Advanced treatment of coking wastewater with peroxymonosulfate oxidation activated by base combined with SBBR

Abstract

The advanced treatment of bio-treated coking wastewater was carried out using peroxymonosulfate(PMS)oxidation activated by base combined with sequencing biofilm batch reactor(SBBR). The effects of pH, PMS concentration, and temperature on the removal of COD and chroma of bio-treated coking wastewater were investigated by base/PMS system with sodium hydroxide as activater. The optimal conditions were temperature of 25 ℃, pH of 10, PMS concentration of 7 mmol/L, reaction time of 4 h. Under this condition,the removal rates of COD and chroma were 45.9% and 96.1%,respectively. EPR analyse indicated that 1O2, O2·-, ∙OH and SO4·- existed in the base/PMS system. After base/PMS system,the biodegradabality of waste water improved. The COD of effluent after SBBR treatment was less than 60 mg/L. The average removal rate of COD reached 66.7% with PMS oxidation activated by base combined with sequencing biofilm batch reactor. The three-dimensional fluorescence spectrum showed that the base/PMS system combined with SBBR could remove aromatic-like protein substances and humic-like acids.

Keywords

• base
• peroxymonosulfate
• bio-treated coking wastewater
• sequencing biofilm batch reactor
• advanced treatment