[Removal of reactive blue 29 dye from water by single-wall carbon nanotubes]

Anthraquinone dyes such as reactive blue29 in water resources and industrial wastewater effluents are one of the most environmental setbacks in many countries. Various methods have been considered to remove these dyes One of which is adsorption. All adsorption experiments were conducted in different pHs and various concentrations of adsorbents. The initial concentration of reactive blue 29 chosen in this study was 30mg/L.Adsorption isotherms were determined and correlated with Longmuir, Freundlich and BET models. The maximum adsorption capacity of reactive blue 29 onto single wall carbon nanotubes was 496mg/g.Results showed that the best pH for adsorption was 5 followed by pH3 and 8. Kinetic study showed that the equilibrium time for adsorption of RB 29 to SWCNT is 4 hr. According to the results obtained BET isotherm fitted well the experiment. It shows the adsorption of reactive blue 29 onto single wall carbon nanotubes is multilayers and the mechanism of SWCNTs adsorption toward RB29 is based on weak van der waals forces

Optimization of operational parameters for decolorization and degradation of c l reactive blue 29 by ozone

Because conventional wastewater treatment of effluent containing anthraquinone dye causes notable environmental problems, it is important to find effective alternative methods for dye removal. This study evaluated the efficacy of ozonation for dye removal and Chemical Oxygen Demand reduction and identified optimal operational conditions for parameters such as pH, contact time and concentration of C.I. Reactive Blue 29 dye in a semi-batch reactor. Values of pH between 3 and 11 and contact times between 15 and 120 minutes were investigated. Dye concentrations were based on the American Dye Manufacture Institute standards and ranged from 1000 to 5000. Although results showed that Chemical Oxygen Demand removal by ozone alone was not very efficient [58%], ozonation proved to be an efficient method for decolorizing Reactive Blue 29 [96%]. pH was found to significantly influence the effectiveness of Chemical Oxygen Demand removal, and optimal pH conditions [95% confidence interval] were between 9 and 11. For decolorization, pH adjustment was not necessary. Degradation and decolorization of dye were found to be strongly influenced by the contact time, optimal conditions [95% confidence interval] for degradation and decolorization were 60 and 30 minutes, respectively. The optimal dye concentration was 1000 American Dye Manufacture Institute

[Determination and emission factories of SO[2], CO[2], CO, NO, NO[]2, NO[x] gases in the fanavaran petrochemical]

Fanavaran petrochemical company is located on the shore of Persian Gulf on west south of Iran, Imam Khomeini Bandar, petrochemical special economic zone with of 25 hectares area. Two units of this company, methanol unit with production capacity 1000000 tons/ years andmonoxide carbon unit with 140000 tons/years were studied for determination and emission factories of SO[2], CO[2], CO, NO, NO[2], NO[x] Gases. With attention to project goals, for implementation of this project 14 months took into from April 2008 till June2009. For goals provide of mentioned research on this basis, 32 case sampling were done from 3 emission sources by using of direct reading device of gas concentration according to standard methods of United State Environmental Protection Agency Results of the study indicate that concentration of issued pollutant gases from these units is in the level lower than Iran department of environment standard level. The total amount of emission Factory of SO[2], CO[2], CO, NO, NO[2], NO[x] gases diffused from these units are11.7 X 10[-6], 81/8 X 10[-6], 0.14 X 10[-6], 431.5 X 10[-6], 19.2 X 10[-6], 681.2 X 10[-6] kg /tons million production in a year respectively. Parameters which optimization is performed in accordance with them, include of additional air percentage, exit air temperature from pre heater, and fuel type, in fact with regarding these 3 factor's. effects, the work is done in a manner that the amount of pollutants diffusion is near to minimum and the selected best fuel

[Optimization of moving bed bioflim reactor using taguchi method]

In recent years, mobile bed biological reactors have been used progressively for municipal and industrial wastewaters treatment. Dissented experiment is a trial that significant changes will accrue for influent variables in the process, and generally used for identification of the effective factors and optimization of the process. The scope of this study was determination of the optimized conditions for the MBBR process by using of Taguchi method. Reactor start up was done by using of the recycled activated sludge from Ahwaz wastewater treatment plant. After that and passing the acclimation period, with hydraulic residence time equal to 9 hours matched for 1000, 2000 and 3000 mg/1 based on COD respectively, for optimization determination of the acclimated microbial growth, the variables change [p[H], nitrogen source, chemical oxygen demand and salinity] were determined in 9 steps, and all of the results were analyzed by Qualitek -4 [w32b]. In this study, organic load removal based on COD was 97% and best optimized condition for MBBR were [inf. COD 1000 mg/1, pH= 8, salinity = 5% and the Nitrogen source= NH4CL]. Based on our finding, we may conclude that Taguchi method is on of the appropriate procedure in determination the optimized condition for increasing removal efficiency of MBBR