(1. 中南大學 冶金與環(huán)境學院，長沙 410083；
2. 湖南城市學院 材料與化學工程學院，益陽 413000)
摘 要: 根據(jù)熱力學數(shù)據(jù)，通過計算繪制Ca-As(Ⅴ)-H2O、Cu-As(Ⅴ)-H2O、Zn-As(Ⅴ)-H2O、Fe-As(Ⅴ)-H2O系lg c-pH圖，以此為理論指導，采用單一金屬鹽和復合鹽處理含As(Ⅴ)廢水，研究各金屬鹽對沉砷效果的影響。結果表明：采用鈣、鐵、銅和鋅鹽單獨處理3.17 g/L含As(Ⅴ)廢水，各金屬鹽沉砷適宜pH值與理論分析結果基本吻合。采用金屬鹽復合后處理3.17 g/L含As(Ⅴ)廢水，適宜沉砷pH=9，在此條件下，處理初始濃度為1~10 g/L含As(Ⅴ)廢水時，濾液中As殘留濃度在《污水綜合排放標準》(GB 8978—1996)范圍內(nèi)。通過改變金屬鹽種類處理含As(Ⅴ)廢水，在pH=9時，鈣鹽對脫砷率影響最大。
關鍵字: 含砷廢水；砷酸鹽；溶度積；溶解
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. School of Chemistry and Environmental Engineering, Hunan City University, Yiyang 413000, China）
Abstract:According to the thermodynamic data, lg c-pH diagrams of Ca-As(Ⅴ)-H2O, Cu-As(Ⅴ)-H2O, Zn-As(Ⅴ)-H2O, Fe-As(Ⅴ)-H2O system were established. Using these as theoretical guide, the single metal salt and compound salt were used to treat As(Ⅴ)-containing wastewater. The results show that the optimum pH value for arsenic precipitation of each metal salt is basically consistent with the theoretical analysis results when the salts of calcium, iron, copper and zinc were separately used to treat 3.17 g/L of As(Ⅴ)-containing wastewater. Using compound salts to treat arsenic-containing wastewater, the suitable pH=9 for arsenic precipitation, under this conditions, when treating As(Ⅴ)-containing wastewater with an initial concentration of 1-10 g/L, As residual concentration in filtrate is within the scope of “Integrated Wastewater Discharge Standard” (GB 8978—1996). Changing the types of metal salts to treat As(Ⅴ)-containing wastewater, calcium salt has the greatest influence on arsenic removal rate at pH=9.
Key words: arsenic-containing wastewater; arsenate; solubility product; solution; pH value
