电镀废水中共存阳离子对Fe(Ⅱ)/O2去除无机磷的影响

通过序批试验,考察了有氧条件下,共存阳离子对亚铁除磷效率的影响并以实际电子废水为考察对象,对比研究Fe(Ⅱ)/O₂与传统石灰工艺的除磷效果及相关技术经济指标。结果表明:NH₄⁺-N对同步氧化Fe(Ⅱ)除磷效率几乎没有影响;Zn(Ⅱ)可通过与磷酸根反应产生沉淀提高磷的去除率。Mn(Ⅱ)可与新生三价铁形成稳定络合物,促进亚铁氧化并改善铁磷沉淀物混凝沉淀性能,当Mn(Ⅱ)投加量为1.0 mg·L^-1时,反应60 min后,磷的去除率提高11%。Cu(Ⅱ)能高效催化亚铁氧化,从而使亚铁除磷效率显著提高,在Cu(Ⅱ)浓度为0.05 mg·L^-1时,除去45%水中磷所需时间由空白的60 min缩短为5 min,Cu(Ⅱ)是所选共存阳离子中最为高效的亚铁除磷催化剂。以实际电镀废水为研究对象,在共存离子的促进作用下,Fe(Ⅱ)/O₂对废水中磷的去除效果优于传统石灰法,且药剂成本及产泥量均低于直接投加石灰的除磷工艺。

Effect of co-existing cations on phosphorous removal in ferrous iron oxidation of electroplating wastewater

The interaction of ferrous ions and phosphorous was studied under aerobic conditions in order to assess effectiveness and feasibility of phosphorous removal.Using Fe(Ⅱ)/O₂ and conventional technologies the removal effectiveness of phosphorous in a real electronic waste water and relative economic indicators was compared.For Fe(Ⅱ)/O₂ system the effect of co-existing cations in simulating natural liquid on efficiency of phosphorous removal was examined using variables analysis.The results show that there was no effect of NH₄⁺-N on phosphorous removal by Fe(Ⅱ)/O₂ oxidation.Precipitation could occur between Zn(Ⅱ) and phosphorous in the system,which could promote removal of phosphorous and decrease of ferrous iron consumption.Mn(Ⅱ)as well as OH^- could form complexes with Fe(Ⅲ)generated newly,the complexes are capable of hastening ferrous iron oxidation and also of improving the coagulation of Fe-P sedimentation.As the inventory of Mn(Ⅱ)increased from 0 to 1 mg·L^-1,the removal rate of phosphorous raised 11% after 60 min reaction.Cu(Ⅱ)could remarkably increase the efficiency of phosphorous removal by its catalytic effect.As Cu(Ⅱ)concentration increased from 0 to 0.05 mg·L^-1,the reaction time required 45% phosphotous removal could be reduced from 60 min to 5 min.For a real electronic wastewater the phosphorous removal was better for Fe(Ⅱ)/O₂ system in the presence of the above mentioned cations than for lime alone,while sludge production and economic cost was lower for the former than for the latter.