A chemical coating strategy for assembling a boron-doped diamond anode towards electrocatalytic degradation of late landfill leachate

Abstract

The high efficiency electrocatalytic degradation of late landfill leachate is still not an easy task due to the complexity and variability of organic pollutants. A chemical coating strategy for assembling a boron-doped diamond anode (BDD) towards electrocatalytic degradation of late landfill leachate was adopted and studied. The results shows the high removal rates of organic carbon (TOC) and ammonia nitrogen (NH₃–N) after electrochemical oxidation for 5 h can reach 99% and 100%. Further, the organic migration and transformation depends on current density, A/V value, initial pH, electrochemical degradation time, and composition of the stock solution. Specifically, alkaline conditions can increase both TOC and NH₃–N removal rates, which is reflected in the NH₃–N removal rate of 100% when the pH is 8.5 after only 5 h. The types of organic matter decreased from 63 species to 24 species in 5 h, in which the removal of fulvic acids is superior to that of soluble biometabolites. Amides/olefins and phenolic alcohols are all degraded and converted into other substances or decomposed into CO₂ and H₂O by BDD, accompanied by the continuous decomposition of alcohol-phenols into alkanes. In all, this study provides a core reference on electrocatalytic degradation of late landfill leachate.