Cooperative removal of Mn^(2+),NH_(4)^(+)-N,PO_(4)^(3-)-P and F−from electrolytic manganese residue leachate and phosphogypsum leachate

电解锰渣渗滤液和磷石膏渗滤液中Mn^(2+)、NH_(4)^(+)-N、PO_(4)^(3-)-P和F^(-)的协同去除

Electrolytic manganese residue leachate(EMRL)contains plenty of Mn^(2+) and NH_(4)^(+)-N,and phosphogypsum leachate(PGL)contains large amounts of PO_(4)^(3-)-P and F^(-).Traditional methods of EMRL and PGL discharge could seriously damage the ecological environment.In this study,an innovative method for cooperative removal Mn^(2+),NH_(4)^(+)-N,PO_(4)^(3-)-P,F^(-)from PG and POFT was studied.The result showed that Mn^(2+),PO_(4)^(3-)-P and F^(-)were mainly removed in forms of Mg_(3)Si_(4)O_(10)(OH)_(2),Mn_(3)O_(4),Mn_(3)(PO_(4))_(2),Mg_(3)(PO_(4))_(2),CaSO_(4)·2H_(2)O,MnF_(2),MnOOH and Ca_(2)P_(2)O_(7)·2H_(2)O,when LG-MgO was used to adjust the pH value of the system to 9.5,and the volume ratio of EMRL and PGL was 1:4,as well as reaction for 1 h at 25℃.NH_(4)^(+)-N was mainly removed by struvite precipitate,when the molar ratio of N:Mg:P was 1:3:2.4.The concentrations of Mn^(2+),NH_(4)^(+)-N and F^(-)were lower than the integrated wastewater discharge standard.The concentration of PO_(4)^(3-)-P decreased from 254.20 mg/L to 3.21 mg/L.This study provided a new method for EMRL and PGL cooperative harmless treatment.

电解锰渣渗滤液中含有大量的Mn^(2+)和NH_(4)^(+)-N,磷石膏渗滤液中含有大量的PO_(4)^(3-)-P和F^(-)。传统处置电解锰渣渗滤液和磷石膏渗滤液方法严重破坏生态环境。本研究提出了一种协同去除电解锰渣渗滤液和磷石膏渗滤液中Mn^(2+)、NH_(4)^(+)-N、PO_(4)^(3-)-P和F^(-)的方法。研究结果表明,当采用LG-MgO调节体系pH值到9.5,电解锰渣渗滤液和磷石膏渗滤液体积比为1:4,在25℃下反应1 h时,体系中的Mn^(2+)、PO_(4)^(3-)-P和F^(-)主要以Mg_(3)Si_(4)O_(10)(OH)_(2),Mn_(3)O_(4),Mn_(3)(PO_(4))2,Mg_(3)(PO_(4))2,CaSO_(4)·2H_(2)O,MnF_(2),MnOOH和Ca_(2)P_(2)O_(7)·2H_(2)O沉淀去除;当N:Mg:P的摩尔比为1:3:2.4时,NH_(4)^(+)-N主要以鸟粪石沉淀去除。处理后的混合渗滤液中Mn^(2+)、NH_(4)^(+)-N、和F^(-)的浓度低于GB8978—1996《污水综合排放标准》;PO_(4)^(3-)-P的浓度从254.2 mg/L降至3.21 mg/L。本研究为电解锰渣渗滤液和磷石膏渗滤液的无害化处理提供了一种新方法。