BIODEGRADABLE DISSOLVED ORGANIC-CARBON FOR INDICATING WASTE-WATER RECLAMATION PLANT PERFORMANCE AND TREATED WASTE-WATER QUALITY

Various methods for measuring biodegradable dissolved organic carbon ( BDOC) in water have been introduced in the last decade. Applications o f the methods have been limited to drinking water. The measure oi BDOC has been used mainly to indicate the quality of raw and finished wate rs and evaluate the performance of biological activated carbon (ozone/ granular activated carbon) systems in water treatment plants. Recently , a modified BDOC protocol was developed for examining reclaimed and s econdary-treated wastewaters. Use of the new BDOC method can be extend ed to the wastewater treatment and reclamation fields. Samples collect ed from a wastewater reuse pilot facility were tested for BDOC. The mo dified BDOC method was able to detect the increase in biodegradability of ozonated tertiary-treated wastewater. Good relationships among BDO C, dissolved organic carbon (DOC), and soluble biochemical oxygen dema nd were obtained. The modified protocol was later used to measure BDOC in secondary-effluent samples from 13 municipal wastewater treatment plants. The results show that BDOC can also be used as an indicator of secondary-effluent quality. Likewise, strong and significant correlat ions were found among BDOC, DOG, and soluble chemical oxygen demand in secondary effluents.