关键词: 权重线性加和模型, 污泥, 土地利用, 环境风险

Abstract:

Environmental problems caused by sewage sludge are the major limiting factor for its large-scale application. Based on weighted linear combination (WLC), an environmental risk control method for land use of urban sludge was established. Also, an environmental risk control scheme of urban sludge application was proposed in Beijing. Environmental effects of different factors of sludge application were quantified: soil heavy metal concentration (0.22) > land use type (0.17) ≈ soil type (0.17) ≈ natural rainfall (0.17) > slope (0.13) > distance from natural water (0.09) > distance from urban residents (0.05). High-suitable area for sludge application in Beijing is mainly located in the junction of Pinggu and Shunyi district, central region of Changping and Yanqing district, and mountain forest land in the eastern part of Fangshan district. The usage area of high-suitable region is 2033 km². Moderate-suitable application area is located in southwest and southeast regions, where land types are woodlands and drylands. The usage area of moderate-suitable region is 5079 km², and usage area of low-suitable area is 380 km². Low-suitable area is located in Shijingshan, northeast of Mentougou, southwest of Fangshan, and north of Pinggu. The prohibited area is 8916 km² and it is mainly distributed in urban areas, suburbs of the city, and some other districts such as Yanqing, Huairou and Miyun.

Key words: WLC, sewage sludge, land use, risk of pollution