Landfills are the main option for waste disposal all over the world. Most of the landfill sites across the world are old and are not engineered well to prevent contamination of the underlying soil and groundwater by the toxic leachate. The present study examines the potential use of raw zeolite and heated activated zeolite in the reduction of COD, NH 3 -N, and colour from leachate. Zeolite was activated using different temperatures at 150 °C, 200 °C, and 250 °C for 3 h. General characterization was conducted for raw zeolite and heat-activated zeolite to investigate the influence of temperature on zeolite properties. Batch experiments were conducted at the optimum dosage of zeolite and pH. Results demonstrated that the optimum dosage of raw zeolite was 10 g with 53.1%, 22.5% and 46% reduction of NH 3 -N, COD, and colour, respectively. The optimum pH for NH 3 -N was 7 with a percentage removal of 55.8% while better reduction of COD and colour was obtained at pH 4 with a percentage removal of 24.3% and 73.8%, respectively. Also, the optimum temperature tested was at 150 °C, where the optimum dosage using activated zeolite heated at 150 °C was 10 g, resulted in the maximum reduction of NH 3 -N, COD, and colour of 45.1%, 11.8% and 43.7%, respectively. The optimum dosage of activated zeolite heated at 200 °C and 250 °C, which was 25 g. This indicates that the use of the activated zeolite heated at 150 °C can achieve the optimum removal at a lower cost which is applicable for a larger scale of wastewater treatment. In addition, it was found that the capacity of the zeolite before and after heat activation was 41.30 cmol/kg and 181.90 cmol/kg, respectively. The adsorption isotherm analysis reveals that both Freundlich and Langmuir isotherms were in agreement with experimental data. However, the Freundlich isotherm model was more favourable than Langmuir isotherm to evaluate the adsorption equilibrium of the three pollutants as verified by the high R 2 values. Contamination of landfill leachate poses significant environmental problems since it percolates through the soil and pollutes the groundwater. Raw zeolite and heated activated zeolite in the reduction of COD, NH3-N, and colour from leachate. Batch study experiments were conducted to measure the optimum dosage of zeolite as well as optimum pH of leachate. The activated zeolite can improve the removal of COD, NH3-N, and colour from 24.3%, 55.8%, and 73.8% using raw zeolite to 46.3%, 75.9%, and 91.4%, respectively. The adsorption isotherm analysis reveals that both Freundlich and Langmuir isotherms were in agreement with experimental data.

中文翻译：

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用于减少垃圾渗滤液中氨氮、颜色和 COD 的热活化沸石

垃圾填埋场是全世界废物处理的主要选择。世界上大多数垃圾填埋场都陈旧，并且没有经过精心设计，无法防止有毒渗滤液污染底层土壤和地下水。本研究考察了原料沸石和加热活化沸石在降低渗滤液中的 COD、NH 3 -N 和颜色方面的潜在用途。沸石在 150 °C、200 °C 和 250 °C 的不同温度下活化 3 小时。对粗沸石和热活化沸石进行一般表征以研究温度对沸石性质的影响。在沸石的最佳用量和pH值下进行批量实验。结果表明，原料沸石的最佳用量为 10 g，NH 3 -N、COD 和颜色分别减少 53.1%、22.5% 和 46%。NH 3 -N 的最佳 pH 值为 7，去除率为 55.8%，而在 pH 值为 4 时，COD 和颜色的降低效果更好，去除率​​分别为 24.3% 和 73.8%。此外，测试的最佳温度为 150 °C，其中使用在 150 °C 加热的活化沸石的最佳用量为 10 g，导致 NH 3 -N、COD 和颜色的最大减少 45.1%、11.8% 和分别为 43.7%。活化沸石在200℃和250℃加热的最佳用量为25g。这表明使用在 150 °C 加热的活化沸石可以以较低的成本实现最佳去除，适用于更大规模的废水处理。此外，发现热活化前后沸石的容量分别为41.30 cmol/kg和181.90 cmol/kg。吸附等温线分析表明，Freundlich 和Langmuir 等温线均与实验数据一致。然而，Freundlich 等温线模型比 Langmuir 等温线模型更适用于评估三种污染物的吸附平衡，如高 R 2 值所证实的那样。垃圾渗滤液的污染会造成严重的环境问题，因为它会渗入土壤并污染地下水。生沸石和加热活化沸石在减少浸出液中的 COD、NH3-N 和颜色方面的作用。进行批量研究实验以测量沸石的最佳用量以及浸出液的最佳pH。活化的沸石可以将 COD、NH3-N 和颜色的去除率从使用粗沸石的 24.3%、55.8% 和 73.8% 分别提高到 46.3%、75.9% 和 91.4%。