Removal Of Sulfate From Industry Wastewater By Aluminum Salts And Magnesium Salts

SO₄^2- is a kind of common ions in natural water and industrial wastewater. Many of the city's water environment in China has been subject to different conditions of sulfate pollution, and the trend is increasing. As the improvement of people's environmental awareness and perfection of sulfate wastewater treatment in China,we must adopt effective methods and measures to produce high concentrations of sulfate in treatment of industrial wastewater. The advantages of sulfate radical removal by precipitation is the low cost and strong practicability, however, lower removal efficiency and product output are both disadvantages. This study was to examine a new salt precipitation to remove sulfate, to achieve high removal rates of sulfate precipitate and be able to build a certain industrial production.First, aim at reduce high concentration of sulfate emissions problem in a Jiangxi gibberellin production company, and using a variety of complex salt dosing to compare and analyze, finally selected the dosing scheme which mix magnesium hydroxide with aluminum nitrate these double salts and do further research for the programme:?1?Using Simulated industrial wastewater in the lab, to study sulfate removal in wastewater. Investigated the dosage of magnesium hydroxide in aqueous solution,aluminium dosage, response time, initial concentration of sulfate, effect of temperature on sulfate removal rate and set the three orthogonal experiment of the three factors, in initial SO₄^2- concentration 2000mg/L,volume of solution is 50 mL cases, The dosage of optimum technology condition is Mg?OH?₂ 1.4g,Al³⁺0.284 g,time 40 min,the removal rate reach to 95.84%;the effect factors from high to low are dosage of Mg?OH?₂,dosage of Al³⁺,response time. This technology gets the highest removal rates which up to 97.68%.XRD analysis measured the sediment as Mg-Al-layered double hydroxides.?2? Based on the actual extraction wastewater to do experimental analysis,actual wastewater sulfate concentration is 2000 mg/L, under the guidance of simulated wastewater sulfate removal experiment, through exploring and adjustingthe optimal experimental parameters and obtained the best conditions to remove SO₄^2-in actual wastewater: magnesium hydroxide 1.6g,water and aluminum nitrate4.68 g,the reaction time is 60 min,the sulfate removal rate was 94.2%,the residual water content of SO₄^2- less than 120mg/L.