Removing nitrogenous compounds from landfill leachate using electrochemical techniques

Abstract

In this research, applicability of electrochemical technology in removing nitrogenous compounds from solid waste landfill leachate was examined. Novel cathode material was developed at laboratory by introducing a Cu layer on Al substrate (Cu/Al). Al and mild steel (MS) anodes were investigated for the efficiency in removing nitrogenous compounds from actual leachate samples collected from two open dump sites. Al anode showed better performances due to the effect of better electrocoagulation at Al surface compared to that at MS anode surface. Efficiency studies were carried out at a current density of 20 mA/cm 2 and at reaction duration of 6 h. Efficiency of removing nitrate-N using Al anode and developed Cu/Al cathode was around 90%. However, for raw leachate, total nitrogen (TN) removal efficiency was only around 30%. This is due to low ammonium-N removal as a result of low oxidation ability of Al. In addition to the removal of nitrogenous compounds, reactor showed about 30% removal of total organic carbon. Subsequently, raw leachate was diluted four times, to simulate pre-treated leachate. The diluted leachate was treated and around 88% removal of TN was achieved. Therefore, it can be said that the reactor would be good as a secondary or tertiary treatment step in a leachate treatment plant.

The Performance of Electrocoagulation Process in Removing Organic and Nitrogenous Compounds from Landfill Leachate in a Three-Compartment Reactor

“…In contrast, the obtained TN removal was 29.8%, slightly lower than the previous study (Nanayakkara et al 2018), which acquired 32.66% of TN removal. The TN removal is due to the electrochemical oxidation and reduction that possibly occurred simultaneously in the anode and cathode compartments, respectively.…”

Development of Hybrid Systems by Integrating an Adsorption Process with Natural Zeolite and/or Palygorskite into the Electrocoagulation Treatment of Sanitary Landfill Leachate

“…Similar to color, delayed NO 3 − -N removals were observed using Fe electrodes at current densities of 10 and 30 mA cm −2 for the first 30 and 20 min, respectively, while negligible NO 3 − -N removal was noticed at 50 mA cm −2 within 10 min of treatment (Figure 3c). The slight increase in NO 3 − -N levels during the initial stages of the process suggests that the NH 4 + -N in the SLL was partially converted into NO 3 − -N at the anodic Fe electrode when the respective electrical currents were applied [77,78]. The NO 3 − -N produced along with that already existing in the SLL were subsequently reduced to nitrite, ammonia (NH 3 ) and nitrogen gas (N 2 ) at the Fe cathode with simultaneous anode oxidation [21,67,78].…”

“…The slight increase in NO 3 − -N levels during the initial stages of the process suggests that the NH 4 + -N in the SLL was partially converted into NO 3 − -N at the anodic Fe electrode when the respective electrical currents were applied [77,78]. The NO 3 − -N produced along with that already existing in the SLL were subsequently reduced to nitrite, ammonia (NH 3 ) and nitrogen gas (N 2 ) at the Fe cathode with simultaneous anode oxidation [21,67,78].…”

Influences of cathode potential and carbon source on parabromoaniline degradation in microbial electrolysis cell

“…MET can be divided largely into two types, microbial fuel cell and microbial electrolysis cell (MEC). This bioelectrochemical technique has attracted considerable attention from an increasing number of researchers because of its unique advantages of strong sustainability, high treatment efficiency, and low cost (Nanayakkara et al, 2019). Under anaerobic condition, pollutants such as nitrobenzene (Wang et al, 2012), chlorophenol (Wen et al, 2013), antibiotics (Kong et al, 2015), and polychlorinated biphenyl (PCB) (Yu et al, 2017) can be reduced effectively using MEC cathode when low DC voltage is applied; meanwhile, MET can also generate electric energy to reduce the external energy consumption (Korshin & Yan, 2018; Tiwari et al, 2017).…”