International Journal Of Environmental Research
Volume:1 Issue: 3, summer2007

Algal growth and the water quality effects were studied and modeled in the lower reaches of the Colusa Basin Drain as a stream system. Statistical Techniques such as the correlation matrix and the stepwise multiple regression are performed on such variables as algal biomass, ammonia, nitrate, orthophosphate, temperature, and the solar radiation intensity in deriving an algae statistical model. Orthophosphate is shown as the limiting nutrient controlling the growth kinetics of algae.. A one-dimensional dynamic mathematical and computer model is formulated to simulate suspended algae and water quality parameters. The mathematical solution is obtained by a finite-difference implicit method. The model is calibrated and confirmed with the data collected from the lower 30 km reaches of the Colusa Basin Drain. The simulation results for both the statistical and the dynamic models are in good agreement with measured values. The model can be used to evaluate water quality in stream systems.

Intra-city natural structures have always had a key role in creating sustainable urban greenspaces. Adapting to natural features and relating the intra-city greenspaces to such natural structures as river-valleys, hillsides, lakes and forests, guarantee the endurance, sustainability and longevity of the natural quality of city. This paper looks at intra-city natural structures which have undergone wholesale changes and been ruined, and considers the lives of these invaluable natural structures which have been endangered due to gross human interference and pressure, regardless of physical and biological features. River-valleys in Tehran have always had a significant role in offering valuable bio-environmental services to the city. From the time of Qadjar era, villages enjoying favorable climate were built outside the city, and the villa of the governors and affluent people were built near hillsides across river-valleys because of the abundance of running water, cool weather in the summer and natural plant life. Little by little green corridors of Shemiranat were built near river-valleys, which formed the axes of the development of the city at the time Pahlavi dynasty. From then, the development of the city towards hillsides, regardless of these natural structures, increased and the destruction of these urban natural spaces have posed serious problems nowadays. Familiarity with these natural structures, their preservation and organization, and making the optimum use of them seem to be a very critical issue. Taking an ecological approach in this paper, is an attempt to look at the intra-city river-valleys. To do so, the data collected from a natural river-valley is used as evidence to back up any claims made in this regard.

Weather and climate have considerable influence on the concentration of air pollutants such as particles and gases. The range and concentration of these particles and gases are very dependent on prevailing weather conditions and air currents. This research concentrates on health effects of benzene, one of the air pollutants of Tehran, as a major city. The concentration of benzene emission to air due to deficient oxidation of fuel in vehicles or evaporation of gasoline at gas stations and the gas tanks of the automobiles, at market station in Tehran shows significantly high values than EPA guidelines that is used in Iran. The result of calculation of risk assessment was 3.6 × 10-5 (3.6 cancers per 100000).

This paper examines the application of a GIS based planning support system, What If? TM, to evaluate alternative growth policies for sustainable urban growth in a rapidly growing city of Iran. The paper describes the study area, Dorood city, and the What If? Model. It then explains the procedures that were used to obtain the required data and to run the model to Dorood city. The paper concludes by considering the results and implications, which the study has for urban growth management of the city to preserve farmland and accommodate growth in the city.

Internationally recognized Golestan forests are among the most endangered features threatened by anthropogenic activities. Being located in north-west of Iran, south-east of Caspian Sea, Gorganroud watershed is mostly influenced by deforestation activities. In this study the identification of regional atmospheric and hydrologic patterns and their role in conforming floods in Gorganroud water basin are discussed. A 33-year period (1970-2003) was taken in to consideration in the process of data gathering. Gradual change from Mediterranean to Semi-arid climate during recent decades in Gorganroud watershed indicates regional climate change. Increased share of 24-hour precipitation in average annual precipitation in one hand and decreasing rate of snowy on rainy days ratio on the other hand stipulate this climate change. The relatively sharp ascending pattern of annual peak flow of the basin during recent years may be considered as an alarming factor concerning streams inundation. Climate study in suspected water basins may provide invaluable data concerning flood forming potential of regional precipitations. The results of this study confirm the fact that precise analysis of climatic and hydrologic in watersheds threatened by flood-forming run-offs may be used efficiently in monitoring such areas and saving human lives.

Air pollutants from iron and steel making operations have historically been an environmental concern. The factory located at Ahwaz, Iran, has two production lines namely, 630 and 650, which produce iron parallel edge. The objective of the study is to determine indoor respiratory particulate matter (RPM) and FeO concentrations and their comparison with NIOSH standards. This is a cross–sectional study of personnel working in different environmental conditions. There were significant differences in mean concentrations of RPM (P< 0.05) in line 650 but not in line 630 as compared to NOISH standard (3 mg/m3). The FeO concentrations in line 630 and 650 are significantly lower than the NIOSH standard (5 mg/m3). There is maximum FeO concentration in station 7 (0.8 mg/m3), due to remains of iron on the billets. In other words, after cutting the beam by saws, carried out with water pressure of 150 Bar and immersing in cooling beds, the temperature decreases from 550 °C to 150 °C. As the result, airborne iron oxide concentrations decrease in the respiratory air zone of workers. There is maximum RPM concentration in station of Billet rejecter for line 630 (7.645 mg/m3), because this station carries out peel action on metal. The primary form of RPM is not directly related to the iron handling but may be related to improper ventilation and exhaust system.

Textile industry is the major source of water consumption and wastewater pollution.There are various treatment techniques to remove textile wastewater pollution. Coagulationflocculation is a widely used process to remove pollution due to suspended particles. In this research, different coagulants like Alum, Lime, FeCl3, FeSO4 and MgCl2 were applied to select the suitable ones with optimum removal efficiency of sulfuric dyes. Settling characteristics of flocs formed in the coagulation process were studied in a laboratory scale settling column unit. Parameters such as color, COD, TSS, turbidity and settled sludge volume have been evaluated. The optimum coagulant dose and pH value were determined by comparing the effectiveness of these coagulants.Results showed other coagulants except lime could eliminate color and COD. In this case, FeSO4 was chosen as an optimum coagulant for color removal because of the lowest required coagulant dose, minimum settled sludge volume and maximum de-colorization.

Environment conservation is the common concern at all levels from local to global. Most of the recent environment problems and ill effects stem from ecological misappropriation and neglect to recognize the limits of ecosystem, its. Rapid population growth, low income, lowest health facilities, poor sanitation, lack of education. Personal and community hygiene poverty has enhanced the incidence percentage of parasite infections. This situation is further worsened due to ignorance about the hazard of parasite infection. In order to minimize the risk factors, Municipal Corporation has taken some bold steps. In order to develop an integrated system for solid waste management, the Municipal Corporation has divided the Lahore city (Pakistan) into six towns. For each of these a decisional model is applied so as to define the composition and amount of solid waste flows to be collected and diverted to the dumping sites.

About half a century ago, following the introduction of urban sprawl up concept, various studies have been conducted to describe the mechanism and the formation of this phenomenon. Some of these studies aimed at finding the negative and positive impacts of such phenomenon on urban area with emphasis on how such concept may be looked open from environmental, economical and social perspectives.The main research objective, in this article, focuses on adverse impacts of urban sprawl on air pollution in a mega city such as Tehran. Therefore, attempts have been made to show a relationship between urban sprawl up and the increase in air pollutants concentration. Three methods have been investigated to validate such a concept methodologically. Tehran has been chosen as a case study to further demonstrate validity of such a correlation between urban sprawl up and rise in air pollution scientifically. The results confirmed a function relating air pollution increase to urban sprawl up.

The method of sampling unit was applied according to the importance of the park in urban landscape structure with the initial purpose of planning method to maximize environmental sustainability and recognizing the structural elements within the park. SWOT technique has been applied to analyze collected data and evaluate the strengths and weaknesses, opportunities and threats of affected areas. We used Geographical Information System (GIS) tools to apply neighborhood functions for extracting correspondent data in structural elements of landscape. The results of present study show that the volume of green spaces decreases in the surrounding area due to construction and farmlands activities.

The effect of organic loading rate (OLR) provided by hydraulic retention time (HRT) and influent chemical oxygen demand (CODin) on the performance of an up-flow anaerobic sludge fixed film (UASFF) bioreactor treating palm oil mill effluent (POME) was studied. Anaerobic digestion of POME was modeled and analyzed with two variables i.e. HRT and CODin. Experiments were conducted based on a general factorial design and analyzed using response surface methodology (RSM). The region of exploration for digestion of POME was taken as the area enclosed by HRT (1 to 6 days) and CODin (5260 to 34725 mg/L) boundaries. A simultaneous increase of the variables determined a decrease of COD removal efficiency, SRT and SRF and an increase of COD removal rate, VFA/Alk., CO2 fraction in biogas, methane production rate. The best COD removal rate for POME treatment in an anaerobic hybrid reactor has obtained at an OLR of 17.6 g COD/l.d while it was at 26.21 g COD/l.d (Corresponds to CODin of 26210 mg COD/l and HRT of 1 day) in the present study. Minimum and maximum SRT values obtained were 16 and 1904 days at OLR of 34.73 and 0.88 g COD/l.d, respectively. The present study provides valuable information about interrelations of quality and process parameters at different values of the operating variables.

Urban settlements and their connectivity will be the dominant driver of global change during the twenty-first century. In an attempt to assess the effects of urban growth on available land for other uses and its associated impacts on environmental parameters, we modeled the change in the extent of Gorgan City, the capital of the Golestan Province of Iran. We used Landsat TM and ETM+ imagery of the area and evaluated possible scenarios of future urban sprawl using the SLEUTH method. The SLEUTH is a cellular automaton dynamic urban-growth model that uses geospatial data themes to simulate and forecast change in the extent of urban areas. We successfully modeled and forecasted the likely change in extent of the Gorgan City using slope, land use, exclusion zone, transportation network, and hillshade predictor variables. The results illustrated the utility of modeling in explaining the spatial pattern of urban growth. We also showed the method to be useful in providing timely information to decision makers for adopting preventive measures against unwanted change in extent and location of the built-up areas within in the city limits.