混凝剂协同复配对丙烷脱氢废水的处理效果

Treatment Effect of Synergistic Coagulant on Propane Dehydrogenation Wastewater

丙烷脱氢废水COD高(5200~5600mg/L)、浊度大(1700~1800NTU),难以直接进行生化处理,需要在进行生物法处理前,先进行混凝处理.使用聚丙烯酰胺(PAM)与常用的无机混凝剂聚合氯化铝(PAC)和聚合硫酸铁(PFS)进行配合使用对丙烷脱氢废水进行处理,以COD、浊度为指标,考察了PAC和PFS的适应性以及不同离子型的PAM与PAC复配的混凝效果.结果显示,单一使用时,PAC适应性好,达到同样效果投加量至多是PFS投加量的10%,总体而言PAC和PFS絮体小,难以固液分离,处理效果不佳;PAM与PAC配合使用时处理效果显著提高,两性离子的PAM效果不佳,阴离子和阳离子聚丙烯酰胺与PAC协同处理废水效果最好,絮体成型好,当废水pH=8,PAC投加量为6mg/L,m(PAC)∶m(PAM1)∶m(PAM2)=6∶0.15∶0.35时,COD和浊度去除率分别达到了85.6%和98.5%,为实际处理丙烷脱氢废水提供了参数指导.

Propane dehydrogenation wastewater,with high COD(5 200-5 600 mg/L)and turbidity(1 700-1 800 NTU),is difficult to treat directly with biochemicals,so it needs to be treated by coagulation.PAM and inorganic coagulants(PAC or PFS)were used together to treat propane dehydrogenation wastewater.With COD and turbidity as indicators,the adaptability of PAC and PFS,and the coagulating effect of PAC and PAM with different ions were studied.Results showed that using PAC only,the adaptabitity was good,and to achieve the same coagulation effect,the dosage of PAC was at most 10% of the dosage of PFS.Using PAC and PFS,the floc was small,so it was difficult to separate solid from liquid,resulting in poor treatment effect.PAM and PAC used together significantly improved the coagulating effect,but the compounding effect of zwitterionic PAM and PAC was not good.However,the compounding effect of anion and cationic polyacrylamide and PAC was the best,and the floc was well formed.when pH was 8,the dosage of PAC was 6 mg/L,and the mass ratio was PAC∶ PAM1∶PAM2=6∶0.15∶0.35,the removal rates of COD and turbidity could be up to 85.6% and 98.5%,which can provide guidance for the actual treatment of propane dehydrogenation wastewater.