(1. 中南大學 冶金與環(huán)境學院，長沙 410083；
2. 中南大學 國家重金屬污染防治工程技術研究中心，長沙 410083)
摘 要: 采用氣液硫化法對模擬含鋅污酸廢水進行處理，考察pH值、H2S氣體分壓、反應溫度、反應時間、Zn2+初始濃度等條件對Zn2+去除效果的影響。在單因素實驗的基礎上進行五因素五水平的正交實驗，并對采用該工藝處理冶煉煙氣洗滌污酸廢水效果進行驗證。研究Zn2+硫化分離的熱力學，及其氣液反應動力學過程，并對鋅沉渣進行分析與表征。結果表明：在最佳工藝條件為模擬溶液初始pH值3、反應時間80 min、溫度35 ℃、H2S氣體的體積分數(shù)為30%、Zn2+初始濃度100 mg/L時，Zn2+脫除率為99.54%，沉渣主要物相為ZnS，鋅的質(zhì)量分數(shù)達63.84%；實際污酸廢水鋅濃度為569和216.7 mg/L時，去除率分別達到99.79%和99.49%。
關鍵字: 污酸廢水；除鋅；氣液硫化；熱動態(tài)
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China）
Abstract:Sulfide precipitation via gas-liquid reaction was used to treat the simulated acidic wastewater containing zinc ion. The effects of pH value, H2S volume fraction, temperature, reaction time, initial concentration of Zn2+ on the removal rate of zinc were investigated. The orthogonal experiments with five factors and five levels were designed based on the results of single factor experiments, which was applied to the treatment of acidic wastewater generated from smelting flue gas washing. The thermodynamic of Zn2+ sulfidation and kinetics of gas-liquid reaction were studied. And then, the sediments were analyzed and characterized. The results show that the optimum operation conditions are as follows pH value of 3, the time for reaction of 80 min, the temperature controlled at 25℃, H2S volume fraction of 30%, and the initial concentration of Zn2+ of 100 mg/L. The removal rate of Zn2+ can reach 99.54% under the optimum operation condition. The sediments mainly consists of ZnS with zinc content of 63.84%. When concentrations of Zn2+ in acidic wastewater are 569 and 216.7 mg/L, the removal rates of Zn2+ are 99.79% and 99.49%, respectively.
Key words: acidic wastewater; zinc removal; gas-liquid sulfidation; thermodynamic
