Study On Earthworm Growth Affected By Change Of Heavy Metals And Microbes In Sludge From Livestock And Poultry Farm Wastewater

With the constantly-developing of livestock industry in our country, great pollution to the environment has been caused in some areas due to a great quantity organic waste of Livestock and poultry breeding without treatment and utilization.The earthworm utilization is one of the most effective ways for recycling of organic waste in the future. However, some problems of practical production about earthworm farm in base stock have arisen after a period of time, such as the serious degradation and weight loss.But there are less studies and no conclusion about the cause for this phenomenon at present. Therefore, the purpose of this article is to preliminary explore the influence mechanism of earthworm growth by researching the material parameters change during the earthworm breeding process,such as the change of heavy metals and microbial community.In this experiment,the earthworm breeding base stock mainly include the sludge which was from the wastewater treatment station.There are 200g base stock in per box(dry substances).And also, inoculating the earthworm which weight is about 150mg for 20. Breeding after about 65 days, the earthworm began to appear the phenomenon of weight loss,which was consistent with the actual production. When the earthworm growth curve fitted by researcher, the highest fitting degree was the "S" type.The parental adult and filial generation earthworm are used as inoculation material, and there are two major types of base stock in this experiment.The first material is sludge feed which has been interacted by earthworm before and earthworms weight decreased then.It mainly includes the original base stock, base stock with EM, base stock with maize paste, base stock with EM and maiz paste.The second material is which hasn’t been interacted by earthworm before.It just includes the base stock and base stock with EM.In all,a total of 12 experimental groups were set up.Breed each group for seven weeks and making destructive sampling every seven days.At every turn,collecting 3 boxes from each group.Then, measure the weight of the parental adult and filial generation earthworm,and also,measure the total Cu and Zn in parental adult earthworm and the total Cu,Zn,N. organic C and the pH in base stock.Finally, through high-throughput 16SrDNA sequencing method to detect the species and amount of bacteria in base stock to study the reason for weight loss of earthworm. The analysis of the experiment suggests the following results and Conclusions:1.The highest fitting degree of earthworm growth curve was the "S" type.2.The base stock contain rich EM in the early farming, it is not necessary to spray EM for it.3. Whether the parental adult or filial generation earthworm,feeding by the base stock with EM always better than without EM.The result of high-throughput 16SrDNA sequencing shows that the base stock which hasn’t been interacted by earthworm contain a higher number microbes than those of residual of earthworms feeding.4.There are two main reasons for the earthworms’ weight loss after a period of time growth: 1) The type of binder significantly reduce the number of microorganisms.2)The base stock contain higher Cu and Zn which would enrich in the earthworms’ body in later life.It will cause weight loss through poisoning them.5.If earthworm began to appear weight loss when they grow in base stock with Cu and Zn, decreasing content of Cu and Zn and spraying EM at the same time has better effects on earthworm growth.