载锆粉煤灰的制备及其对焦化废水中氟化物吸附性能的研究

Study of preparation of zirconium loaded flyash and its effect for adsorption of fluoride in wastewater of coking plant

为了探究载锆粉煤灰对焦化废水中氟化物的吸附性能,以湖南金竹山电厂粉煤灰为研究对象,通过热碱改性和负载改性的方式,在粉煤灰表面负载活性羟基氧化锆,以强化粉煤灰对焦化废水中氟离子的吸附性能。研究结果表明:当锆离子与粉煤灰的质量比为1:30,负载改性时间为60 min时得到的载锆粉煤灰除氟性能最优,处理氟离子浓度为100 mg/L的模拟含氟废水,氟离子平衡吸附量为18.60 mg/g,去除率达93%。吸附热力学研究表明,氟离子的吸附符合Lang-muir模型,其最大饱和吸附量高达50.36 mg/g,是原始粉煤灰吸附量的3倍以上。

In order to explore the capacity of zirconium-modified flyash for adsorption of fluoride in wastewater of coking plant,the flyash of a coal-fired power plant in Hunan Province is taken as the object of study.The flyash is made to carry active zirconium hydroxide through surface modification by using hot alkaline and zirconium loading processes to enhance the capacity of flyash for adsorption of fluoride in the wastewater of a coking plant.As evidenced by test result,a best fluoride removal result can be expected at aZr(IV)/flyash mass ratio of 1:30 and a surface modification time of 60 minutes.For adsorption of fuoride in simulated wastewater containing 100 mg/L of fluoride with the flyash,the equilibrium adsorp-tion capacity is 18.60 mg/g with a fluoride removal rate up to 93%.Adsorption thermodynamics study shows that the capacity is consistent with the Langmuir modeling result with a calculated maximum statu-ration capacity being as high as 50.36 mg/g,three times higher than that of the flyash in its originally untreated state.