Comparative Analysis On Different Waste Treatment Modes In Scale Pig Farms

This study aims to understand current waste treatment mode and exploring ideal waste treatment mode in scale pig farms.Firstly,questionnaires surveys on slurry treatment mode were taken in 34 different ecological recycling pig farms in 5 regions of Jiangsu province.Eight farms with a certain typical mode were randomly selected to collect slurry samples.Indexs like chemical oxygen demand(COD),total nitrogen content,total phosphorus content,Zn and Cu etc.were assayed to put forward an optimal waste treatment mode.The experiment was divided into two parts:1.Analysis of manure processing mode in pig farmThe results showed that wide attention has been aroused to dry manure handling in Jiangsu province in scale pig farms.But the level of treatment varied.There are two main modes "pig-biogas-emission" and "pig-biogas-oxide-emissions",taking advantage of the anaerobic oxidation and fermentation technology.Although,to some degree indicators have been improved,and even some indicators have reached the national emission standards,environmental pollution still existed.Hence,combined with the understanding of the information,based on land resources and environment conditions within and around the farm,we put forward the following three types of farm waste treatment modes:efficient land intensive field farming mode,large farms cycle mode,and the industrial park chain business cycle mode.We hope to achieve to promote the comprehensive development of aquaculture,farming,renewable energy industry,and reduce the pressure on the environment form pig manure.2 Comparative study of manure processing mode in pig farmIn "pig-biogas-emissions" mode processing large-scale farms,final emissions by anaerobic in the manure fermentation have no significant effect on the total nitrogen and total zinc.Finally generated biogas in this mode did not meet the national emission standards for livestock and poultry manure field.The aerobic oxidation of the biogas"pig-biogas-oxidation-emissions",manure final discharge of COD value,total phosphorus,total nitrogen,were significantly decreased(P<0.05),but still did not meet the national emission standards.Combined with land resources and the environment,we proposed land intensive pig breeding farm manure efficient mode.Through anaerobic fermentation,aerobic oxidation,biodegradation and other processes the final slurry COD,total phosphorus,copper,zinc and other indicators were significantly lower than the production area(P<0.01),the result was far lower than the national emission standards for livestock and poultry farm manure and municipal sewage national standards.We proved that the mode could effectively use the remaining farm land for vaccination ditch and biodegradable slurry,have good effect on slurry treatment,so as to achieve a virtuous cycle of waste water of pig farms.