Soluble microbial products (SMPs) production in activated sludge systems: a review

This review is concerning the characterization, production and implications of soluble microbial products (SMP) in biological wastewater treatment. The precise definition of SMP is open to debate, but is currently regarded as ''the pool of organic compounds that are released into solution from substrate metabolism and biomass decay''. Some of the SMP have been identified as humic acids, polysaccharides, proteins, amino acids, antibiotics, extracellular enzymes and structural components of cells and products of energy metabolism. SMP also exhibit several characteristics, such as toxicity and metal chelating properties, which effect the performance of the treatment system and their presence has also been shown to adversely affect the kinetic activity and the flocculating and settling properties of sludge. This review outlines some important discoveries with regard to biodegradability and treatability of SMP and also the effect of process parameters on their production. However, it concludes that the knowledge regarding SMP is far from complete and much work is still required to fully understand their contribution to the treatment process.

کلیدواژه ها:

soluble microbial products (SMP) ، molecular weight distribution ، effluent ، biodegradability ، toxicity