IRANIAN JOURNAL OF HEALTH AND ENVIRONMENT
Year:2009 | Volume:1 | Issue:2 (2)|Papers Count:8

Background and Objectives: Groundwater treatment by nano particles has received increasing interest in recent years. Chromium is a commonly identified contaminant in soils and groundwater.Zero-valent iron, as a natural redu tion agent can be used in controlling of contaminated sites. The aim of this research is investigation of hexavalent chromium removal from aqueous solutions by using of iron nano particles the effective parameters.Materials and Methods: In this research the synthesized of the iron nano particles has performed by addition of NaBH4 to FeCl3 6H2O solution and Cr(VI) reduction efficiency in Batch system was studied. Also the impact of the important field parameters including pH, initial chromium concentration, nano zero valent iron concentration and retention time were investigated.Results: The results of this research showed that synthesized particles were in nano scale. In pH=3, chromium inlet concentration of 10 mg L-1, nano zero valent iron concentration 0.5 g L-1 and 2 minute retention time, 100% of Cr(VI) was removed.Conclusion: The concentration of nano zero valent iron had significant effect on the reduction of Cr(VI).The reaction occurred in a wide range of pH value and the reaction efficiency increased significantly with decreasing initial pH. The significant removal efficiency, high rate of process and short reaction time were showed that iron nano particles have significant potential in removal of Cr(VI) from contaminated water.

Background and Objectives: Atmospheric transport is a key mode of microbial dispersal and the transmission of airborne microbe can have significant impacts on human health. The main objective of this study was to determine the concentrations of airborne bacteria in a children.s hospital.Materials and methods: Three sampling points were selected. Airborne bacteria were collected with 6 days interval at each location using Quick take 30® sampler at an sampling rate of 28.3 l min-1 from November 2007 to March 2008.Results: The results showed that the highest indoor density of bacteria was 429 CFU/m3 that founded in oncology ward. Bacteria identified were representative of normal flora of the skin, respiratory and gastrointestinal tracts.Conclusion: Our analysis revealed that colony of bacteria in 14% in patient room exceeded available guideline value for indoor air quality. That 11% cases was found in the oncology ward.

Background and Objectives: In many countries, there is a popular belief that the simultaneous handling of food and money contributes to the incidence of food - related public health incidents. The objective of this study was to determine the total bacterial count and the presence of food borne bacterial pathogens on Iranian currency notes, collected from food - related shops.Materials and Methods: A total of 120 Iranian currency notes, comprising notes in four denomination (2000, 5000, 10000 and 20000 R) were collected from various food-related shops including, butchery, bakery, confectionary, fast food, ice cream and poultry meat shop. The currency notes were categorized into three groups according to their physical conditions. All currency notes were examined for total bacterial count, Escherichia coli, Staphylococcus aureus, Bacillus cereus, Salmonella and Listeria according to the standard techniques.Results:The average number of total bacterial count in four denomination of currency notes (2000, 5000, 10000 and 20000 R) were 118.49, 106.32, 69.44 and 220.81 CFU/cm2, respectively. The association between total bacterial count and denomination of the currency was not statistically significant. Of the 120 currency notes on which bacteriological analysis was conducted 13.3 %, 32.5% and 10.8 % were contaminated with E. coli, S. aureus and B. cereus, respectively. Salmonella and Listeria were not isolated from samples. Currency notes collected from butchery, bakery,confectionary, fast food, ice cream and poultry meat shop were contaminated with E. coli at the rate of 60, 0, 5, 5, 0 and 10 %; with S. aureus at the rate of 55, 30, 10, 25, 40 and 35 %; with B. cereus at the rate of 0, 10, 20, 5, 20 and 10 %, respectively. There was not a statistically significant association between physical condition and bacterial contamination of the currency notes. The effect of presence or absence of cashier in food-related shops on bacterial contamination of the currency notes was also evaluated.Conclusion: Money has got the potential to change through many different hands and could be exposed to many different environments at a relatively high frequency. Since there is very little information regarding the hygienic history of any forms of currency, great care should be taken when the same person facilitates the handling of money and the preparation and handling of food to avoid cross contamination.

Background and Objectives: A conventional treatment to stabilize the excess activated sludge is the aerobic digestion process but due to longaeration time, it requires large equipments as well as high investment cost. Because of high oxidation potential of ozone, sludge ozonation enhances stabilization rate and reduces sludge treatment equipment size and cost. Therefore, in this study, the combination of pretreatment with ozone and aerobic digestion processes were investigated.Materials and Methods: The experimental set-up consisted of an ozonegenerator and ozonation reactor with the total volume of 2 L. Removal percentages of TSS, VS, total and soluble COD, HPC, fecal coliform and settable solids were measured in integrated process compared to the single ones.Results: The results of this research indicated that the aerobic digestion of waste activated sludge during 10 days could reduce 38% of volatile solids and thus obtaining the EPA standard. Also, the results of combined ozonation and aerobic digestion revealed that the pre - ozonation at 0.25 g O3/g TS or 0.5 g O3/g TS with 6 or 3 days aeration, respectively, could achieve 38% reduction in VS and hence the requirement set by EPA. Therefore, integration of pre-ozonation with aerobic digestion can significantly reduce the digestion time to attain the standards.Conclusion: The sludge pre-ozonation with low dose of ozone due to solids disintegration can enhance the efficiency of aerobic digestion in waste activated sludge stabilization, and consequently decrease size of equipments, air requirement, investment and probably operation cost.

Background and Objectives: Recycling is one of the best alternatives in solid wastes management. Recycling has few benefits from the viewpoint of economics and environmental. Paper and cardboard are the valuable recyclable materials in solid wastes. The rate of paper recycling is 35% in world. The major production source of paper and cardboard wastes is private and governmental offices and organizations. To be informed about paper production is very important in the solid wastes recycling. Thus, the aim of this study was to determine production rate of paper and cardboard waste and also to determine paper recycling potential in the 20 head offices of Mazandaran province.Materials and Methods: This study was conducted in the 20 head offices of at province center. The offices were selected by chance. This study was conducted four months in 2006. paper waste was separated after suspension of work. Collected material weighed on the sensitive scales. Separation and measuring was done for a week per month.Results: The results showed that more than 2 tons of paper waste was produced in the twenty offices. The maximum and minimum of paper production was in education and recycling organization, respectively. The maximum and minimum of production rate was 2.08 and 0.192 kg per capita in month that was in the education and Jihad – e - Agriculture organization, respectively. Also the maximum and minimum of paper waste was produced at first work day of week (Saturday) and last work day of week (Thursday), respectively. However, it was not significantly (P>0.05). Paper recyclingoperation and marketing was done in an office.Conclusion: Findings of this study indicated that office solid waste management needs more notice in Iran. And also calculations showed that paper recycling is economical.

Background and Objectives: Nowadays vermicompost production of food wastes is posed as oneof appropriate methods to food wastes. disposal, itsproduction used in agriculture and gardening.Moreover this process has some by products beside useful fertilizer that one of them is the worms. We can use them in variety of products specially in production of poultry and fish food. So determinationof optimal condition for operating vermicompostproduction process of food wastes and worms.growth in these wastes is important.The aim of this study was determination of optimal temperature and moisture range for processprogression in vermicompost production of food wastes.Materials and Methods: In this study we used Eisenia foetida species. Process performed in potswith 15 cm (h) and 12 cm (d) and in a mouth period of time. Three ranges of temperature including5-15, 15-25, 25-35 oC and three ranges of moisture including 55-65%, 65-75%, 75-85% were appliedin this study.Results: Multivariate analysis was used for analyze of results and it showed that influence of temperature and moisture on C:N ratio is significant invermicomposting process (p<0.05).Conclusion: The results showed that the range of temperature 15-25oC is more appropriate foroperating of process. Due to these study.s results with increasing or reduction of ambient temperature,like summer and winter, conservation of moisture around the range of 65-75 %, is effective in better performance of the process. According to this studys results, it seems that the temperature of15- 25oC and moisture of 65-75% are better conditions for worm.s growth.

Background and Objectives: Upflow Sludge Blanket Filtration (USBF) system is a modification of the conventional activated sludge process that incorporates an anoxic zone with an upflow sludge blanket filtration clarifier in one bioreactor. It has no inherent capacity limits and is used in a wide range of applications in municipal, industrial and agricultural wastewater treatment. The main objective of this study was to evaluate the performance of a continuous USBF reactor for the treatment of sugar industrial wastewater.Materials and Methods: Sixty liter laboratory pilot scale plant was made of plexiglass consists of 14 liter anoxic zone, 38 liter aerobic zone and 8 liter clarifier. Used molasses for raw wastewater was obtained from Varamin Sugar Company. During the study, the wastewater has been initially fed to anoxic zone of the bioreactor. It mixed with recycled activated sludge returned from theclarifier and the mixed liquor entered into aerobic zone of the bioreactor. From aeration zone, the mixed liquor passed through the sludge zone at the bottom of the clarifier which was then separated by upflow sludge blanket filtration and then the clear water discharged from the system. To complete the internal circulation loop, collected activated sludge at the bottom of the clarifier was recycled to the anoxic zone.Results: Experimental studies indicated that average removal efficiency of COD with HRTs from 21 to 26 hours in the aerobic zone and from 8 to 10 hours in the anoxic zone were from 77 to 97 percent depended on input feed (1000 to 30000 mg/L).Conclusion: USBF as an advanced biological process had a proper COD removal efficiency for the biological treatment of sugar industries wastewater compared to other researchers methods.

Background and Objectives: In the production of some high - consumed food products like cake, biscuit, chocolate and spaghetti water is used in the preparing of primary material and in the kneadingprocesses. At the present studymicrobiological and chemical quality of consumed water in food industries of East Azerbaijan Province were studied.Materials and Methods: Eleven factories with different products were selected. Water sampleswere collected and analyzed regarding the microbiological contamination and chemical parameters, and heavy metals. In addition, condition of water quality in selected industry was surveyed duringthe summer.Results: According to the results, monitoring of water quality in the studied industries is not suitable.The chemical characteristics of consumed water in those industries had major differences. Ni, Cr, Zn, Fe and Mn were present in all analyzed water but in lower concentration than national Maximum Contaminant Level (MCL). Pb was measured in higher concentration than MCL in spaghetti factoryno. 2 and close to MCL in wiener and frankfurter and sugar industries. Cd was close to MCL inspaghetti factory no. 2 and wiener and frankfurter industries.Conclusion: It was concluded that for the safety and health of food products the food industriesshould use the public water supply system as water source atleast in food processing units or in the units of preparing of primary materials. Also for the preventing of chemical pollution of food products it is necessary, pay more attention to the subject of water quality control according to the special water standard of food industries, and using less volume of water in some food industry isn.t acceptable reason for neglecting of water quality monitoring and assessing. In addition it is required to analyze heavy metals in the final products of those industries.