BOD and COD studies of synthetic and semisynthetic cutting fluids

It is estimated that between 20 400 and 23 850 × 10⁶ 1 of spoiled cutting fluids are discarded in the U.S. each year. Most undergo some form of biological waste treatment, yet there is little information regarding the effectiveness of such treatment on these fluids. In this study, sixteen commercially available synthetic and semisynthetic cutting fluid concentrates were tested for their susceptibility to biological degradation. The BOD5S of each compound was determined as an indication of biological oxidation potential. Inocula of both sewage and river origin were used, with statistically identical results. It was found that biological utilization ranged from 0 to 31% of the total oxygen demand, as measured by COD. Studies with triazine and morpholine preservatives showed no relationship between effectiveness of preservation and degradability.