UPIIG, del Instituto Politécnico Nacional, Guanajuato 36275, Mexico.
Politécnico Colombiano Jaime Isaza Cadavid, Medellín 4932, Colombia.
Molecules. 2021 Nov 17;26(22):6918. doi: 10.3390/molecules26226918.
Some nitroaromatic compounds are found in wastewater from industries such as the weapons industry or the wine industry. One of these compounds is 3,5-dinitrosalicylic acid (DNS), widely used in various tests and frequently found as an emerging pollutant in wastewater and to which the required attention has not been given, even though it may cause serious diseases due to its high toxicity. This study investigated the adsorption of DNS using granulated activated carbon (GAC) and powdered activated carbon (PAC) at different temperatures. The results show that in equilibrium, the adsorption takes place in more than one layer and is favorable for the removal of DNS in both GAC and PAC; The maximum adsorption capacity was obtained at 45 °C, with values of 6.97 mg/g and 11.57 mg/g, respectively. The process is spontaneous and exothermic. In addition, there was a greater disorder in the solid-liquid interface during the desorption process. The predominant kinetics using GAC (7.14 mg/g) as an adsorbent is Elovich, indicating that there are heterogeneous active sites, and when PAC (10.72 mg/g) is used, Pseudo-second order kinetics predominate, requiring two active sites for DNS removal. External mass transfer limitations are only significant in GAC, and ATR-FTIR studies in PAC demonstrated the participation of functional groups present on the adsorbent surface for DNS adsorption.
一些硝基芳香族化合物存在于工业废水，如武器工业或葡萄酒工业。其中一种化合物是 3,5-二硝基水杨酸（DNS），广泛应用于各种测试中，并且经常作为新兴污染物出现在废水中，但尚未引起足够重视，尽管它可能因其高毒性而导致严重疾病。本研究使用颗粒状活性炭（GAC）和粉末状活性炭（PAC）在不同温度下研究了 DNS 的吸附。结果表明，在平衡时，吸附发生在多层，有利于 GAC 和 PAC 中 DNS 的去除；最大吸附容量在 45°C 时获得，分别为 6.97mg/g 和 11.57mg/g。该过程是自发的和放热的。此外，在解吸过程中，固液界面存在更大的无序性。使用 GAC（7.14mg/g）作为吸附剂时，主要的动力学是 Elovich，表明存在非均相活性位，而当使用 PAC（10.72mg/g）时，拟二级动力学占主导地位，需要两个活性位来去除 DNS。外部传质限制仅在 GAC 中显著，并且 PAC 的 ATR-FTIR 研究表明，在 DNS 吸附过程中，吸附剂表面存在的官能团参与其中。
