Phytotoxicity of chromium-containing wastewater on germination and growth of Oryza sativa L

Abstract

Leather tanning industries in Sukaregang area, Garut district-West Java, have been using chromium since 1980s. Since that time chromium containing wastewater has been polluting river water in the area since there has not been effective waste water treatment available until today. The polluted river water spread bad smell to the environment and the water also has been used by local farmers to irrigate their paddy field. This research was conducted to examine the effect of chromium containing wastewater to growth of paddy, including the physiology stress in plant organs. For examination of the effect of chromium to plant growth, Ciherang variety (Cvar) of paddy was grown in soil and treated with chemical solutions of K2Cr2O7 with concentrations of 50, 100, 200 mg/L, polluted river water (PRW) and distilled water as a control. Direct exposure of chromium 100-200 mg/L killed the plants a week after treatment. Exposure of the plant to wastewater and chromium 50 mg/L reduced plants growth. In Cr 50 mg/L treatment, chlorophyll content in paddy decreased to 60.82%, while the proline concentration in leaves increased by 18.47%. The activity of CAT and APX enzymes also increased, especially in paddy leaves after treated with Cr 50 mg/L, with the highest CAT activity value reached 1990.31 units/mg (an increase of 76.76%) and APX activity of 59.91 units/mg (an increase of 81.02%). The effect of chromium-containing wastewater to paddy was similar to the effect when the plant was exposed to 50 mg/L of chromium.