Optimization of stabilized anaerobic landfill leachate treatment using ozonation with metallic compound using response surface methodology

Malaysia encounters a consistent rise in the generation of solid waste and leachate on a daily basis. It should also be noted that leachate has a low degree of biodegradability (BOD5/chemical oxygen demand [COD]), as shown by its BOD5/COD ratio. Its high toxicity levels significantly threaten the environment, water bodies, and human well-being. High concentrations of COD, color, and ammoniacal nitrogen (NH3-N) in leachate prevent this wastewater from being allowed to be discharged directly into the water body. Therefore, an effective process to remove the pollutant is desired. The aims of this study are to investigate the performance of ozonation with two metallic compounds, ZrCl4 and SnCl4, and optimize their performance using response surface methodology (RSM). In this study, the performance of ozonation with ZrCl4 (O3/ZrCl4) recorded better pollutant removals compared with the ozonation with tin tetrachloride (O3/SnCl4), as seen in the removals of 99.8%, 93.5%, and 46.3% for color, COD, and NH3-N, respectively. These removals were achieved by following the experimental model (optimum experiment condition) generated by RSM at O3 dosage of 31 g/m3, COD and ZrCl4 dosage ratio (COD, mg/L/ZrCl4, mg/L) of 1:1.35, with the pH solution of 8.78 and reaction time of 89 min. The R2 of each parameter for this model was recorded as 0.999 (COD), 0.999 (color), and 0.998 (NH3-N), respectively. These data indicated that the model is well fitted as the predicted data by statistical calculation and in good agreement with the actual data.Practitioner PointsThe performance of O3/ZrCl4 and O3/SnCl4 was examined for remediate stabilized landfill leachate.The performance of O3/ZrCl4 and O3/SnCl4 was optimized using RSM, and a set of experimental models was generated and tested.O3/ZrCl4 recorded the higher removal of COD, color, and NH3-N compared with O3/SnCl4.At best condition, both methods recorded removal as 89% to 99.8% of pollutants in leachate and product clear effluent.This finding gives a new approach to treat landfill leachate effectively and efficiently. The performance of O3/ZrCl4 and O3/SnCl4 in stabilized landfill leachate treatment is investigated and optimized using RSM. In this study, the experiment results obtained agrees that ZrCl4 and SnCl4 have capability to enhance the production of OH radical when combined with ozone and increased the oxidation process. The effectiveness of those methods were evaluated via percentage removal of colour, COD and NH3-N. The O3/ZrCl4 is effectively removed COD, color, and NH3-N as 99.8%, 93.5%, and 46.3%, respectively, compared with O3/SnCl4.image

Automated summary

The performance of ozonation with ZrCl4 and SnCl4 for remediation of stabilized landfill leachate was examined and optimized using response surface methodology. The results showed that ozonation with ZrCl4 achieved better pollutant removal compared to ozonation with SnCl4. At the optimum conditions, both methods achieved removal of 89% to 99.8% of pollutants in the leachate, producing clear effluent.