Innovation to Use Biosolids as a Resource

The majority of Australian Sewage Treatment Plant (STP) operators are now committed to the beneficial use of biosolids. Application to land is the least cost, large volume market that offers long term security. With the focus on cleaner waters, new generation sewage treatment plants use biological processes to extract the N and P. Although these processes effectively produce cleaner effluent, the trade off is a greater volume of lower quality biosolids, ie they are more odourous, hard to dewater, are poorly digested in anaerobic digesters, and difficult to transport (Kempton and Cusack 1999). The major cost is transport, as influenced by distance to market, and the moisture content of the final biosolids, which can vary from 70 - 88%. Traditional technologies to reduce water content such as drying are expensive and potentially problematic.

 

Download the paper.