Emerging Topics in Environmental Science and Natural Resource Management pp 145-152
Editors: Dr.R. S. Khoiyangbam
Dr. Ch. Raghumani Singh (2025)
ISBN: 978-93-94174-59-7
Chapter 14
Nitrate Contamination in Soils used for Storing and Drying Biogas Spent slurry
R.S. Khoiyangbam*
Department of Environmental Science, Manipur University, Imphal – 795003
Abstract
Nitrate contamination in the soils used for storing and drying biomethanation spent slurry discharged from a community-size biogas plant (85 m3 KVIC model) was investigated. Soil samples (0-5, 95-100, and 145-150 cm depth) were drawn from three different sites: (i) Pits used to store freshly discharged slurry (PS), (ii) Ground used to dry the semi-dried sludge (GS) and (iii) Soils free from slurry handling (FS). The NO3 content in the 0-5 cm of the PS was 4, 28, and 85 mg kg-1 on the 0, 10th, and 20th day after emptying the slurry. Nitrate content in 95-100 and 145-150 cm soil showed little change on the 10th and 20th days. In the GS, the nitrate content in the 0-5 cm was found to be highest (152 mg kg-1) when the ground was devoid of overlying semi-dried spent sludge. After the spreading of sludge, the NO3 content decreases on the 10th day (39 mg kg-1) and increases on the 20th day (112 mg kg-1). Nitrate content in the FS was lowest with 13, 7, and 4 mg kg-1, respectively, in the 0-5, 95-100, and 145-150 cm soil depths.
Keywords
Biomethanation, biogas plants, community plants, nitrate contamination
Cite this Chapter: Khoiyangbam, R.S. 2025. Nitrate Contamination in Soils used for Storing and Drying Biogas Spent slurry. In: R. S. Khoiyangbam and Ch. Raghumani Singh (Eds.), Emerging Topics in Environmental Science and Natural Resource Management. Excellent Publishers, India. pp. 145-152. doi: https://doi.org/10.20546/978-93-94174-59-7_14
