Cr(Ⅵ)-bearing wastewater can be treated by natural pyrrhotite which is used for reductant to reduce Cr(Ⅵ) and precipitant to precipitate Cr(Ⅲ) simultaneously. The disposal products can be divided into three parts i...Cr(Ⅵ)-bearing wastewater can be treated by natural pyrrhotite which is used for reductant to reduce Cr(Ⅵ) and precipitant to precipitate Cr(Ⅲ) simultaneously. The disposal products can be divided into three parts in the beakers, namely supernatant in the upper part, the yellowish colloidal precipitates in the middle part and the pyrrhotite in the lower part. The content of total Cr=Cr(Ⅵ)+Cr(Ⅲ) in the supernatant liquid is 0.06 mg/L, which is lower than 1.5 mg/L of the discharge standard of China and near to 0.05 mg/L of the standard of potable water. This one-step disposal composing of both reduction and precipitation which is traditionally divided into two independent steps called reducing technology and precipitating technology respectively. The new method is of obvious economic advantage and favourable to decreasing surplus mud derived from adding Ca(OH)2 to precipitate Cr(Ⅲ) traditionally so as to avoid recontamination. In fact, sodium sulfite (Na2SO3) used in disposal of Cr(Ⅵ) was展开更多
文摘Cr(Ⅵ)-bearing wastewater can be treated by natural pyrrhotite which is used for reductant to reduce Cr(Ⅵ) and precipitant to precipitate Cr(Ⅲ) simultaneously. The disposal products can be divided into three parts in the beakers, namely supernatant in the upper part, the yellowish colloidal precipitates in the middle part and the pyrrhotite in the lower part. The content of total Cr=Cr(Ⅵ)+Cr(Ⅲ) in the supernatant liquid is 0.06 mg/L, which is lower than 1.5 mg/L of the discharge standard of China and near to 0.05 mg/L of the standard of potable water. This one-step disposal composing of both reduction and precipitation which is traditionally divided into two independent steps called reducing technology and precipitating technology respectively. The new method is of obvious economic advantage and favourable to decreasing surplus mud derived from adding Ca(OH)2 to precipitate Cr(Ⅲ) traditionally so as to avoid recontamination. In fact, sodium sulfite (Na2SO3) used in disposal of Cr(Ⅵ) was
基金supported by the National Natural Science Foundation of China(21407052)Key Project in the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(2015BAB01B04)~~
