scholarly journals Removal of 4-chlorophenol from polluted water by aluminum–iron alloys

2019 ◽  
Vol 80 (6) ◽  
pp. 1099-1106
Author(s):  
Shangze Wu ◽  
Ka Tang ◽  
Jingqi Zhang ◽  
Xi Chen ◽  
Hanjun Hu ◽  
...  
Keyword(s):  
Chemical Degradation ◽  
Polluted Water ◽  
Biological Degradation ◽  
Mass Ratio ◽  
Wastewater Remediation ◽  
Promising Strategy ◽  
Initial Ph ◽  
Aeration Conditions ◽  
Water And Wastewater ◽  
In The Beginning

Abstract Chlorophenols are extremely toxic to the environment and recalcitrant to biological degradation. Herein chemical degradation of 4-chlorophenol (4-CP) from aqueous solutions by zero-valent aluminum (Al), zero-valent iron (Fe), Al and Fe mixtures (Al/Fe mass ratio 90/10, labeled as Al/Fe10) and Al-Fe alloy (Al/Fe mass ratio 90/10, labeled as Al-Fe10) were investigated. No removal was found for 50 mg·L−1 4-CP under anoxic conditions at initial pH 2.5 during a period of 10 hrs while 56%, 83%, 78% and 99% of 4-CP were removed by Fe, Al, Al/Fe10 and Al-Fe10, respectively under aeration conditions. The removal of 4-CP by Al/Fe10 mixtures was primarily in the Fe mode in the beginning 4 h and then transitioned to the Al mode. The removal of 4-CP by Al-Fe10 alloy was accomplished via two intermediate products, hydroquinone (HQ) and 4-chlorocatechol (4-CC), and it was speculated that reactive oxygen species and hydroxyl radicals (·OH) play an important role in the degradation of 4-CP and that Al-Fe intermetallic compounds might catalyze the reactions. This study demonstrates that alloying Al with Fe offers a promising strategy for developing new materials for water and wastewater remediation.

Chitosan-based Magnetic Composites - Efficient Adsorbents for Removal of Pb(II) and Cu(II) from Aqueous Mono and Bicomponent Solutions

2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Chemical Properties ◽  
Order Kinetic ◽  
Mass Ratio ◽  
Magnetic Adsorbent ◽  
Magnetic Composites ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Physical And Chemical

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.

Visible-Light Degradation of 2-Chlorophenol by TiO2 doped with Neighboring Transition Metal Cerium via Various Approaches and Operation Parameters

2021 ◽  
Author(s):  
Justin Chun Te Lin ◽  
Nolan C. Tolosa ◽  
Khajornsak Sopajaree ◽  
Anusorn Gongglom ◽  
Thidarat Jitjanesuwan ◽  
...  
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Lower Energy ◽  
Critical Parameter ◽  
Operational Conditions ◽  
Calcination Temperatures ◽  
Initial Ph ◽  
Operation Parameters ◽  
Visible Light Degradation ◽  
In The Beginning

Abstract TiO2-related materials or processes for 2-chlorophenol (2-CP) degradation either under UV or visible light irradiations with key operational conditions was systematically reviewed in the beginning of this study. Cerium (Ce), which was neighboring transition metal elements of titanium (Ti), were individually doped with TiO2 via various methods. Three synthetic parameters in the two approaches were examined their significance by using experimental designs. It was found that the 2-CP can be 100% removal within 4-h irradiation by visible light in the synthetic condition of 0.35 mol.% Ce, 0.15 vol.% nitric acid and calcined at 600oC. Moreover, effects of three operation parameters of the as-prepared catalysts were further investigated. The most efficient condition obtained was 3 g·L− 1 catalysts at initial pH and 2-CP concentration of 7 and 10 mg·L− 1, respectively. A critical parameter, pHpzc of undoped and Ce-doped TiO2, were also determined. In addition, surface area, pore volume and size of both TiO2–based catalysts were found affected by the calcination temperatures and consequently degradation efficiency. The presenting results and mini-review were facilitated the development and applications of TiO2 in the degradation of 2-CP under lower energy radiations.

scholarly journals Spinel Ferrite Based Nanomaterials for Water Remediation Application

2021 ◽  
pp. 218-245
Author(s):  
R. Jasrotia
Keyword(s):  
Wastewater Treatment ◽  
New Technologies ◽  
Spinel Ferrite ◽  
Cost Effective ◽  
Spinel Ferrites ◽  
Water Remediation ◽  
Polluted Water ◽  
Wastewater Remediation ◽  
Inorganic Pollutants

The decreasing levels of consumable water on earth have been a serious issue and this issue makes the researchers and scientists develop new technologies for the purification of polluted water. Several reports have been carried on wastewater remediation by utilizing spinel ferrite-based nanoparticles and their composites. The spinel ferrites-based nanoparticles utilized for wastewater treatment was cost effective, chemically stable, easily retrieved and reusable. The present work addresses the various fabrication techniques for the preparation of spinel ferrite-based nanoparticles and their utilization for the removal of organic and inorganic pollutants through the adsorption paths.

Nanomaterial Surface Modifications for Enhancement of the Pollutant Adsorption From Wastewater

2019 ◽  
pp. 143-170 ◽  
Author(s):  
Hamidreza Sadegh ◽  
Gomaa A. M. Ali ◽  
Hamid Jafari Nia ◽  
Zahra Mahmoodi
Keyword(s):  
Membrane Filtration ◽  
Organic Dyes ◽  
Low Cost ◽  
Aquatic Organisms ◽  
Chemical Degradation ◽  
Photochemical Degradation ◽  
Dye Wastewater ◽  
Biological Degradation ◽  
Operation Costs ◽  
Global Concern

With the development of dyeing, textile, leather, paper, and other chemical industries, an increasing amount of dye wastewater containing refractory organic dyes is discharged. Undoubtedly, much high content dye wastewater will lead to serious environmental issues such as color pollution, light penetration interference, and virulence to aquatic organisms, even endanger human health. Therefore, it is an imminent problem and has become a global concern to degrade dye wastewater efficiently. So far, many techniques have been used to degrade dyeing wastewater, such as chemical degradation, biological degradation, photochemical degradation, coagulation, membrane filtration, and combined methods. These methods have certain impacts on the degradation of dye wastewater, but usually with slow degradation rate, complex and high operation costs, as well as easily causing secondary pollution. The adsorption process is a simple, effective, and low-cost way to remove dyes.

Mechanism of radiation purification of polluted water and wastewater

2001 ◽  
Vol 44 (5) ◽  
pp. 131-139 ◽  
Author(s):  
A.K. Pikaev
Keyword(s):  
Municipal Wastewater ◽  
Paper Mill ◽  
Petroleum Products ◽  
Polluted Water ◽  
Water Radiolysis ◽  
Primary Products ◽  
Removal Of Heavy Metals ◽  
Water And Wastewater ◽  
Cadmium Lead

The paper summarizes the results of the studies on radiation purification of polluted water and wastewater conducted in the author's laboratory in cooperation with other institutions. The removal of heavy metals (cadmium, lead, chromium and mercury) from water and wastewater, the purification of wastewater from surfactant and petroleum products, molasses distillery slops, municipal wastewater in the aerosol flow, river water from colored natural organic pollutants, wastewater of dyeing complex and paper mill, the decomposition of some dyes, hydrogen peroxide, chlorine-containing organic compounds, formic acid, etc. were investigated in detail. As a rule, electron-beam treatment in combination with ordinary methods (biological, coagulation, adsorption, flotation, etc.) was used. The main attention is paid to the mechanism of purification of the studied systems. The role of redox reactions of primary products of water radiolysis and secondary short-lived species formed from pollutants, formation of precipitates capturing the pollutants etc. is discussed.

Synergetic Degradation of Zidovudine Wastewater by Ultrasonic and Iron-Carbon Micro-Electrolysis

2011 ◽  
Vol 347-353 ◽  
pp. 1949-1952 ◽  
Author(s):  
Liang Li ◽  
Bing Zhe Xu ◽  
Chang Yu Lin ◽  
Xiao Min Hu
Keyword(s):  
Reaction Time ◽  
Degradation Rate ◽  
Removal Rate ◽  
Cod Removal ◽  
Mass Ratio ◽  
Initial Ph ◽  
Cod Removal Rate

Zidovudine wastewater is difficult to biodegradation due to high COD and toxicity. The synergetic treatment of Zidovudine wastewater by Ultrasonic and iron-carbon micro-electrolysis technology was studied. The influence of initial pH, reaction time, mass ratio of iron and carbon and mass ratio of iron and water on degradation rate of COD was researched. The result showed that the COD removal rate was only about 54.3% and the degradation speed is very slow when iron-carbon micro-electrolysis treated Zidovudine wastewater　separately. However, when ultrasonic synergy micro-electrolysis to treat Zidovudine wastewater, the COD removal rate could was up to 85% and the reaction time was also decreased. Moreover, the BOD5 / COD rose from 0.15 to 0.35, which meant the wastewater became easily biodegradable.

scholarly journals The comparison of efficiency of Fenton and photo-Fenton treatment of stabilised landfill leachate / Porównanie efektywności oczyszczania odcieków z ustabilizowanego składowiska odpadów komunalnych w procesie Fentona i foto-Fentona

2015 ◽  
Vol 26 (3) ◽  
pp. 49-53 ◽  
Author(s):  
Anna Kwarciak-Kozłowska ◽  
Aleksandra Krzywicka
Keyword(s):  
Landfill Leachate ◽  
Fenton Reaction ◽  
Ferrous Sulphate ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Ammonia Removal ◽  
Mass Ratio ◽  
Leachate Treatment ◽  
Initial Ph ◽  
Removal Efficiencies

Abstract The goal of this article was to compare the efficiency of Fenton and photo-Fenton reaction used for stabilised landfill leachate treatment. The mass ratio of COD:H2O2 was fixed to 1:2 for every stages. The dose of reagents (ferrous sulphate/hydrogen peroxide) was different and ranged from 0.1 to 0.5. To determine the efficiency of treatment, the BOD (biochemical oxygen demand COD (chemical oxygen demand), TOC (total organic carbon) , ammonia nitrogen and BOD/COD ratio was measured. The experiment was carried out under the following conditions: temperature was 25ºC, the initial pH was adjusted to 3.0. Every processes were lasting 60 minutes. The most appropriate dose of reagents was 0.25 (Fe2+/H2O2). It was found that the application of UV contributed to increase of COD, TOC and ammonia removal efficiencies by an average of 14%.

Histamine and Tyramine Production by a Lactobacillus Strain Subjected to External pH Decrease

1994 ◽  
Vol 57 (3) ◽  
pp. 259-262 ◽  
Author(s):  
RIITTA MAIJALA
Keyword(s):  
Lactic Acid ◽  
Room Temperature ◽  
Lactobacillus Strain ◽  
Ph Values ◽  
Initial Ph ◽  
Ph Decrease ◽  
In The Beginning ◽  
Influence Of Ph ◽  
External Ph ◽  
Made In

The preservative effect of fermentation is based on the pH decrease during processing. However, most studies conceming the influence of pH on the formation of biogenic amines have been made in broths with different initial pH values. A histamine- and tyramine-positive Lactobacillus strain isolated from dry sausage was added at an initial level of 3.9- to 4.4-logl0 CFU/ml and incubated on a shaker at room temperature (20.0°C) for 6 days. The pH was decreased in histidine- or tyrosine-fortified MRS broth by adding glucono-delta-lactone (GDL) or lactic acid during the incubation. The external acidification decreased the growth and the production of histamine and tyramine by the strain. GDL was more effective as a preventative than lactic acid. According to these results, a rapid pH decrease resulting in decreased growth of amine-positive lactic acid bacteria in the beginning of fermentation may be a means of preventing the formation of high levels of amines in foods.

Optimization of ultrasonic-assisted copper ion removal from polluted water by a natural clinoptilolite nanostructure through a central composite design

Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 339-347 ◽  
Author(s):  
Mohsen Sheydaei ◽  
Ali Balanejad Gasemsoltanlu ◽  
Asadollah Beiraghi
Keyword(s):  
Ftir Spectroscopy ◽  
Polluted Water ◽  
Sonication Time ◽  
X Ray ◽  
Ion Removal ◽  
Initial Ph ◽  
Ultrasonic Assisted ◽  
Natural Clinoptilolite ◽  
Adsorption Desorption ◽  
Central Composite

AbstractA natural clinoptilolite nanostructure (CNS) along with ultrasonic irradiation was used to remove Cu2+ ions from polluted water. In the first part of this work, natural clinoptilolite was converted to CNS by ball milling. The natural clinoptilolite and prepared CNS samples were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction, N2 adsorption/desorption and pH at the point of zero charge analyses. The SEM images showed the development of CNS from natural clinoptilolite by ball milling. The N2 adsorption/desorption and FTIR spectroscopy confirmed the greater specific surface area, pore volume and number of surface groups of the CNS compared to the natural clinoptilolite. In addition, the crystalline phase of the CNS was the same as the natural clinoptilolite. In the second part of this work, the ultrasonic-assisted sorption of Cu2+ ions from polluted water by CNS was investigated. These experiments were optimized with response surface methodology based on central composite designs. The effects of initial pH of solution, CNS dosage, sonication time and temperature on Cu2+ ion-removal efficiency were investigated. By using a CNS dosage of 500 mg L−1, an initial pH of 6, a sonication time of 12 min and a sonication temperature of 45°C as optimal conditions, 97% of Cu2+ ions were removed from contaminated water. The initial pH was the most effective variable. Ultrasonic-assisted sorption of Cu2+ was more effective than sorption alone, onto the CNS.

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