مجله پژوهش و فناوری محیط زیست
پیاپی 6 (پاییز و زمستان 1398)

Energy consumption is increasing rapidly in the world and it is expected that unrenewable energy sources will expire in the future; therefore, new methods of energy production are becoming more common all over the world. Biogas is one of the new and clean energies, which is produced from anaerobic fermentation of biomass. Guilan province with 238,000 hectares of paddy lands has significant potential for biogas production from organic residues. In this way, this study was carried out to investigate the process of biogas production from the combination of rice straw and animal waste with the ratios of (0-100), (5-95), (10-90), (15-85), (20-80) respectively in three repetitions. The experiment was performed at mesophilic temperature by anaerobic digestion method in the 1/5 lit bottles. An economic and environmental assessment for replacement of biogas produced in this process with fossil fuels was implemented in the village of Pounel in Guilan Province. The results showed that the ratio of 10% of rice straw had the highest biogas production efficiency and by replacing the biogas, 21 percent will save in fossil fuel consumption. It will also prevent the emission of 328.42 kg of CO2 gas into the atmosphere per year.

In recent years, disposal of waste tires is an environmental challenge in many countries. Previous researches has been shown that rubber waste ash and its nanoparticles can be used as an effective source of zinc (Zn) for plant. In this research, feasibility of using nanoparticles and rubber waste (as zinc supplying source in plant) is studied moreover comparing the nanoparticles of rubber waste with commercial zinc sulfate fertilizer available in the market. In this regard, moreover nanoparticles production and characterization them by scanning and transient electron microscope, these wastes were used in cucumber hydroponic culture, then the quantitative and qualitative performance of the fed products were compared with the commercial zinc sulfate fertilizer available in the market. According to the obtained results, by reducing the particle size of the rubber from micron to nano, Zn extractable percentage increased from 1.5 to 2.5%. So, using rubber nanoparticles increased plant performance and also, increased Zn concentration in plant tissues compared with commercial zinc sulfate fertilizer and those grown in control.

In Karaj, the large volume of wastes was produced due to the high level of construction activities such as demolition of old buildings and the construction of new buildings. In this regard, it is necessary to have management system with environmental protection perspective for the construction and demolition wastes (CDW). Therefore, the main purpose of this research was study of the amount and composition of CDW in Karaj municipality zones (10 zones) in 2017 with the financial support of Karaj municipality. In the first step, a little amount of CDW was investigated by Karaj waste management organization's statistics. The results showed that the Karaj construction sector produces 5973 tons (2186410 tons/year) of CDW every day, which is around 3% of the total amount of the country generated CDW. Also, the share of per capita CDW production is 1220 kg/year for each person per year and the maximum CDW generation rate was in the November and December and the minimum one was in March and April. In the second step, the composition of CDW was determined using field observations of the disposal sites and landfills. The average composition of CDW showed that up to 80% of the wastes are composed of the soil operation (soil, sand, stone and …) asphalt and concrete parts, building materials (such as brick, block, plaster, pottery, mosaic, etc.)

Studying the spatial pattern in plant communities is necessary for understanding the many issues in forest ecology and management. The purpose of this study is investigating the effect of recreation on Spatial patterns of trees in Zagros oak forests. Sampling methods were fixedarea plots and T-square methods. In each region, there are 40 sample plots and 40 sampling points were taken to measure the distances in the distance method in each region. To quantify and analyze the distribution patterns in the sample method, Green, Morissita and Standardized Morisita indicators were used and The Hopkins, Eberhardt, Heinz, C, Johnson and Zimmer indicators were used in the distance methods. C, Hopkins and Heinz indicators showed a clumped pattern in the area. But the Johnson Zaimer and Eberhart indicators showed a regular pattern in the control area. The results showed that among the Sample plot indicators the Morissita and Morissita standardized indicators expressed a clumped pattern in the recreational and the control area, and the Green indicator showed a regular pattern in the recreational area and the control area. The values obtained from the distance indicators showed that the degradation in the recreational area caused a change in the spatial pattern and the spatial pattern in the recreational area was changing so that most indicators in this area showed a regular pattern. Among the distance indicators used, C and Hines indicators and among the sample method, the Green indicator showed these differences well and the species of the two regions were identified suitable to describe the spatial pattern.

Many of the pollutants in water are known to be harmful for human health and toxic for environment. Among these pollutants, Arsenic is more important because millions of people are exposed to contaminated drinking water. The World Health Organization (WHO) has identified the permitted limit of below 0.01 mg/L (10 micrograms per liter) for arsenic in drinking water and the same amount for arsenic has been reported in Iran's 1053 standard. In this study, various techniques have been investigated for removing Arsenic and efficiency of different nanoparticles in treatment of Arsenic from drinking water. Common methods of removing Arsenic from water sources are including oxidation, coagulation and flocculation, reverse osmosis and ultrafiltration, ion exchange, phytoremediation and new technologies based on the use of nanoparticles. The findings showed that despite of the high arsenic removal percentage using different methods such as oxidation, ion exchange and floating with dissolved air, these methods are not economic and a lot of time is required to achieve optimal efficiency. Recently, the use of nanoparticles has become very popular, so that metal oxide nanoparticles such as magnetic iron, Zinc, Copper, Serum, and Aluminum can completely eliminate Arsenic soluble with a high concentration of 50 mg/L in water sources and after the adsorbent is saturated, it is possible to use the regeneration of adsorbents, repeatedly by adsorbing the pollutant into the adsorbent. As a result, the use of nanoparticles is better than chemical processes and is economic due to their high efficiency in a short time.

Sand filters are composed of sand-filled containers with determined granulation and specified thicknesses of pressurized sand layers that work under pressure and they are placed in the center control system after the cyclone and before the grid or disk filter. The aim of this study was to determine the relationship between water turbidity and Total suspended solids (TSS). To determine the samples turbidity, they were tested using a spectrophotometer and the percentage of light passing was obtained through each sample separately. The test of determining total suspended solids was also performed. The results of this experiment showed that there is a quadratic equation between the percentage of light passing and total suspended solids, which is presented as the main equation from figure 3, that is more correlated with the data. As can be seen, at 450 nm, there is a higher correlation between the turbidity and the light transmittance and less error. 

These days, the removal of various dyes from industrial wastewater has become an important concern. Synthetic dyes used in industries such as textiles are complex, toxic and mutant organic materials. Congored is also an acidic dye that is considered a high- risk source of contamination and threatens the lives of humans and other living organisms. Different methods, such as electrochemical, physical and biological processes, are used to remove organic pigment from aqueous samples. Adsorption is one of the most effective modern methods of industrial wastewater treatment, which is a relatively simple and inexpensive process that produces non- toxic and low- risk products. The purpose of this study is removing the Congored dye from aqueous solutions and reviewing the accomplished researches for remove it

The purpose of this research is assessing and planning the urban streets of Arak city. In this research, environmental impacts were assessed by using these three methods Multi-criteria like rapid matrix, ANP and fuzzy TOPSIS that both of them are decisionmaking methods. The process that has been followed in this study includes, determining the indicators, (using library studies), specifying geographic area, introducing the options, studying the environmental basic conditions, indicating and predicting and impacts, assessing the impacts using the three mentioned methods and providing the report. In the following, the status of the environmental factors was investigated. Then, the most important factors that might be affected by 58-meter street construction were identified using checklist, and were selected as the criteria for impact assessment. Then environmental impact assessment was separately fulfilled by using three methods like rapid assessment (matrix), fuzzy TOPSIS and ANP. Due to the the more negative impacts relatively to the positive impacts in the rapid matrix method, the project was rejected. In both fuzzy TOPSIS and ANP methods the non-execution option has the most weight and preference. But among these methods, the ANP method is introduced as a suitable method for environment impacts assessment in different projects because of its ability to create a network with interaction between criteria and options at different levels and directions.

To investigate the effects of pennyroyal (Mentha pulegium L.) powder on performances, the concentration of some blood parameters and carcass characteristics of broilers, 160 one-dayold Ross chicks were used in the form of a completely randomized design with four treatments and four repetitions. Experimental treatments included the levels of zero (control), 0.2%, 0.4%, and 0.6% of pennyroyal powder. The treatment containing 0.6% of pennyroyal powder compared to the control group had higher feed consumption in the starter period (P <0.05). However, there was no significant difference during the growth period and the whole experimental period. In terms of average daily weight gain and feed conversion ratio, there was no significant difference between the experimental treatments during the starter, growth and the whole experimental periods. The carcass percentage decreased significantly at the age of 42 days in treatments containing pennyroyal powder compared to the control group (P <0.05). There was no significant difference between experimental treatments in terms of weight percentage of carcass components including thigh, chest, abdominal fat, heart, liver, and gizzard. The concentration of triglycerides and plasma VLDL decreased significantly in treatments containing pennyroyal powder and decreased linearly compared to the control group (P <0.05). In terms of cholesterol and plasma HDL levels, a significant decrease was observed in treatment containing 0.4 level and treatment containing 0.2 percent of pennyroyal powder compared to the control group (P <0.05) respectively. Plasma LDL levels were not affected by experimental treatments. The results of the present study showed that the use of limited levels of pennyroyal powder up to 0.6% has no significant effect on the performance of broilers.

New industrial estates developments must follow the effective factors in protection, management and sustainable development of aquifers and water resources in a plain in order to meet the needs of people. Therefore, assessment of the aquifer vulnerability potential for locating new industrial estates settlements is necessary. So, investigation of the vulnerability of Sari plain groundwater resources for locating the industrial zones is necessery. In this research, the risk map of the plain was prepared using a drastic model to assessment of the effective hydrogeological factors in locating the industrial estates of Sari plain. The results of the Drastic model showed that Sari aquifer vulnerability is classified in three groups of highly vulnerable (10.49%,), very highly vulnerable (56.66%) and too highly vulnerable (32.85%). Sensitivity analysis based on two-way single parameter and parameter deletion methods showed that the depth of the water-table factor is the most sensitive factor on the DRASTIC vulnerability index. Sari aquifer is strongly affected by agricultural and industrial activities' pollutants due to shallow water-table; so, the study area is not suitable for establishment of industrial estates based on the final vulnerability map, the aquifer extreme vulnerability potential and the amount of exsisting pollutant. Also, if environmental considerations are not respected by farmers and the existing industrial units in the plain, the aquifer will be suffering serious damages.

Life Cycle Assessment method is an accepted approach for assessing the environmental impacts of a product's life cycle, which is calculated on the basis of two components: the amount of consuming resources and the release of pollutants to the environment. In this study, the environmental impact assessment of pistachio production from the beginning of planting to the field door was estimated using Life Cycle Assessment (LCA) method in Rafsanjan. Initial data were collected through questionnaire method and interview with local farmers. The collected data were analyzed using Ecoinvent®3.0 database and Simapro8.0.4.30 software. The system boundary, field and work unit were considered as a ton of pistachios in this study. The results of this study showed that the use of diesel and electricity as energy sources lead to the release of CO2, NOx, SOx and heavy metals into the environment. Analysis of the pistachio data showed that emissions from fertilizers in the layers had the highest role in source reduction, global warming, toxicity to humans, toxicity to marine aquatics and chemical photooxidation. Emissions from fuel consumption had the greatest effect on ozone layer depletion.

Forest is a valuable heritage and one of the important factors in the ecosystem of each area that in addition to using and exploiting them, they should be preserved. Zagros’ forests, especially in Lorestan province due to negligence have been destroyed throughout past years. The aim of this research is to investigation, detect and modeling Romeshkan’s forests’ cover changes. To do this, first changes that were taken place between 1987-2017 were extracted by satellite Landsat images and using Fuzzy Object-Based classification method, then, were classified in 5 classes (Agriculture, Forest, Range, water and Residential). Finally, classification results show that there is a sharp decrease of forested areas (81.17 km2 ) and an increase of Range and Farmlands over past 30 years in the forest area. In a period of 1987-2002 forest cover of the study area had not faced major changes, but most of the rangelands turned to farmlands. While in the second period from 2002 onwards forest cover dramatically dipped and its area decreased from 122.58 km2 to 43.42 km2 in 2017, which the rate of forest covers decrement was around 79.16 km2 . Moreover, in order to predict forest cover changes in the future CA-Markov model was applied that indicates 10.70% of current forest covers will be reduced in 2030, and the main changes will be occurred between forest classes to farmlands and rangelands classess by 6.901 and 9.172 km2 , respectively.