatively fingerprinting the sources of Tl contamination in sediments.


Lu H.,Guangdong Provincial Academy of Environmental Science | Lu H.,Sun Yat Sen University | Zhang W.,Sun Yat Sen University | Zhang W.,Guangdong Key Laboratory of Environmental Pollution Control and Remediation Technology | And 6 more authors.
Journal of Analytical and Applied Pyrolysis | Year: 2013

The surface characteristics of sludge-derived biochar (SDBC) made from three feedstocks of wastewater sludge under different pyrolysis temperatures were investigated. Results showed that the sludge from Waste Water Treatment Plant (WWTP) with pure domestic wastewater influent and less mixed industrial wastewater produced the highest biochar yield, and these SDBC samples have the highest isoelectric point (IEP) and the most uniform charge distribution, compared with other sources. For different pyrolysis temperatures, 400 C tend to achieve more uniform surface charge distribution of SDBC, due to the oxidation process more occurred on the external surface than internal matrix at this temperature. In addition, a pyrolysis temperature of 300 C resulted in the most reduction in DTPA-extractable metals of SDBCs, owing to the organo-metallic complex formed with the abundant presence of functional groups and available phosphorus content, which were easily decomposed or degraded at higher temperatures. © 2013 Elsevier B.V. All rights reserved.


Lu H.,Sun Yat Sen University | Lu H.,Guangdong Provincial Academy of Environmental Science | Zhang W.,Sun Yat Sen University | Zhang W.,Guangdong Key Laboratory of Environmental Pollution Control and Remediation Technology | And 5 more authors.
Water Research | Year: 2012

Lead sorption capacity and mechanisms by sludge-derived biochar (SDBC) were investigated to determine if treatment of acid mine drainage (AMD) containing metals with SDBC is feasible. It was found that the biochar derived from pyrolysis treatment of sewage sludge could effectively remove Pb 2+ from acidic solution with the capacities of 16.11, 20.11, 24.80, and 30.88mgg -1 at initial pH 2, 3, 4 and 5, respectively. Lead sorption processes were pseudo-second order kinetic and faster at a higher pH. Furthermore, the relative contribution of both inorganic mineral composition and organic functional groups of SDBC for Pb 2+ removal mechanisms, was quantitatively studied at pH 2-5. The results showed that Pb sorption primarily involved the coordination with organic hydroxyl and carboxyl functional groups, which was 38.2-42.3% of the total sorbed Pb varying with pH, as well as the coprecipitation or complex on mineral surfaces, which accounted for 57.7-61.8% and led to a bulk of Ca 2+ and Mg 2+ release during sorption process. A new precipitate was solely observed on Pb-loaded SDBC as 5PbO·P 2O 5·SiO 2(lead phosphate silicate) at initial pH 5, confirmed by XRD and SEM-EDX. The coordination of Pb 2+ with carboxyl and hydroxyl functional groups was demonstrated by FT-IR, and the contribution of free carboxyl was significant, ranging from 26.1% to 35.5%. Results from this study may suggest that the application of SDBC is a feasible strategy for removing metal contaminants from acid solutions. © 2011 Elsevier Ltd.


Liu J.,Guangzhou University | Liu J.,National Taiwan University | Wang J.,Guangzhou University | Qi J.,South China Institute of Environmental Sciences | And 4 more authors.
Clean - Soil, Air, Water | Year: 2012

This study was designed to investigate heavy metal (Tl, Pb, Cu, Zn, and Ni) contamination levels of arable soils and vegetables grown in the vicinity of a sulfuric acid factory in the Western Guangdong Province, China. Health risks associated with these metals by consumption of vegetables were assessed based on the hazard quotient (HQ). The soils show a most significant contamination of Tl, followed by Pb, Cu, Zn, and Ni. The heavy metal contents (μg/g, dry weight basis) in the edible parts of vegetables range from 5.60 to 105 for Tl, below detection limit to 227 for Pb, 5.0-30.0 for Cu, 10.0-82.9 for Zn, and 0.50-26.0 for Ni, mostly exceeding the proposed maximum permissible level in Germany or China. For the studied vegetables, the subterranean part generally bears higher contents of Tl and Zn than the aerial part, while the former has lower contents of Cu and Ni than the latter. In addition, the results reveal that Tl is the major risk contributor for the local people since its HQ values are mostly much higher than 1.0. The potential health risk of Tl pollution in the food chain and the issue of food safety should be highly concerned and kept under continued surveillance and control. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Su Y.,CAS Nanjing Institute of Geography and Limnology | Deng Y.,CAS Nanjing Institute of Geography and Limnology | Deng Y.,Guangdong Provincial Academy of Environmental Science | Du Y.,CAS Nanjing Institute of Geography and Limnology
Journal of Molecular Catalysis A: Chemical | Year: 2013

Microcystins generated by Microcystis aeruginosa are commonly detected in freshwater bodies and their removal becomes an emerging field recently owing to the toxicity. Here we report the structural characterization of degradation products from the photocatalysis of microcystin-LR (MC-LR). To achieve efficient photocatalytic degradation of MC-LR, we fabricated highly ordered TiO 2 nanotubes using anodization method. The surface morphology of TiO2 nanotubes depends primarily on the anodic voltage and the optimum value is 20 V. Under UV irradiation, the concentration of MC-LR decreases by 84.6% when using TiO2 nanotubes anodized at 20 V within 30 min. The degradation intermediates of MC-LR are detected with mass spectrometry (MS) and seven main intermediates are observed in liquid chromatography mass spectrometry (LC/MS) chromatogram. We propose the possible structures of the intermediates of MC-LR and infer its possible degradation pathways. The results indicate that the conjugated double bond and methoxy group in the Adda chain, as well as the conjugated system in the Mdha amino acid, are susceptible to be initially attacked by hydroxyl radicals. In addition, it is deduced that the peptides undergo breakdown from Mdha, then their carboxyl and amino groups are stepwise hydrolyzed and the side chain of the amino acid is oxidized. © 2013 Elsevier B.V.


Wang C.,Guangdong Provincial Academy of Environmental Science | Chen Y.,Guangzhou University | Liu J.,Guangzhou University | Wang J.,Guangzhou University | And 3 more authors.
Ecotoxicology and Environmental Safety | Year: 2013

Thallium (Tl) contamination in soils poses a significant threat to human health due to the high toxicity of Tl and its ready assimilation by crops. Consumption of food crops contaminated with Tl is a major food chain route for human exposure. The health risks of Tl in contaminated food crops irrigated with wastewater from a sulfuric acid factory were investigated in this paper. Results indicate that long-term Tl-containing wastewater irrigation resulted in Tl contamination of arable soils and crops. The pollution load index values indicated that the arable soils were moderately enriched with Tl. Tl was highly accumulated in the crops. The content of Tl in the edible plant portions of crops ranged from 1.2. mg/kg to 104.8. mg/kg, exceeding the recommended permissible limits for food crops. The daily intake of metals (DIM) values of Tl for both adults and children via the consumption of the food crops except soya beans were higher than the reference oral dose (RfD) limit recommend by the United States environmental protection agency (US-EPA). Health risk index (HRI) values were generally higher than 1, indicating that health risks associated with Tl exposure are significant and assumed to be dangerous to the health of local villagers. Therefore, much attention should be paid to avoid consumption of these Tl-contaminated crops that can cause great potential risks. © 2012 Elsevier Inc.


Chen B.,Guangdong Provincial Academy of Environmental Science
Procedia Environmental Sciences | Year: 2010

In order to determine a suitable outlet location of wastewater marine discharge engineering in the Maogang economic development zone of Maoming city, Guangdong, the paper analyzed the hydrological conditions, marine environmental function zoning, sensitivity degree and economic cost near the Maogang district and initially identified two optional outlets: the industrial discharge area of the district (outlet A) and the Shuidong bay port area (outlet B).Then the marine numerical model ECOMSED was applied to simulate the physical self-purification ability of the waters and the seawater exchange capacity of the outlet A and outlet B, respectively. Before the application of the ECOMSED model, it was validated with the hydrological data of the Shuidong bay and its neayby waters provided by the estuarine and coastal institute of Sun Yat-sen university. The simulation result shows that the physical serf-purification ability of the outlet A is stronger than that of the outlet B under the most unfavourable situation, with smaller influencing scope for the outlet A when the concentration increment of CODMn is bigger than O.Olmg/L. In terms of seawater exchange capacity, the outlet A also turns to be better than B, with the water residence of the outlet B 2.7 times as much as that of the outlet A. Between the two schemes of outlet location of the engineering, the best outlet location was determined to be A. © 2010 Published by Elsevier Ltd.


PubMed | CAS Research Center for Eco Environmental Sciences and Guangdong Provincial Academy of Environmental Science
Type: | Journal: Scientific reports | Year: 2016

In this study, we proposed a Regional Probabilistic Risk Assessment (RPRA) to estimate the health risks of exposing residents to heavy metals in different environmental media and land uses. The mean and ranges of heavy metal concentrations were measured in water, sediments, soil profiles and surface soils under four land uses along the Shunde Waterway, a drinking water supply area in China. Hazard quotients (HQs) were estimated for various exposure routes and heavy metal species. Riverbank vegetable plots and private vegetable plots had 95


PubMed | CAS Beijing Institute of Geographic Sciences and Nature Resources Research, CAS Research Center for Eco Environmental Sciences and Guangdong Provincial Academy of Environmental Science
Type: Comparative Study | Journal: International journal of environmental research and public health | Year: 2016

Public involvement is critical in sustainable contaminated site management. It is important for China to improve public knowledge and participation, foster dialogue between urban managers and laypeople, and accelerate the remediation and redevelopment processes in contaminated site management. In this study, we collected 1812 questionnaires from nine cities around China through face-to-face interviews and statistically analyzed the perception of residents concerning contaminated sites. The results show that respondents concern about soil pollution was lower than for other environmental issues and their knowledge of soil contamination was limited. The risks posed by contaminated industrial sites were well recognized by respondents, but they were unsatisfied with the performance of local agencies regarding information disclosure, publicity and education and public participation. Respondents believed that local governments and polluters should take the primary responsibility for contaminated site remediation. Most of them were unwilling to pay for contaminated site remediation and preferred recreational or public service redevelopment. Moreover, our research indicated that public perception varied among different cities. This variation was mainly determined by implementations of policy instruments and additionally affected by remediation technology, pollutant type, regional policy response and living distance.


PubMed | Helmholtz Center Dresden, Guangzhou University, South China Institute of Environmental Sciences and Guangdong Provincial Academy of Environmental Science
Type: | Journal: Environmental pollution (Barking, Essex : 1987) | Year: 2016

Thallium (Tl) is a toxic and non-essential heavy metal. Raw Pb-Zn ores and solid smelting wastes from a large Pb-Zn smelting plant - a typical thallium (Tl) pollution source in South China, were investigated in terms of Tl distribution and fractionation. A modified IRMM (Institute for Reference Materials and Measurement, Europe) sequential extraction scheme was applied on the samples, in order to uncover the geochemical behavior and transformation of Tl during Pb-Zn smelting and to assess the potential environmental risk of Tl arising from this plant. Results showed that the Pb-Zn ore materials were relatively enriched with Tl (15.1-87.7mgkg(-1)), while even higher accumulation existed in the electrostatic dust (3280-4050mgkg(-1)) and acidic waste (13,300mgkg(-1)). A comparison of Tl concentration and fraction distribution in different samples clearly demonstrated the significant role of the ore roasting in Tl transformation and mobilization, probably as a result of alteration/decomposition of related minerals followed by Tl release and subsequent deposition/co-precipitation on fine surface particles of the electrostatic dust and acidic waste. While only 10-30% of total Tl amounts was associated with the exchangeable/acid-extractable fraction of the Pb-Zn ore materials, up to 90% of total Tl was found in this fraction of the electrostatic dust and acidic waste. Taking into account the mobility and bioavailability of this fraction, these waste forms may pose significant environmental risk.

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