选矿废水中残留药剂生物降解技术研究进展

Research progress on biodegradation technology of residual agents in mineral processing wastewater

选矿药剂通常用于调节矿物表面和浮选介质的物理化学性质,扩大有用矿物与脉石矿物间的亲疏水性差异,从而达到更好的分选效果。选矿药剂种类繁多,含有残留药剂的选矿废水直接外排会造成环境污染。生物降解作为一种新型生化处理方法,具有成本低、能耗少、无二次污染等优点,因此研究高效降解选矿废水中残留药剂的方法尤为重要。论述了当前黄药、黑药、羟肟酸类、松醇油等选矿药剂生物降解技术的研究进展,分析了影响降解效果的工艺因素和选矿药剂生物降解研究存在的主要问题,并对今后的研究工作进行展望。影响黄药生物降解效果的因素有黄药初始浓度、pH、温度,振荡速率、降解时间、碳氮比、氮源和金属离子等。外加碳源可促进黄药的降解。CS2、ROCSSH和单硫代碳酸盐是烃基黄药的主要降解产物,并伴有少许双黄药油液滴生成,属于一级酶促降解动力学。黄原酸盐分解的中间产物是过氧化黄原酸盐。不同外加碳源同样会促进黑苯胺药的降解。羟肟酸类捕收剂降解反应是一级反应动力学。影响对松醇油的降解因素有pH值、接种量、温度、摇床转速、松醇油初始浓度、反应时间等。针对选矿药剂生物降解研究存在的主要问题,今后的研究工作应借鉴相近领域的生物技术手段筛选出高效降解菌株,在降解机理上开展更深入研究,在分子水平上改造基因,利用基因工程技术构建新的降解菌株。同时,应加快选矿废水生物降解设备的研制。

Beneficiation agents usually regulate the physical and chemical properties of selected minerals and flodation media,which can expand the hydrophilic-to-hydrophobic differences between valuable minerals and gangue minerals and then achieve the best separation effect.There are many kinds of beneficiation agents and the direct discharge of mineral processing wastewater which contains residual chemicals will cause serious pollution to the environment.As a new biochemical treatment method,biodegradation has many advantages,such as low lost,low energy consumption and no secondary pollution.Therefore,it is of practical significance to study high efficiency biodegradation of residual agents in mineral processing wastewater.In this paper the current biodegradable research progress of mineral processing agents,such as xanthate,aerofloat,hydroxamic acid and pine oil were reviewed.The main factors affecting the degradation and biodegradation problems of beneficiation agents were analyzed and the future research work were also forecasted.The results show that the initial concentration,p H,temperature,shaking rate,time,C/N ratio,nitrogen source and metal ions are the main factors affecting the biodegradation of xanthate.External carbon sources can promote the degradation of xanthate.CS2,ROCSSH and mono-thiocarbonate are the main degradation products of alkyl-xanthate,accompanied by a few oil droplets of double-xanthate,which belongs to the first-order enzymatic degradation kinetics.The intermediate product of xanthate decomposition is xanthate peroxide.The analysis concluded that additional carbon sourses can promote the degradation of aniline aerofloat.Hydroxamic acid collectors are a first-order reaction kinetics.Besides,factors influencing the degradation of pine oil include p H,inoculation amount,temperature,shaking speed,initial concentration,time,etc.In view of the main problems about biodegradation of mineral processing agents,the future work should imitate the biotechnological means of similar fields to screen highly efficient degradation strains.The research on degradation mechanism should be deeply studied and new biodegradable strains should be constructed by genetic engineering at the molecular level.Meanwhile,the development of biodegradation equipment should be accelerated.