Technology progresses of swine wastewater treatment from large-scale pig farms

Abstract

For the large-scale swine wastewater with the characteristics of high concentration of organic matter, suspended solids and more high ammonia nitrogen, odor, complex pollution ingredient and large emissions, combined with Chinese national conditions, adapting conditions and characteristic of the three of back-to-field mode, ecological processing mode and bio-processing mode are analyzed. Meanwhile, it is proposed that the development direction and main problems of the current swine wastewater treatment. The specialization and scale level of pig farms contributed to improve the management level, raising technology and the capability of epidemic prevention, Compared with the traditional dispersive family raising, the scale raising can greatly increase the production efficiency and feed conversion ratio, reduce the production cost, thus the economic benefit is improved, However, the scale raIsmg will generate enormously environmental stress due to the excessive concentration fecaluria and the large increasing wash water [I l , water-flush, water-steep-excrement and dry purging waste process [ 8l , The water-flush process is used in most scale pig farms of our country. The water-flush process is convenient and quicker. But it will wash both the excrement, scattered feed along with the pig urine into the wastewater, and cause the high concentration of organic, suspended and ammonia matter, bad smell, complex pollution and large emission, Every index exceeded several times and even dozens times of the national standards. The study shows that the BOD5 of pig manure is about 60000mg / L, the BOD5 of swine is about 30000mg / L, the BOD5 of discharge wastewater of pig farm is up to 2000 � 8000mg / L.