Although the aluminum ion in our country has not stipulated emission standards, but research shows that excessive intake of aluminum ions will directly destroy people inside nerve genetic material DNA function, easy to make people suffer from Alzheimer's disease, the premature aging. Colloidal suspensions of AIOH3 into farmland soil aeration oxygen, resulting in soil compaction, crop root rot of death. So should try to remove, but also only remove the sewage aluminum ions, in order to truly achieve suspended emissions standards. In addition the mold processing workshop discharge high concentration NaOH waste liquid, its pH value of up to 12, also need to be processed.
Treatment principle of sewage discharge pH value is small, at this time due to the role of acid aluminum ion has not been hydrolyzed. When the pH value recovered to 6 ~ 8.5 range, the original aluminum ions dissolved in water was hydrolyzed to AlOH3 white colloidal suspension mass; when the pH value of >8.5, and part of the AlOH3 complex is soluble in water, white suspension decreased significantly.
According to this characteristic, the key to remove aluminum ion is the control of pH value. As long as the wastewater neutralization and the pH value is around 7, while adding coagulant, AlOH3 suspension performance form improved after neutralization, can make the separation of large quantities of AlOH3 removal, the sewage indicators meet the national emission standards. From the economic benefits that waste recycling can reduce operating costs, reduce business costs; from the social benefits that governance standards after the tannery production meet the prerequisite in ensuring the enterprise profits at the same time, eliminate hidden dangers of pollution; from the environmental benefits that the wastewater treatment standards in most of the organic matter was removed, has an extremely important significance for environmental protection.
