ABSTRACT
Background: the phenomenon of dust is a serious environmental problem in dry and semi dry regions. It has a destructive effect for the residents of such regions. Over two-thirds of Iran is in areas of dry and semi-dry climate conditions
Methods: in this research, dust fall measurements were taken in 41 stations across Yazd city using a marble dust collector [MDCO] located in different parts of the city. Next, the chemical characteristics of dust were determined using the XRF method. Finally, levels of dust fall across the 4 seasons of the year and status of the constituent elements of dust were determined through ArcGIS software and the Kriging technique. The Raster calculator function was used to make determinations of the effects of dust fall at each of the stations over the course of the year. Remote sensing system, along with maps taken from Landsat and the band combination technique were processed using ENVI software to extract vegetation density and building density maps of the studied region
Results: results showed that spring had the highest level of dust fall with a value of 200 g/cm[2]. In total, in 109 km[2] of the studied region had average dust fall of 110 g/m[2] that contributed to 12 057 tons of dust over Yazd city in 2015. The constituent elements of the dust fall according to decreasing amounts were as follows: Si>Ca>Al>C>Mg>Fe>K>Na>S>Ti>Cl>P>Mn>Sr>Zn
Conclusion: these results indicate accuracy of the Kriging technique for application in dust zoning. The factors of vegetation and green space were determined as effective on adsorbing dust. Increased building density and height of buildings also contributed to development of dust fall
ABSTRACT
Introduction: The development of an appropriate model for the quality control of an industrial wastewater treatment system can save the time as well as the cost
This study was performed to determine an appropriate model in order to predict the COD and TKN parameters by BOD[5] and NH4+ in the Meybod industrial estate waste water treatment plant [WWTP]
Methods: This descriptive - analytical study was performed on 120 samples of the influent and effluent of the industrial estate wastewater treatment plant in JahanAbad, Meybod, Yazd in 2015. The studied parameters were BOD[5], TKN, COD, and NH[+4]
After measuring, they were imported to SPSS and Excel software to determine the relationship between them and then the linear regression model of the statistical method was used
Results: The predictive results of COD values on the basis of BOD[5] in the regression model showed that the coefficient of determination was 0.88 and the correlation coefficient was 0.93 [p = 0.000] for this relationship. The prediction of TKN values on the basis of NH[+4] in the regression model showed that for this relationship the determination coefficient of TKN and NH[+4] influent parameters was 0.877 and the correlation coefficient was 0.93 [p = 0.000]
Conclusion: This study represented that using the linear regression model for predicting COD and TKN values through BOD[5] and NH[+4] was in close accordance with the laboratory data and can thus be applied when the Meybod industrial estate WWTP faces time limitations or sampling problems
ABSTRACT
Introduction: Today, the growing amount of paper consumption and consequently deforestation and environmental destruction have imposed financial burden on different countries around the world. This study aimed to determine the level of knowledge, attitude, and performance of Yazd health volunteers on cutting down the consumption of paper
Methods: This descriptive-cross sectional study was conducted on 120 health volunteers of Shahid Sadoughi university of Medical Sciences and Health Services in 2015. A self-made questionnaire containing demographic, knowledge, attitude, and performance questions was applied as the data collection tool. The data was imported into SPSS software V.I8 and analyzed with t-test and ANOVA statistical tests
Results: The participants' knowledge about importance of paper consumption was 80.03%. The mean and standard deviation scores of knowledge, attitude, and performance of health volunteers were 11.09 +/-2.90, 59.82+/-2.23, and 41.11 +/-9.50 respectively
The results suggested that the average scores of knowledge and attitude among those with academic degrees were higher than that of other participants and this relation was statistically significant [p<0.001]
The attitude of married subjects compared to single volunteers' was more positive and there was a significant difference between their attitude and income levels. According to the results, there was a positive and significant correlation between knowledge and attitude as well as attitude and performance [P< 0.05]
Conclusion: The findings showed that the level of knowledge, attitude, and performance of health volunteers in Yazd regarding cutting down paper consumption is at a satisfactory level. This suggests that trainings provided for them at different time intervals have been well enough
ABSTRACT
Introduction: sequential batch reactor [SBR] is one of the modified biological treatment systems which is able to remove BOD[5], Nitrogen, and phosphorus from wastewater. The object of this study is to determine the removal efficiency of nitrogen, phosphorus, and heavy metals from municipal wastewater by the advanced SBR system
Methods: This descriptive-analytical and cross-sectional study was conducted on advanced SBR in Yazd city wastewater treatment plant during a one-year period [from September, 2014 until August, 2015]
The samples were collected from the influent and effluent of the advanced SBR as a composite in order to measure BOD[5] TKN, NH[+4], TP parameters, and heavy metals monthly
Also, statistical t-test was used to compare heavy metals quantities with standard ones
Results: The results showed that the mean of removal efficiency of BOD[5], TKN, NH[+4], and TP were 92.24, 80.36, 90.41, and 66.41 percent, respectively. Also, the removal efficiency of Iron [Fe], Plumbum [Pb], Nickel [Ni], Zink [Zn], Chromium [Cr], and Cadmium [Cd] were 47.77%, 40.71%, 24.79%, 12.29%, 5.70%, and 5.65%, respectively
Conclusion: The high removal efficiency of BOD[5], TKN, and NH[+4] showed that this advanced SBR system had an appropriate efficiency for nitrification. Phosphorus removal [TP] had a lower efficiency than those of NH[+4] and TKN, but it was within the environmental standard limits. On the other hand, in the advanced SBR the removal efficiency of heavy metals for Cd was not within the standard limits