Study On The Effect And Mechanism Of Reducing Heavy Metal Cu In Vesicular Feces By Low Potential Method

With the rapid development of large-scale and intensive aquaculture,it has brought people abundant meat products,but also brought many environmental problems,especially a large amount of aquaculture manure pollution to the surrounding areas of the farm.In recent years,with the combination of agriculture and animal husbandry and the development of circular agriculture,a large amount of manure has turned waste into treasure.After harmless treatment,the manure is supplied to the surrounding farmland or converted into fertilizer to return to the land.However,the passivation and reduction of heavy metals are often neglected in the current manure treatment process.While manure is fertilized,a large amount of heavy metals also enter the soil,resulting in a certain degree of soil heavy metal pollution.On the basis of on-the-spot investigation on the treatment process and heavy metal residue of "blister dung" in a pig farm in Fengyang County,Chuzhou City,Anhui Province,this study proposes to use low potential method to reduce heavy metal copper in blister dung with heavy metal Cu as the target pollutant,and studies the influence of different electrolytic conditions on different forms of copper in blister dung,as well as the promotion effect of adding microbial inoculum on low potential method.The experimental conditions are optimized by the combination of single factor and orthogonal experiment,and the influence of low potential method on organic matter composition in blister dung is judged by FTIR characterization experiment.The contents are as follows:(1)The study on the effect of low potential method on the reduction of heavy metal copper in blister dung,and the best action condition of low potential method on the reduction of blister dung was determined by single factor method and orthogonal test method.The low potential method has a good effect on reducing copper in blister dung.The reduction effect of different electrolysis conditions on different forms of copper is very different.The reduction rate of total copper is most affected by time.When the electrolysis voltage is 20 V and the electrolysis p H value is 7.5,the reduction effect of total copper in blister dung is the best,with the reduction ratereaching 72.54%.(2)Study on the promotion effect of microorganisms on the reduction of heavy metal copper in blister manure by low-potential method.Three dominant microorganisms in pig manure that are beneficial to the reduction of heavy metal copper are found through microbial culture experiments: Bacillus subtilis,yeast and lactic acid bacteria.The blister manure is treated by microbial agents with different concentration gradients,and the following results are achieved: by adding composite microbial agents,the concentration of each bacterium is not less than 3.6×108cfu/ml.Electrolytic treatment of soaked feces resulted in 93.98% exchangeable copper,97.27% carbonate bound copper,88.05% iron-manganese bound copper,81.94%organic bound copper,82.23% residue copper,and 81%-85% total reduction.(3)Through FTIR characterization experiment,the effect and mechanism of potential digestion of blister dung were preliminarily discussed.The results show that electrolysis can enhance the adsorption sites of heavy metals chelated by organic matters in blister dung,thus improving the ion exchange capacity,chelation capacity and adsorption capacity.