Environmental Sciences
Year:2017 | Volume:15 | Issue:1|Papers Count:12

Introduction: Participatory teaching as a teaching method is a form of inter-personal relationship (Hsiung, 2012). There is an obvious gap in using the participatory teaching method for conveying environmental principles and monitoring them and examining studies of this teaching method would significantly help environmental educators (Baker and Clark, 2010) and activists in selecting the most effective method for conveying the principles (Alton-Lee, 2012). Such training can be effective in developing interpersonal and mental skills and high-level critical thinking skills, bringing about more learning, efficient memorizing of information and classrooms enjoyment. This article aims to compare and monitor the effectiveness of inculcating urban environmental topics using the Jigsaw participatory and a traditional teaching method. The main questions outlined here are as follows: Which of aforementioned teaching methods is more effective in conveying urban environmental topics? How is the sustainability of environmental principles over time.Materials and methods: This is a quasi-experimental study with a pre-test/post-test design among two groups (participatory and traditional teaching methods). The statistical population consisted of male grade-three elementary students in Ahwaz, Iran. A total of 62 students (32 in the participatory teaching group and 30 in the traditional teaching group) were enrolled as the sample using random cluster sampling. Identical groups were verified using the pre-test and reliability was verified using Cronbach's alpha (0.84). The teaching methods were performed for three consecutive weeks and post-test was performed after one week and one month. Independent and dependent t-tests and effect size were employed to analyze the data using SPSS.Results and discussion: The results of the independent t-test of pre-test in participatory and traditional groups showed that the level of awareness concerning the urban environment is equal among the students and no significant difference was observed between two groups. The mean scores of participatory and traditional teaching methods were 18.68 and 18.66 in the pre-test concerning urban environmental topics, respectively. The results of post-test after a week showed that the mean scores were 26.28 and 23.10 in the participatory and traditional groups, respectively. They were 25.65 and 21.93 after a month, respectively. The mean scores were greater in the participatory group than in the traditional group at the post-test stage after one week and one month. The results of effect size showed that the effect size of the Jigsaw participatory method was 1.870 over a one-week interval and 2.137 over a one-month interval. According to the results of the dependent t-test, the level of awareness had a significant difference before the intervention and one week after the training programme. One month after the training course, the level of awareness decreased from 26.28 to 25.65 in the participatory group, and from 23.10 to 21.93 in the traditional teaching method group. A significant difference was found compared with the test prior to the training course. These results showed that students taught through the Jigsaw participatory method learn better than those taught through the traditional teaching method.Conclusions: The results of analyses showed that the level of awareness about the urban environment was significantly greater in students taught by the Jigsaw participatory teaching method than those in the traditional teaching group. The results of monitoring the effectiveness also showed that the Jigsaw participatory teaching method was superior to the traditional method.

Introduction: Nowadays, the study of estuarine zones is essential because more than half of the world’s population is living along estuaries. As a result, estuaries are potentially facing a lot of different pollutants, including heavy metals. For this purpose, estuary conditions must be simulated. Since the formation of estuaries is the result of mixing of fresh river water with saline sea water, they can be simulated by creating different salinity regimes.Materials and methods: this simulation was an attempt to study the behaviour of heavy metals (Zn, Pb, Ni, Cu and Mn) in the estuary of the biggest river of northern Iran, the Sefidrud River that flows into the Caspian Sea. For this purpose, fresh and saline water were mixed in 5 different proportions until salinity regimes of 1 to 3.4 psu were created. After flocs were formed, each of samples was filtered separately by 0.22 -μm Millipore membrane filters. Filters containing the flocs were put in small beakers, and 5 cc of acid nitric was added to the beakers. After 6 hours both filters and the flocs on the filters were digested. The volume of liquid inside the beakers was increased to 10 cc by using 1 N HCl. The metal contents of the metals were measured by ICP. Cluster analysis, a statistical method, was used to determine the effect of chemical and physical parameters on the flocculation process.Results and discussion: Estuaries act as filters to reduce the load of heavy metals in saline water environments such as seas. The present investigation provides a laboratory experimental study of eliminating soluble and colloidal elements of manganese, zinc, lead, nickel and copper during the estuarine mixing of Sefidrud River water with Caspian Sea water due to the flocculation process. The results obtained show that the two elements zinc and lead are, respectively, flocculated at 100% and 0% during the estuarine mixing. Such extremely high and low flocculation is indicative of the conservative and non-conservative nature, respectively, of Pb and Zn. The flocculation rates of copper, nickel and manganese are as follows: Cu (55%)>Ni (41%)>Mn (4%). In other words, various portions of the studied metals are removed during estuarine mixing in the form of tiny flocculants. Statistical analyses indicate that S, E, C, pH and Eh govern the flocculation of zinc. Dissolved oxygen was the only parameter that affected the flocculation of copper. It should be pointed out that the flocculation of nickel and manganese is not governed by S, EC, pH and Eh.Conclusion: estuarine zone has different effects on different metals because of the various forms of the metals and chemical and physical parameters.

Introduction: Today, meddling by human beings in nature has distorted the environmental systems and this has led to uncontrolled flooding, extreme storms, warming of the Earth, the extravagant consumption of natural resources and, recently, drying up of lakes. One of the most significant environmental threats that have happened in Iran over recent years is the reduction in the volume of Lake Urumia’s water. The objectives of this study are to assess the effect of the aforementioned issue upon the economic, social and environmental status of the residents living around the margins of the lake, the residents' perspectives on the contributing factors to the drying up of the lake, procedures for reviving it and also prioritizing the economic, social and environmental consequences.Materials and Methods: the current research is an applied research and the procedure used for data collection is causal-comparative. The required data were collected from a sample of 300 of the residents of Malekan Township who filled out a questionnaire in 2015. In the descriptive part, the frequency, cumulative percentage, variance, standard deviation and average were calculated. In the inferential part, variance analysis, average comparison and the t test were applied. By applying an analytic hierarchy process, the priority among the economic, social and environmental consequences of the drying up of Lake Urmia was identified according to the residents' opinions.Results and Discussion: The results indicated that, after 2009, all of the products except the gardens have significantly reduced in comparison to the previous period. Assessing the data indicated that the economic condition of the region had worsened in comparison with that of 2009. However, the average of this variable decreased before 2009 by moving away from the lake, while it increased after 2009 by moving away from the lake. In other words, environmental conditions improved by moving away from the shoreline after 2009. Consequently, as time goes by, the residents' status has worsened by drying up of the lake. The aforementioned results are compatible with that of Rahmati and Nazarian (2010) in relation to the negative consequences on rural regions of constructing the Upper Gotvand Dam. According to the residents of the region, the Government has played the most significant role in the drying up of Lake Urumia by constructing highways, dams and not preventing the construction of unlawful roads. The authorities have proposed transferring water to the lake, freeing the water of the dams, cloud seeding, using better irrigation methods and planting crops with high efficiency as ways for resuscitating Lake Urumia. The analytic hierarchy process indicated that the residents of the region have considered environmental consequences as the most significant factors in the drying up of the lake and considered social and economic consequences as placed at the next levels.Conclusion: considering the fact that more than half of the residents have considered freeing the water of the dams as a significant factor in revitalising the lake, despite loss of their income, the revitalisation of the lake is a priority to them. The environmental consequences of the lake drying up are threatening. However, on the other hand, it p rovides politicians with enough motivation to consider people’s priorities over economic consequences. Consequently, they would be able to plan restoration of the lake while considering the aforementioned results.

Introduction: Based on Kaya equation, this paper evaluates the effects of macroeconomic variables on the environment quality in MENA region. The process of economic growth and development in developing countries, including the Islamic Republic of Iran and other the Middle East and North Africa countries, have created increasing pressure on the environment. The costs of environmental degradation in the MENA region is about %5 of gross domestic production and in the Islamic Republic of Iran is over of %7 (Croitoru, Lelia et al, 2010). In the other hand, Environment damages and emissions have faced sustainable growth and development with doubt. Given the importance of the environment and energy resources in sustainable development, we try to identify impacts of the factors such as population, gross domestic production, energy intensity and carbon intensity on carbon dioxide emission as an important indicator to measure performance consistent with environment quality and sustainable development, because of all the greenhouse gases, the share of carbon dioxide emission in global warming is %94.7 (Nordhaus, 1990).Materials and methods: According to the above, on basis of Kaya relationship and by using the data from (1990-2011), we assessed the contribution of macro factors, the kaya identity has been widely discussed in analyses of energy-related carbon dioxide (CO2) emissions (O' Neill et al., 2000). In the first step, the share of each macroeconomic variables was investigated by using the Logarithmic Mean Divisia Index, Which is considered one of the most widely used decomposition techniques in the short term. To long-term analysis, After determining the input values related to MENA region, The panel data method was used that indicate the presence of co-integration in the model, Co-integration concept is reminiscent of a long-run equilibrium relationship between economic systems move over time towards it (Noferesti, 1999). The models such as fully modified ordinary least square (FMOLS) or dynamic ordinary least square (DOLS) is more effective method in the case of co-integration panel data estimation (Chen et al., 1999). So FMOLS co-integrated model was applied on the variables and the results of parameter estimation was achieved in the long run.Results and discussion: Background checks in developed countries and areas shows that gross domestic production and demographic variances have increased the carbon dioxide emissions in these countries, whereas this change is largely offset by the decrease in energy intensity and substitution of renewable energies, in the long- run term. Parameter estimation results in this research suggest a significant long-term impact on GDP, population and the carbon intensity on carbon dioxide emission. In the region, Results of the Logarithmic Mean Divisia method in the short term show that the demographic factor has the greatest impact on emissions and gross domestic production, energy intensity and carbon intensity are. At five-year intervals and on average, demographic, gross domestic production and energy intensity have been increasing emissions and carbon intensity has been the reverse impact. Coefficients of panel models show that in the long term population growth in the MENA region has the greatest impact on carbon emissions, Energy intensity is the next.Conclusion: According to the results of short-term and long-term, compared with developed countries, energy intensity index can play a key role in enhancing the quality of the environment in MENA countries. hence, the region needs attention from policy-makers to improve energy intensity index.

Introduction: Parishan wetland is one of the most valuable and ecologically important ecosystems in the world which has completely dried up in recent years due to successive droughts (Dehghani, 2007). Considering that heavy metals are among the most important pollutants of the environment, their survival time is high in sediments (Ullah et al., 2017). Also, these metals have harmful effects on aquatic ecosystems, and sediments are both a source of and a place to store these elements. Acquiring information about these metals is important (Bhuiyana et al., 2010).Materials and methods: The purpose of this study was to estimate the level of contamination of Perishan wetland sediments with the heavy metals copper, iron, manganese and zinc using the enrichment index, geochemical accumulation index, degree of contamination and the comprehensive pollution factor index. In this study, 40 sediment samples with a weight of 200 g were systematically harvested. After acid digestion and filtering to read the concentration of toxic metals liberated in each sample, an AAS atomic absorption device by the Thermo Company (UK) was used. In this study, because of the lack of any specific standard for soil contamination in our country, standards from other countries were used. The average concentration of the metals studied in the region is lower than the maximum acceptable concentration (mg / kg) for the countries of Poland, Canada and Australia.Results and discussion: The changes in pH and electrical conductivity (Ec) were calculated in the range of 2.7-9.2 and 4.2-34, respectively, and the concentration of heavy metals based on mg/kg was found in most samples including manganese (2.18-3.71), iron (3.6-4.26), zinc (2.15-8.3) and copper (5.3-8.13), respectively. The background concentration for manganese, copper, iron and zinc was 950, 50, 41000 and 75 mg/kg, respectively. The geochemical accumulation index, the pollution factor and the comprehensive pollution factor index were all used to determine contamination levels in the area. The geochemical accumulation index was less than zero for all metals, which shows the non-contamination class of the area. In addition, the factor of contamination index for most of the samples was in the class unpolluted, and the contamination factor for all metals was less than one, so that all data were placed in the non-contaminated class. The results also showed that the elements of manganese, copper, iron and zinc have a geological and agricultural origin, while the concentration of metals in the soil was related to their natural origin.Conclusion: Finally, it can be stated that the studied area has the lowest risk of contamination with heavy metals. In fact, it can be said that the copper, iron, manganese and zinc found in this region have a geological origin and they change through the natural processes of geology and through springs in the wetland.Acknowledgement: We would like to thank Khorramshahr University of Marine Science and Technology for supporting this work under research grant contract No.75.

Introduction: According to a World Bank report, the urban growth rate is increasing more than the rate of population growth throughout the world. Such an urban growth rate may cause environmental crises on different levels (global, national and local) if there is a failure to consider ecological factors. It is obvious that development of metropolises such as Tehran is also impossible without considering some master plan which defines the appropriate urban development planes based on ecological criteria.Materials and methods: It seems that land suitability indicators based on ecological criteria may provide a suitable basis for urban planning purposes in order to identify a better solution and prevent environmental crisis. Multi-criteria assessment is required to find the suitable ecological criteria for evaluating urban development potential, therefore a multi-criteria decision making approach using GIS techniques was employed during present research to find appropriate ecological criteria. Besides that and due to inherent uncertainty governing the decision making process as well as the incompatibility of different judgments made by various decision makers, we were encouraged to use fuzzy logic to eliminate ambiguity of decisions in this research.Results and discussion: During the present study the necessary factors were extracted through a literature review and the Delphi Technique, and were entered into a GIS database. Information layers were combined using weights derived from Delphi Techniques and the ultimate decision was made based on the two Boolean and Fuzzy Logic using ARC GIS 10.1.Conclusion: Final results revealed that there is no more room for horizontal development in the City of Tehran.

Introduction: Sludge treatment in wastewater treatment plants is one of the most difficult challenges for professionals and officials (Heidari et al., 2014). The most important indicator of the presence of pathogens in the sludge and wastewater is the presence of coliforms (Tchobanoglous et al., 2003; Metcalf & Eddy, 2003). Ultrasound waves at frequencies of 20 to 200 kHz with high levels of energy is one of the new methods for disinfection of water and wastewater treatment plants (Foladori et al., 2010; Show et al., 2007; Pilli et al., 2011). The purpose of this study is to determine the effect of ultrasonic waves with a low wavelength to improve removal rate of total coliform and Escherichia coli in sludge and determine the optimum operating parameters of the ultrasonic method.Materials and methods: This study is a cross-sectional study that was conducted in a laboratory-scale batch. Accordingly, during two seasons, 12 samples were taken at an interval of 15 days. In this research, variables include ultrasound density (0.375, 0.75, 1, 1.3 and 2.5) in watts on ml and time (1, 5, 10, 15 and 30) in minutes. In this research the influence of these variables on the total coliform and E coli of sludge is measured. The ultrasonic device used in this study was a probe with a maximum output power of 750 watts and frequency of 20 kHz. All bacteriological tests were conducted using the MPN method in a few steps of possibility, confirmation and completion and they were performed using 15 tube methods with units of MPN per 100 ml. All the experiments have done in the Nano, Water and Wastewater laboratory of the Department of the Environment at the University of Tehran. All the experiments were performed on the basis of standard methods for water and wastewater experiments with No.9221 (APHA, 2005).Results and discussion: With ultrasonic waves and through the destruction of the cell walls of pathogens, viruses and microbes and the disintegration of pathogens result in the disinfection of sludge. The high temperatures caused by cavitation can also be locally led for the elimination of pathogens. It seems that the hydrodynamic force and local high temperature zones caused by the cavitation phenomenon are the most important mechanisms influencing sludge disinfection process through applying ultrasonic waves. The results of this study showed that removal of total coliform and E. coli increased with an increase in the time and ultrasound density. The experiments determined that the optimum operating parameters are a sonification time of 30 minutes, ultrasound density of 2.5 W/ml in a frequency of 20 kHz. The removal rate of total coliform and Escherichia coli under these circumstances was more than 99 percent which is equal to the removal of 2 logs.Conclusion: Based on the results of this research, ultrasound waves can remove coliform and disinfect the sludge and can increase the treatment rate.

Introduction: biofouling is the term applied to the colonization, accumulation and growth of living organisms on different substrata exposed to an aquatic environment. These structures include natural and artificial substrates. biofouling communities are both economically and ecologically important and play a basic role in transferring of energy in food chains and ecosystems functioning. Also, by creating multi-dimensional substrates these communities provide different habitats for other organisms. From an economic viewpoint, the colonization by these organisms on ship hulls, boats, aquaculture cages and marine structures such as pipelines can cause economic losses (Yebra et al., 2004; Schultz et al., 2011). In spite of all this, there is little information about these communities in the Caspian Sea and there is almost none concerning the Iranian coastline of the Caspian Sea.Materials and methods: This study was conducted in May 2015 till May 2016 in Astara Port in order to investigate the effect of substrate surface on temporal variations in biofouling assemblages. Five replicates of PVC panels (12×12×0.3 cm) were deployed horizontally at a depth of 1m. The panels were retrieved and replaced with new series every two months for a period of one year. At each sampling event, the upper and under sides of the panels were photographed separately and then analyzed using CPCe software (Kohler and Gill, 2006) for estimating the percentage of cover on each surface. The biomass and inorganic to organic ratio were calculated using dry and ash weight.Results and discussion: In total, six major groups including barnacles, bryozoan, algae, polychaete, mussels and hydroids were identified. Amphibalanus improvisus was the most dominant species in this study and was observed all year round. Cheilostome and Ctenostome bryozoans were the second most dominant groups. These two groups mostly provided the temporal variations in studied communities. Two-way ANOVA analysisshowed that the period of submersion and the surface have a significant effect on percentage of cover, total biomass and inorganic to organic ratio of fouling communities (p<0.05). Generally, the percentage of cover, total biomass and inorganic to organic ratio were higher for the under sides of the panels than the upper sides. The greatest total biomass and inorganic to organic ratio were observed during summer, whereas, the highest percentage of cover was observed in autumn. The results showed that the upper side of the panels had more autotrophic species such as algae, while, the under sides mostly consisted of heterotrophic species with calcium carbonate structures.Conclusion: Since the shipping industry and human-made marine structures are continuously increasing and predictions indicate that fouling pressure and its economic costs will also increase as a result of global warming, the results of this study have implications for management strategies dealing with biofouling issues. Therefore, more studies in the long-term must be performed to monitor the biofouling communities in this area.

Introduction: The global environmental governance system (GEG) has not proved very successful in achieving its main goals, namely protection of the environment and achieving sustainable development. The reasons for this failure, among other things, are the lack of cooperation and coordination among international actors, proliferation of multilateral environmental agreements (MEAs) as well as other international environmental instruments, inappropriate institutions and structures, non-compliance with international MEAs, failure to implement the obligations stipulated in agreements and other international instruments, inefficient use of resources, undemocratic decision-making methods, a global environmental governance system operating outside the environmental arena and the absence of non-state actors in this state-centric system (Najam et. al., 2006). This paper has sought to find reasons of failure of the global environmental governance system and identify the type of measures required to overcome such failures.Method: Employing the library research method and using research papers and monographs by researchers who work on the subject of global environmental governance system as well as primary sources, the present paper has studied the current condition of global environmental governance system. Taking into account the serious global deterioration of the environment, this paper has surveyed some of reasons in respect of inefficiency of the current global environmental governance system and presents a number of proposed solutions in respect of global environmental governance reform.Results and discussion: In the global environmental governance system (GEG), through a process of producing documents and institutions, a structure consisting of necessary soft law and hard law documents has been developed for implementation of such documents and their obligations and requirements (Saunier and Meganck, 2007). However, even if states possess the political will for the protection of the environment, it is very unlikely that such states can actually protect the environment through the uncoordinated responses of such states, and one cannot expect to bring such trans-boundary phenomena, namely environmental deterioration, under control, without achieving an acceptable level of cooperation and coordination. Besides, current institutions like the United Nations Environment Programmeme (UNEP) suffers from inefficiency in protecting the environment (Charnovitz, 2002), and despite the numerous Declarations, Conventions, and other international instruments, there still remain a number of environmental challenges like climate change, air pollution, soil erosion, ocean contamination, hazards caused by nuclear activities or genetically modified organisms, depletion of natural resources, extinction of species, and landscape destruction. Therefore, it is essential for states to comply with the current multilateral environmental agreements as well as other international instruments, and implement and enforce such instruments through strengthening coordinating institutions, UNEP, and instituting closer and a more efficient cooperation of international actors including states, civil society institutions like non-governmental organizations, and the private sector.Conclusion: Reform in the global environmental governance system (GEG), among other things, requires cooperation and coordination between states, civil society institutions, and the private sector. It also need compliance with MEAs strengthening United Nations Environment Programmeme (UNEP), expanding the role of the Global Ministerial Environment Forum (GMEF), reforming existing United Nation’s bodies, strengthening financing sources and mechanisms, building up the environmental competence of the World Trade Organization (WTO), different possible models for a World Environment Organization, reforming the United Nations Trusteeship Council, expanding the mandate of the United Nations Security Council and establishing a World Environment Court.

Introduction: Transportation and traffic flows are the main factors of air pollution in Iran. Therefore it is essential to investigate their effects on the air quality of urban areas to forecast more accurately and manage better traffic and pollution. Unfortunately, not much research has been conducted on this issue in Iran. Identification of pollutant sources is the most important and time-consuming stage of air pollution modelling. We cannot consider only one variable for air pollution modelling in a single region. Hence, different variables should be taken into account, studied and planned. Some measures make significant changes in the air pollution of a metropolis. Hence, undertaking a series of measures can reduce the air pollution, and adopting new methods to evaluate the air pollution is one of these measures. The main goal of this research is to offer a smart model by which concentration of pollutants such as CO can be estimated with the appropriate accuracy and, by examining the causes of these pollutants and predicting the air pollution, the necessary actions to manage and control the air pollution can be planned (Hassan and Croether, 1998).Materials and methods: In this paper, a neural network model and a nonlinear state space model were designed based on urban traffic in Shiraz. In these models the concentrations of CO, NO2 and SO2 pollutants were analyzed and also estimated using a Kalman Filter for a 24 hour cycle. The models are based on the correlation between the volume of pollution, traffic, initial pollution and meteorological information. The extended Kalman Filter algorithm was used to analyse and predict the air pollution in Shiraz over a 24 hour period. A key factor of the proposed system is its adaptation with the short time pollution changes (Safavi, 2008; Brown et al., 2007).Result and discussion: In this research, traffic and pollution data caused by pollutant concentrations has been studied, then an attempt was made to match these air pollution data with significant parts in Shiraz city and many traffic and pollution data were excluded due to a mismatch in terms of location. Finally, modelling was updated based on this data and the result was adapted to real data. This nonlinear model structure offers the advantage of being evolutionary and sufficiently flexible, in the sense that the overall evaluation of the model performance can easily be undertaken by excluding or adding input variables. On the other hand, if the corresponding data of each new station is available, the study can be extended to other parts of Shiraz city. So, if traffic data is available in some parts of the city, the pollution can be extended to some other parts and be reduced in critical areas using certain traffic strategies.Conclusion: The neural network method and the Kalman Filter were tested on Shiraz pollution data which revealed that the models, specially the Kalman Filter, work reasonably well.