Department of Earth and Environmental Studies, Montclair State University, Mallory Hall 252, 1 Normal Ave, Montclair, NJ 07043, USA.
Water Res. 2011 Nov 15;45(18):6189-94. doi: 10.1016/j.watres.2011.09.015. Epub 2011 Sep 21.
Typically, a mature landfill leachate contains high levels of non-biodegradable organics and ammonia nitrogen. Simultaneous removal of the both persistent leachate pollutants is a significant challenge. This paper reports the first scientific study to apply a sulfate radical (SO(4)(·-)) - based advanced oxidation process (SR-AOP) to treat a mature leachate, with an emphasis of concurrent removal of refractory organics and ammonia. In this study, all the experiments were run in a batch reactor with temperature control. In the thermal persulfate oxidation (TPO) process, persulfate (S(2)O(8)(2-)) was activated by heat to produce powerful oxidants, SO(4)(·-) (E(o) = 2.6 V). Three factors affecting the removal efficiencies of chemical oxygen demand (COD) and ammonia nitrogen were investigated, including initial solution pH (3-8.3), temperature (27-50 °C), and chemical dose (S(2)O(8)(2-):12COD(0) = 0.25-2.0). Typically, acidic pH (3-4), higher temperature, and higher dose favored the removal of COD and ammonia. At S(2)O(8)(2-):12COD(0) = 2 and 50 °C, the COD removal rates were 79% and 91% at pH 8.3 (no pH adjustment) and 4, respectively; and the ammonia nitrogen removal reached 100% at pH 8.3 or 4. SR-AOP appears to be more advantageous over hydroxyl radical (OH∙)-based advanced oxidation processes (HR-AOPs) because OH∙ almost does not oxidize ammonia. Furthermore, compared with Fenton treatment of the same batch leachate sample, the TPO could achieve a higher COD removal at an identical chemical dose. For example, COD removal was 40% at H(2)O(2):2.125COD(0) = 2 during Fenton treatment (pH 3), but 91% at S(2)O(8)(2-):12COD(0) = 2 during TPO (pH 4). These findings demonstrate that SR-AOP is a promising landfill leachate treatment method.
通常情况下，成熟的垃圾渗滤液中含有大量不可生物降解的有机物和氨氮。同时去除这两种持久性渗滤液污染物是一项重大挑战。本文报道了首例应用硫酸根自由基（SO(4)(·-)）基高级氧化工艺（SR-AOP）处理成熟渗滤液的科学研究，重点是同时去除难降解有机物和氨氮。在这项研究中，所有实验均在带有温度控制的批式反应器中进行。在热过硫酸盐氧化（TPO）过程中，过硫酸盐（S(2)O(8)(2-)）通过加热激活产生强氧化剂 SO(4)(·-)（E(o) = 2.6 V）。研究了三个影响化学需氧量（COD）和氨氮去除效率的因素，包括初始溶液 pH 值（3-8.3）、温度（27-50°C）和化学剂量（S(2)O(8)(2-)：12COD(0) = 0.25-2.0）。通常情况下，酸性 pH 值（3-4）、较高的温度和较高的剂量有利于 COD 和氨氮的去除。在 S(2)O(8)(2-)：12COD(0) = 2 和 50°C 时，pH 值为 8.3（无需 pH 调节）和 4 时的 COD 去除率分别为 79%和 91%；在 pH 值为 8.3 或 4 时，氨氮去除率达到 100%。与基于羟基自由基（OH∙）的高级氧化工艺（HR-AOPs）相比，SR-AOP 似乎更具优势，因为 OH∙几乎不氧化氨氮。此外，与相同批次渗滤液样品的芬顿处理相比，TPO 可以在相同的化学剂量下实现更高的 COD 去除率。例如，在芬顿处理（pH 3）时，H(2)O(2):2.125COD(0) = 2 时 COD 去除率为 40%，但在 TPO（pH 4）时 S(2)O(8)(2-)：12COD(0) = 2 时 COD 去除率为 91%。这些发现表明，SR-AOP 是一种很有前途的垃圾渗滤液处理方法。
