污泥中重金属污染程度和生态风险评估优化
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摘要
重金属是城市污水处理厂污泥中的一种典型无机污染物。对重金属污染程度和生态风险的准确识别对于污泥的安全处理或处置至关重要。目前,有关污泥中重金属污染程度和生态风险的评估方法主要包括2种:总量因子法和形态因子法,但各方法之间缺乏统一的分类等级。此外,有关污泥中重金属污染程度和生态风险评估的总量因子法和形态因子法不够完善。该研究首先在参考河流底泥和土壤中重金属污染程度和生态风险评估研究成果的基础上,进一步完善污水处理厂污泥中重金属污染程度和生态风险评估方法,并建立统一的分类等级。然后,以南昌市4个主要污水处理厂污泥为研究对象,应用上述建立的方法对污泥中重金属的污染程度和生态风险进行评估。最后,依据评估结果对总量因子法和形态因子法之间的关联性和一致性进行探讨。研究结果表明:在评估Cu、Zn、Ni和Cr单一重金属污染程度时,总量因子法和形态因子法呈现显著正相关和较高的一致性;在评估Zn和Ni单一重金属生态风险时,总量因子法和形态因子法呈现显著正相关和较高的一致性;在评估重金属综合污染程度和生态风险时,总量因子法和形态因子法呈现正相关和较高的一致性。该研究的开展将进一步为污水处理厂污泥中重金属的污染程度和生态风险评估提供理论参考,与此同时可为南昌市污水处理厂污泥中重金属的污染风险管理提供数据支撑。
Heavy metals are typical inorganic pollutants in sewage sludge. The accurate identification of heavy metals' pollution degree and ecological risk is crucial for the safety treatment and disposal of sewage sludge. At present, the evaluation models of heavy metals' pollution degree and ecological risk in sewage sludge can be divided into two kinds: the total content indices and the speciation indices. However, there is lack of a unified classification level among these methods. In addition,the evaluation methods of heavy metals' pollution degree and ecological risk in sewage sludge, including the total content indices and the speciation indices, are inadequate. This study firstly further improved the assessment methods of pollution degree and ecological risk of heavy metal in sewage sludge and established the unified classification level, referring to the research results of the contamination level and ecological risk assessment of heavy metal in river sediment and soil. Then, the improved evaluation methods were applied to the assessment of heavy metals' contamination degree and ecological risk in sewage sludges collected from four main sewage treatment plants located in Nanchang City. According to the evaluation results, the correlation and correspondence between total content index and speciation index were explored. The research results showed that when assessing the pollution degree of Cu, Zn, Ni and Cr, significant positive correlations and higher correspondences were found between above two approaches; when assessing the ecological risk of Zn and Ni, significant positive correlations and higher correspondences were found between above two approaches; when assessing the pollution degree and ecological risk of multi-metal(Cu, Zn, Pb, Cd, Ni and Cr), significant positive correlations and higher correspondences were found between above two approaches. This research will further provide theoretical reference for the assessment of the contamination level and ecological risk of heavy metals in sewage sludge. Meanwhile, it can provide data support for the pollution risk management of heavy metals in sewage sludge produced in wastewater treatment plants located in Nanchang City.
Heavy metals are typical inorganic pollutants in sewage sludge. The accurate identification of heavy metals' pollution degree and ecological risk is crucial for the safety treatment and disposal of sewage sludge. At present, the evaluation models of heavy metals' pollution degree and ecological risk in sewage sludge can be divided into two kinds: the total content indices and the speciation indices. However, there is lack of a unified classification level among these methods. In addition,the evaluation methods of heavy metals' pollution degree and ecological risk in sewage sludge, including the total content indices and the speciation indices, are inadequate. This study firstly further improved the assessment methods of pollution degree and ecological risk of heavy metal in sewage sludge and established the unified classification level, referring to the research results of the contamination level and ecological risk assessment of heavy metal in river sediment and soil. Then, the improved evaluation methods were applied to the assessment of heavy metals' contamination degree and ecological risk in sewage sludges collected from four main sewage treatment plants located in Nanchang City. According to the evaluation results, the correlation and correspondence between total content index and speciation index were explored. The research results showed that when assessing the pollution degree of Cu, Zn, Ni and Cr, significant positive correlations and higher correspondences were found between above two approaches; when assessing the ecological risk of Zn and Ni, significant positive correlations and higher correspondences were found between above two approaches; when assessing the pollution degree and ecological risk of multi-metal(Cu, Zn, Pb, Cd, Ni and Cr), significant positive correlations and higher correspondences were found between above two approaches. This research will further provide theoretical reference for the assessment of the contamination level and ecological risk of heavy metals in sewage sludge. Meanwhile, it can provide data support for the pollution risk management of heavy metals in sewage sludge produced in wastewater treatment plants located in Nanchang City.
引文
[1] Qian L L, Wang S Z, Xu D H, et al. Treatment of municipal sewage sludge in supercritical water:a review[J]. Water Research, 2016,89:118-131.
[2] Kacprzak M, Neczaj E, Fijalkowski K, et al. Sewage sludge disposal strategies for sustainable development[J]. Environmental Research, 2017,156:39-46.
[3] Huang H J, Yuan X Z. The migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge[J]. Bioresource Technology, 2016, 200:991-998.
[4] Mulchandani A, Westerhoff P. Recovery opportunities for metals and energy from sewage sludges[J]. Bioresource Technology, 2016,215:215-226.
[5] Li J, Luo G B, Gao J F, et al. Quantitative evaluation of potential ecological risk of heavy metals in sewage sludge from three wastewater treatment plants in the main urban area of Wuxi, China[J]. Chemistry and Ecology, 2015,31(3):235-251.
[6] Huang H J, Yuan X Z. Recent progress in the direct liquefaction of typical biomass[J]. Progress in Energy and Combustion Science, 2015,49:59-80.
[7] Hakanson L. Ecological risk index for aquatic pollution control:a sedimentological approach[J]. Water Research, 1980,14:975-1001.
[8] Müller G. Index of geoaccumulation in sediments of the Rhine River[J]. Geojournal, 1969,2:108-118.
[9] Perin G, Craboledda L, Lucchese M, et al. Heavy Metal Speciation in the Sediments of Northern Adriatic Sea:a New Approach for Environmental Toxicity Determination[R]. in:Lekkas TD(Ed.), Heavy Metal in the Environment, Edinburgh:CEP Consultant, 1985:454-456.
[10] Liang X, Ning X A, Chen G X, et al. Concentrations and speciation of heavy metals in sludge from nine textile dyeing plants[J]. Ecotoxicology and Environmental Safety,2013,98:128-134.
[11] Zhang X Q, Tian Y, Wang Q, et al. Heavy metal distribution and speciation during sludge reduction using aquatic worms[J]. Bioresource Technology, 2012,126:41-47.
[12] Zhao S, Feng C H, Yang Y R, et al. Risk assessment of sedimentary metals in the Yangtze Estuary:new evidence of the relationships between two typical index methods[J]. Journal of Hazardous Materials, 2012,241/242:164-172.
[13] Xiao Z H, Yuan X Z, Leng L J, et al. Risk assessment of heavy metals from combustion of pelletized municipal sewage sludge[J]. Environmental Science and Pollution Research, 2016,23(4):3934-3942.
[14]马倩,朱伟,龚淼,等.超临界水气化处理对脱水污泥中重金属环境风险的影响[J].环境科学学报, 2015,35(5):1417-1425.Ma Qian, Zhu Wei, Gong Miao, et al. Effects of supercritical water gasification on the environmental risk of heavy metals in dewatering sludge[J]. Journal of Environmental Science, 2015,35(5):1417-1425.
[15]张凌,曹红霞,苏萌,等.开封市污水处理厂污泥中重金属形态分布及其潜在生态风险评价[J].河南大学学报:自然科学版, 2016,46(2):207-212.Zhang Ling, Cao Hongxia, Su Meng, et al. The distribution of heavy metals in sewage sludge in Kaifeng Sewage Treatment Plant and its potential ecological risk assessment[J].Journal of Henan University:Natural Science Edition, 2016,46(2):207-212.
[16] Yang T, Huang H J, Lai F Y. Pollution hazards of heavy metals in sewage sludge from four wastewater treatment plants in Nanchang, China[J]. Transactions of Nonferrous Metals Society of China, 2017,27:2249-2259.
[17] Ikem A, Egiebor N O, Nyavor K. Trace elements in water,fish and sediment from Tuskegee Lake, southeastern USA[J]. Water Air Soil Pollution, 2003,149:51-75.
[18]国家环境保护部.中国土壤元素背景值[M].北京:中国环境科学出版社, 1990.Ministry of Environmental Protection. Background Value of Chinese Soil Elements[M]. Beijing:China Environmental Science Press, 1990.
[19] Huang H J, Yuan X Z, Zeng G M, et al. Quantitative evaluation of heavy metals’pollution hazards in liquefaction residues of sewage sludge[J]. Bioresource Technology, 2011,102:10346-10351.
[2] Kacprzak M, Neczaj E, Fijalkowski K, et al. Sewage sludge disposal strategies for sustainable development[J]. Environmental Research, 2017,156:39-46.
[3] Huang H J, Yuan X Z. The migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge[J]. Bioresource Technology, 2016, 200:991-998.
[4] Mulchandani A, Westerhoff P. Recovery opportunities for metals and energy from sewage sludges[J]. Bioresource Technology, 2016,215:215-226.
[5] Li J, Luo G B, Gao J F, et al. Quantitative evaluation of potential ecological risk of heavy metals in sewage sludge from three wastewater treatment plants in the main urban area of Wuxi, China[J]. Chemistry and Ecology, 2015,31(3):235-251.
[6] Huang H J, Yuan X Z. Recent progress in the direct liquefaction of typical biomass[J]. Progress in Energy and Combustion Science, 2015,49:59-80.
[7] Hakanson L. Ecological risk index for aquatic pollution control:a sedimentological approach[J]. Water Research, 1980,14:975-1001.
[8] Müller G. Index of geoaccumulation in sediments of the Rhine River[J]. Geojournal, 1969,2:108-118.
[9] Perin G, Craboledda L, Lucchese M, et al. Heavy Metal Speciation in the Sediments of Northern Adriatic Sea:a New Approach for Environmental Toxicity Determination[R]. in:Lekkas TD(Ed.), Heavy Metal in the Environment, Edinburgh:CEP Consultant, 1985:454-456.
[10] Liang X, Ning X A, Chen G X, et al. Concentrations and speciation of heavy metals in sludge from nine textile dyeing plants[J]. Ecotoxicology and Environmental Safety,2013,98:128-134.
[11] Zhang X Q, Tian Y, Wang Q, et al. Heavy metal distribution and speciation during sludge reduction using aquatic worms[J]. Bioresource Technology, 2012,126:41-47.
[12] Zhao S, Feng C H, Yang Y R, et al. Risk assessment of sedimentary metals in the Yangtze Estuary:new evidence of the relationships between two typical index methods[J]. Journal of Hazardous Materials, 2012,241/242:164-172.
[13] Xiao Z H, Yuan X Z, Leng L J, et al. Risk assessment of heavy metals from combustion of pelletized municipal sewage sludge[J]. Environmental Science and Pollution Research, 2016,23(4):3934-3942.
[14]马倩,朱伟,龚淼,等.超临界水气化处理对脱水污泥中重金属环境风险的影响[J].环境科学学报, 2015,35(5):1417-1425.Ma Qian, Zhu Wei, Gong Miao, et al. Effects of supercritical water gasification on the environmental risk of heavy metals in dewatering sludge[J]. Journal of Environmental Science, 2015,35(5):1417-1425.
[15]张凌,曹红霞,苏萌,等.开封市污水处理厂污泥中重金属形态分布及其潜在生态风险评价[J].河南大学学报:自然科学版, 2016,46(2):207-212.Zhang Ling, Cao Hongxia, Su Meng, et al. The distribution of heavy metals in sewage sludge in Kaifeng Sewage Treatment Plant and its potential ecological risk assessment[J].Journal of Henan University:Natural Science Edition, 2016,46(2):207-212.
[16] Yang T, Huang H J, Lai F Y. Pollution hazards of heavy metals in sewage sludge from four wastewater treatment plants in Nanchang, China[J]. Transactions of Nonferrous Metals Society of China, 2017,27:2249-2259.
[17] Ikem A, Egiebor N O, Nyavor K. Trace elements in water,fish and sediment from Tuskegee Lake, southeastern USA[J]. Water Air Soil Pollution, 2003,149:51-75.
[18]国家环境保护部.中国土壤元素背景值[M].北京:中国环境科学出版社, 1990.Ministry of Environmental Protection. Background Value of Chinese Soil Elements[M]. Beijing:China Environmental Science Press, 1990.
[19] Huang H J, Yuan X Z, Zeng G M, et al. Quantitative evaluation of heavy metals’pollution hazards in liquefaction residues of sewage sludge[J]. Bioresource Technology, 2011,102:10346-10351.