A review of chemical, electrochemical and biological methods for aqueous Cr(VI) reduction

Treatment of textile wastewater using titanium dioxide (TiO2) photocatalysis has been started from the last decade and reached attention to the researchers because of its versatile application. The variety of applications of TiO2 as a photocatalyst has been taken place because of low operating temperature, biologically inert nature, low energy consumption, water insolubility, ease availability and photoactivity, less toxicity, high chemical stability, suitable flat band potential, narrow band gap and environmentally benign. The successful and efficient application of photocatalysis depends on quality of photocatalyst, nature of pollutants, and source of light, which should be in close contact with each other. The TiO2 photocatalyst is used for the effluent treatment of textile wastewater in the presence of ultraviolet (UV) irradiation. Heterogeneous UV-TiO2 photocatalysis is capable to remove organic pollutants from textile wastewater, which has been widely studied and the technology also being commercialized in many developing countries in the world. This review focuses on the mechanism of UV-TiO2 photocatalysis, modification of TiO2 photocatalyst, and application of doping and co-doping in order to improve the photocatalytic activity in wastewater treatment. In addition, the review conveys comprehensive and fundamental assessments of the photocatalytic activity for the removal of organic dyes and phenolic compounds from textile wastewater.

Photocatalytic Activity Improvement and Application of UV-TiO2 Photocatalysis in Textile Wastewater Treatment: A Review

TiO2 based photocatalytic membranes: A review

SnS2 nanocrystals with adjustable sizes were synthesized via a hydrothermal method from the aqueous solution of common and inexpensive SnCl4·5H2O, thioacetamide and citric acid, simply by varying the reaction temperature and reaction time. The structures, Brunauer–Emmett–Teller (BET) specific surface areas and optical properties of the resultant SnS2 nanocrystals were characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption/desorption isotherms, and UV–vis diffuse reflectance spectra. Besides, their photocatalytic properties were tested for the reduction of aqueous Cr(VI) under visible light (λ > 420 nm) irradiation. It was found that the photocatalytic activities of SnS2 nanocrystals in aqueous suspension depended on their synthesis conditions. The product synthesized under suitable hydrothermal conditions (for example, at 150 °C for 12 h) not only showed high visible light-driven photocatalytic activity in the reduction of aqueous Cr(VI), but also showed good photocatalytic st...

Size-tunable hydrothermal synthesis of SnS2 nanocrystals with high performance in visible light-driven photocatalytic reduction of aqueous Cr(VI).

Synergy of photocatalysis and adsorption for simultaneous removal of Cr(VI) and Cr(III) with TiO2 and titanate nanotubes

On the photocatalytic properties of elongated TiO2 nanoparticles for phenol degradation and Cr(VI) reduction.

The invention discloses a catalyst which can optically catalyze and degrades benzene and nitrate, a preparation method and application of the catalyst. The catalyst is dual-metal A-B-TiO2-typed catalyst carried by TiO2; wherein, metal A is Pd, Pt or Au; metal B is Cu, Ag or Ni. The preparation method comprises the steps as follows: TiO2 is added into solution of A salt or B salt, dipped and dried by steaming; the catalyst is subsequently gained by a reduction method under the conditions of H2 and high temperature. The invention takes TiO2 carried by dual metals as catalyst; when the optical catalysis is carried out, the benzene and nitrate pollutant in water can be degraded; the operation is simple, the raw material is easily gained, furthermore, the catalyst has no secondary pollution, the disposal effect is obvious and the catalyst has wide application prospect in micro-polluted water disposal field.

Catalyst for photocatalysis and degradation of benzene and nitrates

The invention discloses a method for eliminating tetracycline in the water by a adsorption method; Mesoporous carbon is taken as adsorbent to adsorb and eliminate the tetracycline in the water; the method particularly includes the following steps: 1) synthesizing a template SBA-15 of the mesoporous carbon; 2) taking the SBA-15 as the template to synthesize mesoporous carbon CMK-3; 3) taking the mesoporous carbon CMK-3 as an adsorbent to adsorb tetracycline in water. By adopting the adsorption method to eliminate the tetracycline in the water, the method of the invention can achieve the adsorption performance which is significantly superior to that of the traditional adsorbing material (like activated carbon). Furthermore, the method of the invention has simple operation and significant treatment effect, and the material is easy to be obtained. The method of the invention has high economic and environmental benefits on the elimination of the tetracycline in the water of a micro-polluted water source.

Method for removing tetracycline in water by adsorption method

The invention discloses an application of Fe3O4@SiO2 composite particles modified by amido to removing heavy metal ion pollutants in waters. The invention also discloses a method of using the Fe3O4@SiO2 composite particles to remove heavy metal ion pollutants in waters. The Fe3O4@SiO2 composite particles are used to adsorb and remove heavy metal ions when the pH value is 4 to 8, the adsorption time is 30min to 24h and the temperature is 288 K to 318K. The application and the method adopt the Fe3O4@SiO2 composite particles to absorb and remove heavy metal ion pollutants in water and the composite particles represent relatively strong adsorption performance. Besides, the material of the application and the method is easy to prepare, the application and the method are convenient to operate, have low cost and obvious treatment effect and can adopt magnetic separation to carry out separation. Therefore, the application and the method are applied to remove heavy metal ions in micro-polluted water and have excellent economic and environmental benefits.

Method for processing heavy metal ion in water using amidocyanogen modified Fe3O4@SiO2 composite microparticle

The invention discloses application of molecular sieve loading zirconium oxide for removing fluoride ions from water The invention also discloses a method by employing the molecular sieve loading zirconium oxide to remove the fluoride ions from water, namely absorbing and removing the fluoride ions by modified molecular sieve loading zirconium oxide from polluted water at a temperature of 10-40DEG C under the acidic or alkaline condition The invention shows remarkable adsorption capacity superior to than of conventional adsorption materials by the time when removing fluorine contaminants from the water by the adsorption method In addition, the invention has the advantages of simple operation, easy obtaining of materials, low cost and obvious treatment effect, thereby the invention has perfect economic and social benefits for removing the fluoride ions from source water of slightly polluted water

Rongxin Mu

Papers

On the photocatalytic properties of elongated TiO2 nanoparticles for phenol degradation and Cr(VI) reduction.

Catalyst for photocatalysis and degradation of benzene and nitrates

Method for removing tetracycline in water by adsorption method

Method for processing heavy metal ion in water using amidocyanogen modified Fe3O4@SiO2 composite microparticle

Method for removing fluorine ion from water by using zirconium oxide carried molecular screen