ENTRAPMENT OF MIXED MICROBIAL-CELLS FOR WATER AND WASTE-WATER TREATMENT

An entrapment of mixed microbial cells process was used to remove the pesticide Ethylene Dibromide (EDB), Trichlopropane (TCP) and nitrate contaminated in the groundwater. The mixed microbes were entrapped into a polymeric cellulose triacetate. The system is able to remove (aerobically) more than 90% of EDB (influent concentration of 300 mug/l) at more than 30 minutes of hydraulic retention time (HRT). TCP (influent concentration of 2.81 mug/l) could not be detected in the effluent at the same HRT. The system is also able to remove (anaerobically) more than 99% of nitrate influent concentration of NO3-N ranging from 50 to 850 mg/l) at an HRT of more than 2 hours. The system has shown very promising results in respect of the removal of trace pesticide and nitrate contaminated groundwater. It can also be considered as an alternative for direct treatment of nitrate-rich water or in a combination with an ion exchange process with an intermittent to eliminate the high nitrate concentration from the spent regenerant. The system could easily develop a package plant for removal of trace organics and inorganics from the groundwater.