Behavior of solid carbon sources for biological denitrification in groundwater remediation

The present study was conducted to compare the behavior of wheat straw, sawdust and biodegradable plastic (BP) as potential carbon sources for denitrification in groundwater remediation. The results showed that a greater amount of nitrogen compounds were released from wheat straw and sawdust than from BP in leaching experiments. In batch experiments, BP showed higher nitrate removal efficiency and longer service life than wheat straw and sawdust, which illustrated that BP is the most appropriate carbon source for stimulation of denitrification activity. In column experiments, BP was able to support complete denitrification at influent nitrate concentrations of 50, 60, 70, 80, and 90 mg NO₃⁻-N/L, showing corresponding denitrification rates of 0.12, 0.14, 0.17, 0.19, and 0.22 mg NO₃⁻-N.L⁻¹.d⁻¹.g⁻¹, respectively. These findings indicate that BP is applicable for use as a carbon source for nitrate-polluted groundwater remediation.