铁改性锰矿对砷的吸附性能研究

Study of the Arsenic Adsorption Properties on Modified Manganese Ore of Iron Ore

研究了影响铁改性锰矿除砷效果的各种因素,并对改性前后锰矿的吸附等温线进行了研究。结果表明,铁改性的最佳浓度为20g/L。在改性锰矿投加量为0.100 0g、反应温度为20℃、反应时间为60min、pH为3.0的条件下,对质量浓度为200μg/L的含砷水样,改性锰矿对As(Ⅴ)的去除率高达98.34%,而对As(Ⅲ)的去除率只有85.11%。水中Ca2+、Fe3+有增强砷的去除效果的趋势;SiO23-、CO23-和HCO3-能明显降低其去除效果。正交实验表明,SiO23-对改性锰矿除砷效果的影响大于CO23-,反应温度和时间对其影响则较小。改性前后锰矿的吸附等温线表明,在反应温度为20℃、改性锰矿投加量为0.100 0g的条件下,改性锰矿对As(Ⅴ)和As(Ⅲ)的饱和吸附量分别为1.701 5mg/g和2.112 0mg/g,分别比改性前提高了96.77%、87.23%。

The management and restoration of Arsenic pollution,which is urgent to be solved currently,has become China＇s environmental problems.This paper studies various factors which affect the removal efficiency of arsenic on iron modified manganese ore.The adsorption isotherm of modified and unmodified manganese ore has also been studied.The results show that the optimal concentration of iron modification is 20 g/L.The percentage of As（Ⅴ） removing of modified manganese ore is up to 98.34%,while the As（Ⅲ） removal rate is only 85.11% under the conditions of that the dosage of modified manganese ore is 0.100 0 g,reaction temperature is 20 ℃,reaction time is 60 min,pH 3.0,the concentration of arsenic in water samples is 200 μg/L.The existence of Ca2＋,Fe3＋ in water can enhance the trend of arsenic removal,while SiO2-3,CO2-3,HCO-3 can obviously reduce efficiency of the arsenic removal by modified manganese ore.Orthogonal experiments show that the effect of SiO2-3greater than CO2-3,the temperature and time of reaction has less effect on the removal.The adsorption isotherm of modified and unmodified manganese ore shows that the saturated adsorption quantity of As（Ⅴ） and As（III） on modified manganese ore is respectively 1.016 and 2.112 mg/g in conditions that reaction temperature is 20 ℃,the dosage of modified manganese ore is 0.100 0 g,96.77% and 87.23% higher than that by unmodified manganese ore.