吸附—络合同步去污工艺预处理冶金焦化废水研究

Application of adsorption-complex synchronous decontamination process in coking wastewater pretreatment system

针对武汉某冶金焦化公司焦化综合废水负荷变动大,预处理设施较为简单,缺乏对综合性污染物如COD、硬度、氨氮等污染物的去除能力的情况,研究了在现有条件下,如何通过采用吸附—络合—沉降同步去污工艺来优化运行,从而达到同步去除SS、氰化物、硬度的目的。设计中,碳酸钠的投加同时发挥了促进混凝反应进行、去除非碳酸盐硬度的作用,并将pH分两阶段控制从而更有效地去除氰化物,另外对工艺中产生的污泥进行回流,利用回流污泥中的结晶核等有益成分来强化絮凝效果。经为期一个月运行调节,水样检测结果表明,出水水质可达《炼焦化学工业污染物排放标准》(GB 16171-2012)的直接排放标准,工艺经优化后的处理费用为3.87元/m3,与传统处理方法相比,经济效益显著。

In view of the situation that the load of coking comprehensive wastewater of a coking company in Wuhan was greatly changed,the pretreatment facilities were relatively simple,and the removal ability of comprehensive pollutants such as COD,hardness,ammonia nitrogen and other pollutants was lacking,this paper studied how to optimize the operation by adopting adsorption-complexation-settlement synchronous decontamination process under the existing conditions,so as to achieve the purpose of synchronous removal of suspended solids,cyanide and hardness.In the design,the addition of sodium carbonate played a role in promoting the coagulation reaction and removing the hardness of carbonate,and the pH was controlled in two stages so as to remove cyanide more effectively.In addition,the sludge generated in the process was recirculated,and the beneficial components such as crystallization nucleus in the recirculated sludge were utilized to enhance the flocculation effect.After a month-long operation adjustment,water testing results showed that the effluent water quality met the direct discharge criteria specified in Discharge standard of pollutants for coking chemical industry(GB 16171-2012).The operation cost of the combined process is 3.87 yuan/m~3,and the economic benefit is remarkable while compared with the traditional methods.