“十四五”期间宁夏畜禽养殖污染趋势与污染防治对策研究

Pollution Trend and Prevention Measures of Livestock and Poultry Breeding in Ningxia During the 14th Five-Year Plan Period

为了评估“十四五”期间宁夏高速发展的畜禽养殖业带来的污染及对环境承载压力的影响,基于宁夏畜禽养殖数据,采用排泄系数法估算了化学需氧量(COD)、氮磷产生情况,在此基础上计算了畜禽粪便的耕地负荷。基于计算畜禽养殖环境适宜性、土地承载力及养分承载力,评估“十四五”期间将面临的环境承载压力。结果发现:(1)全区畜禽养殖所带来的COD、氮、磷排放量分别为123万、6.86万、7440 t。(2)从全区的环境承载压力来看,全区畜禽养殖环境适宜性区域主要分布在南部山区。各市畜禽粪污土地承载能力均大于畜禽养殖量,而利通区养殖量是粪污土地承载能力的3.1倍,超出当地土地承载能力,养殖污染风险极大。银川市区、利通区及泾源县无法实现粪肥全部还田,养分承载压力大。(3)“十四五”期间,畜禽养殖量逐年增加,在2025年氮排放量达12万t,比2020年增加了5万t;磷及COD排放量达1.2万、251.7万t,分别是2020年的1.7、1.5倍。在2025年耕地负荷预警值更是达到了3.50的高度,因此从适当控制养殖规模、严格执行生态消纳、加强粪污肥料化利用、科学治污、粪污集中处理中心建设及政策扶持6个方面提出对策建议。

To assess the pollution risk and environmental loaded pressure(ELP)caused by the rapid development of livestock and poultry breeding(LPB)during the 14th Five-Year Plan period in the Ningxia Hui Autonomous Region,according to the data of LPB,the emissions of livestock and poultry manure(LP),chemical oxygen demand(COD),nitrogen(N)and phosphorus(P)were estimated by the pollutant discharge coefficient method.Environmental loaded pressure of LPB was evaluated by the indexes,including the suitability evaluation,land-loaded pressure and the nutrient-loaded pressure.The results showed that:(1)the emissions of COD,N and P were 1.23 million,68600 and 7440 tons,respectively;(2)the suitability areas of LPB were mainly distributed in the southern mountainous area,in total,the land-loaded capacity was greater than the amount of LPB;however,the amount of LPB in Litong District was 3.1 times that of the land-loaded pressure,which posed a great risk of breeding pollution;the manure could not be all returned to field in Yinchuan urban area,Litong District and Jingyuan County;(3)the N emission was estimated to reach 120000tons in 2025,showing an increase of more than 50000 tons compared with that of 2020;the P emission was estimated to reach 12000 tons,correspondingly 1.7 times that of 2020;the COD emission was estimated to reach 2.517 million tons,correspondingly 1.5 times that of 2020.In 2025,the loaded warning value of cultivated land for LP will reach 3.50.Therefore,countermeasures were put forward from six aspects:proper control of breeding scale,strict LP returning to field,strengthening fertilizer use of LP,scientific treatment of LP pollution,setting up LP centralized treatment center and policy support.