scholarly journals Photocatalytic abatement of emerging pollutants in pure water and wastewater effluent by TiO2 and Ce-ZnO: degradation kinetics and assessment of transformation products

2019 ◽  
Vol 18 (4) ◽  
pp. 845-852 ◽  
Author(s):  
Debora Fabbri ◽  
María José López-Muñoz ◽  
Alessandro Daniele ◽  
Claudio Medana ◽  
Paola Calza
Keyword(s):  
Removal Efficiency ◽  
Emerging Contaminants ◽  
Degradation Kinetics ◽  
Pure Water ◽  
Transformation Products ◽  
Emerging Pollutants ◽  
Wastewater Effluent ◽  
Transient Transformation ◽  
Water And Wastewater

A good removal efficiency was obtained for a mixture of seven emerging contaminants in wastewater effluent using two catalysts, Ce-ZnO and TiO2-SG, as evidenced by the formation of several transient transformation products.

scholarly journals Removal of Emerging Pollutants from Water Using Environmentally Friendly Processes: Photocatalysts Preparation, Characterization, Intermediates Identification and Toxicity Assessment

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215
Author(s):  
Nina Finčur ◽  
Paula Sfîrloagă ◽  
Predrag Putnik ◽  
Vesna Despotović ◽  
Marina Lazarević ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Sol Gel ◽  
Toxicity Assessment ◽  
Emerging Pollutants ◽  
Simulated Sunlight ◽  
Aquatic Life ◽  
Mgo Nanoparticles ◽  
Emerging Pollutant ◽  
Wheat Germination ◽  
Modern Technologies

Pharmaceuticals and pesticides are emerging contaminants problematic in the aquatic environment because of their adverse effects on aquatic life and humans. In order to remove them from water, photocatalysis is one of the most modern technologies to be used. First, newly synthesized photocatalysts were successfully prepared using a sol–gel method and characterized by different techniques (XRD, FTIR, UV/Vis, BET and SEM/EDX). The photocatalytic properties of TiO2, ZnO and MgO nanoparticles were examined according to their removal from water for two antibiotics (ciprofloxacin and ceftriaxone) and two herbicides (tembotrione and fluroxypyr) exposed to UV/simulated sunlight (SS). TiO2 proved to be the most efficient nanopowder under UV and SS. Addition of (NH4)2S2O8 led to the faster removal of both antibiotics and herbicide fluroxypyr. The main intermediates were separated and identified for the herbicides and antibiotic ciprofloxacin. Finally, the toxicity of each emerging pollutant mixture and formed intermediates was assessed on wheat germination and biomass production.

scholarly journals Synthesis, characteristics, and photocatalytic activity of zinc oxide nanoparticles stabilized on the stone surface for degradation of metronidazole from aqueous solution

2021 ◽  
Vol 8 (1) ◽  
pp. 55-63
Author(s):  
Amir Nasser Alibeigi ◽  
Neda Javid ◽  
Majid Amiri Gharaghani ◽  
Zhila Honarmandrad ◽  
Fatemeh Parsaie
Keyword(s):  
Zinc Oxide ◽  
Removal Efficiency ◽  
Zno Nanoparticles ◽  
Advanced Oxidation Process ◽  
Degradation Kinetics ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Thermal Method ◽  
Average Crystalline Size ◽  
Stone Surface

Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level of pollutants to a standard level in water. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4 ) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the stone surface were investigated. Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV. The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2 /g. The EDS spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum removal efficiency was 98.36% for the synthetic solution under a specific condition (pH = 11, reaction time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10 mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics. Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and effective photocatalytic materials for degradation of pharmaceutical contaminants.

scholarly journals Emerging contaminants : a tutorial mini-review

2013 ◽  
Vol 14 (1) ◽  
pp. 72-79 ◽  
Keyword(s):  
Emerging Contaminants ◽  
Residue Analysis ◽  
Sewage Treatment ◽  
Emerging Pollutants ◽  
Environmental Issue ◽  
Published Data ◽  
Aquatic Environments ◽  
Contamination Source ◽  
Toxicological Effects ◽  
Reliable Methods

Nowadays, the scientific community has focused and prioritised research on “emerging pollutants”. The term “emerging pollutants” stands for the substances that are released in the environment for which currently no regulations are established for their environmental monitoring. Their occurrence is reported worldwide in a range of aquatic environments, such as lakes, rivers, freshwater catchments, estuaries, reservoirs and marine waters. Nevertheless, due to their large number (ranging in an order of thousands), only few of these compounds are toxicologically evaluated. Published data concerning occurrence and potential toxicological effects is limited. The contamination source of the aquatic environment is mainly the effluents from the sewage treatment plants (STPs). Reliable methods are available for residue analysis of these pollutants down to low ng L-1 levels. However, an urgent need is highlighted for the investigation (primarily in environmental media and following in biological ones) of the toxicity and transformation pathways of all emerging pollutants. The aims of this mini-review are to briefly present: (a) the major classes of emerging pollutants; (b) the reasons why these substances constitute an environmental issue; and (c) developments and applications of environmental analysis in this field.

scholarly journals Photo-transformation of aqueous nitroguanidine and 3-nitro-1,2,4-triazol-5-one : emerging munitions compounds

2021 ◽  
Author(s):  
Julie Becher ◽  
Samuel Beal ◽  
Susan Taylor ◽  
Katerina Dontsova ◽  
Dean Wilcox
Keyword(s):  
Aqueous Solutions ◽  
Degradation Products ◽  
Pure Water ◽  
Transformation Products ◽  
Water Soluble ◽  
Uv Exposure ◽  
Degradation Pathways ◽  
Solution Ph ◽  
Photo Degradation ◽  
Degradation Rates

Two major components of insensitive munition formulations, nitroguanidine (NQ) and 3-nitro-1,2,4-triazol-5-one (NTO), are highly water soluble and therefore likely to photo-transform while in solution in the environment. The ecotoxicities of NQ and NTO solutions are known to increase with UV exposure, but a detailed accounting of aqueous degradation rates, products, and pathways under different exposure wavelengths is currently lacking. We irradiated aqueous solutions of NQ and NTO over a 32-h period at three ultraviolet wavelengths and analyzed their degradation rates and transformation products. NQ was completely degraded by 30 min at 254 nm and by 4 h at 300 nm, but it was only 10% degraded after 32 h at 350 nm. Mass recoveries of NQ and its transformation products were >80% for all three wavelengths. NTO degradation was greatest at 300 nm with 3% remaining after 32 h, followed by 254 nm (7% remaining) and 350 nm (20% remaining). Mass recoveries of NTO and its transformation products were high for the first 8 h but decreased to 22–48% by 32 h. Environmental half-lives of NQ and NTO in pure water were estimated as 4 and 6 days, respectively. We propose photo-degradation pathways for NQ and NTO supported by observed and quantified degradation products and changes in solution pH.

Removal of Emerging Contaminants from Water and Wastewater Using Nanofiltration Technology

2016 ◽  
pp. 72-91
Author(s):  
Yang Hu ◽  
Yue Peng ◽  
Wen Liu ◽  
Dongye Zhao ◽  
Jie Fu
Keyword(s):  
Membrane Filtration ◽  
Water Distribution ◽  
Emerging Contaminants ◽  
Low Cost ◽  
Distribution Networks ◽  
Comprehensive Overview ◽  
Environmental Cleaning ◽  
Promising Tool ◽  
Drinking Water Distribution ◽  
Water And Wastewater

Conventional water/wastewater treatment methods are incapable of removing the majority of Emerging Contaminants (ECs) and a large amount of them and their metabolites are ultimately released to the aquatic environment or drinking water distribution networks. Recently, nanofiltration, a high pressure membrane filtration process, has shown to be superior to other conventional filtration methods, in terms of effluent quality, easy operation and maintenance procedures, low cost, and small required operational space. This chapter provides a comprehensive overview of the most relevant works available in literature reporting the use of nanofiltration for the removal of emerging contaminants from water and wastewater. The fundamental knowledge of nanofiltration such as separation mechanisms, characterization of nanofiltration membranes, and predictive modeling has also been introduced. The literature review has shown that nanofiltration is a promising tool to treat ECs in environmental cleaning and water purification processes.

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