Due to the environmental consequences corresponding to leachate penetration, a sequence of inexpensive conventional processes proposed leachate treatment. The main objective was maximizing the COD and heavy metal removal efficiencies while minimizing generated sludge volume and material consumption rate. Walnut-shell adsorption complements lime treatment by eliminating heavy metals and low molecular-weight organic compounds. Samples gathered from Nazlou-landfill, Urmia, Iran. The relative significance of independent variables (lime and walnut-shell dosages and pH) on the removal efficiency was investigated using response surface methodology. By estimating the gradient of relative equations of the experimental results, the ideal direction of independent variable change was found as such increasing COD removal. A new variable called OSVLDR was utilized for measuring the ratio of the observed sludge volume to used lime dosage. The proposed sequence resulted in 43.24% COD removal under optimal conditions (i.e., 6.83, and 25 g/L of lime and walnut-shell dosage and pH values of 6, and 4 for two sets). Furthermore, effective removal in heavy metal concentrations was observed, i.e., 98.17, 67.45, 91.03, and 88.02% for nickel, cadmium, zinc, and lead, respectively. The results showed that a change in variables’ amount affects associated costs while making a variation at removal efficiency. Reducing the initial pH value of leachate to 3.50 might decrease the consumed raw materials and OSVLDR value, resulting in a considerable decline in material costs (by 10%). Also, the inactive walnut-shell surface with a more crushing degree was used to reduce costs in walnut-shell set experiments rather than the activated surface.

由于与渗滤液渗透相对应的环境后果，一系列廉价的常规工艺提出了渗滤液处理。主要目标是最大限度地提高 COD 和重金属去除效率，同时最大限度地减少产生的污泥量和材料消耗率。核桃壳吸附通过消除重金属和低分子量有机化合物来补充石灰处理。从伊朗乌尔米亚的 Nazlou 垃圾填埋场收集的样本。使用响应面方法研究了自变量（石灰和胡桃壳用量和 pH 值）对去除效率的相对显着性。通过估计实验结果的相关方程的梯度，找到了自变量变化的理想方向，即增加COD去除率。一个名为 OSVLDR 的新变量用于测量观察到的污泥体积与使用的石灰剂量的比率。在最佳条件下（即，6.83 和 25 g/L 的石灰和核桃壳用量和 6 和 4 的 pH 值，两组），建议的序列导致 43.24% 的 COD 去除。此外，观察到对重金属浓度的有效去除，即镍、镉、锌和铅的去除率分别为 98.17、67.45、91.03 和 88.02%。结果表明，变量数量的变化会影响相关成本，同时也会影响去除效率。将渗滤液的初始 pH 值降低到 3.50 可能会降低所消耗的原材料和 OSVLDR 值，从而导致材料成本的大幅下降（降低 10%）。还，