Iranian Journal of

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Backgrounds and Objectives: The school is the most appropriate place for flourishes children, adolescents and juniors, and prepares safe and vigorous life. Thus, the aim of this research is to study  of the hygienic conditions in primary schools in region 1 of Sari city.
Materials and Methods: This article is a descriptive study. In which 45 non-for-profit and governmental schools were sampled using census method. The Fools of sampling was questionnaire filled in during interview with school principals and direct observation. Collected information was analyzed using "Excell" and spss soft wares.
Results: The results of this search showed that %93.4 of schools had dimention smaller than minimum standard. Only in %35.6 of schools, lavatory and drinking places were separate and the quality and quantity of lighting in %32 of. schools were classes proper.
Conclusion: The most important finding of this search was the ignorant of indicators in environmental healthas overlooking of standards, and the schools are merely established on quantity and urgent need despit of their quality.

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Backgrounds and Objectives: One of environmental outcomes in industrial towns is developing environmental pollution such as production of industrial wastewaters. These industrial wastewaters should be appropriately treated before entering to receiving waters. However we can't solve environmental anxieties by establishing of wastewater treatment plants alone but permanent and regular assessment of these treatment plants performance is necessary for achieving environmental standards. Thus, this research has been done in order to investigation of activated sludge performance in wastewater treatment of Agghala industrial town in Golestan province.
Materials and Methods: This cross-sectional study implemented in sewage treatment plant laboratory of Agghala industrial town in Golestan within 12 months at 2007. Chemical Oxygen Demand (COD) parameter determined twice in week, But Biochemical Oxygen Demand (BOD) test accomplished weekly. pH measured by pH meter daily. Experiment of total suspended solids (TSS) and total dissolved solids (TDS) carried out every 10 days. All tests accomplished according to standard method for water and wastewater examination (2005). Then data analyzed using excel 2007.
Results: The average of BOD, COD and TSS in influent was 11196.17, 1854.58, 1232.25 mg/L respectively.Maximum influent organic loading rate was related to Shahrivar andMehr months. The total average of removal efficiency for BOD, COD and TSS was calculated 99.66, 98.2, and 97.6% respectively.
Conclusion:Quality of this treatment plant effluent was according to effluent disposal standards all over year. In sum, efficiency of this treatment plant (activated sludge system) was very good ininfluent pollutant removing. However occasionally effluent was not adapted with environmental standards but these deficiencies is solvable by accurate management and supervision on flow rate and influent organic loading rate easily.

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Background and Objectives: Weather pollution, caused by Ozone (O3) in metropolitans, is one of the major components of pollutants, which damage the environment and hurt all living organisms. Therefore, this study attempts to provide a model for the estimation of O3 concentration in Tabriz at two pollution monitoring stations: Abresan and Rastekuche.
Materials and Methods: In this research, Artificial neural networks (ANNs) were used to consider the impact of the meteorological and weather pollution parameters upon O3 concentration, and weight matrix of ANNs with Garson equation were used for sensitivity analysis of the input parameters to ANNs.
 Results: The results indicate that the O3 concentration is simultaneously affected by the meteorological and the weather pollution parameters. Among the meteorological parameters used by ANNs, maximum temperature and among the air pollution parameters, carbon monoxide had the maximum effect.
Conclusion: The results are representative of the acceptable performance of ANNs to predict O3 concentration. In addition, the parameters used in the modeling process could assess variations of the ozone concentration at the investigated stations.

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Background and Objectives: Emission of volatile organic compounds and unpleasant smell are the important characteristics of the rendering plant, causing disturbance for the workers and nearby residents. In order to prevent the spread of air pollutants and to provide favorable environment, application of treatment technologies is essential. Materials and Methods: In this study, in order to select suitable collector and ventilation system for rendering plant, air sampling was performed via NIOSH sampling methods (1501, 1300, 1600, and 2002). Totally, 24 air samples were collected from the ambient air, air pollution source, and worker’s breathing zone using two sorbent, activated charcoal and silica gel and were analyzed using GC-MS. Then, the local ventilation system was designed based on the qualification and quantitation analysis of air samples. The stairmand high efficiency cyclone and thermal oxidizer were designed for dust control and gas cleaning respectively. Results: In total, 41 chemical pollutants in exhaust air from rendering plant were identified these compounds included hydrocarbons, aldehydes, ketones, alcohols, ethers, halogenated compounds, sulfur compounds, nitrogen compounds, and acids. The results of ventilation system designing showed that the system with airflow of 5725 m³/h and a cyclone with the diameter of 1 m and the height of 4 m could remove 50% of particles with 9.45-micron diameter. Gaseous pollutants were removed using thermal oxidation via the consumption of 96 m³/h fuel gas flow. The chamber volume was 6.67 m³. The daily fuel costs were estimated 310000 RLS. Conclusion: Application of local exhaust ventilation system and integrated collectors for control of air pollutants in rendering plant can remove large amounts of particulate and gaseous pollutants. Control of these pollutants can cause loss of smell nuisance and environmental pollution and improving the health and welfare of workers and neighboring residents of such industries.

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Background and Objective: The role of groundwater has always been an important issue in order to provide drinking water especially in desert areas. However, studies and decision-making on water supply from the water source is more costly and difficult rather than surface water. Therefore, it is important to note the newest methods like zoning. Due to the effects of water chemical parameters on the quality, application of AHP, ANP, FAHP, and FANP methods lead to more accurate results.  The aim of this research was to zone groundwater quality using ANP and FANP models and comparison of the results obtained by those achieved, by AHP and FAHP models.

Materials and Methods: For this purpose, the study was conducted to zone groundwater quality in Tabas aquifer located at the east of Iran with latitude between 33˚ 19’-33˚ 50’ and longitude between 60˚ 42’-63˚ 12’. In this study, the parameters studied were Mg, Ca, SO₄, Cl, total dissolved solids (TDS), electrical conductivity (EC),  and total hardness (TH). Raster maps for each parameter were prepared and these maps were converted to fuzzy maps. Then, the maps were integrated together using the weights from AHP and ANP methods.

Results:  The research indicated that the most weighted parameters using ANP method were Cl (0.172), Mg (0.161) and EC (0.159). Cl (0.457), TDS (0.163) and EC (0.141) were the most weighted parameters using AHP methods. In addition, the concentration of each parameter was increased from the east and southeast to the northeast.

Conclusion: Based on the results and groundwater flow path, water quality was reduced due to water flow in aquifer (from the east and southeast to northeast). Hence, the east and the southeast were the best location to provide drinking water. The area of these regions were 22.12, 25.08, 57.35 and 58.24% out of total area as determined using AHP, ANP, FAHP, and FANP, respectively.

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Background and Objective: Nutrient-rich effluents (mainly nitrogen and phosphorus) may lead to algae blooms and many harmful effects in aquatic environments. Micro-algae have been more effective among the various methods used for the removing of nutrients from wastewater. Microalgae Chlorella vulgaris has specific characteristics such as rapid growth, resistant to systems manipulation, simple and inexpensive production technology, as well as the rapid uptake of nutrients such as phosphate and nitrate.
Materials and Methods: In the present study, two concentrations of chlorella vulgaris microalgae (13 and 26 million cells/mL) were injected into dairy effluent, diluted using distilled water by 25, 50 and 75%, and the amount of nutrient removal and microalgae growth were examined during the growth period.
Results: Results indicated that different concentrations of algae at various percentages of dilution (25, 50, 75%) had a significant effect on the removal of nutrients and algal growth (p<0.05). The absorption of nutrients (nitrate, phosphate and ammonia) were 57.01, 51.84 and 43.15 percent respectively that containing lower density of initial algae compared to the treatments of 2nd group (29.15, 51.84 and 43.15 percent) with higher algae concentration. In both algal concentrations, the highest percentage of phosphate and ammonia adsorption were in dilution of 25% effluent and the highest percentage of nitrate adsorption were in the first group with 50% dilution and in the second group with 75% dilution.
Conclusion: The more percentage of nutrients (nitrate, phosphate, ammonia) was eliminated compared to the second group (26 million cells / mL) when the microalgae concentration (group I) was 13 million cells / mL. Absorption of nutrients was decreased by increasing the concentration of microalgae. Regarding to the percentage of nitrate adsorption, the higher absorbance in the dilution was occurred at the highest concentration of algae.

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