混合污泥制备吸附剂回用于污水处理研究

Preparation of the adsorbent from hybrid chemical and biological sludges and effect of its reuse in wastewater treatment

摘要:

用城市污水厂化学与生物混合污泥为原料,以质量比1∶3浸渍于18.0mol/L浓硫酸中,在550℃下活化1h,可以制备出性能较好的吸附剂.通过检测混合污泥吸附剂的表面物理形态、比表面积、孔结构,铁、铝含量用及元素成分表征其物理化学特性.将混合污泥吸附剂回用于城市污水,去除有机污染物.试验结果表明,吸附剂对UV254的去除率虽然低于商品活性炭,但其对COD的去除率高于商品活性炭.当回用于污水化学强化一级处理时,吸附剂可以大大减少聚合氯化铝铁的投加量.0.3g/L的吸附剂与15mg/L的聚合氯化铝铁联用时,UV254和COD的去除率分别是26.1%和61.6%.投加吸附剂后,混凝剂的投加量减少50%即可达到对UV254和COD同样的去除率.

Abstract:

Using the hybrid chemical and biological sludges as raw material,the adsorbent was prepared by chemically activating with 18. 0 mol/L H2SO4 in the mass ratio of 1∶ 3,and thereafter pyrolyzing at 550 ℃ for 1 h. The physical and chemical characteristics of the hybrid sludge-derived adsorbent were examined in terms of the surface physical morphology,the specific surface area and pore structure,the aluminum and iron contents, and element composition. Furthermore,the adsorption effect of the adsorbent for organic substances in wastewater was also investigated. The results indicated that the adsorption capacity of the sludge-derived adsorbent for UV254 was lower than that of a commercial activated carbon (AC),while its capacity of adsorbing COD was higher than that of the commercial AC. Further study showed that the sludge-originated adsorbent could reduce the polymeric ferric aluminous chloride (PFAC) dosage when it was reused in chemically enhanced primary treatment. With the simultaneous dosing of 15 mg/L of PFAC and 0. 3 g/L of the adsorbent,the removal efficiencies of UV254 and COD reached to 26. 1% and 61. 6%,respectively. The coagulant dosage could be reduced to about 50% through the addition of the adsorbent to achieve similar removal efficiencies of UV254 and COD.