强酸性高氟有机金属精饰废水处理工艺研究

Study on the Treatment Process of Highly Acidic and Fluorinated Organometallic Finishing Wastewater

金属表面精饰行业产生的废水成分复杂,其中富含各种强酸、氟化物、有机物、重金属等。工业上常采用三效蒸发装置对高盐废水进行处置,然而该装置对废水的氟离子含量要求较高,首先需解决废水高氟的问题。目前常见的高氟废水处理方法主要有化学沉淀法、吸附法、氧化还原法等,其中钙盐沉淀法应用最为广泛,然而仅使用钙盐沉淀法生成的氟化钙沉淀溶解度小,氟离子去除效果有限。因此,以金属精饰行业产生的高氟有机废酸为研究对象,采用化学沉淀法、焚烧工艺与三效蒸发技术相结合的方法对其进行综合处理。结果表明钙盐-磷酸盐法可实现对氟离子的高效去除,钙盐投加量为0.05 g/mL,钙盐、磷酸盐质量比为10∶1时,氟离子的浓度可降低至10 mg/L以下,此时药剂的投加成本也相对较少。结合焚烧工艺与三效蒸发技术可最终实现废物的减量化、资源化、无害化处置。

The composition of wastewater produced by the metal surface finishing industry is complex,and it is rich in various strong acids,fluorides,organics,heavy metals,etc.In industry,three-effect evaporation devices are often used to treat high-salt wastewater.However,this device requires a high fluoride ion content in wastewater.Therefore,it is necessary to solve the problem of high fluoride in wastewater first.Currently,the common methods for treating high fluorine wastewater include chemical precipitation,adsorption,oxidation reduction,etc.Among them,calcium salt precipitation method is the most widely used,but the calcium fluoride precipitation generated by using only calcium salt precipitation method has low solubility and limited fluoride ion removal effect.Therefore,the research object is high fluorine organic waste acids generated in the metal finishing industry,a comprehensive treatment method combining chemical precipitation,incineration process,and three-effect evaporation technology was adopted to treat it.The results show that the calcium salt-phosphate method can achieve efficient removal of fluoride ions.When the dosage of calcium salt is 0.05 g/mL and the mass ratio of calcium salt to phosphate is 10∶1,the concentration of fluoride ions can be reduced to below 10 mg/L.At this time,the dosing cost of the agent is also relatively small.The combination of incineration process and three-effect evaporation technology can ultimately achieve waste reduction,recycling,and harmless disposal.