JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
Year:2002 | Volume:- | Issue:13|Papers Count:11

The Operation of Industries results in high levels of noise. These may have severe adverse effects to workers. Here we look at the noise levels and impacts associated with the operation of an automobile part manufacturing company. 400 workers with mean age 28 years-old and work duration ranged 1-3 years engaged in 8 workshops.A total of 139 sound measurements were made at all workshops. 35 stations of them were also analyzed at octave band frequencies separately (again). 11 workers in material grinding, ultrasonic and forging workshops were exposed to 112.1, 104.8 and 86.11eq dBA (8) respectively. Mean sound pressure levels at the other workshops were under the standard level for an 8 hours exposure (85 dBA).50 out of 400 workers and 15 out of 85 non-exposed officials as a control group were examined for noise-induced hearing losses. The audiograms of 11 workers who engaged in high level noise workshops showed 8% hearing loss more than those for the control group. The observed hearing losses have occurred mainly in the lower frequencies and there was no significant difference between two groups for losses at the 4000Hz frequency. Workers at the material grinding and ultrasonic workshops always wear earplug with earmuff simultaneously but the rest did not use any personal protective equipment.The interference of sound levels to the speech was assessed at all workshops for times the noisy machines have been working. Noise at the material-grinding workshop prevents any conversation between workers. Speaking in ultrasonic and forging workshops was only possible by very loud speaking from 1-meter distance. There was no major problem to speaking in the other workshops at the material grinding and ultrasonic workshops were earplug with earmuff simultaneously but the rest did not any personal protective equipment.the interference of sound levels to the speech was assessed at all workshops for time the noisy machines have been working. Noise at material-grinding workshop prevents any conversation between workers. Speaking in ultrasonic and forging workshops was only possible by very loud speaking in ultrasonic and forging workshops was only possible by very loud speaking from 1-meter distance. There was no major problem to speaking in the other workshops.

Alborz Industrial City is situated at the southern foothills of Alborz Mountain Range and 13 kilometers southeast of Ghazvin city. It is located at 50.5 longitudes and 36.12 latitude.The altitude of the aforesaid industrial city is 1,304 meters above the sea level and it is at the vicinity of three major transportation routes, namely Tehran- Tabriz Railroad, the Old Tehran-Ghazvin Road and Tehran-Ghazvin Freeway. Currently, its area is 860 hectares and it is surrounded by Alvand City and the nearby agricultural lands. The limits and boundaries of the industrial city are: from north to Alborz Industrial City Boulevard and the Old Karaj Road, from south to Albrorz Industrial City Treatment Facility, from east to the agricultural lands of Nosrat Abad Village and from west to the territories of Eizaj Village.Alborz Industrial City was established in 1966 in accordance with the ratifications of Finance Commission of the Parliament during the Third Development Plan and the five year tax exemption of industrial centers constructed outside the 120 kilometer radius of Tehran city limits. The objectives of its establishment were to promote the industrial decentralization policy and to emphasize on creation of suitable consumption market and development facilities.This region could be divided into two sections based on environmental, economic and social impact of Alborz Industrial City. The highly affected section is within the 15 kilometers radius of the industrial city and the moderately affected section starts from the 15 kilometer radius of the compound to the political boundaries of Ghazvin Province. After studying the environmental consequences of waste water on flora, fauna, humans, soil and water of the region, a complete Environmental Impact Assessment (EIA) using check list method was conducted in order to identify the environmental impact of Alborz Industrial City on the health and well being of humans, fauna and flora as well as to determine the overall environmental status of the region. Fortunately, the positive consequences of this industrial city surpassed its negative impacts. Moreover, the negative impact was determined to be reversible.

The subject of air pollution has obtained a great interest for study and research. Development of numerical solution methods, has presented considerable contribution in this respect In this paper, the continuity equation and the equation of motion for in viscid flow are coupled with equation of pollution concentration transport This numerical model presents a system of simple convective equations. A Finite Volume Method is applied for solving the governing equations on triangular unstructured meshes. Using unstructured meshes provides great flexibility for modeling the flow in arbitrary and complex geometries, such as urban environments. The equation of continuity is simultaneously solved with convective equations in a coupled manner using Artificial Compressibility technique. In order to verify the model, numerical model results have been compared with available experimental measurements for pollutant dispersion in an urban street canyon. The efficiency of the developed computer code is demonstrated by its application to simulation pollutant transport in urban environments. Finally, some conclusions are drawn, and a few recommendations for further research on numerical works are made.

Chemical treatment of textile wastewater by use of coagulating materials has been used as one of the most effective methods in removing dye and organic materials in wastewater.In this research, for determination of output of omitting dye and turbidity of Aluminium Sulphate (Al2So4 - 6H2O) and ferric Chloride (FeCl2 - 6H2O) coagulants and polyelectrolete coagulant aid have been used. Optimum pH and density used for each coagulant were received regarding removal of dye and turbidity. Wastewater being tested was of direct dyes group, disperse, and reactive. As a sample, alum direct dye and polyelectrolyte, as the best coagulant and ferric chloride as sample of disperse wastewater had the best output considering removal of dye and turbidity.Further, alum together with lime snowed the best output considering omission of dye and turbidity for wastewater of different reactive dyes.

Dry periods in the recent years and unconditional usage of ground water without attention to its actual potential have been cased to enhance depletion of the Hashtgerd aquifer. The study of the Hashtgerd plain was conducted to show its negative effects. The current study is for past ten years periods (1369-1379). The presented article contains geology, meteorology and hydrology of the study area. With collected data from the respected organizations, analyses of ground water potential were performed. The results showed a 6.14 meter ground water depletion for the current period with an average of 30 million cubic meter depleted storage.Proposed recommendations are to control discharge of authorized wells, installation of water meters and to prevent discharge of unauthorized wells. Considering the geological and climatic conditions of the Kordan River with its 11 million cubic meter annual surplus water, artificial ground water recharge was proposed.

Air Pollution is one of the, man's most important environmental difficulties. Therefore, this problem should be controlled and solved by using suitable and efficient methods. Phenol and its derivatives which are used in many of Chemical, Petrochemical Oil, Paints and Explosive industries; are dangerous gas and vapor contaminants that spread in the environment and cause air pollution. Biofiltration is one of the simple, reliable and low investment cost methods of gaseous contaminants removal.This investigation carried out in two Batch and Continuous methods to achieve an applicable removal of phenol by its biodegradation. In batch test a pure culture of microorganisms that affected by phenol for two months in biofilter bed; prepared. Finally a few distinct colonies cultured in a shaking incubator for 48 hours introduced with varying and we got significant results. In continuous test during 110 days we achieve a mean removal efficiency of 61%-75% with changing the volumic flow and residence time of23, 28, 38, 57 and 75 seconds, and in low concentrations of 40-125 mg/m3.