Shell West Hollow Technology Center
Shell Development used an ultraviolet system to disinfect effluent before discharging into the bayou.
UV irradiation (245 NM) disinfects by direct cleavage of bonds and subsequent denaturization of metabolic molecules within the cells and viruses. Lamps are arranged so all effluent passes within ½ inch of any lamp to ensure adequate UV exposure. The system was commissioned March 1992, as the last step in treating effluent before discharging it into the ditch. The system that replaced the original chlorine disinfection system met the 1992 permit requirements including the no more than 0.1 mg/L of residual chlorine in the effluent stream.
Elimination of one ton chlorine gas cylinders which posed a safety issue as well as environmental hazard. The cylinders were changed out approximately every three months. This was used to treat 200 gal/min of effluent. No aquatic toxic effects are associated with using the UV system.
Details of Reductions
Additional Information :
This system received acceptance by the operators compared to chlorination/dechlorination process. This system offers over $1,000 per month savings.