Defect- and nitrogen-rich porous carbon embedded with Co NPs derived from self-assembled Co-ZIF-8 @ anionic polyacrylamide network as PMS activator for highly efficient removal of tetracycline hydrochloride from water

In the photocatalysis process, photon energy is mainly converted into chemical energy with the help of both light and catalyst. This process can be used in different applications like photocatalytic degradation of hazardous compounds, fixation of nitrogen, hydrogen production, air purification, water splitting, carbon dioxide reduction etc. In this research work, multiplicative ZnO and MoS2/ZnO (MZ) composites were synthesized using green chemical methods like the hydrothermal process and used in two different applications i) photocatalytic degradation of ciprofloxacin (CIP) antibiotic and ii) hydrogen production. CIP is not easily biodegradable and is mainly used in various antibacterial treatments. The photocatalytic activity was tested for ZnO and different MoS2/ZnO composites along with this the effect of different amounts of catalysts doses was studied. MoS2/ZnO composites exhibit superior photocatalytic performance than ZnO for photocatalytic degradation of CIP. Using the LC-MS technique possible degradation pathways are proposed. The same photocatalyst materials were used to test the photocatalytic H2 production activity. H2 production rates were found to be 22, 39 and 235 µmol/g/h for ZnO, MoS2 and MZ-30 composite respectively. Superior photocatalytic activity of MZ-30 composite than ZnO is chiefly attributed to the extended light absorption capacity, effective charge transfer, suitable band alignment between the ZnO and MoS2, minimum recombination of charge carriers etc. 

Visible light activated MoS2/ZnO composites for photocatalytic degradation of ciprofloxacin antibiotic and hydrogen production

Industrial and hospital effluents are often dumped into water streams. Since these effluents consist of higher concentrations of pharmaceutical residues, they are difficult to eliminate using conventional wastewater treatment plants (WWTP) and are hazardous to humans and the environment. In contrast, biological treatment of wastewater is an environmentally friendly method that forms less sludge and is relatively inexpensive. However, like WWTP, biological treatment is less efficient in eliminating pharmaceutical residue from wastewater. Therefore, several other treatment options have been investigated globally, e.g., electro-Fenton (EF), and processes such as photocatalytic oxidation (PCO). Among them, the advanced oxidation processes, such as the Fenton process, were found to be comparatively more effective at the removal of pharmaceutical residues and have gained the continued attention of researchers. However, a primary disadvantage of the Fenton process is its significantly high energy consumption that makes its large-scale deployment cost-prohibitive. To overcome this challenge, several integrated treatments have been proposed by many scientific communities. This paper intends to review the available literature to explore the remediation of pharmaceutical wastewater using different versions of the Fenton oxidation process and finds that the integration of the Fenton's oxidation process with a biological process results in the complete degradation of the pharmaceutical residue in wastewater.

New insights into the integrated application of Fenton-based oxidation processes for the treatment of pharmaceutical wastewater

Coupled adsorption and photocatalysis of g-C3N4 based composites: Material synthesis, mechanism, and environmental applications

Zeolite-based Fenton-like catalysis for pollutant removal and reclamation from wastewater

Herein, a novel hexapod-like pyrite nanosheets mineral cluster was prepared via a facile hydrothermal method. Compared with classical homogeneous Fenton processes, this catalyst possessed a higher adsorption capacity and catalytic activity to ciprofloxacin (20 mg/L), which could be completely degraded within 10 min at pH 4.0. •OH was the main reactive oxygen species responsible for ciprofloxacin degradation. Br− (≥ 1 mM), I− (≥ 1 mM), and high concentration of F− ions (≥ 10 mM) exhibited an inhibition effect on ciprofloxacin degradation, but the Cl− ions (0–100 mM) did not show obvious effects on ciprofloxacin removal. Thirteen intermediates were qualitatively identified, and degradation mechanism was tentatively proposed for ciprofloxacin. Several toxic intermediates were produced, but they could be fully mineralized and detoxified by this heterogeneous Fenton catalyst after 30 min reaction. The work provides a novel heterogeneous Fenton catalyst to purify and detoxify antibiotics as well as other refractory organic pollutants contaminated wastewater.

Highly efficient adsorption and catalytic degradation of ciprofloxacin by a novel heterogeneous Fenton catalyst of hexapod-like pyrite nanosheets mineral clusters

Shanshan Li

Papers

Highly efficient adsorption and catalytic degradation of ciprofloxacin by a novel heterogeneous Fenton catalyst of hexapod-like pyrite nanosheets mineral clusters