CHEMICAL AND TEXTURAL PROPERTIES OF CROP RESIDUE PERTINENT TO THEIR APPLICATION IN THE REMEDIATION OF CONTAMINATED SOIL

Abstract

This study investigates the chemical and textural properties of cassava peel (CP), groundnut husk (GH), and plantain peel (PP) to evaluate their potential in remediating contaminated soils. The physicochemical properties, including pH (CP: 7.18 ± 0.03, GH: 6.60 ± 0.26, PP: 7.40 ± 0.00), bulk density (CP: 0.33 ± 0.01 g/ml, GH: 0.43 ± 0.00 g/ml, PP: 0.51 ± 0.01 g/ml), and electrical conductivity (CP: 3.02 ± 0.07 mS/cm, GH: 4.47 ± 0.01 mS/cm, PP: 6.64 ± 0.97 mS/cm), indicate their ability to enhance soil conditions and microbial activity. BET analysis reveals that plantain peels have the largest specific surface area (440.49 m²/g), enhancing their adsorption capacity for contaminants, while groundnut husks have the highest pore volume (1.70 cm³/g), promoting microbial growth and nutrient retention. Scanning electron microscopy (SEM) analysis shows that cassava peel biomass has a low pore size structure and irregular shapes, while groundnut husk and plantain peel biomass are non-porous. Surface oxygen functional groups, such as carboxylic acid, lactonic, and phenolic groups, were analyzed, revealing their capacity to immobilize heavy metals and reduce their mobility. In addition, the heavy metal content of these biomasses is within safe limits, ensuring they do not contribute to additional contamination. Elemental analysis highlights essential nutrients, such as carbon, oxygen, and calcium, as well as iron, nitrogen, magnesium, potassium and phosphorus improving soil fertility and supporting microbial activity crucial for bioremediation. The study concludes that CP, GH, and PP possess favorable properties for effective soil remediation, making them valuable for sustainable soil management.