Synthesis of hydrophobically modified cellulose-based flocculant and its application in treatments of kaolin suspension and machining wastewater

In this work, an efficient and hydrophobic bamboo pulp cellulose-graft-sodium silicate–polyacrylamide (BPC-g-Si–PAM) flocculant was designed and synthesized to improve its flocculation performance as well as the dewatering efficiency of coagulation sludge. The optimal synthesis process of BPC-g-Si–PAM and its optimal flocculation conditions on wastewater treatment were investigated in detail. Compared with unmodified BPC-g-PAM and commercial PAM, hydrophobic BPC-g-Si–PAM flocculant exhibited better flocculation performance with SV30 of 5.8%. Moreover, TSS, COD and turbidity reduction for machining wastewater reached upto 98.1, 86.8 and 97.6%, respectively. Compared with commercial PAM, removal rate increased by 2.69, 7.68 and 2.68%, respectively. And also BPC-g-Si–PAM exhibited higher removal efficiency for ammonia nitrogen (77.7%), total iron (99.3%), total phosphorus (93.6%) and total zinc (96.7%) than PAM. All the results demonstrated that hydrophobic BPC-g-Si–PAM has a potential application prospect in industrial wastewater treatment.