Nutrient recovery options from human urine: A choice for large scale application

Human urine is a potential source of nitrogen, potassium, phosphorus and other trace elements essential for plant growth. Though different study reports indicated its considerable nutrient content, large scale application of urine as a fertilizer is very limited. The aim of this work was to evaluate the different nutrient recovery processes from urine for large scale application in agriculture. Single and integrated nutrient recovery systems such as struvite precipitation, forward osmosis, nitrification/distillation, ammonia stripping and absorption/adsorption with evaporation, fertigation among others were reviewed. Though efficient at optimum conditions in laboratory scales, most of the technologies are not promising for commercialization due to investment and operational costs, uncertainty of economic returns and sustainability issues. Among them, fertigation is the first priority for large scale applications. (c) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.