Study On Salt Control And Water Conservation Cleaner Production Technologies In The Fur Tanning

The fur industry is a polluting industry,which has a high water consumption and waste water emissions,in view of the traditional end treatment is difficult to deal with the serious pollution situation,so there is an urgent need of the fur industry to implement cleaner production technology.Through the data access and business research,expert consultation and reference standards of the tanning industry cleaner production,the study advices fur industry cleaner production evaluation index.Fur processing wastewater has characteristics of large emissions and high salt content,to study the salt control technique and process operating liquid recycle technology in fur production,this article investigated the status quo for some typical fur production process,experimental studies were carried out in fur skin wash step,degreasing step,pickling step and tanning process.The study results showed: there was no acid swelling phenomenon in pickling step and tanning process by setting salt gradient tests.It can achieve the ideal effect of tanning when the salt concentration in pickling process and tanning process were 30 g/L,20 g/L;the COD concentration,total bacterial count,and the quality of the skin plate and wool were the reference standard,the washing operation liquid can be used directly for 3 times,but after filtering it can be reused for 6 times;the skim working fluid can be used directly for 4 times,and after filtering it can be reused for 6 times;the operation liquid of the pickling process can be used for 10 times whether or not through filtration,and it can still be recycled;the operation liquid of the tanning process can be used for 10 times whether or not through filtration,and it can still be recycled,however,the actual production of water is only used once.The average loss rate of the operating fluid after filtering in the process of washing operation is 14.5%,compared with the conventional process using only one time,it can save water 71.3% and salt 83.3%;the average loss rate of the operating fluid after filtering in the process of degreasing operation is 10.5%,compared with the conventional process using only one time,it can save water 74.6% and salt 83.3%;the average loss rate of the operating fluid after filtering in the process of pickling operation is 10.6%,compared with the conventional process using only one time,it can save water 79.4% and salt 73.7%;the average loss rate of the operating fluid after filtering in the process of tainning operation is 15.3%,compared with the conventional process using only one time,it can save water 75.3% and salt 78.5%,the empirical value of each addition of ammonium alum and aluminum powder were 11.8 g/L and 1.6 g/L.There is alinear relationship between NaCl content and Baume degree of skin washing liquid,and its coefficient of determination reaches 0.94,Baume degree of operation liquid can be measured firstly in the production,and reference formula y=8.93x+8.72 to determine the content of NaCl,then add salt according to the process requirement;there is a linear relationship between NaCl content and Baume degree of degreasing liquid,and its coefficient of determination reaches 0.64,Baume degree of operation liquid can be measured firstly in the production,and reference formula y=4.85x+14.92 to determine the content of NaCl,then add salt according to the process requirement,when the salt is dissolved completely,measure the Baume again;the coefficient of determination of the linear relationship between NaCl content in the pickling operation liquid is only 0.26,which indicates that the concentration of other ions in the pickling solution is affected,due to the addition of lactic acid and formic acid,the pH of pickling liquid is low,protein is decomposed into small molecules,which may affect the linear relation between the content of sodium chloride and Baume;there is a linear relationship between NaCl content and Baume degree of tainning liquid,and its coefficient of determination reaches 0.89,Baume degree of operation liquid can be measured firstly in the production,and reference formula y=7.52x-4.03 to determine the content of NaCl,then add salt according to the process requirement,therefore scientific data can be used to guide production;the chloride ion in the proportion of TDS in fur skin wash step,degreasing step,pickling step and tanning process is 40%,33%,36%,26%,so the contribution ratio of chloride ion in TDS is about 30~40%.