Research On Filtration Technology Of Poultry Washing Wastewater Based On Corn Stalk Filter Material

Since the reform and opening up,the scale of my country’s livestock and poultry breeding industry has continued to expand.As traditional breeding methods have moved closer to large-scale and intensive production methods,my country has become the world’s largest livestock and poultry breeding and consumer country.However,the discharge and treatment of livestock and poultry wastewater has brought tremendous pressure to the surrounding environment.Large-scale poultry farming washing wastewater has complex components,a large amount of solid particle sludge,high ammonia nitrogen content,single pretreatment means and high treatment costs.By using corn stalks with wide sources and low cost,it can be used as a filter material to filter pretreatment of poultry washing wastewater,which can effectively improve wastewater treatment efficiency.It is an economical and effective means of treating waste with waste,and also an effective way to realize the resource utilization and harmless treatment of poultry washing wastewater.It provides a new idea for the resource utilization of corn stalks and the harmless treatment of poultry washing wastewater.By using corn stalks to filter poultry washing wastewater to achieve solid-liquid separation of wastewater as the main line,the removal effect of corn straw filter material on main pollutants in poultry washing wastewater was studied under different particle size,different filter thickness and different filter compactness,summarizes the optimal filtering conditions of each experimental factor on poultry washing wastewater,obtains the optimal level combination and verification,and designs the poultry washing wastewater filtering device on this basis.The results and conclusions are as follows:（1）The particle diameters of the corn stalk granular materials used in this experiment were determined to be 1cm,2cm,3cm,and 4cm,and the bulk densities of the four filter media were measured as 54.06kg/m³、52.10kg/m³、49.15kg/m³、44.23kg/m³.Through single-factor experiments,the filtration characteristics of the main pollutants in poultry washing wastewater under different particle sizes,different filter thicknesses and different filter compactions were studied separately,and the boundary conditions of each factor were determined.It is found that the smaller the particle size of the filter material,the thicker the filter layer thickness and the greater the degree of compaction of the filter,the better the filtration effect on wastewater;at the same time,when the particle size of the filter material is too small,the thickness of the filter layer is too thick or the filter layer is too compact large,it will cause the filter layer to be easy to block,the filter efficiency is low,and the filter material utilization rate is low;the boundary conditions for each factor are:filter material particle size 1cm～2cm,filter layer thickness 30cm～50cm,filter layer compaction 1.2～1.4.（2）Through the analysis of the corn stalk material characteristics and the factor boundary conditions determined by the single factor test,the three test factors were selected at three levels,and the three-factor three-level orthogonal test was designed to investigate the effect of the corn stalk filter on the poultry washing wastewater.The influence of filter material particle size,filter layer thickness and filter compaction on TS,VS,COD_Cr,NH₄⁺-N and p H in the effluent.Orthogonal test optimization results are:under the conditions of filter material particle size of 1cm,filter layer thickness of 50cm,and filter compaction of 1.4 times the density,the corn stalk filter material can achieve the best effect in filtering large-scale poultry washing wastewater.Through the verification test,it is concluded that under the condition of better process parameters,the TS content in the filtered wastewater is 1.82%,the TS removal rate is 31.22%;the VS content is 0.89%,the VS removal rate is 44.51%;and the COD_Cr content is 14124.67mg/L,the removal rate of COD_Cr is 24.07%;the content of NH₄⁺-N is 886.81mg N/L,the removal rate of NH₄⁺-N is 21.20%;and the p H is 7.23;and The filtration rate per unit area is 96.25 L/（m²·min）.（3）According to the optimal process parameters,a filter device for poultry wastewater was designed,and the analysis and verification of the filter barrel,support arm and water distribution device were completed.The prototype model of the filter device was built under laboratory conditions,and the trial operation of the prototype was carried out.The results show that:during the working process,the stress of the filter barrel and the support arm are within the allowable stress range of the material,the water distribution device distributes water evenly in the water distribution area,and the pollutant content in the filtered water is consistent with the optimal combination,which meets the design parameters requirements of the device.