A Study Of Pollution Production And Blowdown Characteristics Of Typical Pig Breeding In Middle Reaches Of Tiaoxi River

With the rapid development of animal husbandry in China, a large number of output and irrational use of livestock and poultry manure has caused a certain impact on the regional environment. "The Gazette on the first national census of pollution sources" showed that agricultural non-point source pollution has become the main pollution source in China. Annual emissions of COD, TN and TP of livestock accounted for 41.87%,21.67% and 37.9% in the national total emissions of pollutants, it’s an important part of agricultural non-point source pollution. How to calculate discharge of pollutants from the livestock and poultry breeding industry is critical to judgment of environment situation as well as planning and decision-making for the environment, and the calculation is an important basic datum for designing livestock and poultry breeding pollution control projects. At present, pollutants producing and discharging coefficients are the mainly method, which is adopted in the calculation of the sewage producing and discharging of livestock and poultry breeding industry pollution in the macro level in our country. We selected two pig farms with different scale in middle reaches of Tiaoxi River, with the goal of calculate the pig breeding industry sewage producing and discharging coefficient in basin. And discussed the characteristics of pig waste pollutants concentration and yield from different farming methods, different breeding stages, different seasons, etc. And integrate the pollutants producing and discharging coefficient of pig, Finally, the pollutant emission of the pig breeding industry in the river basin was estimated.. The research results show that:(1) During a pig breeding cycle the sewage production of TN、TP、Cu、Zn、 Pb、Cr per pig respectively:262 kg/head,1.48 kg/head,1.182 g/head,53.15 g/ head,0.32 g/head,9.45 mg/head,2.17 g/head; and the average discharge amount of COD, TN & TP were:286.80,101.40,38.15 g/head.(2) In addition to the TP concentration in aquaculture wastewater of JinAi is much higher than that of DaguanShan farm, the aquaculture waste pollutant concentration is higher than most of JinAi, but the yield of wastewater and fecal contaminants of JinAi were higher than that of DaguanShan farm.(3) The differences of content of pollutants in different pig breeding stage waste is obvious, but different pollutants with different characteristics, the pollutants yield were increased with the increasing size of pig.(4) The concentration and yield of pollutants in aquaculture wastewater were the highest in November, and the most concentrations of pollutants in pig fecal were highest in August, but most of their yield were highest in May.(5) The sewage treatment facilities of typical pig breeding field in middle reaches of TiaoXi River were running well, the discharging coefficient of pig breeding industry in TiaoXi basin were less than other of research results in similar areas. The total annual emissions of COD、TN、TP were 67.97,26.43,8.66t.(6) The results of this study are similar to those of other scholars in similar areas, It could reflect the pollutants production and blowdown characteristics of typical pig breeding in middle reaches of Tiaoxi basin.