Jundishapur Journal of Health Sciences
Year:2013 | Volume:5 | Issue:2|Papers Count:8

Introduction: To stabilize organic matter of sludge, aerobic digestion is commonly applied for small wastewater treatment plants (0.2 m3/s), but recently it has also been used for large scale wastewater treatment plants. Digested sludge is readily dewatering and for use in agriculture.Methods and Materials: Aim of this Bench scale study is determination of aerobic digestion performance for mixed sludge of west Ahwaz sewage treatment plant by batch reactor. In this study cubic glacial bioreactor with (33×15×21) dimensions has been used. Then 7 liter of mixed sludge (3L from primary and 4 L from secondary sludge) loaded. Aeration was carried out in 25 day by aquarium aerators. COD, VSS, TVS, TSS, TS, OUR tests examined in bioreactor.Results: Results showed that after 12 days 38% of TVS reduced. This meets the environmental standards. After 19 days detention time in the bioreactor, COD, VSS, TVS, TSS, TS, were 40, 56, 54.5, 50.4, 44.7 percent respectively. Kd coefficient was, 0.173day-1.Conclusions: aerobic digestion was useful for mixed sludge of west Ahwaz sewage treatment plant.

Introduction: Odor emission is a common environmental problem in septic tank. The feasibility of using trickling filter to eliminate the malodorous gases from the septic tank was studied.Methods and Material: A trickling filter is set up at the outlet of the waste gases of the septic tank, which was attached to the university's cafeteria. In this investigation, the trickling filter system was used, measuring the hydrogen sulfide and ammonia concentration to control the odor and to determine the elimination capacity (EC) of filtration.Results: The obtained results showed insignificant amount of ammonia, while the concentration of H2S was recorded at 90 ppm. Empty Bed Residence Time (EBRT) in the filter represented a significant relevance with the inlet concentration and the elimination rate of H2S. There is a significant linear relationship between the mass flow rate of H2S and the amount of cooked food as well as temperature. Also a significant relationship between EC and inlet concentration of H2S was observed. The trickling filter in an optimum condition with an EBRT of 200 seconds was able to remove H2S up to 99.9%. An empirical equation is developed to design a trickling filter.Conclusions: Trickling filter is an affordable and cost-effective method to remove hydrogen sulfide from the septic tank.

Introduction: Heavy metals in water resource are one of the most important environmental problems of countries. Chromium is considered as one of the important environmental pollutants due to its toxicity considered as water contaminant that may disturb metabolic activity. This research aims to study the potential of Jujube fruit powder for low cost adsorption of Cr (VI) in compression with Granular Activated Carbon (GAC).Methods and Materials: In the present study, adsorption of dissolved Chromium (VI) onto Jujube fruit powder Jujube fruit charcoal and standard granular activated carbon (GAC) has been investigated and compared. The effect of contact time, pH value, initial concentration of dissolved Chromium and amount of adsorbent on the adsorption of Cr by the mentioned adsorbents was investigated.Results: Results showed that the adsorption process was highly dependent on pH. Maximum Cr removal was achieved when the pH of the mixture fell within 2. The amounts of Cr (VI) adsorbed increased with the increase in dose of three adsorbents. Adsorption test results revealed that Cr adsorption on the studied adsorbents could be better described by Longmuir isotherm.Conclusions: Maximum Cr removal efficiencies were obtained by Jujube fruit powder, Jujube fruit charcoal and GAC 66, 35 and 62 mg/g. Experimental results show low cost biosorbent was effective for the removal of hexavalent Chromium from aqueous solution.

Introduction: Nitrate is one of the pollutants of groundwater and the great amount of nitrate in drinking water can bring about some hygienic problems such as methemoglobinema phenomena in children. Therefore, this research aims to study the efficiency of photo- Fenton in removing nitrate and investigating the variables affecting it in aqueous solutions.Methods and Materials: This research was carried out in water and wastewater chemistry lab at public health faculty of Hamadan medical science university. The variable parameters in this study included pH (in four ranges 3, 5, 7 & 11), the concentration of zerovalent iron powder (in four ranges of 10, 15, 20 & 30 g/L), the concentration of peroxide hydrogen (in four ranges of 5, 10, 15 and 20 ml/L), contact time (in four ranges 30, 60, 90 & 120 min)., along with the use of UV lamp with overage pressure of 30W and wavelength of 247.3 nm as the source.Results: According to the results from this study, decreasing pH can increase the efficiency of removal. The highest efficiency of removal occurred in pH=3, contact time 120 min, H2O2 of 10 ml/L and iron powder of 30 g/L, which was equal to 98.8 percent.Conclusions: Given the results of this research, photo-Fenton process could be used efficiently for the removal of nitrate from water resources.

Introduction: Oral health as an essential indicator of public health significantly affects public health. Adequate Knowledge, attitude and practice can effectively prevent many oral diseases. Therefore, this Study examines students’ knowledge, attitude and practice toward oral health.Methods and Materials: The study used a descriptive - analytical method and immediate sample available for gathering data. This study included the views of 131 students of Abadan Nursing College. A questionnaire was used which integrated both demographic and oral health questions. SPSS analyses included variance, Pearson correlation and t-test.Results: The results showed that the mean of students’ attitude score was 11.3 ± 2.4, which suggested a moderate attitude toward oral health. The correlation between students’ attitudes and gender (P: 0.01), students’ attitudes and underlying disease (P: 0.02), students’ attitudes and economic status (P: 0.007) were all significant. The mean of students’ knowledge score was 8.17 ± 3.3 as 36.6% of participants had enough knowledge about oral health. However, there was no significant association between oral health and demographic information. The results also showed that most participants had adequate practices for oral health.Conclusions: Since attitudes and knowledge of the participants were not satisfactory, but rather moderate, it could be said that oral health requires more training to compensate for the vacancies.

Introduction: The removal of organic precursors of disinfection byproducts (DBPs), i.e. natural organic matter (NOM), prior to disinfection is considered as the most effective approach to minimise the formation of DBPs. Trihalomethanes (THMs) as the main group of DBPs are categorized and considered to have the potentiality of increasing the rate of liver, kidney and CNS adverse effects.Methods and Materials: This study which presents experimental results, aimed at the reduction of organic matters using the powdered activated carbon (PAC) in the process of coagulation in Koot Amir water treatment plant in Ahwaz city. The affect of two coagulant such as ferric chloride and poly aluminum chloride (PACl) with PAC in removing Total Organic Carbon (TOC) considering different parameters such as concentration and the kind of coagulants, concentration of PAC, pH changes and contact time has been surveyed.Results: The results of this study clearly indicated that maximum removal in optimum pH of ferric chloride was 40% while 44% TOC removal was achieved at pH 6.5 for Poly Aluminum Chloride coagulant. In use of powdered activated carbon with optimum pH and concentration of ferric chloride, TOC reduction will increase with increasing PAC concentration and up to 90%. Also by addition of powdered activated carbon at similar conditions together with poly aluminum chloride 87% reduction of TOC was occurred.Conclusions: Poly aluminum chloride was more effective in TOC removal than ferric chloride and PAC adsorption as coagulant aid improved TOC removal efficiency.

Introduction: Infants and children are valuable human resources for our future. Their desirable growth influences the quality of human resources for the future. Nutritional education is one of the most important ways to improve children's health. The purpose of this study was to determine the impact of nutrition education program on reducing growth failure among children based on Health Belief Model (HBM) in two Hamadan Urban Health Centers (UHC).Methods and Materials: 100 mothers whose children were growth impaired randomly participated in this quasi- experimental study. Mothers form one UHC as experimental group (n=50) attended a 4 session educational program based on HBM components. The data were collected using valid questionnaire tool set and the check list of making child food aid, before, immediately and two month after the educational intervention among 2 groups. Data were analyzed by SPSS 16 and descriptive - analyzes statistics methods, such as paired T-test, independent T test, ANOVA, repeated measure and X2.Results: The average mean scores related to knowledge and HBM components variable showed significant differences among two groups of mothers immediately and 2 months after the educational intervention (P<0.05).Mean performance scores of mothers in experimental group were significantly higher than those for control group (P<0.05).Conclusions: The findings showed that the mother's nutrition educational program based on HBM, as the effective approach in healthcare requires new ways of teaching based on models and theories of behavior change.

Introduction: The work exposure conditions such as dust concentration, exposure time, use of respiratory protection devices and smoking status are effective to cause pulmonary function disorder. The objective of this study was prediction of pulmonary disorders in workers exposed to silica dust using artificial neural networks and logistic regression.Methods and Materials: A sample of 117 out of 150 workers employed in the stone crushing workshops placed in Hamadan province, in the west of Iran, was selected based on simple random approach. Information about occupational exposure histories were collected using a questionnaire. To assess the pulmonary disorder status in the workers exposed to silica dust based on the spirometry indices as well as the workers characteristics the prediction models of artificial neural networks and logistic regression were employed using the SPSS software version 16.Results: Measurements of pulmonary function indices of the studied workers showed that the indices for workers having pulmonary disorder versus the others were statistically significant (P<0.01). The results of the obtained models showed that the artificial neural networks and the logistic regression had a high performance for prediction of pulmonary disorder status. However, the developed neural networks model had a better performance than the logistic regression model in viewpoint of sensitivity, specificity, kappa statistic and the area under ROC curve.Conclusions: The neural networks prediction model was more accurate compared with the logistic regression. In this regards, the developed prediction model can be used as a helpful tool and guideline by occupational health experts for evaluating workers exposure conditions and determining the health priorities and control measures in the stone crushing workshops.