Author(s)

H. S. Doma & S. I. Abou-Elela

Abstract

Treatment of black liquor derived from non-woody feedstocks H. S. Doma & S. I. Abou-Elela Water Pollution Control Department, National Research Center, Cairo, Egypt Abstract Black liquor disposed from paper mills using rice straw as a feed stock was treated via sequenced chemical-aerobic biological process. Lignin separation was achieved by chemical coagulation using anionic polymer and at a low pH-value. The lignin removal efficiency reached 80% at 1.5% lignin concentration; whereas the removal of the COD reached 53%. The delignified effluent was subjected to biological oxidation using activated sludge process. The effects of three different concentrations of the delignified black liquor were studied using activated sludge as a post treatment. The post treatment of the delignified effluent removed up to 75% and 72% of the chemical and biological oxygen demands, respectively. These values decreased as the concentration of the spent liquor increased. The treated wastewater was amenable for wast

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