Research progress on sludge reduction technologies in China

The use of conventional sludge treatment processes becomes increasingly challenged with the rapid growth of wastewater quantity. Such developed theories for sludge reduction in China as uncoupling, cryptic growth and predation on micro-zoon, hold great promise to provide better sludge treatment and disposal, and thus are reviewed in this paper. The emphasis is placed on their basic principles, main application technologies, including ozonation, sonication, chemical uncoupler and oxic-setting-anaerobic process. Advantages and disadvantages of these technologies are introduced to highlight their current limitations and future research needs. It can be concluded that, along with the growing knowledge, the applications of these technologies will be increased greatly.