Question

A domestic wastewater source has 550 mg L-1 BOD, 60 mg L-1 total nitrogen (comprising Total Kjeldahl Nitrogen (TKN), nitrate and nitrite, and ammonia) and 15 mg L-1 soluble phosphorus (SP). These parameters need to be brought to < 30 mg L-1 BOD, < 15 mg L-1 for total nitrogen, <1 mg L-1 for ammonia, and < 2.5 mg L-1 for SP before being discharged into a local river. Investigate possible wastewater treatment methods that could be applied to remove these pollutants to the levels required. Calculate the percentage removal required for each pollutant. If the wastewater is to be used for a recycled water supply to domestic households for non-potable use, such as watering gardens, toilet flushing and washing of pavements, investigate what further treatments should be applied and outline one possible treatment process.

Answer 1