ENIVRONMENT ASIA

Volume 12, No. 02, Month MAY, Year 2019, Pages 49 - 57

Mobility retardation of cd, pb and mn in acid soil using phosphate fertilizers

Chompoonut Chaiyaraksa, and Natthanan Rodsa

Abstract Download PDF

Contamination of heavy metals in soil is a major problem that causes damage to the environments. The aim of this research was to observe the efficiency of phosphate fertilizer, including phosphate rock, di-ammonium phosphate, and monopotassium phosphate in stabilizing lead, cadmium, and manganese in contaminated soil. The sampling soil was an acid sandy clay loam soil from Rayong Province which is one of the most industrialized provinces in Thailand. After applying fertilizers to the soil, the determination was on soil pH, the total concentration of heavy metals, heavy metal forms in soil and potential of heavy metals to enter the biological system. The results showed that phosphate rock, diammonium phosphate, and monopotassium phosphate increased the soil pH from 3.60 to 6.5, 7.0 and 5.2, respectively. Phosphate fertilizers could change an unstable form to a more stable form of heavy metals. Phosphate rock (7.5 g/kgsoil) has the highest potential for reducing the mobility of all three metals (about 80% for manganese, 60% for cadmium, and 50% for lead), followed by monopotassium phosphate. The results obtained from the extraction with DTPA and CaCl2 were closely related to the results obtained from the sequential extraction method. Phosphate rock was the best to reduce potentially toxic metals phytoavailability. Soil improvement with phosphate fertilizer was considered a good alternative for stabilizing soils contaminated with cadmium, lead, and manganese.

Keywords

Correlation; Heavy metals; Mobility retardation; Phosphate fertilizer; Soil-amendment

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