Separation Science and Technology, Vol.52, No.9, 1583-1593, 2017
Physico-chemical treatment of pulping effluent: Characterization of flocs and sludge generated after treatment
The present study deals with the treatment of simulated pulping effluent (pH = 11, and total organic carbon (TOC) = 1900 mg/L) by acid precipitation and coagulation-flocculation processes. The maximum TOC removal (= 4845 mg/g Al3+) from the effluent was found with Al-2(SO4)(3) coagulant. Addition of sufloc (a flocculant) improved the sludge settling significantly. Hydrolyzed mono- and polynuclear species generated from Fe and Al coagulants could have resulted in TOC removal. Thermal analysis of sludge showed release of gases like CO, CO2, HCHO, CH3SH and SO2 during combustion. Afterwards, the dissolved metal species in treated wastewater samples should be removed.
Keywords:Acid precipitation;coagulation-flocculation;floc morphology;pulping effluent;sludge characterization