ABSTRACT
Background: Furfural is a toxic chemical, so, to avoid its effects on humans and the environment, furfural-containing wastewater must be treated with an appropriate method prior to dispose in the environment. In this study, advanced oxidation methods based on ozone was used to removal of various concentrations of furfural in laboratory scale
Material and Methods: This study is an applied research and the required samples was taken in desired times. The effects of single ozonation process [SOP], catalytic ozonation process [COP], and single adsorption on activated carbon [SAP] on furfural removal efficiency in different conditions were studied
Results: In this study, the influence of some important parameters such as pH, activated carbon dosage and reaction time on the efficiency of SOP, SAP and COP was studied. In the case of pH, the results showed that the efficiency of all three processes in very acidic and very alkaline conditions were higher than the other pH. By increasing activated carbon dosages, the removal efficiency was also increased. Finally, the removal efficiency for the processes studied, increased by increasing reaction time
Conclusion: The higher removal efficiency of furfural in acidic conditions can be due to direct and catalytic oxidation of furfural by ozone. Higher efficiency in the alkaline pH may be due to indirect oxidation because of hydroxyl radicals generation. About the effect of reaction time, the removal efficiency of COP indicates that there was a synergistic effect in catalytic ozonation processes. The increase of reaction surfaces available for ozoneactivated carbon-furfural reactions could be the reason of increased efficiency with increasing dosages of activated carbon
ABSTRACT
Over the last three decades environmental pollutions became a more noticeable problem in all around of the world. In many countries, noise pollution as a basic problem has a great importance.Development of the city, increasing of industrial centers, increasing vehicles, other annoying noise resources and also little information about the noise pollution of Tabriz city, has led to the doing of this research. Sampling and measuring of noise pressure levels was done 180 times According to the EPA standards, measuring was done simultaneously in two stations [commercial-residential areas], three times a day [morning 7:30 -9:30 am, midday 12:30-14:30 pm and night 19:00-21:00 pm] and 30 days in month. Sound pressure level in both stations was higher than the standards and the highest average level with 71.4 db was recorded in Raste-koche station at midday. Also lowest calculated average value with 68.5 db was measured in Golbad station at the morning time that is 8.5 db higher than the standards. Average measured sound pressure level in two stations was higher than the standards. The results show that Tabriz has a noise pollution in commercial and residential - commercial areas. It is suggested that other noise pollution resources identified and the proper management actions for its reduction be done
ABSTRACT
Entrance of phosphorous into the lakes leads to algae growth and eutrophication the aim of this study was to assess the efficiency of iron nano particles as a new suitable and applicable method for removal of phosphorous. In this study Lewatit FO36 resin was covered with Fe [III] nano-particles, and it was used as a new way to eliminate phosphate. Column experiments were carried out in 11 stages in fixed bed columns with constant flow rate of 9 ml/min and the empty bed contact time [EBCT] of 2.1 min. phosphate solutions with concentrations of 1 to 16 mg produced at neutral PH were used in 6 steps of experiment NaOH and NaCl solutions were used for regeneration of resin. Then the effect of competing anions, chloride, sulfate, bicarbonate and their compounds on the efficiency of the resin was assessed. Finally the efficiency of the resin for removal of phosphate from water treatment plant sewage in Ghods suburb was studied. Data were analyzed by SPSS 13 soft ware. The capacities of adsorption of phosphate, with concentrations of 1 to 16 mg, by each gram of resin were 1.31, 1.35, 1.53, 1.64, 1.7 and 1.75. The capacity of regenerated resin for removal of phosphate with a concentration of 6 mg/l was 1.6 mg for each gram of resin which showed a 8.5% decrease. The result of this study showed increased adsorptive capacity of resin with increased concentration of phosphate. Chloride, sulfate, bicarbonate ions and the combined anions had no effect on phosphate removal