Keijirou Morita*, Kazuyosi Matsunaga*, Motoichi Kondoh*, Tsutomu Itadani*, Tadasige Mori*, Takumi Saitoh** and Hirohisa Hinata**

* Okayama Prefectural Institute for Environmental Science and Public Health
** Kawasaki Steel Corporation

+ Correspondence should be addressed to Keijiro Morita:
(739-1 Uchio, Okayama 701-02 Japan)

Abstract

Previously, we reported a new method for producing activated carbon from sewage sludge for the purpose of sludge utilization and minimization.

Herein, we studied whether the improvement of KOH-HCl treatment was suitable for various kinds of organic sludge, and how to treat waste water generated from the process of activated carbon production.

The activated carbons, which were made from various kinds of organic waste sludge such as sewage sludge, sludge from a GAPPEI SYORI JOHKASOU, sludge from a night soil septic tank, sludge from a synthetic fiber factory and sludge from a dairy factory, had 140-350ml/g for the methylene blue adsorption and 460-1,771m2/g for the specific surface area. The waste water after KOH-HCl treatment contained various heavy metals, which were removed by the neutralizing coagulation treatment. The quality of the treated waste water showed values under the effluent standard. The yield of activated carbons obtained from dry sludge ranged from 8% to 19%.

Key words: organic sludge, production method for activated carbon, KOH-HCl treatment, removal of heavy metals, coagulation treatment