Evaluation of sewage-sludge based products for indoor basil production

As human population continues to rise, more sustainable methods of food production are required. Current practices of producing nitrogen fertilizer from the Haber-Bosch process have been affected recently by geopolitical strife, rising natural gas prices and the global pandemic of 2020. This work has investigated the use of several municipal wastewater streams as mineral fertilizer replacements on a nitrogen basis. Waste activated sludge and digested sludge were transformed using pyrolysis at low (300°C) and high (600°C) temperatures to produce biochar products that were applied to pot experiments growing basil. Reject water from dewatering digested sewage sludge was also used after filtration and two different ozone treatment for sterilization as liquid fertilizer options. Though the products did not perform as well as the mineral fertilizer control, the sludge based fertilizers were able to provide enough nutrients for the herbs to grow. Further experimentation on the proper dosing of these products has the potential to produce a material competitive with mineral fertilizer.