The Study Of Composite Coagulant And Its Application In Paper Industry Waste Water Treatment

Paper industry bring humen being huge benefit as well as serious environmental pollution,the high discharge load,content complex,high content of organic matter were the characteristics of the waste water that come from this industry.And the discharge load is the top 1 in the array of 10 biggest industry in our country,the COD accounted for about 40%-45% among the countrywide total discharge load,it's the highest.So,the treatment against the paper industry pollution was so important.Coagulation process was a important method in the field of paper industry waste water treatment.In this research,the dosage of FPAS under different concentration of waste water was studied and the treatmental effect of composite-use of polymeric ferric FPAS and polyacrylamide PAM under different concentration was comfirmed.The result of research was shown:Under the same condition,the removal rate of FPAS on COD is 80%,and BOD,SS are over 75% respectively,it's meet the requirement ofⅡemission standard in《Emission standard of Paper industry Pollutant in Waste Water)) GB3544-2001,and its cost is just 70% compare with the akin product.So the effect of these factors (pH,additive sequence,segmental addition,stirring intensity and time) on treatmental effect of paper industry waste water by FPAS.The results show that the pH, additive sequence, stirring intensity and time are the most influential factors in effects of flocculent result of polymeric ferric flocculant.By experiment,the best pH for FPAS is 7-10, the best way for stirring is two-segments-stirring,keeping the rev at 150 r/min for 5 minutes after FPAS being added and standing for 20 minutes,the removal rate of COD reach the peak point.The removal rate of COD and SS are 85% and 81% respectively,and absolutely meet the requirement ofⅡemission standard in《Emission standard of Paper industry Pollutant in Waste Water》GB3544-2001.The experimental result proved that the FPAS is a efficient and cost-efficient treatment agent for paper industry waste water.Meanwhile, a comparison was made between the cost of PAC,PAFC,PFS and FPAS,the treatmental cost of FPAS for every ton of waste water is conspicuous lower than other three kind of flocculant and it's only 70～80% in comparison with akin product.Besides that,the synergy of PAM,SDS- and activated silicic acid in water treatment was studied too,and the result says the combination of PAM and FPAS can make the greatest treatmental effect,synergy treatment is better than haploid treatment in efficienct field and economical field.Moreover,against the characteristics of flocculent method for removing of water-soluble organic matter,aerobic biochemical method for lignin decomposing and the unstability of waste water content,the method of biochemical-flocculent project was proposed by summarizing the result and experience of civil and domestic research,and the treatmental effect of this method was studied by practice.It's meet the requirement ofⅡemission standard in《Emission standard of Paper industry Pollutant in Waste Water》GB3544-2001,the effect of pH on bacteriors-living condition was also studied.When the pH is stay in 7,the removal rate of COD and SS can be 96% and 95%,repectively.Comprehensive research are shown:The treatmental effect of FPAS is conspicuous better than current main coagulant in the market,and use it with biochemical method can create higher effect of treatment,it is a kind of new,efficient, high quality and cost-efficient product,the applied value is excellent.