陕西省畜禽粪便负荷量估算及环境承受程度风险评价

在调查陕西省各地(市)畜禽养殖数量、养殖结构的基础上,通过估算各地(市)畜禽粪便排放量及负荷量,评价了各地(市)畜禽养殖业的发展对环境产生的污染压力,为陕西省畜禽养殖业可持续发展及畜禽粪便环境污染防治提供科学依据。研究结果表明:(1)陕西省畜禽养殖饲养量中,家禽饲养量最大,其次分别为猪和羊。(2)2006—2010年陕西省各类畜禽粪便产生量在年际间波动较大,2008处于低谷,之后又快速增长;按年粪便产生量多少排序,依次为牛猪羊家禽兔。(3)陕西省畜禽粪便农田负荷量总体呈上升的趋势,由2008年的10.78 t·hm-2·a-1上升到2010年的18.4 t·hm-2·a-1,增长了70.7%;禽粪便警报值由2008年的最小值0.36增加到2010年的0.60,从对环境构成污染威胁的程度看,由不构成污染威胁到对环境稍有污染。(4)2010年,陕西省畜禽粪便COD、BOD总产生量分别为121.25万t和104.09万t;与2008年相比,2010年陕西省各类畜禽污染物排放量COD、BOD、NH3-N、总氮,总磷分别增长了73.2%、69.4%、76.7%、72.6%、58.2%;据估算,2010年陕西省畜禽粪便淋溶进入水体的COD、BOD、NH3-N、TN、TP分别达36.38万t、31.23万t、3.44万t、83.4万t、39.85万t。

Estimations of livestock manure load and risk assessment of environmental tolerance in Shaanxi Province

On the basis of investigations on the number of livestock and cultivation pattern, pollution and environmental risks caused by the development of the livestock and poultry industry were evaluated by means of estimating livestock manure discharge amounts and loads in Shaanxi area, providing a scientific basis for sustainable development of livestock and poultry industry and environmental pollution control. Results showed that the number of poultry was the largest, followed by pig and sheep, among the livestock and poultry breeding in Shaanxi Province. The amount of livestock manure excrements had obviously fluctuated from 2006 to 2010, and was at a low level in 2008, but later became increased rapidly. For the annual amounts of livestock manure excrements, the rank was cattle, pig, sheep, poultry and rabbit. The livestock manure loads showed an increasing tendency, which was increased 70.7% from 10.78 t·hm^-2·a^-1 in 2008 to 18.4 t·hm^-2·a^-1 in 2010. The alarm value of livestock manure loads had been increased from the minimal value of 0.36 in 2008 to 0.60 in 2010, and the degree of pollution threat effects on the environment was changed from none to being subtle. In 2010, the total production number of COD and BOD from livestock manure was 121.25×10⁴ t and 104.09×10⁴ t, respectively. Compared with 2008, the discharge of COD, BOD, NH₃-N, total nitrogen and total phosphorus from livestock manure in 2010, were increased respectively by 73.2%, 69.4%, 76.7%, 72.6% and 58.2%, respectively. It was estimated that the number of COD, BOD, NH₃-N, TN and TP that were leached out from livestock manures into water bodies reached 36.38×10⁴, 31.23×10⁴, 3.44×10⁴, 83.4×10⁴ and 39.85×10⁴ tons in 2010, respectively.