Landfill leachate is categorized as recalcitrant wastewater and its treatment is a necessary measure for environmental protection. Recently, photocatalytic treatment of recalcitrant wastewaters using N-, P-, and N-P-type TiO₂ nanoparticles under visible light irradiation has attracted researchers’ attention. This study aims at investigating the photocatalytic removal efficiency of leachate chemical oxygen demand (COD) using tungsten (W)-Carbon (C)-codoped titanium dioxide (TiO₂) nanoparticles under visible light irradiation. A cascade photoreactor with immobilized W-C-codoped TiO₂ nanoparticles was applied to overcome the limitations of mass transfer and aeration in immobilized photocatalytic treatment processes. The effect of operating parameters such as coating surface density, light intensity, leachate recirculation flow rate, and initial leachate COD on the COD removal efficiency was experimentally investigated. Based on the results, 84 % of leachate COD was removed after 40 h treatment under the conditions of 550 mg.L⁻¹ initial leachate COD, 40 W light intensity, 10.59 g.m^-2 coating surface density, and 1 L.min⁻¹ leachate flow rate. In addition, the COD removal efficiency of leachate with 550 mg.L⁻¹ initial COD under 40 h sunlight irradiation, which was 46 %, was equal to that under 40-W light irradiation. The photocatalytic COD removal efficiency of leachate with high initial COD (10,100 mg.L⁻¹) was 32 % after 60 h treatment. The findings of this research offer new insights about efficient photocatalytic treatment of landfill leachate using cascade photoreactor under visible light irradiation on a modest and large scale.

垃圾渗滤液被归类为难处理废水，其处理是环境保护的必要措施。近年来，在可见光照射下使用N，P和NP型TiO ₂纳米粒子的光催化处理难处理的废水引起了研究者的关注。本研究旨在研究在可见光照射下使用钨（W）-碳（C）-掺杂的二氧化钛（TiO ₂）纳米粒子对渗滤液化学需氧量（COD）的光催化去除效率。固定有WC掺杂的TiO _2的级联光反应器纳米颗粒用于克服固定化光催化处理过程中传质和曝气的限制。实验研究了涂层表面密度，光强度，渗滤液再循环流量和初始渗滤液COD等操作参数对COD去除效率的影响。根据结果​​，在550 mg.L ^-1初始渗滤液COD，40 W光强度，10.59 gm ^-2涂层表面密度和1 L.min ^-1的条件下处理40 h后，去除了84％的渗滤液COD。渗滤液流速。此外，渗滤液中550 mg.L ^-1的COD去除效率在40 h阳光照射下的初始COD为46％，与40 W光照射下的初始COD相等。处理60小时后，具有较高初始COD（10,100 mg.L ^-1）的渗滤液的光催化COD去除效率为32％。这项研究的发现为在可见光照射下适度和大规模地使用级联光反应器对垃圾渗滤液进行有效的光催化处理提供了新的见识。