ABSTRACT
Biodegradation, the breakdown of chemical compounds via biotic systems to less complex structures, is primarily the result of bacterial action. Biodegradation can be subdivided into primary, the oxidation or alteration of a molecule resulting in the loss of measurable physical or chemical properties, and ultimate, the complete conversion or mineralization of a compound to carbon dioxide, water, and other inorganic compounds. Polyethylene glycols, which might have arisen from microbially-initiated central cleavage of AE have also been measured in sewage effluent samples. For linear oxo-alcohol ethoxylates, branching of the alkyl chain has little effect on primary biodegradation whereas ethoxylates derived from highly branched oxo alcohols biodegrade more slowly. Based on laboratory-scale experiments, the primary factors affecting rate of biodegradation of nonionic surfactants are the length of the ethoxylate chain and the linearity of the alkyl chain. For linear oxo-alcohol ethoxylates, branching of the alkyl chain has little effect on primary biodegradation whereas ethoxylates derived from highly branched oxo alcohols biodegrade slowly.
