Title: Effective organic fertiliser through a novel approach of biocatalyst activated from biochar
Authors: N.S. Gunasekara; R.T.K. Ariyawansha; B.F.A. Basnayake
Addresses: Department of Agricultural Engineering, Faculty of Agriculture, University of Peradeniya, 20400, Sri Lanka ' Sustainable Environment Research Group, School of Technology, Faculty of Engineering and Technology, Sri Lanka Technological Campus (SLTC Research University), Padukka 10500, Sri Lanka ' Department of Agricultural Engineering, Faculty of Agriculture, University of Peradeniya, 20400, Sri Lanka
Abstract: Instead of simply mixing biochar into compost, it was decided to activate the biochar. Aqueous biocatalysts were produced in the aerobic reactor (AR) and anaerobic reactor (ANR), containing water, shredded market waste, and rock phosphate (RP) by adding biochar intermittently to reach neutral pH. AR surpassed pH 7 to reach 9.07 but the ANR could only attain 5.92 on 44th day. In AR, available P content increased from 55.24 mg/L to 2,196 mg/L and ANR from 113.86 mg/L to 2,183 mg/L. Aerobic and anaerobic biocatalysts were mixed separately into two piles of shredded garden wastes of 1 kg each with the third as the control. Total P contents of aerobic, anaerobic, and control compost were 2.45 mg/g, 1.93 mg/g, and 0.78 mg/g. respectively. Slightly less total N in biocatalysts but converted to organic acids while increased available K compared to control. Aerobic biocatalyst is the best because enzyme kinetics reveal competitive inhibition existed in ANR in forming the catalyst and non-competitive inhibition manifested when aerobic catalyst was added to garden wastes.
Keywords: aerobic; anaerobic; biochar; biocatalyst; composting; market waste; organic fertiliser; solubility of rock phosphate.
DOI: 10.1504/IJEWM.2024.142508
International Journal of Environment and Waste Management, 2024 Vol.35 No.3, pp.323 - 337
Received: 24 Aug 2021
Accepted: 06 Jul 2022
Published online: 05 Nov 2024 *