Determination of Nutrient Deficiency in Stormwater from the Wood Industry for Biological Treatment

The efficiency of biological treatment systems in degrading organic matter is affected by both the available nutrients and the efficiency of the microbial organisms that carry out the degradation. This study assesses whether a wetland treatment system treating stormwater from a wood industrial site faced nutrient deficiency or lacked efficient microbes, and whether addressing these possible problems could enhance the degradation of organic matter in the system. The stormwater was a mix of industrial stormwater, irrigation water and leachate from woodchip piles. The industry mainly processes pedunculate oak, which is known to create a leachate high in polyphenols. This water is currently treated in a pilot-scale wetland system and an aerated lagoon. To study whether the treatability could be enhanced by addition of nutrients (phosphorus, nitrogen, micronutrients), headspace respirometry was used. The effect of adding microbes from a paper mill activated sludge system was also evaluated. Our results showed that all nutrient additions had a positive effect on the treatability of the stormwater. In particular, the addition of nitrogen showed a 12% rise in chemical oxygen demand reduction over 336h. However, addition of paper mill activated sludge did not enhance the degradation of organic matter; instead, a toxic effect of the stormwater was shown.