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In this work, Ag nanoparticles were loaded on ZIF-67 covered by graphene oxide (Ag/ZIF-67@ GO), and its catalytic performance was studied for the heterogeneous activation of peroxymonosulfate (PMS) under visible-light. The catalyst surface morphology and structure were analyzed by FT-IR, XRD, XPS, DRS, FE-SEM, EDX, TEM, BET, ICP-AES and TGA analysis. The efficacy of PMS activation by the Ag/ZIF-67@ GO under visible light was assessed by phenol degradation and E. coli inactivation. Phenol was completely degraded within 30 min by HO•, SO 4•− and O 2•− generated through the photocatalytic PMS activation. In addition, total E. coli inactivation was attained in 15 min that confirmed the highly efficient catalytic activation of PMS by t
The toxic effects of heavy metals in landfill soils have become a significant concern for human health. The present study aimed to estimate the health and ecological risk associated with soil heavy metal in Tehran landfill. A total of 48 soil samples were taken from the landfill and residential area and were analyzed using inductively coupled plasma-optical emission spectroscopy. The results showed the following order for heavy metal levels in landfill soil: Al > Fe > Mn > Zn > Cr > Cu > Pb > Ni > Co > As > Cd. The investigated ecological indices showed moderate to high heavy metal pollution. The principal component analysis revealed that the concentration of Pb, Cu, Zn, Cr, and Ni in the investigated soil was mainly affected by anthropogen
In this work, novel magnetic Fe 3 O 4@ CeO 2@ BiOI nanospheres were synthesized for the heterogeneous photocatalytic activation of peroxymonosulfate (PMS) towards sulfamethoxazole (SMX) degradation. The phase purity, morphology, and surface properties of the nanocomposite were fully characterized and confirmed the formation of a heterojunction between the magnetic Fe 3 O 4@ CeO 2 and BiOI. Low catalyst (0.1 g/L) and PMS addition (0.2 mM) under UVA-LED light irradiation led to high catalytic activity in SMX degradation (97%, k app= 0.221 min-1) within 15 min. The highest quantum yield (QY) value (5.02? 10-4 molecules photon-1) was measured for the ternary Fe 3 O 4@ CeO 2@ BiOI nanocomposite, which is 3.54, 3.76, and 4.04 times higher than Fe
A new mesoporous Ag/ZnO@ NiFe 2 O 4 nanorod was prepared by a facile, low-cost, and environmentally friendly strategy from a bimetallic Fe 2 Ni-MIL-88 metal organic framework (MOF), as an effective catalyst and peroxymonosulfate (PMS) photo-activator. The structural, morphological, optical, and magnetic properties, as well as the material composition were investigated by XRD, FE-SEM, EDX, HR-TEM, XPS, DRS, PL, EIS, VSM, N 2 adsorption-desorption and ICP-AES analysis. 1.0% w/w loading of Ag nanoparticles on ZnO 0.04@ NiFe 2 O 4 led to the best catalytic activity for PMS activation under UVA in acetaminophen (ACT) degradation. The maximum degradation efficiency for ACT was 100% within 15 min (at pH= 7.0), with a first-order rate constant of 0
This work demonstrates a highly efficient photocatalytic reduction of Cr (VI) to Cr (III) by using a AgI/CeO 2@ gC 3 N 4 nanocomposite, under visible light (Vis) irradiation. The as-prepared samples were characterized by FT-IR, XRD, FE-SEM, TEM, XPS, DRS, PL, PC, and BET. Optimization of the treatment conditions included systematic parameterization, such as initial solution pH, photocatalyst dosage, and Cr (VI) concentration were investigated in the reaction. Compared with pure gC 3 N 4, CeO 2, AgI, and CeO 2@ gC 3 N 4 binary nanocomposite, the as-made AgI/CeO 2@ gC 3 N 4 ternary nanocomposite showed significantly higher photo-reduction efficiency. The ternary photocatalyst shows a 99.6% reduction efficiency for Cr (VI)(15 mg/L) within 75 m
Ag-doped S-MgO powder was synthesized by doping of S-MgO with Ag and its photocatalytic activity was investigated under UVA-LED light irradiation for diclofenac (DCF) degradation. The S-MgO doped with 1 mol% of Ag showed the highest photocatalytic activity under UVA irradiation. The Ag-doped S-MgO was nanosphere with a band gap of 2.20 eV and the surface defects. Introducing Ag in the lattice of S-MgO accelerated the charge transfer and thus its photocatalytic activity. Complete degradation of 50 mg/L DCF was achieved via non-radical singlet oxygen mechanism within 15 min in the UVA/LED photocatalytic process with Ag-doped S-MgO in natural pH. In addition, 86% of DCF was mineralized within 60 min in the process. Reusability of the
Biotrickling filters (BTFs) applied to hydrophobic volatile organic compounds (VOCs) suffer from limited mass transfer. Phase transfer kinetic and equilibrium effects limit the biodegradation of hydrophobic VOCs especially at high concentrations. This study evaluates two strategies for overcoming the problem. First, a natural process was used to enhance the aqueous availability of styrene, a hydrophobic VOC model, by inoculating the BTF with a mixture of biosurfactant–generating bacteria. This method achieved a maximum elimination capacity (ECmax) of 139?g?m-3h−1 in the BTF at an empty bed residence time (EBRT) of 60s. The highest concentrations of the biosurfactants surfactin and rhamnolipid were 205 and 86?mg L-1, respectively, in thi
In this study, benzene was selected as an indicator of VOCs, and a modeling procedure was carried out on benzene removal (outflow concentration of benzene, C/inflow concentration of benzene, C0), in DC and AC non-thermal plasma systems. Different diameters (18, 23, and 36?mm) of wire-tube plasma reactors were prepared, and models were raised based on the results of experiments with influencing factors of the used voltage, gap size inside the reactor, current density, and specific energy. The results showed correlation between the factors and benzene removal in both DC and AC discharge non-thermal plasma. The applied voltage as an electrical factor had negative correlation with C/C0, and the correlation was stronger than for gap size which
The present study presents a highly efficient, visible light-induced photocatalytic degradation of Bisphenol A (BPA) by a CuO/Fe2O3/ZnO composite, synthesized using a sol-gel combustion method. The catalyst was characterized by XRD, SEM, BET, EDX, DRS, TEM, and XPS techniques. The synthesized CuO/Fe2O3/ZnO catalyst was found to perform optimally at neutral pH and 0.04 g/L catalyst dosage, while H2O2 addition initiated further radical degradation pathways. HCO3- and NO3- in the water had a negative effect on BPA degradation, but SO42-, Cl- and PO43- demonstrated a significant increase in reaction kinetics, thus allowing a real-water application. Radical scavenger tests revealed that hydroxyl radicals and holes play the main role in BPA degra
Background & Objectives: One of the most important problems facing the water treatment plants is seasonal turbidity removal from the drinking surface waters. In this work, the efficiency of turbidity removal from water surface has been studied using a batch rotary reactor model and electrocoagulation process and different electrodes including iron and aluminum were tested. Finally, the optimum values of the studied parameters were evaluated at different operating conditions.Methods: In order to eliminate the turbidity from drinking water, the discontinuous rotary reactor model with monopolar electrodes was used in parallel connection. The sample volume in the experiments was 377 liters, and the rotation of the model caused all fluid particl