TREATMENT OF LAGOON SLUDGE, PRIMARY CLARIFIER SLUDGE, AND BLEACH PLANT EFFLUENT BY SUPERCRITICAL WATER OXIDATION

Primary clarifier sludge mixed with bleach plant effluent, and decant pond sludge were sampled, analysed, and treated by supercritical water oxidation (SCWO). A promising new waste treatment technology, SCWO ox idises organic material directly in water to produce water, carbon dio xide and ash. Results show that both the decant pond sludge and the mi xture of primary clarifier sludge and bleach plant effluent were succe ssfully oxidized by SCWO to produce essentially colourless, neutral pH liquid effluents with low TOC values and very low AOX values. The AOX destruction with primary clarifier sludge and bleach plant effluent a ppears to be complete, with no AOX detectable in the ash leachate or t he liquid effluent. The ash compounds generated by the oxidation of bo th sludges appear to be suitable for landfilling.