| In recent years,with the rapid development of the breeding industry,large-scale livestock and poultry farms have emerged one after another in my country.The environmental pollution problem caused by the arbitrary discharge of breeding waste liquid is becoming more and more serious,which not only threatens the ecological environment and human health,but also affects the sustainable development of the breeding industry development adversely affected.At present,the treatment of aquaculture waste liquid mainly adopts sedimentation and filtration,and then directly discharges it to rivers,lakes or farmland,which seriously pollutes the water environment.Using biological fermentation method to turn aquaculture waste liquid into biological inoculum can not only solve the problem of environmental pollution,but also can be used as a microbial inoculant for regulating the growth and development of crops.While solving the problem of environmental pollution,it can also bring about the regulation of crop growth and increase the yield,thereby obtaining important economic and social benefits.In this paper,microbial strains are added to aquaculture waste liquid,and solid biological fermentation products are prepared by biological fermentation and low-temperature decompression concentration and drying methods.Fermentation effect of aquaculture waste liquid and changes in the number of bacterial cells,the organic matter,nitrogen,phosphorus,potassium,p H,and the composition of condensed water in the drying process were analyzed in the fermentation concentrate,Validation of the application effect of solid bio-fermentation products on rice.The specific research results are as follows:(1)Fermentation of aquaculture waste liquid can increase the content of concentrated products.Bacillus subtilis,yeast and their compound bacteria have different fermentation effects on aquaculture waste liquid,it is shown that the fermentation effect of single strain is better than that of compound strain,the best effect is molasses 2%+Bacillus subtilis 1%,48.07%higher than the control.(2)The number of bacterial cells increased significantly after fermentation of aquaculture waste liquid.With the increase in the amount of molasses and bacterial liquid added,discovery:when Bacillus subtilis fermented aquaculture waste liquid with molasses 2%+Bacillus subtilis 1%fermentation,the number of cells was the largest,reaching 4.87×10~9 cfu/m L;After the yeast fermented the aquaculture waste liquid with 3%molasses+1%yeast,the effective viable count reached 1.96×10~9 cfu/m L.(3)The organic matter,total nitrogen,total phosphorus,total potassium,humic acid and p H of the biological fermentation concentration and drying products were 50.1%,1.74%,0.83%,6.11%,3.57%and 6.8,respectively,all in line with the technical indicators stipulated in the NY525-2021standard.(4)The chemical oxygen demand,sulfide,animal and vegetable oils,petroleum,volatile phenol and p H content of condensed water produced in the fermentation and concentration process are as follows:103 mg/L,0.005 mg/L,0.08 mg/L,0.08 mg/L,0.0003 mg/L,and 6.7 did not exceed;the standard and met the emission standard.The contents of heavy metals copper,zinc,lead,mercury,chromium and hexavalent chromium were 0.01 mg/L,0.02 mg/L,0.005 mg/L,0.00004 mg/L,0.004mg/L and 0.004 mg/L,respectively,which did not exceed the standard,the standard and met the emission standard.(5)The concentrated and dried products of aquaculture waste liquid are sprayed on stems and leaves after rice transplanting,the number of effective tillers,plant height,average number of panicles per plant,average number of grains per panicle,1000-grain weight and yield of rice were significantly increased,respectively.Among them,the application rate of 7.5 kg/hm~2 had the best effect,and the yield was significantly increased by 28.12%compared with the control. |
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