Solutions for the nutrient challenge

摘要

Nutrient removal only continues to impress itself further on the water industry's agenda, and utilities need to get smarter with their operations to ensure stricter discharge permits are met. This month's Market Map (see P41) considers the technologies for treatment of sludge dewatering liquors - typically rich in ammonia and phosphorus following anaerobic digestion - but there is an alternative to reduce the nutrient loads being recycled back to the main WWTP. Post-aerobic digestion (PAD) is employed to reduce nitrogen and phosphorus loads in anaerobic digester effluent, upstream of the dewatering step. Its main advantage over treatment of the dewatering liquor is that it can also enhance the sludge dewatering process and achieve additional volatile solids removal, however it typically consumes more energy than the alternative.