Nutrient-Reduced Effluent

Some waterways are unable to assimilate the nutrients remaining in carbon-reduced effluent. This situation occurs because the waterway is highly sensitive to contamination or is already impaired by high levels of pollution and must be protected from further degradation or because the flow in the waterway is insufficient to assimilate the carbon-reduced effluent. Nutrient-reduced effluent has had nearly all of the biodegradable organic material removed and the nutrient content reduced—in some plants, just nitrogen is reduced and in others, both nitrogen and phosphorus are reduced. Nutrient-reduced effluent is usually disinfected and may be discharged to sensitive waterways that cannot tolerate high nutrient levels or applied to land in controlled conditions. The technologies used may include biological nutrient reduction or chemical phosphorus reduction and constructed wetlands.