Determination of total acidity and aluminum ion concentration in wastewater of aluminum profile surface treatment by thermometric titration

The aluminum profile surface was usually treated by some chemical methods such as acid treatment to improve the protective property and functionality,enlarge the application range and prolong the use life.The wastewater generated in aluminum profile surface treatment contained high-concentration H+ and Al3+.Therefore,the effective monitoring of their content had important significance whether in process control or environmental protection.In this study,the content of H+ and Al3+ in wastewater was quantitatively determined by thermometric titration in first time.This method was applied to the determination of actual wastewater from aluminum factory.The results showed that the found results of this method were consistent with the theoretical values or those obtained by conventional manual titration.The recoveries of method were 99.8 % and 104.1 % for H+ and Al3+,respectively.The relative standard deviations(RSD,n=7) in precision test were both less than 2 % for H+ and Al3+.