回收Fenton铁泥制备高效磁性聚合硫酸铁的研究

Preparation of Efficient Magnetic Polymeric Ferric Sulfate with Recycled Fenton Iron Sludge

以某造纸厂所产生Fenton铁泥作为原料,制备絮凝剂聚合硫酸铁(PFS)及磁性聚合硫酸铁(MPFS)。研究表明,以20:1的液固质量比加入3 mol/L硫酸和干燥铁泥,在60℃下水浴搅拌50 min,此时铁的回收率达到95%以上;PFS和MPFS均含有大量高分子铁聚合物,出现相应的官能团,MPFS还表现出明显的磁性晶体结构,磁性颗粒与PFS混合均匀。处理造纸废水的混凝实验中,PFS优化投加量为150 mg/L,此时浊度和COD去除率分别为98.86%和67.35%;MPFS优化投加量为100 mg/L,此时浊度和COD去除率分别98.61%和67.11%,均高于商品聚合硫酸铁。MPFS混凝絮体在沉降速度与致密程度上远优于无磁性的PFS与商品聚合硫酸铁,絮体稳定时间从20 min减少到4min,大大缩短了混凝工艺处理时间。

Fenton process produces a large number of high iron content sludge. The flocculants of polymeric ferric sulfate （PFS） and magnetic polymeric ferric sulfate （MPFS） are produced by the Fenton iron sludge, which is recycled from a paper mill. The recovery rate of iron can reach above 95% stably, under the temperature of 60 ℃ water bath, liquid-solid mass ratio of 20：l with 3 mol/L sulfuric acid, and 50 rain mixing time. The produced PFS and MPFS, which contain lots of macromolecule polymer, can be found the corresponding functional groups. MPFS also showed obvious magnetic crystal structure, and magnetic particles and polymeric ferric sulfate mixed evenly; In the coagulation experiments of papermaking wastewater, the results reveals that 98.86% of turbidity reduction, 67.35% of COD removal efficiency can achieved at the optimum dosage of PFS 150 mg/L, and while the optimum dosage of MPFS h is 100 rag/L, with 98.61% 0f turbidity reduction, 67.11% of COD removal efficiency, which are both higher than PFS. After adding magnetic particles, the coagulation floe is much better than the non-magnetic PFS and commodity polymeric ferric sulfate in settling velocity and density level, and the settling time can be reduced from 20 min to 4 rain, which greatly shortens the coagulation process of time.