JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
Year:2012 | Volume:13 | Issue:4 (51)|Papers Count:9

In this paper, the capability of autoregressive static and artificial dynamic neural networks models was compared for forecasting of monthly inflow of Dez reservoir. In previous researches, static and artificial dynamic neural networks models have not been compared for above-mentioned propose. In addition, using artificial neural network model as an autoregressive model is innovation point of this research. Monthly flow data of Dez station in Dez River in years1955 to 2001 is used in this research. Data of 42 former years and 5 recent years are used for Training and testing data set, respectively. Different structure for the static and artificial dynamic neural network models were evaluated by comparing the root-mean-square error (RMSE) of the models. First, static and artificial dynamic neural network models were selected in training phase using data from October 1955 to September 1997. Then, using the selected structures, the monthly forecasted inflow of reservoir was compared with observed data from October 1997 to September 2001. Also, two types of radial and sigmoid activation function and the number of neurons in the hidden layer were investigated in this study. Results showed that the best model to forecast the reservoir inflow is autoregressive artificial neural network model associated with the sigmoid activation function and 17 neurons in the hidden layers. Artificial dynamic neural network model with sigmoid activation function can forecast reservoir inflow for 5 years better than static artificial neural network's model.

One of the particle control methods is electrostatic charging with scrubbing to produce the charged wet scrubber (CWS). This technology has been used since. This system is practical where the scrubber can be used to remove the pollutants. In fact this system can increase the collecting efficiency and it is not a new technology to control the air pollution. Silica has a very high application in industry. The workers are exposed to these particles and these particles are so dangerous for man kind.Therefore according to ACGIH offer the local ventilation system on pilot has been designed and installed at the first step. Then with a 1275-Volt direct current (DC) power, While the water was charging, 3×1014 electron were produced in the system.With measuring pressure loss by pitot tube and on isokenetic condition, prop diameter became millimeters. Sampling was based on tree method and samples were taken.The result of examination indicated that: 1- In a specified water flow, charging droplet increased inhalation particles collecting efficiency, but this charging droplet isn't effective to non inhalation particles collecting efficiency. 2- Positive charging droplet is the most effective than negative charging droplet. 3- Increasing water flow leads to increasing efficiency in collecting particles.

Wastewater of coal tar plants is counted wastewater pollutant for the environment. For degradation wastewater, usage of Biological systems is a common way. The percentage of removal pollutant is depended on rare types of microorganisms' activities. Some of the materials that are presented in wastewater are inhibitors for microorganism's activities such as: toluene and phenol. Phenol and its compounds are so toxic for human and environment which makes this removal very important. There is a lot of ways for removal or degradation of phenol but the best way is biodegradation. In this study isolated phenol degradation bacteria is from a phenol wastewater of Isfahan steal meal plant. It takes some activities such as diagnosis, phenol removal and adaptation to high concentration of phenol. Results show that one of the isolated bacteria's removals is 2233 (mg/l) phenol which happens during 96 hours and another happens during 120 hours. By usage different isolated bacteria types which are adapted to high concentration of phenol, degradation of it takes much shorter time.

The white- rot fungus phanerochaete chrysosporium immobilized on the mineral igneous was grown in both stationary and agitated cultures using either carbon- or nitrogen-limited growth medium to study the ability of the fungus to degrade various types of textile dyes. Kiss iris immobilized white-rot fungi phanerochaete chrysosporium could completely decolorize 45 ppm of divers structural dye classes: azoic, reactive, acid, basic, disperse and metal-complex within 7-15 days. Except metal-complex the only decolorized by biological absorption, other classes of dyes degraded by lignin's and manganese peroxides enzymes produced by the fungus.During the decolorizing process, activity of lignin's and manganese peroxides enzymes was observed. Maximum activity of each of them, in the shaken and immobilized culture within 8 & 9 was 174 U/L and 500 U/L, respectively.

Impact of irrigation with municipal sewage on accumulation of soil by heavy metals (Fe, Mn, Cr, Pb and Cd) was investigated in two artificial stands Eldar pine (Pinus eldarica Meadow.), 1) irrigated by municipal sewage and 2) irrigated by well water in the suburban areas of Tehran. In each stand, soil profiles were dug and soil samples taken from depths of 0-15, 15-30 and 30-60 centimeter. Municipal sewage and well water were sampled daily (3 days in each month) from early June to late November. Results indicated that municipal sewage had significantly (P < 0.01) higher amounts of Fe, Mn, Cr and Pb compared to well water. Level of these heavy metals in municipal sewage was upon the internationally recommended (WHO) maximum permissible limits set for land use. Application of municipal sewage resulted in a 1.5-fold increase in the concentrations of soil Fe, Mn, Cr and Pb. These heavy metals showed their greatest values in the upper layer of soil (0-15 cm). The concentration of soil heavy metals, with the exception of Pb, was below the critical limits. Cd was not detected in water and soil samples. With regard to high concentration of heavy metals in sewage, it was concluded that the long-term use of municipal sewage in irrigation might enriched soil with heavy metals to concentrations that may pose potential environmental and health risks. Hence regulations about the utilization of sewage in irrigation should consider in order to:1-Control the content of heavy metals that may be added to soil and2- Minimize the risk of negative effects to ecosystem health.

Toluene is one the common and main environmental pollutant factors which often contaminates sites. it is a result of spillages of fuels, solvents or chemicals, also it is one of the major products of petro chemical activities. Because of being highly toxic, it represents a significant environmental hazard for human and has potential toxicity, carcinogenicity, negative effects on reproduction and mortality rates of aquatic animals. This material is a mutagen as well.Microbial degradation represents the major responsible route for removing these pollutants including fungus, aerobic and anaerobic bacteria. It is important that this component degrades in a high dosage that certain species of bacteria will able to degrade it.6 Toluene-utilizing bacteria is isolated from petrochemical of Isfahan soils. Amongst them one strain tolerant toluene is highly concentrated. They were isolated when bacteria exposed on vapor pressure of toluene (1-100%). They used toluene as sole sources of carbon and energy.This strain was identified by biochemical characteristic and 16S rRNA sequencing as Bacillus. Also amount of deletion of toluene were detected by gas chromatography (GC) during growth of the bacteria. The investigated isolates are considered to have a good potential for application in remediation of toluene contaminated environments and industrial wastewater and soils.

The design to construct Sazbon dam and power plant is a sub-group of designs that have anything to do with the tributaries of KARKHE BASIN. The location where the design is going to be implemented is in the province of Illam and eastern part of SARABLEH which is about 3 Km’s after the confluence of two rivers named Simoreh and Cherdaval respectively within the straits of SAZBON. To determine the value of plant covering on the reservoir, first the values of trees and pasture were estimated subject to valuation codes and about 3269 acres of pastures (Echinops orientalis, Astragalus gossypinus, Hordeum spontaneum….,) and about 71 acres of woods shall (Amygdalus scoparia, Pistacia, Quercus brantii, …) be flooded by constructing this dam. The damages were estimated to be 3198970040 billion IR-Rials which are evaluated to be very little against 660 billion IR-Rials of profits as gained by constructing the dam but can be compensated for by powers consumption revenues.

Emrgence of water quality control measure has become more important as a result of water source limitation and increased discharge of pollutants arises from human activities. Besides, social and economic consequences of direct and indirect consumption of polluted waters have duplicated the importance of this control. One of the important and vital problems in healthy water is fecal contamination of water that is important to determine for controlling of epidemic of microbial intestinal disease. In order to study and determine water quality of Haraz river, this river was studied in during 2003-2004 in 17 sites from Emamzade hashem to police station of Bayjan. Water sample were analyzed for microbial (E.coli, Coli form and Total count) contamination. The results showed that the downstream have much higher E.coli and Coli form than upstream and microbiological pollutant in spring season is much higher than other seasons in all of the stations. The results showed that the average E.coli and Coli form in Haraz river water comparing with global standard, because of the various municipal, domestic, agricultural waste water and crowd… is much higher than standards for most applications and it dose not have suitable hygienic quality.