What is a potential byproduct of nutrient recovery systems?

Nutrient recovery systems are designed to extract valuable nutrients, such as nitrogen and phosphorus, from wastewater or other organic material. One of the significant benefits of these systems is their ability to transform nutrients into beneficial byproducts, among which biomass fertilizer is a key outcome. Biomass fertilizer is essentially organic material that is rich in nutrients and can be used to improve soil fertility and promote plant growth. This makes it an environmentally friendly alternative to chemical fertilizers, helping to close the nutrient loop and minimize waste.

In contrast, options like polluted water, organic waste, and harmful gases do not represent the intended positive outcomes of nutrient recovery systems. Polluted water would imply a failure in the system's operation, while organic waste, though it can be a raw material for recovery systems, is not a product of the system itself. Harmful gases, such as those potentially emitted during decomposition or treatment processes, also do not reflect the primary objectives of nutrient recovery, which focuses on transforming waste into useful products. Therefore, the focus on producing biomass fertilizer highlights the effective and sustainable approach of nutrient recovery systems in sewage treatment.