BIODEGRADATION OF NOM - EFFECT OF NOM SOURCE AND OZONE DOSE

Batch degradation experiments were conducted to evaluate the extent of biodegradation of natural organic matter (NOM) as a function of ozone dosage. Four NOM sources that might be encountered in drinking water treatment were characterized and tested. The biodegradability of all s ources was enhanced as the ozone dose was increased from 0 to 7.3 mg o zone/mg total organic carbon (TOC). Increased ozonation resulted in co nsistently improved TOC removals for NOM sources having a large fracti on of high-molecular-weight organics. Greater biodegradation was obser ved for the unozonated sources with lower UV-absorption-to-TOC ratios and a larger fraction of low-molecular-weight organics.