Response of chemical and biochemical soil properties to the spreading of biochar-based treated olive mill wastewater

Giuseppe Di Rauso Simeone; Giuseppina Scala; Marcello Scarpato; Maria A Rao

doi:10.1016/j.heliyon.2023.e22894

Response of chemical and biochemical soil properties to the spreading of biochar-based treated olive mill wastewater

Heliyon. 2023 Nov 25;9(12):e22894. doi: 10.1016/j.heliyon.2023.e22894. eCollection 2023 Dec.

Authors

Giuseppe Di Rauso Simeone¹, Giuseppina Scala¹, Marcello Scarpato¹, Maria A Rao¹

Affiliation

¹ Department of Agricultural Sciences, University of Naples Federico II, via Università 100, 80055, Portici, Italy.

Abstract

Olive mill wastewater (OMW) is the effluent derived from the oil extraction processes from olives. Despite the polluting potential OMW can be a useful source of nutrients and organic compounds to improve soil properties. OMW could negatively affect soil and water quality as this waste is rich in phenolic compounds and has high COD and BOD₅. Biochar-based treatment could be an efficient method to remediate OMW. In this study poplar biochar (BP) was more effective than conifer biochar (BC) in terms of adsorbing phenols and reducing phytotoxicity at different biochar rates (5 and 10 %). BP-treated OMW was used in soil amendment and induced an increase in chemical properties, especially in organic carbon after 30 days of incubation. In soil amended with 10 % BP-treated OMW microbial biomass, enzymatic activities, and cress seed germination were significantly enhanced after 30 and 90 days.

Keywords: Microbial biomass; Organic amendment; Phytotoxicity; Poplar biochar; Soil enzymes; Total phenols.