Estimation of biochemical oxygen demand in slurry and effluents using ultra-violet spectrophotometry

The absorbance at 280 nm was determined for samples of dirty water, and pig and cow slurry effluents collected annually over a period of 3 years. Regression analysis showed an exponential relationship between absorbance and biochemical oxygen demand (BOD5). Well fitted regressions of absorbance (280 nm) on BOD5 were obtained for each year, especially for exponential regression analysis. Such regressions were then used to estimate BOD5. Once a relationship is established between UV absorbance and BOD, UV absorbance measurements can be used to rapidly analyse large batches of samples, and also to improve the efficiency of the BOD5 test by indicating dilution ranges. Copyright © 1996 Elsevier Science Ltd