活化赤泥去除猪场废水生化处理出水中的磷和重金属

以铝矿工业废渣赤泥为原材料,采用焙烧活化方法进行活化处理,并将其用于畜禽废水生化处理出水中磷和重金属的吸附去除.同时,研究考察了吸附剂除磷、除重金属的能力以及投加量、pH值和反应时间对去除效果的影响.结果表明,赤泥和活化赤泥对磷、铜、锌、砷吸附规律符合Langmuir吸附等温方程;焙烧改性后,赤泥对磷、铜、锌、砷的去除能力显著提高,900℃焙烧活化饱和吸附量可分别由46.26、18.18 、15.45、18.83 mg·g-1提高至149.00、65.17、99.20、27.51 mg·g-1;pH显著影响除磷、除重金属的效果,高pH条件有利于磷、铜、锌、砷的去除;赤泥和活化赤泥除磷、铜、锌、砷的作用机理包含金属氧化物表面的表面络合作用机理,其对砷和磷的去除机理还包括共沉淀作用.

Use of activated red mud to remove phosphate and heavy metals from the effluent of biologically treated swine wastewater

Red mud ( RM) , a waste tailing from the alumina industry, was calcined at different temperatures and the calcined RM was used as adsorbent for removal of phosphate and heavy metals from the effluent of swine wastewater treated with a sequencing batch reactor ( SBR). Adsorption of phosphate and heavy metals to raw RM and activated RM was studied as a function of dosage, pH and reaction time. The adsorption of phosphate, copper, zinc and arsenic to both RM and activated RM fit the Langmuir isotherm. Calcination enhanced the adsorption capacity greatly. The adsorption capacity of RM calcined at 900℃ for phosphate, copper, zinc and arsenic increased from 46.26, 18. 18, 15.45 and 18.83 mg·g~(-1) to 149.00, 65. 17, 99.20, 27.51 mg·g~(-1), respectively. The pH has an obvious effect on the removal and high pH favors the removal of phosphate, copper, zinc and arsenic. The adsorption mechanism is suggested to include surface complexation reactions, and the mechanism of phosphate and arsenic removal may include coprecipitation.