City hazardous gas monitoring network

In our today's societies, many dangerous chemicals are produced and transported. Due to the vast use of chemicals, more chemical accidents are taking place with huge losses. In this study a city hazardous gas monitoring network was designed to detect the dispersion of toxic and combustible gases in the primary stages. The network could cover hazardous chemical facilities, important hazardous chemical routes, warehouses and special locations which may be the targets of terrorist attacks. The network is consisted of several local networks and a central control panel complex. Each local network has a local control panel in the center and many detectors and sounders around it at distances less than 3000 m that communicate with the local control panels wirelessly. In each location there are two types of gas detectors, toxic and combustible, and a sounder which are equipped with a wireless, radio frequency modem allowing the units to communicate readings and other information on a real-time basis with a remotely located local control panel. High sensitive Photo Ionization Detectors, PIDs, are used to provide fast and low-level on-site screening for chemicals contamination. Combustible gas detectors are the second choice to sense the combustible gas and verify the readings of PIDs in this regard. The central panel consists of several connected control panels work uniquely helping a computer set and the appropriate software and communicate with local control panels via telephone lines. All of the network components are shown on the monitor of central panel with special symbols by geographical information system program. The system is fully addressable so that the high level detection of a detector produces a blinking color double-circle around its symbol in GIS plan. In case of high level gas detection, a team of experts who are fully equipped with different portable detectors depart to the site to test the field to identify the chemicals. All readings of detectors are saved in a data bank and then analyzed to find any chemicals spills and leakages. The network was simulated by a special program so that the components of local networks and the central panel are shown in separate windows. By clicking on one detector on environmental window the formerly designed responses will be activated in central panel window.     

A mini review of bisphenol A (BPA) effects on cancer-related cellular signaling pathways

Environmental Science and Pollution Research - Bisphenol A (BPA) is a plasticizer used widely in many industrial products and is now well established as an endocrine-disrupting chemical (EDC). BPA...     

Application of dynamic models to estimate greenhouse gas emission by wastewater treatment plants of the pulp and paper industry

Greenhouse gas (GHG) emission in wastewater treatment plants of the pulp-and-paper industry was estimated by using a dynamic mathematical model. Significant variations were shown in the magnitude of GHG generation in response to variations in operating parameters, demonstrating the limited capacity of steady-state models in predicting the time-dependent emissions of these harmful gases. The examined treatment systems used aerobic, anaerobic, and hybrid—anaerobic/aerobic—biological processes along with chemical coagulation/flocculation, anaerobic digester, nitrification and denitrification processes, and biogas recovery. The pertinent operating parameters included the influent substrate concentration, influent flow rate, and temperature. Although the average predictions by the dynamic model were only 10 % different from those of steady-state model during 140 days of operation of the examined systems, the daily variations of GHG emissions were different up to ±30, ±19, and ±17 % in the aerobic, anaerobic, and hybrid systems, respectively. The variations of process variables caused fluctuations in energy generation from biogas recovery by ±16, ±17, and ±14 % in the three examined systems, respectively. The lowest variations were observed in the hybrid system, showing the stability of this particular process design.     

Optimal redesign of groundwater quality monitoring networks: a case study

Assessment and redesign of water quality monitoring networks is an important task in water quality management. This paper presents a new methodology for optimal redesign of groundwater quality monitoring networks. The measure of transinformation in discrete entropy theory and the transinformation–distance (T–D) curves are used to quantify the efficiency of sampling locations and sampling frequencies in a monitoring network. The existing uncertainties in the T–D curves are taken in to account using the fuzzy set theory. The C-means clustering method is also used to classify the study area to some homogenous zones. The fuzzy T–D curve of the zones is then used in a multi-objective hybrid genetic algorithm-based optimization model. The proposed methodology is utilized for optimal redesign of monitoring network of the Tehran aquifer in the Tehran metropolitan area, Iran.     

Heavy metal contamination in feathers of Western Reef Heron (Egretta gularis) and Siberian gull (Larus heuglini) from Hara biosphere reserve of Southern Iran

The main objectives of article were monitor the metal concentrations of cadmium, lead, copper, zinc, cobalt, and iron, in the feather of shorebirds species, Western Reef Heron (Egretta gularis) and Siberian Gull (Larus heuglini) from Hara Biosphere Reserve of Southern Iran; and identify any relationships between species. Assaying heavy metals by using Shimadzu AA 680 flame atomic absorption spectrophotometer, the results were given as micrograms per gram dry weight. The concentrations of heavy metal were found to follow the order of iron>zinc>copper>lead>cadmium>cobalt for E. gularis and of iron>zinc>lead>copper>cadmium>cobalt for L. heuglini. Also, they showed that the cadmium, copper, and cobalt concentrations were higher in females than in the males, while the lead concentration for E. gularis and L. heuglini was higher in males. The cadmium concentration means they were measured as1.16 and 1.37 μg/g for E. gularis and L. heuglini, respectively, whereas the lead concentration means 7.04 and 5.48 μg/g for E. gularis and L. heuglini, respectively. The concentrations of nonessential trace elements in E. gularis and L. heuglini were generally comparable to values reported in other studies. The average levels of lead we observed in these birds were greater than 5 μg/g dry weight in the feather that is known to be associated with adverse behavioral or reproductive effects. Data analysis showed that there was a positive correlation between copper and zinc (P?相似文献   

Contamination of lead (Pb) in the coastal sediments of north and south of Iran: a review study

Coastal areas of Iran are heavily affected by urbanisation, industrialisation, and maritime activities. One consequence of this environmental pressure is the contaminants accumulation, as heavy metals, into the marine ecosystem. In this review, the coastal areas in the north and south of the country were assessed for lead (Pb) contamination of, one of the most toxic metals found in the environment. All studies conducted during 2006–2016 with at least 10 specimens that reported the mean and standard deviation of Pb were considered in this review. Heterogeneity between studies was assessed using the Q and I² statistics. The Pb mean concentration overall studies was estimated to be 21.88?µg/g (95% CIs: 16.25–27.50). Random effect model showed no statistical difference in mean Pb concentration levels between south and north coasts. However, the variability in Pb mean concentrations within southern coasts was considerable and statistically significant. Moreover, the Pb concentrations in the northern coasts of Persian Gulf and Oman Sea, in south of Iran, decreased in the following order Hormozgan > Khuzestan > Sistan-VA-Balluchestan > Bushehr while in the southern coasts of Caspian Sea, in north of Iran, decreased in the order Guilan > Mazandaran > Golestan.     

Development of urban planning guidelines for improving emergency response capacities in seismic areas of Iran

This paper presents the results of research carried out to improve emergency response activities in earthquake-prone areas of Iran. The research concentrated on emergency response operations, emergency medical care, emergency transportation, and evacuation—the most important issues after an earthquake with regard to saving the lives of victims. For each topic, some guidelines and criteria are presented for enhancing emergency response activities, based on evaluations of experience of strong earthquakes that have occurred over the past two decades in Iran, notably Manjil (1990), Bam (2003), Firouz Abad-Kojour (2004), Zarand (2005) and Broujerd (2006). These guidelines and criteria are applicable to other national contexts, especially countries with similar seismic and social conditions as Iran. The results of this study should be incorporated into comprehensive plans to ensure sustainable development or reconstruction of cities as well as to augment the efficiency of emergency response after an earthquake.     

Designing a developed model for assessing the disaster induced vulnerability value in educational centers

To date, the models developed for assessing the vulnerability of societies have only taken account of the economic problems in the societies. Offering a model based on analytical hierarchy process and failure mode and effect analysis logic, the current study aims to determine the factors influencing the vulnerability of a higher education center and finally defines a vulnerability index. This model divides the factors influencing vulnerability into three categories: (1) the structure and layout of the buildings, (2) the occupants’ characteristics, (3) the controlling and warning systems. The academy community center of Science and Research Branch was assessed in terms of vulnerability. The findings indicated that the vulnerability value relating to various sections and university buildings was higher than the acceptable level which entailed the due attention of educational managers. The findings showed that if some parts of the educational and administrative buildings were used for laboratory as well as for the storage of hazardous and flammable materials, then the vulnerability value will be increased to 200. This highlights the impact that the type of buildings application has on the level of vulnerability. The study has been performed in the Science and Research Branch as an educational center in Tehran during 2009–2010.     

Sources of lead and zinc associated with metal smelting activities in the Trail area,British Columbia,Canada

The spatial distribution and deposition of lead and zinc emitted from the Trail smelter, British Columbia, Canada, was studied by strategically locating moss bags in the area surrounding the smelter and monitoring the deposition of elements every three months. A combined diffusion/distribution model was applied to estimate the relative contribution of stack-emitted material and material emitted from the secondary sources (e.g., wind-blown dust from ore/slag storage piles, uncovered transportation/trucking of ore, and historical dust). The results indicate that secondary sources are the major contributor of lead and zinc deposited within a short distance from the smelter. Gradually, the stack emissions become the main source of Pb and Zn at greater distances from the smelter. Typical material originating from each source was characterized by SEM/EDX, which indicated a marked difference in their morphology and chemical composition.     

Distribution of mercury in some organs of the Kani Barazan wetland common coot (Fulica atra)

We document mercury distribution in the tissues (kidney, liver, breast feathers and pectoral muscle) of a waterbird, the common coot (Fulica atra) from the Kani Barazan wetlands in north-western Iran. Bird samples were collected between November 2011 and January 2012, and mercury was assayed by using a Varian 220 atomic absorption spectrophotometer. Mean levels of mercury in kidney, liver, breast feathers and pectoral muscle were 0.13, 0.22, 0.20 and 0.09 μg/g, respectively. Mercury concentrations in tissues of F. atra were in the following order: liver>feather>kidney>pectoral muscle. The mercury level was significantly (one-way ANOVA, p<0.05) different between kidneys, livers, pectoral muscles and feathers in F. atra. Although mercury concentrations were higher for all tissues in female birds compared with males, significant (p<0.05) differences were observed in muscle only.