Study on UV-LED/TiO2 process for degradation of Rhodamine B dye

Discipline of Inorganic Materials and Catalysis, Central Salt and Marine Chemicals Research Institute (CSMCRI), Council of Scientific and Industrial Research (CSIR), G.B. Marg, Bhavnagar-364 021, Gujarat, India
Chemical Engineering Journal (Impact Factor: 4.06). 05/2011; 169:126-134. DOI: 10.1016/j.cej.2011.02.066

ABSTRACT UV-light emitting diodes (UV-LEDs) was used for the photocatalytic degradation of Rhodamine B (RhB) dye to study the various parameters, effectiveness and feasibility for designing of photocatalytic reactor based on UV-LED irradiation in different conditions. The photocatalytic experiments were conducted using 5 UV-LED lights with same specification and Degussa P-25 TiO2 as a photocatalyst. The effects of operational parameters such as catalysts loading, initial dye concentration, pH, addition ofH2O2 and effect of metal ions (Zn2+, Ag+, Fe3+, Cu2+ and Cd2+) were studied for the photocatalytic degradation of RhB. A detailed degradation pathway has been suggested, which was based on the electrospray ionization mass spectrometry (ESI-MS) analysis. It was observed that the degradation of RhB occurred via N-de-ethylation process. N-de-ethylated product was further oxidized into acids and alcohols. The complete mineralization of RhB dye (2.08×10−5 M) was confirmed by chemical oxygen demand (COD), total organic carbon (TOC), total inorganic carbon (TIC) and high pressure liquid chromatography (HPLC) analysis. The optimum conditions for higher percentage degradation of RhB dye obtained with amount of catalyst (1.6 g/L), dye concentration (6.26×10−5 M) and pH= 3.05. Results demonstrated that the UV-LED/TiO2 process can
effectively degrade RhB dye with optimum conditions.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Photocatalytic degradation of phenol by titanium dioxide illuminated by one light emitting diode (LED) in a batch photocatalytic reactor is reported in this paper. The effect of catalyst loading, catalyst type, phenol–hydrogen peroxide ratio, pH, initial phenol concentration and irradiance by applying pulse width modulation (PWM) was studied. The effect of the beam width on photocatalytic degradation of phenol is also included in this paper as is the use of different type of reflectors outside the reactor. With both an LED beam width of 120° and optimal chemical conditions of 10 ppm phenol concentration with a hydrogen peroxide–phenol molar ratio of 100 and pH of 4.8, a degradation rate of 42% was achieved after 4 h. Decreasing the beam width to 40° raised degradation to 87%. In order to study the irradiance distribution and its effect on the reactor performance, experiments were conducted incorporating various catalysts loading, reactor heights and beam widths. The irradiance was measured for different amount of catalyst loading ranging from 0.17 to 1.8 g L−1at different reactor heights. The results are compared with optimal catalyst loading measurement to assess the correlation between phenol degradation and irradiance distribution. The UV LED in combination with titanium dioxide is appropriate for water treatment to degrade organic pollutants at low concentration.
    Chemical Engineering and Processing 09/2013; · 1.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An open channel photo-bioreactor irradiated with visible and UVA light-emitting diode (UVA–vis LED) was evaluated in a recirculated mode. The novel process was composed of TiO2nanoparticles/polyurethane (PU) and glucose oxidase (GOx)/TiO2/PU. The ability of LEDs as a light source in decolorization of acid orange 7 (AO7) was investigated using the mentioned simultaneous method. Furthermore, decolorization of AO7 was studied under various conditions including different feed flow rates and glucose concentrations in the photo-bioreactor. The results demonstrated that application of GOx/TiO2/PU photo-biocatalyst under UVA-LED and Blue-LED was technically feasible due to high percentage (>99%) of decolorization in 45 and 90 min with recycling rate of 10 mL/min, respectively.
    Journal of the Taiwan Institute of Chemical Engineers 07/2014; · 2.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The experimental design methodology was used to model and optimize the operational parameters of the photocatalytic degradation of Acid Red 73 using immobilized TiO2 nanoparticles. Four experimental parameters were chosen as independent variables: pH, initial dye concentration, H2O2 concentration, and anion concentration. A multivariate experimental design was used to establish a quadratic model as a functional relationship between the efficiency of Acid Red 73 degradation (response) and four independent variables. The degradation efficiency was significantly affected by the initial dye concentration and the pH. The optimal values of the parameters were found to be a pH of 3, an initial dye concentration of 25 mg/L, an H2O2 concentration of 0.5 mg/L, and an anion concentration of 0.69 mg/L. The degradation efficiency approached 92.24% under optimal conditions. Regression analysis with an R2 value of 0.9785 indicated a satisfactory correlation between the experimental data and predicted values.
    Industrial & Engineering Chemistry Research 03/2012; 51(11):4199–4207. · 2.24 Impact Factor


Available from
May 20, 2014