نشریه علوم و تکنولوژی محیط زیست
سال چهاردهم شماره 4 (پیاپی 55، زمستان 1391)

Today, collection and treatment of leachate is one of the necessary measures in the waste management. Leachate is defined as the aqueous effluent generated as a consequence of precipitation percolation through wastes, biochemical processes in wastes body and the inherent water content of wastes themselves. Leachate is not limited to the Landfill. It is also produces with considerable organic load in composting plants. Usually in treating of strong wastewater, anaerobic process is followed by aerobic methods to boost the process efficiency. The aim of this research was assessing the efficiency of aerobic reactors (plug flow & CSTR) to complete anaerobic method in treating of composting leachate. In this study the aerobic system was consisted of four concrete reservoirs. The first two of them was CSTR reactors which were paralleled. The dimension of each of them was 4×6×6.5 m with the effective volume of 163 m3. The second two (in order) were also paralleled plug flow reactors with the dimension of 13.3×2.5×3 m and effective volume of 89 m3. Wastewater was aerated by means of fine bubble diffusers at the bottom of each reactor. After each two paralleled reactors one sedimentation tank was also predicted. According to experiments the best food to microorganism ratio (F/M) in CSTR reactor was estimated in the range of 0.5-0.15. The average of COD removal efficiency was 80% in CSTR reactors, while ratio of MLVSS/MLSS was 55%. The average of SVI was also 100 ml/g in these reactors. In plug flow reactors with average loading rate of 0.32 Kg COD/m3.d the average of COD removal efficiency and MLVSS/MLSS was 37% and 57% respectively. The average of SVI was also calculated as 84 ml/g in plug flow reactors.

Vegetable Oils can be combined with alcohol (typically Methanol) to produce chemical combinations so-called Ester. They are also called biodiesel if used as fuel. This fuel is biologically decomposable. In addition, as this kind of fuel is used as component, minor changes in engine is required. Computations on effective combustion factors show that Net Heating Value is 18577 Btu/1b for a combination of 20% biodiesel and 80% diesel (B20), and it is 19159 Btu/1b for diesel fuel. The amounts of Adiabatic Flame Temperature of fuel are also calculated as 3899 ˚F for B20 and 3879 ˚F for diesel fuel. As a result of analyzing effective diesel engine performance indicators for a model of diesel engine, the amount of heat efficiency of biodiesel and diesel fuel, are the same as 41%. It is also calculated that Indicated Power of the engine model is 78.2 kW for diesel fuel and 75.7 kW for bio diesel. Diesel engine Volumetric Efficiency, as the third effective parameter of engine performance, was also introduced, and the amount of results for B20 fuel and diesel fuel were 83% and 80% respectively. The results show minor differences in the amounts of combustion and engine performance factors for both mentioned fuels. Hence, according to environmental requirements and decreasing trend of fossil resources, the renewable bio diesel fuel is spotlighted as one of the essential alternatives for diesel fuel.

A little amount of Fe and Mn in drinking and industrial water cause many problems. In river and surface water system, these metals distributed between solute and solid phase (volatile and sediment), that considering different situation, the distribution and exchange of these metals is not in uniform shape. Temperature, pH and alkalinity are the main factors in exchange of these metals between mentioned phases. This research aim is to investigate the variation of factors with mineral and organic compound of Fe and Mn. In this research solution with concentration of 10 mg/L of sulphat and acetat iron and 2mg/L of sulphat and acetate Mn were utilized. The proceed include the preparation of solutions, investigation the impact of pH, Alkalinity and temperature, which the solubility of these mineral and organic compound of Fe and Mn was investigated in pH of 6 to 12, alkalinity of 50 up to 400 and temperature 0 to 35, respectively. The results were investigated after digestion of metals in the solution and was applied the atomic absorption device. Increase of alkalinity has more effect on the iron sulphate reduction which the minimum solution in alkalinity of 400 is about 0.486mg/L. Increase of pH has the most effect on the solution reduction of iron acetate that the minimum solution is happen in pH=12 and equals 0.441.Meanwhile, increase of pH has the most effect on the solution of sulphate and Mn acetate which minimum solution in pH=12 are respectively as 0.247 and 0.372. By increasing the temperature, the solution is reduced that this reduction is high in Mn value than Fe compound and also is more than in mineral compound than organic compound. In addition, in total experiment about 90% Mn was soluble in water while the maximum solubility of iron was about40%.

The fiberglass furnace flue discharges not only a variety of air pollutants but also a tremendous amount of heat. Its’ high discharged air temperature, limits the application of a cost effective dust collector. The application of a heat recovery system seems not only to make it possible for application of a cost effective dust collector but also may reduce heating costs considerably. In the present study, the air pollutants discharged from a fiberglass furnace flue were measured and evaluated. In the next step, the reduced fuel and social costs were estimated if a proposed heat recovery system was applied. For this purpose, five air pollutants including CO, CO2, NO, NO2, NOx, and air velocity were measure using TESTO 350XL. Particulate matter (PM) was also monitored using TCR TECORA ISO TRACK, all through direct readings. Temperature was monitored automatically through installed instrumentation at the furnace control room. More than nine hundred thousand air temperature readings were screened to select 2043 reliable readings. The recovered heat was estimated using the measured data. Direct and indirect savings from the recovered heat was predicted using the Environmental software. The results revealed that the average concentration of CO, NOx, and PM were respectively 1.45, 1.38 and 6.477 times higher than environmental permissible limits. The recovered heat was equivalent to almost 1500 million cubic meters of natural gas saving per year which costs 24.4 million US$. The extraction of statistic data and research hypothesis test was done by Mini Tab 14 software. The data of mean society examination (with determined variance) and mean of two societies and also probability plot used for contaminant changes forecast in the next years.

Food industries are one of the most important industries in our country that have significant ratio in the production of crop, the usage of water and the production of sewage. Food industries located in Dezful consist of: Golestan Agric-industrial Company (Saei oil), Dez Dasht Company (Takin meaty productions), Khuzestan leaven Company and poultry Company that their sewage vacates into agricultural drain. This research is aimed on the effect of company sewage in the quality of drain waste for agricultural usages under the support and protection of General agency of Khuzestan Environmental Protection. Considering the facilities and restriction, it's considered sampling four stations around each factory, first station (upward factory as first Shahed), second station (exit sewage factory), third station (200 meter from drainage), forth station (500 meter from drainage). Samples are done in both summer and winter. Physical-chemical parameters of water and sewage in each factory such as PH, turbidity, ISS, EC, BOD, COD,,, oil and fat, phosphate, Koli Form sums, Nickel, Kadiom and Iron are analyzed. Statistical analysis on final results from sampling of observational stations showed that there wasnt a meaningful difference in % 95 confidence levels between measured parameter in both summer and winter in all factories. Also, there wasnt a meaningful difference in both summer and winter with the same confidence level between stations. The discussion on changing the procedure showed the more increase of factories from Shahed station and their decrease in 4 stations (500meter); however, they had maximum distance from standard of Iran Environmental Protection Agency.

Flood hydrograph is a one of most important component in hydrological and hydraulics analysis. Estimation of design flood with consideration uncertainty of random variable is important in design of hydraulic structure. In conventional method, peak of design flood is estimated by use of frequency analysis. In this approach uncertainty of other variable such as rainfall, loss and base flow is missed. In this paper flood hydrograph is generated in Jamishan dam catchment with consideration of uncertainty of random variable by use of combination of RPG model, HEC-HMS and Monte Carlo simulation. Result is shown; methodology that be used in this paper has good accuracy to flood hydrograph generation and 100 percent of volume, peak and hydrograph of flood is located in confidence band.

Iran is connected to free ocean and other countries through Persian Gulf, Oman Sea and Caspian Sea. Thus, it is necessary to increase practical and scientific knowledge of seas rapidly. Knowing heat distribution in Persian Gulf helps one to forecast weather condition, predict the habitat of aquatic animals and plants, and provide other accurate information about sea. Generally the total in flow and outflow heat flux of the oceans should be zero; otherwise this oceans will freeze or will be very hot. The heat balance in Persian Gulf is examined in the article. Considering the point that the amount of rain and the inflow water to Persian Gulf is about 90cm/a and evaporation is 213cm/a, therefore, the amount of evaporation is 20-25cm/a more than rain in Persian Gulf annually. Since the Persian Gulf volume of inflow and outflow is 0.186*106 and 0.169*106 m3 /s, the net transfer of heat to this Gulf is 25w/m2. The aim of this article is to explain this extra heat entering Persian Gulf by heat flux terms. The annual mean values of upward heat transfer due to solar radiation, sensible heat, latent heat and infrared radiation fluxes are 245, -4, 179 and 92 w/m3 respectively. The result is upward flux of about 22 w/m2 at the sea surface of this Gulf. This is in fair agreement with the extra heat transport in the Persian Gulf.

The process of wave breaking is one of the most important events occurring in coastal zones. This process is so important at the point of coastal constructions and coastal industrial development and managing direction of beaches. On this research the bottom slope, breaker type, surf zone, wave length and wave height in break point, have been studied by using wave field parameters which are measured by Bushehr coastal stations of Iran Meteorological (28° 57' N & 50° 44' E) and region's hydrography maps. Utilizing the field data and practical relations and bottom slope, the maximum of breaking wave height is estimated as 2.65 m. Surf zone width is at least 42 m, although most of breaking waves occur in 200 m to 600 m distance of the beach. In next step, compute dimensionless steepness and relative wave height parameters and were compared with the findings of other scientists’ such as Sevendsen, Mc Cowan, Davies, Miche, Weggel. A correction coefficient concluded for Miche relationship in Bushehr coast. Maximum wave set down is calculated as 9.8 cm. Also in this region the type of breakers is mostly spilling breaker.

This study was carried out for surveying the efficiency of biofilm sequencing batch reactor (SBR) for treatment of wastewater with high organic loading. A cylindrical lab scale biofilm SBR was used in this study. Primary microorganisms for startup of the reactor were obtained from return activated sludge of a municipal waste treatment plant. Reactor was feed with synthetic wastewater containing mono ethylene glycol as the main carbon source and NH4Cl and KH2PO4 as nutrients. Following startup and acclimation of microorganisms, organic loading was increased via influent COD concentrations of 500, 1000, 1500 and 2000 mg/L in constant hydraulic retention time. The most removal efficiency of 94% was achieved in influent COD concentration of 100 mg/L. According to data obtained in this work, it can be concluded that biofilm SBR has acceptable efficiency for high strength wastewaters.

A large number of implementation projects regarding construction or rehabilitation of urban infrastructure systems are conducted in heavily populated areas; As a result, noise pollution generated from these operations is not limited to only a few people and will annoy community in large scale. Noise pollution may cause sleep disturbance, stress, loss of productivity in schools, offices, etc; This fact necessitates the need for considering social costs of noise pollution more carefully in urban areas. In this paper a model for evaluating monetary equivalent of noise pollution social costs in implementation of urban infrastructures has been proposed; General approach in this model is based on determining maximum allowable noise pollution in the affected area as well as determining intensity of the noise generated from operations in the adjacent receptors; Difference between the “existing” and “maximum allowable” noise levels is considered as part of the social costs of the project; Some methods for evaluating monetary equivalent of this social cost has been proposed in this paper; if the estimated value was large, some mitigation measures shall be taken to reduce the social costs of noise pollution; A number of these measures are also reviewed in the final part of the paper. In the end, suggested model has been utilized for quantification of noise pollution social costs in a small pilot area of Tehran where a sewage network has been implemented.

Materials used in traditional and local architecture in Iran derived from their deployment environment and are provided the necessary compatibility with the environment. Analysis of the use of such materials in buildings, on the one hand reduce the natural resources use and other energy resources saving during the production process materials, traditional buildings and the construction and maintenance stages of protection and restoration of such buildings will provide. This article is thoroughly compatible encoding used traditional materials in Iran, the vernacular architecture of limestone and lime-based mortar, including the cheap materials, easy collection, availability, and would reveal durable building. In this study on the related experiences of others and the results of mechanical tests on clay soil mixed with lime and analysis of the mentioned results; technical, economic or executable practice of using lime in the construction of new buildings and even local Iran has been approved. Patterns can be as a results from getting the technical message predecessors and taking advantage of new technologies associated with new products industries causing lime to make optimal rate consumption of natural resources and energy saving. We are able to material produced reversible resorting in nature unlike industrial cements; even with the capture carbon dioxide from industrial production of construction can the greenhouse effect of air pollution in the environment and abilityto reduce destructive effects of acidy rain in the environment.

The aim of this study was to evaluate awareness, attitude and action of Amirkabir University of Technology (AUT) students on general aspects of environment. A questionnaire was designed and 75 students were asked to fill it. The results of this research showed that environmental issues are the last option of the students in compared with the other issues. The obtained results also showed that knowledge of the mechanical engineering department students on general aspects of environment were relatively higher. It is nessecary to improve level of general environmental knowledge of university students in Iran. For example, a course of “environmental science and technology” is suggested to be set as a part of every academic curriculum.

Critics and scholars with assessment of typology of urban construction believe that contrary to appearances of these Types to respond Poor quality of life in cities especially after The Industrial Revolution, and approaches in consequent Of social-economic conditions have been based on Disorder in human environments. However these types with Creation of strategy and design had effective achievements to develop, organize, Rehabilitation and Reconstruction the cities. Observing increasing difficulties in cities such as population density, poverty, Environmental pollution Economic inefficiency and social anomalies addition to lack of services and infrastructure And space for living faces experts and people with this question: What is the main reason for the ineffectiveness of these typologies? To sum up, the aim of this research is to find reason of inefficiency of current urban construction typology. Beside, this research looks to achieve solution to improve urban construction system. The research method is appropriated with subjects from Combination of documentary, historical descriptive and comparative techniques to surveying Case study and mixed techniques. After analysis of current urban system problems, Results and findings represent and finally, Proposed solutions to improve the current and future urban construction system represent.

In current investigation، acute toxicity of ferrous iron was determined based on OECD guideline and Semi-static method. 190 fries of common carp (mean weight: 15±5 gr) were divided in six treatments (10 fries in each treatment) and one control group. There replicates run for each treatment. Qualitative Parameters of water including pH، dissolved oxygen، total hardness، temperature and other parameters were monitored and recorded during test period. Due to constancy of ferrous concentrations in test solutions، pH was maintained at 5. 5±0. 1. Furthermore، to ensure that desirable ferrous concentrations were created and constant during test period، ferrous concentrations were determined by use a spectrophotometer، based on Orthophenontroline method. According to results of acute toxicity test، LC50 values in 24، 48، 72 and 96 hours were calculated by probit analysis method، respectively: 2. 35، 2. 15، 1. 95 and 1. 85 mg/l Fe2+. LOEC and NOEC values were also determined by an analysis of variance، respectively 1. 1 and 1. 5 mg/l Fe2+. MATC value was calculated 1. 5 mg/l Fe2+ as the geometric mean of the LOEC and NOEC.