Examining Soil Erodibility, Soil pH, and Heavy Metal Accumulation in a Nickel Ore Mine: A Case Study in Tubay, Agusan del Norte, Philippines

Abstract

Mining activity always presents threats to soil and water pollution. As an extractive industry, it disturbs the ground and the biodiversity associated with soil and plants. Its operations have led to severe geological and environmental problems, including the depletion of land and water resources, geological dangers, and ecological landscape devastation that may have accelerated the desertification of mining areas. This case study analyzed the soil’s physical and chemical properties in a nickel laterite mine, including soil erodibility K factor, soil pH, and heavy metal accumulation, as a basis for establishing mine management protocol during and post-mining operations in Tubay, Agusan del Norte, Philippines. Results determined a slightly alkaline pH level. An estimate of soil erodibility ranging from 0.016 to 0.066 was determined using the USLE-K factor, with the highest erodibility at Mine 7, where % silt is high and % sand is lowest. X-ray fluorescence (XRF) spectroscopy was used to analyze soil samples. The findings show that Ni, Fe, Co, and Mn in the soil were above the WHO-permitted limits. The surface soil had mean values of 9,239 ppm for nickel, 302,618 ppm for iron, 639 ppm for cobalt, and 5,203 for manganese. Heavy metals in soil may be consumed by crops and pollute land and water.