A new application of sewage sludge utilization-lightweight aggregate (LWA)

Lots of sewage sludge are generated each year as more wastewater treatment plants appeared in nowadays. How to disposal and utilize sewage sludge has become an urgent problem need to solved. The imposition of more stringent regulations about disposal and utilization of sewage sludge caused some of the traditional methods have been limited, so prompted a drive for alternative uses for sewage sludge. Many researchers have recognized sewage sludge as a resource with much potential for beneficial reuse other than direct disposal. Because the silicon and aluminum-rich characteristics, the dried sludge also exhibits significant specific surface area and cation exchange capacity. Therefore production of lightweight aggregate using dried sludge is a new effective approach for disposal of sludge. This paper seeks to review the published research in this field: it covers the means of production, the characteristics and the potential applications of LWA made from sewage sludge and other waste.