改性淀粉絮凝剂DTCS-AM的制备及絮凝性能

Preparation and flocculation performance of modified starch flocculant DTCS-AM

以淀粉为原料,通过交联、醚化等反应得到二硫代氨基甲酸盐改性淀粉(DTCS),然后以DTCS为骨架与丙烯酰胺在引发剂作用下进行接枝共聚反应,合成DTCS-AM改性淀粉絮凝剂。考察单体用量、引发剂浓度、反应温度和反应时间对接枝共聚反应的影响,通过红外光谱、扫描电镜对产物进行表征,并考察DTCS-AM改性淀粉絮凝剂对胜利油田钻井废水的絮凝能力。结果表明,DTCS-AM改性淀粉絮凝剂的最佳合成条件为:反应温度40℃,时间3 h,引发剂用量4 mmol/L,淀粉与单体质量比1∶2.2;DTCS-AM具有较好的絮凝结构,对胜利油田钻井废水具有较强的絮凝能力,絮凝剂用量为80 mg/L时,其COD去除率大于95%。

The dithiocarbamate modified starch （DTCS） was obtained by the cross linking reaction and etherification reaction with the starch as raw material.Then the modified flocculant DTCS-AM was prepared using the DTCS as backbone through the graft copolymerization reaction with acrylamide.The influences of some parameters on the graft copolymerization reaction,such as amount of monomer,reaction temperature,time,as well as the concentration of the initiator,were investigated.Afterward the product was characterized by using infrared spectroscopy and scanning electron microscopy （SEM）.The DTCSAM＇s flocculation ability of treating Shengli Oilfield drilling wastewater was evaluated.The results indicate that the optimal synthetic conditions are obtained as follows：T=40 ℃,t=3 h,initiator concentration 4 mmol/L,mass ratio of starch to acrylamide monomer 1 ∶ 2.2.The images of the SEM show that there exists a good flocculation structure of the DTCS-AM.Under 80 mg/L of the flocculant dosage,the COD removal rate of Shengli Oilfield drilling wastewater can be more than 95％when the DTCS-AM is used to treat the wastewater.