polyhydroxyalkanoates (phas) are naturally occurring polyester that can be accumulated in bacterial cells as a carbon and energy storage compound. they are metabolized by many microorganisms. these biopolymers accumulate in microbial cells under stress conditions such as limitation of nitrogen, phosphate, sulfur, oxygen, and excess carbon source. currently, phas have attracted increasing intere...

Abstract Sludge is one of the by-products wastewater treatment plants (WWTPs). To assist biological processes, part produced sludge returned to process and excess removed from plant whereby it undergoes thickening dewatering. Numerous studies have been conducted investigate effect different coagulants on dewatering sludge, but using divalent iron for this purpose has not investigated so far. In...

The potential for using readily available and cost-effective complex carbon sources such as primary sewage sludge for a range of biological processes, including the bioremediation of acid mine drainage, has been constrained by the slow rate of solubilisation and low yield of soluble products, which drive the above mentioned processes. Previous research into the hydrolysis of complex organic mat...

The chemical basis for improved removal rates of toxic heavy metals such as Zn and Cu from wastewater secondary sludge has been demonstrated in this study. Instead of using excess corrosive chemicals as the source of free nitrous acid (FNA) for improved solubility of heavy metals in the sludge (in order to enhance electrokinetics), an optimized use of aqua regia has been proposed as an alternat...

Membrane Bioreactor (MBR) process consists of a biological reactor integrated with membranes that combine clarification and filtration of an activated sludge process into a simplified, single step process. The membrane is an absolute barrier to suspended matter and microorganisms and it offers the possibility of operating the system at high mixed liquor suspended solids (MLSS) concentration. Th...