In 1990, Shiga Prefectural Government started to operate a full scale sludge melting plan. The plant has the capacity for handling 40 ton dewatered sewage sludge cake per day. The slag has been reused for construction material, primarily as a substitute for coarse aggregate. Six years operation showed that dewatered cake could be reduced to 1/7 in weight and to 1/14 in volume by this melting and solidification process. The operation cost of the process was $125.4 for each ton of dewatered sewage sludge cake with 65% moisture content, which represented approximately 5–7% sewerage user's charge.

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