MCMA Group, Department of Inorganic Chemistry and Materials Institute (IUMA), University of Alicante, Ap. 99, E-03080 Alicante, Spain; Université Blida 1, Laboratoire de Chimie Physique des Interfaces des Matériaux Appliquées à l'Environnement, Faculté de Technologie, B.P. 270 Route de Soumaa, 09000 Blida, Algeria.
MCMA Group, Department of Inorganic Chemistry and Materials Institute (IUMA), University of Alicante, Ap. 99, E-03080 Alicante, Spain.
Environ Res. 2024 Jun 1;250:118510. doi: 10.1016/j.envres.2024.118510. Epub 2024 Feb 21.
The literature rarely compiles studies devoted to the removal of pollutants in aqueous media comparing adsorption and photocatalytic degradation, and does not pay enough attention to the analysis of combined adsorption-photocatalytic oxidation processes. In the present manuscript, the removal of malachite green (MG) from aqueous solutions has been investigated in three different sustainable scenarios: i) adsorption on activated carbon (AC) derived from a residue, luffa cylindrica, ii) photocatalytic oxidation under simulated solar light using titanium dioxide (TP) and iii) combined adsorption-photocatalytic oxidation using TP-AC (70/30 wt./wt.) under simulated solar light. The study has revealed that in the three scenarios and studied conditions, the total removal of this endocrine-disrupting dye from the solution takes place in the assayed time, 2 h, in some cases just in a few minutes. MG adsorption in the AC is a very fast and efficient removal method. MG photocatalytic oxidation with TP also occurs efficiently, although the oxidized MG is not totally mineralized. MG removal using the TP-AC composite under simulated solar light occurs only slightly faster to the MG adsorption in the AC, being adsorption the dominating MG removal mechanism for TP-AC. Thus, more than 90% of the removed MG with TP-AC under simulated solar light is adsorbed in this carbon-containing composite. The obtained results highlight the interest in adsorption, being the selection of the most suitable removal method dependent on several factors (i.e., the cost of the AC regeneration, for adsorption, or the toxicity of the intermediate oxidation species, for photooxidation). Paying attention to MG photooxidation with TiO, comparison of two working photodegradation schemes shows that the direct photodegradation of MG from solution, avoiding any initial dark equilibrium period, is more efficient from a time perspective. The use of scavengers has proved that MG photodegradation occurs via an oxidation mechanism dominated by superoxide anion radicals.
文献很少将比较吸附和光催化降解的用于去除水介质中污染物的研究汇编在一起，也没有充分关注联合吸附-光催化氧化过程的分析。在本手稿中，从三种不同的可持续情景研究了从水溶液中去除孔雀石绿（MG）：i）在活性炭（AC）上吸附，活性炭由丝瓜残留物制成，ii）在模拟太阳光下使用二氧化钛（TP）进行光催化氧化，iii）在模拟太阳光下使用 TP-AC（70/30wt./wt.）进行联合吸附-光催化氧化。研究表明，在三种情景和研究条件下，在规定的时间 2 小时内，溶液中的这种内分泌干扰染料的总去除率达到 100%，在某些情况下仅需几分钟。AC 上的 MG 吸附是一种非常快速有效的去除方法。TP 光催化氧化 MG 也能有效进行，尽管氧化的 MG 没有完全矿化。在模拟太阳光下使用 TP-AC 复合材料去除 MG 仅略快于在 AC 上的 MG 吸附，吸附是 TP-AC 去除 MG 的主要机制。因此，在模拟太阳光下使用 TP-AC 去除的 MG 中，有超过 90%被吸附在这种含碳复合材料上。所得结果强调了吸附的重要性，选择最合适的去除方法取决于多种因素（例如，AC 再生的成本，对于吸附而言，或中间氧化物种的毒性，对于光氧化而言）。关注 TiO 2 的 MG 光氧化，对两种工作光降解方案的比较表明，从时间角度来看，避免任何初始暗平衡期的直接从溶液中光降解 MG 更有效。清除剂的使用证明 MG 光降解是通过超氧阴离子自由基主导的氧化机制发生的。
