湖北省畜禽养殖污染现状及总量控制

POLLUTION STATUS AND TOTAL AMOUNT CONTROL OF LIVESTOCK AND POULTRY BREEDING IN HUBEI PROVINCE

通过畜禽产排污系数以及2011年湖北省的统计数据,估算出湖北省2011年畜禽养殖业畜禽粪便总量及COD、氮、磷的产生量,分析了污染物对环境污染的情况,并对湖北省畜禽养殖的环境容量和污染风险进行了初步评估。结果表明,2011年湖北省畜禽的粪便总量为8 479.8万t,主要分布在襄阳市、黄冈市、孝感市。全省粪便耕地负荷为16.2 t/hm^2/a,警报值为0.54,分级级数为II,对环境构成污染的威胁为"稍有"。全省氮、磷的耕地负荷分别为157.9 kg/hm^2/a、24.5 kg/hm^2/a,其中,鄂州市、黄冈市均超过欧盟限量标准(氮170 kg/hm^2/a、磷35 kg/hm^2/a)。2011年湖北省的实际养殖总量分别为7 868.5万头猪当量(N)、9 725.3万头猪当量(P),都超过畜禽50%环境容量(为4 599.4万头猪当量(N),7 161.1万头猪当量(P)。除了荆州市外,其他大部分地区的实际养殖数量都超过50%环境容量,这些地区应该严格控制畜禽的养殖数量并同时做好污染物消减措施。

According to the pollutant excretion coefficient of livestock and poultry as well as the statistical data of Hubei Province in 2011, the total amount of livestock and poultry manure, the discharge amount of COD, nitrogen and phosphorus were estimated to analyze the environmental pollution status posed by livestock and poultry husbandry in Hubei province. Besides, the environmental capability, pollution risk of livestock and poultry husbandry were also preliminary assessed. The results showed that in 2011, the total amount of livestock and poultry manure in Hubei Province was 84.8 million tons and was mainly distributed in Xiangyang city, Huanggang city and Xiaogan city. The load of animal excretion per hectare of arable land in Hubei Province was 16.2 t/hm2/a, the alarm value was 0.54 and the risk level was II, indicating the environment pollution was ＂slightly＂. The average nitrogen and phosphorus load per unit area of arable land in Hubei province were 157.9 kg/hm2/a （TN） and 24.5 kg/hm2/a （TP）, respectively. However, the nitrogen and phosphorus load per unit area of arable land in Ezhou city and Huanggang city had surpassed the EU＇s standard of limitation on nitrogen and phosphorus which were 170 kg/hm2/a, 35 kg/hm2/a, respectively. The actual total amount of livestock and poultry in Hubei province were 78.7 million heads （equivalent based on nitrogen） or 97.3 million heads （equivalent based on phosphorus） exceeding 50% of holding capacity of environment for livestock and poultry husbandry. In addition to Jinzhou city, the actual total amount of livestock and poultry in most of the cities had exceeded the 50% of holding capacity of environment for livestock and poultry husbandry. Therefore, the total amount of livestock and poultry in these areas should be controlled and some effective measures for reducing pollutants should be taken.