常规水处理工艺降铝方案研究

Study on scheme of aluminum reduction suitable for traditional water treatment process

对自来水厂水质净化过程中来自原水和混凝剂的铝元素,就其可溶性和不溶性的含铝成分转化规律进行了分析,得出了导致自来水厂出厂水中可溶性铝元素超标的主要原因来自于混凝剂,因原水pH偏高使混凝过程中形成的Al(OH)_(3)再溶。根据pH值与溶解态铝浓度的相关性分析,提出了以控制沉淀池出水pH≈7.5的控铝关键性技术方案。最终形成了通过适当提高酸化混凝剂投加量的手段来控制沉淀池出水pH,进而控制出厂水中溶解铝的浓度降低到0.15 mg/L的推荐方案。

The transformation law of soluble and insoluble aluminum components of aluminum from raw water and coagulant in water purification process of waterworks is analyzed.It is concluded that the excess of soluble aluminum in outlet comes from coagulant,which is the result of redissolution of Al(OH)_(3)formed in coagulation process due to high pH of water.According to the correlation analysis of pH and dissolved aluminum concentration,the key technology scheme of aluminum control was that put forward to control the pH of effluent from sedimentation tank to be 7.5.Finally,a recommended scheme is formed to control the pH of the effluent of the sedimentation tank by appropriately increasing the dosage of acidification coagulant,and then control the concentration of dissolved aluminum in the effluent to 0.15 mg/L.