Iranian Journal of

Background and Objectives: Water complexes including Jacuzzi are among the most popular water recreation centers that noncompliance with health standards can lead to increased microbial growth in water and thus the risk of infection. This study aimed at comprehensive study of jacuzzis water in Yazd city and comparing the results with national and international standards. Materials and Methods: This was a descriptive - analytical study that statistical society included all Jacuzzis of Yazd city. Sampling of jacuzzis was performed every two weakes for 3 months (Summer 2011). We tested the water samples for parameters such as temperature, pH, amount of residual chlorine, turbidity, alkalinity, hardness, the population of heterotrophic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, fecal streptococci, and fecal coliforms accordance with standard methods. The SPSS software and ANOVA, T-test statistical tests, and/or Kruskal-Wallis, and Mann-Whitney were used for description of data and the obtained results were analyzed by comparing with standards. Results: we found that the mean of residual free and combined chlorine was equal to 0.628 and 0.337 mg/l respectively. The alkalinityand hardness were 141.928 and 275 mg/lCaCo₃ respectively. Mean of pH, turbidity and temperature were equal to 7.88, 0.457 NTU and 38.121˙C respectively.Moreover, the mean population of fecal streptococci bacteria, heterotrophic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, and fecal coliforms were 20465.7, 120.77, 209.91 and 7131.4 in 100 ml respectively. Statistical analysis of data showed that there is a direct relationship between water turbidity and pH (Pvalue=0.018) however, population of heterotraphic bacteria and residual free chlorine had indirectl relationship (Pvalue= 0.026). Conclusion: According to the results achieved, the parameters of heterotrophic bacteria population and alkalinity had the least compliance with the standard indicating the need for continuous monitoring of physical, chemical, and microbial parameters of Jacuzzi water and control of the number and density of people using Jacuzzi and continuous monitoring of Jacuzzi water filtration and chlorination process performance.

Background and Objective: Predicting municipal solid waste generation has an important role in solid waste management. The aim of this study was to predict municipal solid waste generation in Isfahan through time series method and system dynamics modeling.

Materials and Methods: Verified data of solid waste generation was collected from Waste Management Organization and population information was collected from the National Statistics Center, Iran for the period 1996-2011. Next, the effect of   factors on solid waste generation such as population, urbanization, gross domestic product was investigated. Moreover, the relationship between each of these factors was identified using generalized estimating equation  model. Finally, the quantity of the solid waste generated in Isfahan city was predicted using system dynamics modeling by Vensim software and time series method by ARMA technique.

Results: It was found that population and gross domestic product have a significant relationship with the amount of solid waste with P value 0.026 and 0 respectively. The annual average of municipal solid waste generation would be 1501.4 ton/day in 2021 estimated by the time series method and 1436 ton/day estimated by the system dynamics modeling. In addition, average annual growth rate achieved was 3.44%.

Conclusion: According to the results obtained, population and gross domestic product have a significant effect on MSW generation. Municipal solid waste generation will increase in future. Increasing solid waste is not the same in different areas and methods. The prediction of the time series method by ARMA technique gives precise results compared with other methods.