Studies On The Synthesis Of A New Flocculant (PASC) And Its Application

Flocculation is the most widely adopted and cheaper technique in wastewater treatment. The flocculant is the key of this technique,and its properties influence directly flocculation efficiency.The development of the high efficient,innoxious and cheap flocculant is the core of the technology that optimizes flocculation process,and is also a project on which researchers in environmental science concentrate.In this paper,the new type of flocculant PASC is synthesized by using acid aluminum salt A and alkaline aluminum salt B as basic synthetic materials with the simultaneous addition of aid flocculant X and carboxymethyl starch(CMS) in particular technical conditions.The first step is the preparation of prefabricated liquid by using B,X and CMS. Then the prefabricated liquid is pumped into the saturated solution of A with the certain velocity in the high-speed fluid shearing condition.After a few time,the whole reaction solution is displaced into three-necked flask for the last step of aging.The reaction optimal procedure is determined by orthogonal experiments.The reaction conditions are as following: the ratio of raw materials are 50.00 gA,5.55 gB,2.90 gX,0.50 gCMS;the reaction time is 30 min;the aging temperature is 45℃;the aging time is 7 h.The flocculation test showed that there is a widely pH range for PASC that is prepared by optimal parameters,and PASC is hardly affected by temperature.In the course of wastewater treatment,consumption of PASC is low and turbidity removal efficiency is high; subsiding is rapid and the COD removal ratio is high,especially its flocculantion performance in the treatment of low-temperature and low-turbidity water is much superior to that of PAC.PASC flocculant is tokened with IR and SEM to analyze its structure.For the essential theory,effect experiments are made with PASS and CMS separately comparing with PASC. The conclusion is that inorganic section and organic section have an interaction that strengthens the properties of flocculant.In this paper,PASC is synthesized under normal temperature and pressure,using cheap raw materials by one-step synthesis.This method takes the advantages of raw materials cheap and easy to get,short procedure,simple operation,lower cost and green environment protection.