Nov 1, 2000 · In 1996, China had more than 100 municipal sewage treatment plants treating 10.22 million m 3 per day, and produced about 0.5–1.2 million tonnes dry sewage sludge and 43.8–83.95 million tonnes wet sludge (Zhu et al., 1998, Yang et al., 1999a), but only about one-quarter of municipal wastewater treatment plants have sewage sludge stabilization equipment; less than one-tenth of these plants