SYNTHESIS, CHARACTERIZATION AND APPLICATION OF BIOSURFACTANT MODIFIED PSEUDO ACTIVATED CARBON AND MEMBRANE MATERIAL FOR REMOVAL OF PESTICIDES FROM SOILRISHI KUMAR SINGH PAL AND R.P. SINGHAbstract This study describes the synthesis, characterization and application of membrane material (MM), biosurfactant modified membrane material (MM*), pseudoactivated carbon (PAC) and biosurfactant enhanced pseudoactivated carbon (PAC*) for the removal of four chloro-organic pesticides (COPs) from contaminated soil. The regeneration of these materials with mild chemicals was also studied. These sorbents could remove COPs from the soil in the broad order of endosulfan > lindane > chloropyrifos > 2,4-D over a wide range of initial concentration 0.01-10 mg/L at sorbent dose 10 g/ l, pH 7.0, temperature 25 °C, rpm 150 for 5 h. The broad order of COP removal capacities of the sorbents was MM* > MM > PAC* > PAC over a wide range of above conditions. This is probably due to several factors such as molecular size and polarity, pH, COP interaction and retentivity, sorbent properties and environmental conditions. Two types of biosurfactants, rhamnolipid (RL) and trihalose (TH), were harvested from the culture supernatants of Pseudomonas aeruginosa and Nocardia erythropolis respectively. MM and PAC each modified with 5% RL were called MM* and PAC* respectively that had 10 to 20% enhanced removal, largely because MM* had much larger surface area, uniform pore structure and functional groups. Micellar enhancement with RL was always more than TH. Thus MM* and PAC* are promising sorbents for removal of organic pollutions from the environment.
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