粤港澳大湾区典型城市遗留地块土壤污染特征研究

通过识别各类工业企业搬迁遗留地块的环境风险等级，可实现差异化的环境管理，在保障人居环境安全的同时，提高地块开发效率，纾解城市土地资源紧张的问题.该研究通过分析粤港澳大湾区某典型城市2013—2018年开展调查的93个遗留地块的土壤污染风险、污染程度、污染类型及分布特征，探讨行业类型对地块土壤污染风险及污染特征的影响.结果表明:该城市金属表面处理及热加工业、化学原料及化学品制造业、金属冶炼及延压加工业等3个行业的污染地块占比超过85%，单位面积污染量（污染地块每平方米调查面积的污染土方量）超过0.32 m3，污染负荷指数大于0.5，为土壤高污染风险行业；其中，金属表面处理及热加工业地块表现为无机污染，主要污染物为重金属，化学原料及化学品制造业地块主要表现为有机污染，主要污染物为苯系物、石油烃和多环芳烃，金属冶炼及延压加工业地块主要表现为复合污染，主要污染物为多环芳烃、铅、砷、镍、锌；电气机械及器材制造业、装卸搬运和仓储业、商务服务业、纺织业、文教及工美体育和娱乐用品制造业、塑料制品业、农业和畜牧业等7个行业类型为土壤低污染风险行业.该市污染地块以复合污染为主，污染物类型主要为重金属、氰化物、氟化物和有机污染物，其中，砷和多环芳烃在污染地块中的出现频率最高，均接近50.0%.因此，遗留地块的土壤污染风险、污染特征与其区域特点、历史行业类型密切相关，在对关闭搬迁遗留污染地块进行环境调查和环境监管中，进一步对不同类型行业进行区别化监管具有重要意义. 

Characterization of Soil Contaminations in Brownfield Sites in a Typical City in Guangdong-Hong Kong-Macao Greater Bay Area

Differentiated environmental management can be achieved by identifying the environmental risk levels of brownfield sites. This can increase the efficiency of land development under the premise of residential environment safety and mitigate the shortage of land resources in the city. By analyzing the soil contamination risk, levels, types, distribution characteristics of 93 brownfield sites in a typical city of Guangdong-Hong Kong-Macao Greater Bay Area during 2013-2018, the influences of industrial types on soil contamination risk and characteristics were discussed. The results show that more than 85% of the brownfield sites were from metal surface/thermal treatment, chemical raw materials and chemical manufacturing, and metal melting/pressing industries. The contaminated soil volume per square meter of these three industrial types of brownfield sites exceeds 0.32 m3 and the pollution load index exceeds 0.5. Thus, these three industrial types are identified as high contamination risk types. The brownfield sites of metal surface/thermal treatment industries are mainly contaminated by inorganic pollutants, and the main contaminants are heavy metals. On the contrary, organic pollutants such as BTEX, polycyclic aromatic hydrocarbons (PAHs) and petroleum hydrocarbons are mainly in the brownfield sites of chemical raw materials and chemical manufacturing industries. The coexistence of inorganic and organic contaminants mainly occurs in the brownfield sites of metal melting/pressing industry, and the main contaminants are PAHs, lead, arsenic, nickel and zinc. The industries of electrical machinery and equipment manufacturing, handling and warehousing, commercial service, textile, cultural/athletic/recreation products manufacturing, plastic product, agriculture, and livestock are identified as low contamination risk industrial types. The brownfield sites in this city are mainly complex pollution, and the main contaminants are heavy metals, cyanide, fluoride, and organic compounds. The frequencies of occurrence of arsenic and PAHs are approximately 50.0%, which were the highest among all the contaminants. Thus, the soil contamination risk, levels, types, and distribution characteristics of the brownfield sites are closely related to their regional characteristics and historical land-use patterns. Therefore, it is of great significance for environmental protection authority to differentiate the investigation and supervision of closed brownfield sites according to the industrial types.