Many microorganisms synthesize a wide range of surface active compounds (SACs), classified according to their molecular weights, properties and localizations. The low molecular weight SACs or biosurfactants lower the surface tension at the air/water interfaces and the interfacial tension at oil/water interfaces, whereas the high molecular weight SACs, also known as bioemulsifiers, are more effe...

Batch experiments were conducted to characterize the degradation of benzo[a]pyrene, a representative high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH), by Sphingomonas yanoikuyae JAR02. Concentrations up to the solubility limit (1.2 microg l(-1)) of benzo[a]pyrene were completely removed from solution within 20 h when the bacterium was grown on salicylate. Additional experiments...

the major sources of pahs are anthropogenic. these may be generated by pyrolytic and petrogenic processes. low molecular weight pahs come into the aquatic system through the accidentally leakage of oil spills. incomplete combustion at high temperature will release high molecular weight pahs by products of pyrolytic processes. the methods for assigning sources of pahs include paired isomeric rat...

   High strength and elastic biodegradable membranes are of great demand in modern technology. Similar membranes have been developed by irradiating different weight poly (vinyl alcohol) (PVA) – hydroxypropyl guar gum (HPG) blends and followed by combining with ex situ nanosilica. Polarized light microscopic (PLM) study indicates that electron beam irradiation produced crosslinks and develop...