Labiadh Lazhar, Fernandes Annabel, Ciríaco Lurdes, Pacheco Maria José, Gadri Abdellatif, Ammar Salah, Lopes Ana
FibEnTech/UBI and Department of Chemistry, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; Dép. de Chimie, Faculté des Sciences de Gabès, Université de Gabès, Cité Erriadh, 6072 Gabès, Tunisia.
FibEnTech/UBI and Department of Chemistry, Universidade da Beira Interior, 6201-001 Covilhã, Portugal.
J Environ Manage. 2016 Oct 1;181:515-521. doi: 10.1016/j.jenvman.2016.06.069. Epub 2016 Aug 5.
Conventional sanitary landfill leachate treatment has recently been complemented and, in some cases, completely replaced by reverse osmosis technology. Despite the good quality of treated water, the efficiency of the process is low and a large volume of reverse osmosis concentrate has to be either discharged or further treated. In this study, the use of anodic oxidation combined with electro-Fenton processes to treat the concentrate obtained in the reverse osmosis of sanitary landfill leachate was evaluated. The anodic oxidation pretreatment was performed in a pilot plant using an electrochemical cell with boron-doped diamond electrodes. In the electro-Fenton experiments, a boron-doped diamond anode and carbon-felt cathode were used, and the influence of the initial pH and iron concentration were studied. For the experimental conditions, the electro-Fenton assays performed at an initial pH of 3 had higher organic load removal levels, whereas the best nitrogen removal was attained when the electrochemical process was performed at the natural pH of 8.8. The increase in the iron concentration had an adverse impact on treatment under natural pH conditions, but it enhanced the nitrogen removal in the electro-Fenton assays performed at an initial pH of 3. The combined anodic oxidation and electro-Fenton process is useful for treating the reverse osmosis concentrate because it is effective at removing the organic load and nitrogen-containing species. Additionally, this process potentiates the increase in the biodegradability index of the treated effluent.
传统的卫生填埋渗滤液处理方法近来得到了补充，在某些情况下，还被反渗透技术完全取代。尽管处理后的水质良好，但该工艺效率较低，大量反渗透浓缩液必须排放或进一步处理。在本研究中，评估了采用阳极氧化结合电芬顿工艺处理卫生填埋渗滤液反渗透过程中产生的浓缩液。阳极氧化预处理在中试装置中进行，使用带有硼掺杂金刚石电极的电化学电池。在电芬顿实验中，使用硼掺杂金刚石阳极和碳毡阴极，并研究了初始pH值和铁浓度的影响。对于实验条件，在初始pH值为3时进行的电芬顿试验具有更高的有机负荷去除水平，而当电化学过程在自然pH值8.8下进行时，氮去除效果最佳。铁浓度的增加在自然pH条件下对处理有不利影响，但在初始pH值为3时进行的电芬顿试验中提高了氮去除率。阳极氧化和电芬顿联合工艺可有效去除有机负荷和含氮物质，因此对处理反渗透浓缩液很有用。此外，该工艺还能提高处理后出水的生物降解性指数。
