Study On Hot Pressing Of Waste Acetate Fiber And Its Purification For Livestock Wastewater

In order to solve the problem of waste water treatment in large-scale livestock and poultry breeding,waste acetic acid was made into filter material by needling and hot pressing treatment.This paper studied the influence of temperature,holding time,pressure and other parameters on the molding of waste acetate fiber,as well as the purification characteristics of the molding filter material for aquaculture wastewater and the degradation characteristics of the molding filter material.The test results showed that:1.Hot pressing temperature,hot pressing time and hot pressing pressure are the main factors affecting the melting,bonding and stability of the vinegar fiber filter material.The performance of the filter material is changed by affecting the density of the filter material,the internal heat of the filter material and the contact area of the filter material.When the hot pressing temperature is 160 ℃,the holding time is 20min,the hot pressing pressure is 10MPa,the mechanical properties of the filter material reach the best,its maximum tensile strength is 374.62N,the tensile length is 56.33mm,At this time,the removal rates of TS,COD,TP and TN in aquaculture wastewater were 81.32%,64.29%,54.72%and 44.99%.2.The direction of infiltration affects the purification effect when filtration of aquaculture wastewater.The filtration device consists of an internal galvanized pipe and an external acrylic pipe.When the aquaculture wastewater permeates from the galvanized pipe to the external acrylic pipe,it is the forward osmosis.When the aquaculture wastewater flows from the external acrylic pipe to the galvanized pipe,it is the reverse osmosis.When the COD removal rate is taken as the evaluation index for forward filtration,the optimal hot pressing parameters are as follows:hot pressing temperature was 170℃ holding time was 20min,hot pressing pressure was 10MPa;When the removal rate of TS was taken as the evaluation index,the optimal hot-pressing parameters were as follows:hot-pressing temperature was 160℃,holding time was 20min,and hot-pressing pressure was 7.5MPa.When the COD removal rate is taken as the evaluation index for reverse filtration,the optimal hot pressing parameters are as follows:hot pressing temperature was 160℃,holding time was 25min,and hot pressing pressure was 12.5MPa.When the removal rate of TS was taken as the evaluation index,the optimal hot-pressing parameters were as follows:hot-pressing temperature was 160 ℃,holding time was 20min,and hot-pressing pressure was 10MPa.3.Hot pressing can significantly improve the filtration performance of the vinegar fiber filter material and extend the saturation time of the filter material.When the flow rate of the wastewater is controlled at 400L.h-1,the COD removal rate of the livestock wastewater by needled felt cloth reaches the peak of 53.07%after continuous filtration for 4h,and the COD removal rate drops to 34.91%after continuous filtration for 7h.After forward filtration for 7h,the COD removal rate of the molded filter material on the livestock sewage decreased from 64.61%to 52.44%.After 7h of reverse filtration,the COD removal rate of the formed filter material on the livestock sewage decreased from 71.66%to 59.67%.4.Aerobic compost can promote the degradation of vinegar fiber filter material.When the filter material was placed in cow dung:straw(mass ratio 6:4)by aerobic fermentation for 30 days,the mass loss reached 15.44%,the maximum tensile loss reached 23.76%,and the tensile length loss reached 36.02%.When the mass fraction of acetic acid is 40%,the maximum mass loss of the filter material is 21.99%and the maximum tensile loss is 36.95%after the filter material is soaked in acetic acid at room temperature for 24h.Tensile length loss of 22.68%;When the mass fraction of acetic acid is more than 40%,the filter material began to dissolve in a large area.