Fenton-Like Catalysis and Oxidation/Adsorption Performances of Acetaminophen and Arsenic Pollutants in Water on a Multimetal Cu–Zn–Fe-LDH

Abstract

Acetaminophen can increase the risk of arsenic-mediated hepatic oxidative damage; therefore, the decontamination of water polluted with coexisting acetaminophen and arsenic gives rise to new challenges for the purification of drinking water. In this work, a three-metal layered double hydroxide, namely, Cu-Zn-Fe-LDH, was synthesized and applied as a heterogeneous Fenton-like oxidation catalyst and adsorbent to simultaneously remove acetaminophen (Paracetamol, PR) and arsenic. The results showed that the degradation of acetaminophen was accelerated with decreasing pH or increasing H2O2 concentrations. Under the conditions of a catalyst dosage of 0.5 g·L(-1) and a H2O2 concentration of 30 mmol·L(-1), the acetaminophen in a water sample was completely degraded within 24 h by a Fenton-like reaction. The synthesized Cu-Zn-Fe-LDH also exhibited a high efficiency for arsenate removal from aqueous solutions, with a calculated maximum adsorption capacity of 126.13 mg·g(-1). In the presence of hydrogen peroxide, the more toxic arsenite can be gradually oxidized into arsenate and adsorbed at the same time by Cu-Zn-Fe-LDH. For simulated water samples with coexisting arsenic and acetaminophen pollutants, after treatment with Cu-Zn-Fe-LDH and H2O2, the residual arsenic concentration in water was less than 10 μg·L(-1), and acetaminophen was not detected in the solution. These results indicate that the obtained Cu-Zn-Fe-LDH is an efficient material for the decontamination of combined acetaminophen and arsenic pollution.

The Sonophotocatalytic Degradation of Pharmaceuticals in Water by MnOx-TiO2 Systems with Tuned Band-Gaps

“…A high concentration of Mn provokes the recombination of electron-hole pairs, which is due to the induced lattice defects [40,56]. In a photocatalyst, when Mn 2+ traps electrons, its electronic configuration changes from 3d 5 to 3d 6 , (Equation (1)) and when it traps holes its electronic configuration changes to 3d 4 (Equation 3). Both states are unstable, and to restore its stable configuration, Mn donates the trapped electron to an oxygen molecule (Equation 2) and the trapped hole to the water adsorbed onto the surface (Equation (4)) to generate superoxide (O2 − ) and hydroxyl (OH • ) radicals, respectively:…”

“…Water quality is a gargantuan socio-economic issue [1,2]. Improper disposal of drugs, illicit discharge during manufacturing, and the direct or indirect releases by humans and animals are the leading causes of water contamination [3,4]. Micropollutants damage the ecosystem even in the ng L −1 to µg L −1 range, which is enough to interfere with the endocrine systems of complex organisms and to induce their microbiological resistance.…”

“…Antibiotics, anti-inflammatories, hormones, blood lipid regulators, analgesics, and many other recalcitrant pharmaceuticals pollute water in the g L −1 orders of magnitude [7]. Acetaminophen (APAP) and amoxicillin (AMO) are the most prescribed analgesics and antibiotics worldwide, respectively [4,8]. APAP's concentration in several treatment plant effluents is higher than 200 µg L −1 , which is sufficient to cause liver-related pathologies and other severe ailments [9][10][11][12].…”

Simultaneous adsorption study of ammonium and phosphate by ZnFe-layered double hydroxide (ZnFe-LDH)-modified adsorbents.

“…The stunning affinity to phosphate due to the weak interlayer bonding makes LDHs a promising adsorbent in wastewater purification [20][21][22]. Researchers have proved that ZnFe(III)-based oxides/hydroxides own tremendous capacity for oxyanions scavenge [23][24][25][26]. Also, a screening study proposed that Cl − as the exchangeable anions better benefited the LDH adsorption performance than other intercalated substances [27].…”

Fenton-like Catalytic Performance of CuFe-LDH for Degradation of Florfenicol

“…The cycle of valence change of iron or copper may be produced on the surface of CuFe-LDH, and in this process possibly generates free radicals with strong oxidation ability. It has been pointed out in previous literatures that the HO-Cu 2+ -OH in the hydrotalcite might be the catalytic center of reaction [5], HO· is likely to be produced by H 2 O 2 redox reaction via HO-Cu 2+ -OH. The possible reaction pathways of florfenicol in this Fenton-like catalyzed oxidation include: (1) the additive reaction of hydroxyl on benzene ring; (2) the substitution reaction of hydroxyl to fluorine atom; (3) the scission reaction on the side chain.…”