[Cadmium adsorption by a bacterial biofilm supported on clinoptilolite from aqueous solution]

Heavy metals pollution represents a serious problem for human health and for life in general and bacterial biofilms are able to adsorb heavy metals from dilute aqueous solutions and accumulate them within their cell structure. The aim of this study was to investigate the ability of Escherichia coli biofilm [an effective agent for metal adsorption] supported on clinoptilolite for the removal of cadmium from aqueous solutions. Adsorption experiments were carried out in a laboratoryscale batch model with clinoptilolite alone and clinoptilolite covered by a bacterial biofilm. The effects of initial heavy metal concentrations, pH, and agitation time on the removal efficiency were studied. Finally, experimental results were analyzed using isotherm equations. The results of this study revealed that cadmium adsorption to clinoptilolite was lower than that of clinoptilolite covered by biofilm and adsorption of the cadmium was influenced by several parameters such as initial concentration of cadmium, biosorption time and solution pH. The uptake values for clinoptilolite and for clinoptilolite covered by biofilm were 6.8 mg/g and 9.6 mg/g respectively in the batch model, for initial cadmium concentrations of 25 and 100 mg/L. It was also observed that as the initial cadmium concentration increased, the uptake increased, but the removal rate decreased. Maximum adsorption efficiency was achieved at pH value of 6. The biosorption equilibrium for cadmium was best described by the Freundlich and Longmuir models. It is concluded that the presence of biofilm increased the uptake efficiency of clinoptilolite and the biofilm tested in our study seems very promising for the removal of cadmium from aqueous solution

[Comparison of the efficiency of photochemical processes combined with UV/H[2]O[2] and UV/TiO[2] in removal of Acid Red 18 from aqueous solutions]

Development of manufacturing industries of textile dyes has resulted in marketing new dyes with better dyeing qualities. Improvement of the dye quality is related to the structural stability of the chromogenic materials which make dyes resistant against chemical and biological dissociation. The purpose of this study was to investigate the efficiency of the photochemical processes combined with UV/H2O2 and UV/TiO[2] in removal of Acid Red 18 dye from aqueous solutions in a batch reactor. This study was an experimental-laboratory study. A reactor was designed and fabricated in our laboratory. Then optimum pH was determined in stable condition. The effect of initial concentrations of hydrogen peroxide, titanium dioxide, contact time, and different concentrations of Acid Red 18 dye were systematically assessed while keeping optimum pH constant. Data were analyzed and interpreted using Excel software and regression coefficient. The results of this study revealed increased removal efficiency of Acid Red 18 in acidic pH in the above mentioned processes; however, this efficiency decreased with increased initial concentration of Acid Red 18 dye. Moreover, the removal efficiency of dye increased by increasing contact time and concentrations of hydrogen peroxide and titanium dioxide. In general, our results showed that the photochemical processes combined with UV/H[2]O[2] and UV/TiO[2] could be used as an effective method for removing Acid Red 18 from aqueous solutions. Moreover, comparison of the results indicated that the removal efficiency of the photochemical process combined with UV/H[2]O[2] was higher than that of the photochemical process combined with UV/TiO2. Because of availability, time-effectiveness, and lack of sludge production this process is recommended for removal of Acid Red 18

[Comparison of efficiency of photochemical and sonochemical processes combined with hydrogen peroxide in removal of direct blue 71 [DB71] from aqueous solution: a kinetic study]

One of the important sources of environmental pollution existing in different industrial wastewater, including loom wastewater are dyes which are harmful for human health and environment. The purpose of this study was to investigate the efficiency of photochemical and sonochemical processes combined with hydrogen peroxide in removal of DB71 from aqueous solution. This study was experimental - laboratory study. At first, a reactor was designed and made. Then, optimum pH was determined which was 7 for photochemical and 3 for sonochemical process in constant condition. The effects of initial concentration of hydrogen peroxide, DB71 and contact time were studied at the constant optimum pH. Then data were interpreted and analyzed by use of Excel software and regression coefficient. The results of this study showed that with increased initial concentration of DB71, its removal decreased. But removal efficiency of DB71 increased by increasing contact time and initial concentration of hydrogen peroxide. In addition, kinetic parameters were obtained by application of first-order [Langmuir-Hinshelwood] equations. The results showed that UV/ H[2] O[2] and US/ H[2]O[2] processes can be effective in the removal of DB71 from aqueous solutions. Considering dye removal efficiency and availability, photochemical process combined with hydrogen peroxide can be recommended as a fast effective method for removal of dyes from aqueous solutions

[Relationship between emotional intelligence with conflict management strategies among educational and research managers of Shiraz university of medical sciences]

Introduction: Successful managers integrate strong interpersonal skills with technical knowledge to improve their performances. Emotional Intelligence not only provides the basis to further these skills, but also plays an important role in efficiency of group members and solves conflicts using emotions. The aim of this study was to determine relationship between Emotional Intelligence with conflict management strategies among educational and research managers of Shiraz University of Medical Sciences

Methods: In this cross-sectional study, 81 educational and research managers from faculties and research centers were selected using random sampling. Three questionnaires including Robin's conflict management, Schering Emotional Intelligence and individual traits were used for data gathering. Data were analyzed using t-test, Chi-square, and Pierson correlation tests

Results: The mean of emotional intelligence was 115.01. About half of the managers [50.6%] used avoidance strategy, and only 47.2% used collaboration strategy. Educational managers [87.6%] and males [59.6%] tend to use avoidance strategy more. Research managers [62.86%] and females [34.5%] used control strategy more. There was no statistically significant correlation between emotional intelligence with the strategies. Among educational managers, there was a statistically significant negative relationship between control strategy and management experiences. Among males, there were significant negative relationships between emotional intelligence and avoidance/collaboration strategies

Conclusion: Emotional Intelligence is an important factor to recognize and solve conflicts. It is necessary to improve top managers' performances through learning emotional intelligence strategies to them. The continuing education of conflict management strategies would help managers to recognize and manage conflicts timely and properly

[Assessment of chemical pollution of groundwater resources in downstream regions of Sanandaj landfill]

Groundwater pollution due to leakage and penetration of leachate containing variety of compounds and contaminants is a problem in landfill sites that leads to diverse healthy and environmental problems. The purpose of this study was to assess groundwater chemical pollution in downstream regions of Sanandaj landfill. In this study, 5 wells near the landfill were selected. Water samples were obtained 6 times in spring and summer, and different parameters such as hardness, alkalinity, turbidity, COD, PO4, NO3, TDS, pH and EC were measured by standard methods and the results were compared with those of control wells and standards of drinking and agricultural water. Results of this investigation showed the chemical parameters in water of surveyed wells, compared with those in water of control wells and standards of drinking water, were higher and showed significant differences [p<0.05]. But, most of these parameters in surveyed wells were lower than those of standards of agricultural water. The water of the wells of the study area due to the high values of most of the chemical parameters measured is not potable, but can not be used in agriculture. Therefore fundamental and continuous monitoring of groundwater resources in this area is necessary to prevent contamination of water and soil resources

Reduction of humic substances in water by application of ultrasound waves and ultraviolet irradiation

Humic substances mainly humic acids constitute the major fraction of natural organic matter in water supplies. They play an important role in the formation of harmful disinfection by products. Degradation of humic acids by means of ultraviolet radiation and ultrasonic irradiation processes was investigated in a laboratory-scale batch photoreactor equipped with an 300 W immersed-type medium-pressure mercury vapour lamp and sonoreactor with low frequency [42 kHz] plate type transducer at 170 W of acoustic power with emphasis on the effect of various parameters on degradation efficiency. Experiments were performed at humic acids initial concentrations varying between 2.5-10 mg/L. Oxidation of humic substances has been followed over time by measuring total organic carbon and UV absorbance in 254 nm and 436 nm. Initial results indicated a strong capacity of photolysis for degradation of humic substances. The results also showed that ultrasonic alone cannot be an efficient method for degradation of humic substances in comparison with UV process. The maximum degradation efficiency of humic substances after 90 min of irradiation, however, was only 5.7% and reached a maximum value of 9.5% after 300 min of irradiation. It was found that total organic carbon can be removed effectively by photolysis. It was also found that lower concentrations of humic substances favor the humic substances degradation. Also, the experimental results indicated that the kinetics of ultrasono-oxidation and photo-oxidation processes fit well by pseudo-first order kinetics

[Biological removal of propylene glycol from wastewater and its degradation in soil by the activated sludge consortia]

Propylene glycol is the main compound of anti-freezing chemicals. A significant amount of propylene glycol is released to the environment after application and contaminates the soil. The main objective of this study was to determine the biological removal of propylene glycol from wastewater and its degradation in soil by the isolated bacteria from activated sludge process. In the present study, the sludge taken from the return flow in a local activated sludge treatment system was used as the initial seed. The performance of the bioreactor in treating the wastewater was evaluated at four different retention times of 18, 12, 6 and 4 h, all with the inlet COD concentration of 1000 mg/L. This phase lasted around 4 months. Then, a part of the adapted microorganisms were transported from the bioreactor to the soil which was synthetically contaminated to the propylene glycol. The average of propylene glycol removal efficiency from the wastewater in detention times of 18, 12, 8 and 4 h in steady state conditions was 98.6%, 97.1%, 86.4% and 62.2% respectively. Also, the maximum degradation in soil was found to be 97.8%. According to the results obtained from this study, it appears that propylene glycol is inherently well biodegradable and can be biodegraded in liquid phase and soil after a short period of adaptation

Treatability of Babolsar fiberboard unit effluent

A pilot anaerobic filter was used to remove COD from Babolsar fiberboard production wastewater. The anaerobic filter was packed with ceramic packings and operated at different organic loading rates of 2.4 and 8 kg COD/m3 /day, in 20, 10 and 5 days hydraulic retention time [HRTI], respectively. The reactor achieved COD removal of 80.3%, 81% and 79% for HRT 20, 10 and 5 days, respectively. In addition BOD and oil removal efficiencies were shown to be 80% and 60%, respectively. The results of this study suggest that using anaerobic filter is a reliable process for removal of COD from fiberboard manufacturing effluent