Managing Organic Sludge and Biosolids
Managing organic sludge and biosolids, the major by-products from wastewater treatment plants (WWTPs), persists as a widespread challenge that often constitutes the majority of WWTP operating costs. Self-sustained smoldering combustion is a new approach for organic waste treatment, in which the waste – the combustion fuel – is destroyed in an energy efficient manner after mixing it with a porous matrix.
Laboratory proof-of-concept testing and large-scale prototype testing using Savron’s STARx Hottpad systems have been conducted to evaluate the conditions under which smoldering can be used to treat WWTP sludge and biosolids. It was found that a self-sustaining reaction is achievable using WWTP sludge and biosolids with water content as high as 80% and that at larger scales, using a solid organic waste product (such as wood chips) as the porous matrix greatly enhances the uniformity of treatment and expands the range of WWTP sludge and biosolids materials that can be successfully treated. The higher temperatures achievable using a solid organic matrix material may also allow for the treatment of emerging recalcitrant contaminants sometimes found in WWTP sludge and biosolids.
Prototype testing continues and opportunities for a field demonstration of the technology are being evaluated.