Addition of CMC was effective in reducing the leaching toxicity
of leachate-polluted soils and increasing soil pH and enzyme
activities (amylase and catalase). The alleviating effect of CMC
on biotoxicity of soil extract was mainly attributed to either pH
increase, high content of P and organic matter, or promotion on
soil microbial metabolism. Higher pH values and enzyme activities
are considered to be of great benefits for decreasing soil leaching
toxicity reasonably because leaching toxicity is negatively correlated
with pH, amylase and catalase. However, excessive CMC has
no benefit for decreasing leaching toxicity of polluted soils. Overall,
CMC can be safely and effectively used for reducing the toxicity
risks of leachate-contaminated soils and TP was proved effective
as a test organism. And further studies are needed to unambiguously
determine the comprehensive effects of CMC for soil
remediation.