The Effect Of Three Manure Cleaning Methods To The Pollution Discharge In Pig Farms

Dry-cleaning,water-soaking and water-flushing are common methods used to clean munure in modern pig farms.Different manure cleaning methods significantly contribute to the output of manure pollution in pig farms.To research pollutiondischarge characteristics of different manure cleaning methods in pig farms can provide reference for scientific utilization of manure pollution in pig farms.Our research object was manure and urine sampled after different cleaning method from several pig farms in Guang-xi,related indicator of feed,manure and sewage were tested,and statistical analysis was implemented then.This research showed that: The p H value of munure cleaned in dry method was higher than that cleaned by soaking and water-flushing,and water content was lower than that cleaned by soaking and water-flushing;the content of organic matter of Dry-cleaned manure was as much as water-soaked manure while higher than water-flushed;the TN,TP,and TK of drycleaned manure was higher than that cleaned in water-soaking and water-flushing,and the mortality of ascaris eggs was higher in dry-cleaned munure than that cleaned via water-soaking and water-flshing method,while the manure colititre was higher than that cleaned via water-soaking and water-flushing.There’s no significant difference of p H value,and ascaris mortality in sewage which produced from different cleaning method;the COD,SS,ammonia nitrogen,TN,TP,TK,the quantity of ascaris eggs,and content of heavey metal in sewage produced from the manure cleaned in dry method were lower than that from soaking method,while the manure colititre was significantly higher.Except TP,TK,Hg,Cd in manure and Se in sewage,pollutiondischarge charachteristics of different muanure cleaning methods were possitively correlated to feed nutrition index.Comparing to national standard,the TP and TK content were slightly diffrent to national standard,while moisture content,and conent of Cr,Pb,Cu,Zn,Cd basically comply to industry related standard,the content of Hg in part of samples exceeded the standard limitation value;all of the moisture content exceeded the standard,and the motarlity rate of ascaris eggs was lower than limitation value,colititre of the manure sample cleaned via water-soaking and water-flushing exceeded the limtation value,while colititre of 50% of manure sample cleaned in dry method complied to standard limitation,and the content of Cu,Zn,and As all complied to standard;the p H value,and content of Se,and As all complied to standard,COD,SS,ammonia nitrogen,TP,manure colititre,ascaris-egg quantity,mortality rate of ascaris eggs,content of Hg,Pb,and Zn exceeded the standard value,content of Cr,Cu,And Cd in part of sewage sample from dry-cleaning method complied to standard.Conclusion: The research of pollution-dischage charachteristics of different manure cleaning methods used in pig farms provided effective reference for scientific utilization of manure pollution in pig farms.Effective components of manure cleaned in dry method was lost less comparing to that of other cleaning method,it was beneficial to return manure to farm field as fertilizer.The pollutant content in sewage was less than that in other cleaning method,it positivey contributed to sewage treatment in pig farm,and it provided pig farms a preference to choose it as manure cleaning method in pig farms.