浙江省人为镉排放源与汇时空格局解析

Spatial and temporal variation assessments on anthropogenic cadmium emission sources&sinks in Zhejiang Province

近年来,随着工农业的迅猛发展,大量的人为镉排放对我国生态环境安全构成了严重威胁,而污染源识别在污染治理中具有举足轻重的作用.为此,本文以工农业集产区浙江省为案例,通过文献调研,构建了浙江省人为镉工农业排放因子清单,并采用清单核算法对浙江省人为镉排放的源汇进行了估算.结果表明,浙江省人为镉排放在1995—2017年期间基本呈上升趋势,从1995年的39 t增加到2007的141 t,自2007年以后,浙江省的镉排放量达到了一定的峰值,其排放量在140 t·a^(-1)左右.其中75%以上的镉通过固废的形式排放进入环境,而进入大气和水体的镉分别约占15%和10%.在所有排放源中,原煤燃烧的镉排放贡献率最大,占总排放量的50%以上;其他排放源从大到小依次是钢铁生产、有色金属冶炼、造纸生产、水泥生产、塑料生产、有色金属开采、油料消费、磷肥生产、蓄电池生产、平板玻璃生产和陶瓷生产.各个地区镉排放表现出较大的空间差异,2015年杭州市和宁波市镉排放量已达到20 t以上,以杭州和宁波为中心的北部区域远远高于南部区域.因此,建议未来浙江省镉污染排放源头治理重点是减少原煤燃烧,其次是钢铁生产、有色金属冶炼、造纸生产、水泥生产,尤其北部区域.

In recent years,a great amount of anthropogenic cadmium(Cd)emission into environment and China poses a serious ecological health risks due to the rapid development of industry and agriculture.Source identification plays an important role in Cd pollution mitigation.Therefore,this research conducted at Zhejiang Province(an intensive industrial and agricultural region)as a case study.According the literature review,the emission factors of Cd emission in Zhejiang have been developed.And the emission sources and sinks of anthropogenic Cd in Zhejiang Province evaluated by multiple pollution sources inventory method.The results show that the anthropogenic Cd emission in Zhejiang was increasing from 39 t in 1995 to 141 t in 2007.After 2007,the total Cd emission reached a certain peak with around 140 t·a^(-1).The majored sink was solid waste which counted more than 75%of total emission.The sinks of atmosphere and water were only about 15%and 10%of total emission.Regarding Cd emission sources,raw coal combustion was the largest contribution with over 50%of total emission.And it followed by iron and steel production,non-ferrous metal smelting,paper production,cement production,plastic production,non-ferrous metal mining,oil consumption,phosphate fertilizer,battery production,flat glass production and ceramic production.For the spatial distribution,the northern area was much higher than southern area.Hangzhou and Ningbo showed very high Cd emission during the study period of 1995—2017 and it was up to over 20 t·a^(-1) in 2015.To mitigation Cd pollution in Zhejiang,it suggested that focus on reducing raw coal combustion,iron and steel production,nonferrous metal smelting,paper production,cement production,especially in the northern region.