Effects of soaking, acidity and temperature on cadmium and lead removal from rice.

• Few samples show Pb concentration above the limit set by WHO and FAO of 0.2 mg/kg. • Cd concentration was decreased with increasing the water acidity. • Temperatures and acid concentrations had more significant effects on Cd than Pb. • Cd levels were found to be higher in brown rice than white rice. In this research, effect of soaking time, acidity and temperature on the removal of lead and cadmium from rice was investigated. Different rice treatments were involved i.e. three soaking times (0, 15, and 30 min), three temperatures (20, 25, and 30 °C) and four concentrations of glacial acetic acid (0.5%, 1%, 2%, and 3%). Results showed that few samples have shown lead concentrations above the maximum limit set by the World Health Organization (WHO) and the UN Food and Agriculture Organization (FAO) of 0.2 mg/kg, whereas, all cadmium concentrations were below the limit of 0.4 mg/kg. A decrease in lead and cadmium concentrations were observed with increasing time of soaking. Lead had the lowest concentration at 20 °C, while cadmium had the lowest concentration at 30 °C. Cadmium concentration decreased with increasing water acidity, while the lead concentration reached the lowest concentration with 1% acidity. [ABSTRACT FROM AUTHOR]