Iranian Journal of Health, Safety and Environment (IJHSE)
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Bacteria of Phlebotominae Sand Flies Collected in Western Iran
Get PDFMicroorganisms particularly bacteria presenting in insects such as Phlebotominae may play an important role in the epidemiology of human infectious disease. Nowadays, because of vector implications, the routine methods of controlling and spraying have no more beneficial effects on vectors and reservoirs. Little knows about the prevalence and diversity of sand fly bacteria. The main objective of this study was to determine the presence of bacteria of phlebotominae sand flies collected in Hamadan, west of Iran. This information is important in order to development of vector control strategies.
The microbial flora of Phlebotomus papatasi and P. sergenti the main vector of Cutaneous Leishmaniasis in the old world, were investigated.
We characterized 8 bacteria, including 5 Gram-negative bacteria: Acinetobacter lwoffii, Pseudomonas aeruginosa, Enterobacter cloacae, Edvardsiela sp. and Proteus mirabilis and Gram-positive bacteria: Bacillus subtilis, Staphylococcus saprophyticus and Micrococcus luteus.
Our study provides some data on the microbiota diversity of field-collected sand flies for the first time in Hamadan. Our results indicate that there is a range of variation of aerobic bacteria inhabiting sand fly, which possibly reflect the ecological condition of the habitat where the fly breeds. Microbiota is increasingly regarded as an important factor for modulating vector competence in insect vectors. So, mirobiota can be effects on the biology of phlebotominae and their roles in the sandfly-Leishmania interaction.
Further experiments are required to clearly delineate the vectorial role of sand flies. Because it is probable that in the future, factors such as environmental changes, migration and urbanization can ease the transmission of leishmaniasis in this area
Community environmental consciousness in Nigeria
Get PDFAssessment of community consciousness of environmental problems in Nigeria is at best incoherent, and incomplete. Two views, however, seem to predominate. First, there are those who speculatively believe that the vast majority of people are unaware of the magnitude of environmental problems confronting them and that only the better – educated and high income groups seem to be able to make a connection between the health of their family and environment in which they live. Second, there are those who through direct research surveys have come to some form of conclusion that ordinary people possess a substantial knowledge of the complexities of environmental problems besetting them and indeed make efforts to articulate and adjust favorably to them. In order to investigate this problem, one hundred copies of questionnaires were distributed to selected Government ministries, departments and agencies(MDAs), non-governmental organizations(NGOs) and community-based associations(CBAs) in two geo-political zones of south-south and south- east Nigeria. Respondents unanimously selected four of the six policy alternatives suggested for a solution to the environmental problems. These included: institutional policy and legal framework, capacity building and institutional strengthening, private initiatives and collaboration with international organizations. Whatever conclusion may be reached from these opposing views, one thing is certain and that is consciousness of environmental issues, especially pollution, is low and least understood in Nigeria
Stabilization and dewatering of wastewater treatment plants sludge using the Fenton process
Get PDFWastewater sludge typically contains large amounts of water and organic materials; therefore, its stabilization and dewatering is of particular importance. In this study, Fenton oxidation process is used for stabilization and dewatering of sludge in the output of a wastewater treatment plant. To evaluate the sludge stabilization and dewatering, specific resistance to filtration (SRF), volatile organic compounds (VSS), total suspended solids (TSS), soluble chemical oxygen demand (SCOD) and heterotrophic bacteria were measured. During the experiment, the optimal values of various parameters such as pH (2-9), hydrogen peroxide (0.015- 0.18mol/L), Fe2+ (0.008- 0.1mol/L) and time (5 - 60 minutes) for optimum sludge dewatering and stabilization were investigated. The results showed that the highest percentages of SRF reduction and removal rates of SCOD, VSS and TSS were 99.48, 61, 42, and 41 percent respectively. These results were obtained in optimum pH 5, 0.05 mol/l Fe2+, 0.12 mol/l hydrogen peroxide, and the retention time of 15 minutes. The removal rate of heterotrophic bacteria increased with increasing dose of hydrogen peroxide, so that a removal rate of 84 percent was observed at a dose of 0.18 mol/l. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering
Determination of Lead Ion by a Modified Carbon Paste Electrode Based on Multi-Walled Carbon Nanotubes (MWCNTs) andLigand (N-(4-Hydroxyphenyl) Ethanamide)
Get PDFoai:ojs.localhost:article/85The preparation of a new modified carbon paste electrode (CPE)to measure lead ion has been reported in this study. Lead is a highly toxic element which can have a negative impact on the environment. Therefore, measurement of lead in aquatic environments is very important. Although several methods have been developed for determination of lead ion in aquatic environments, there is no a cheap, simple, accurate and rapid method to measure this ion. Aim of this study is to develop a new method to measure the lead based on using multi walls carbon nanotubes (MWCNTs) and Paracetamol as an ionophore for modificationof a CPE.The optimum composition of modified CPE was determined as 64% of graphite powder, 20% of paraffin oil, 12% of nanotube and 4% of ionophore.This optimum composition was shown high selectivity, with appropriate Nernestian slope (-29.73 mV/decade), linear range (from 1.0×10-1to 1.0×10-8M), low lead concentration detection limit (7.5×10-9M) and good response time (equal of 25 sec).The results of this study to introduce a cheap, accurate and simple method for determination of lead ion in aquatic environments
Fire Risk Assessment and Its Economic Loss Estimation in Tehran Subway, Applying Event Tree Analysis
Get PDFSubway system is one of the critical infrastructures in a society. In economic optimizations of risk control measures, valuing the loss of life and other financial losses in terms of money on the other hand, could influence the optimal investments in safety. The purpose is to contribute to the implementation of HSE in the transportation system. In this research, a fire risk assessment along with its economic loss estimation in the Direct Current (DC) trains and rectifier substation (RS) of Tehran subway is implemented. The number of fatalities, the extent of damage on the train equipment, etc., is then calculated in monetary unit.
By using Event Tree Analysis (herein ETA), after identification of initiating events through observation, interviews, and evaluation of documents, event tree was constructed for each of them and the probability of multiple scenarios were computed.
The scenario with the highest probability of fire in RS, including increased heats in the RTU panels generate a loss of at least 730 Million Rials. Accordingly, the minimum and maximum economic loss caused by fire on DC trains is minimum 510 and 1230 Million Rials, respectively.
Conclusion: Given the findings of this study, the financial and human life risks, along with all tangible and intangible losses, which is considerable, the relevant managers must compare investments in safety, with the decrease of calculated economic risks as a result of fire accident in Tehran subway
An Examination of the Relationship between Visual Fatigue Symptoms with Flicker Value Variations in Video Display Terminal Users
Get PDFIn most sensitive occupations such as nuclear, military and chemical industries closed circuit systems and visual display terminals (VDTs) are used to carefully control and assess sensitive processes. Visual fatigue is one of the factors decreasing accuracy and concentration in operators causing faulty perception. This study aimed to find out a relationship between visual fatigue symptoms (VFS) of Flicker value variations in video display terminal (VDT) operators.
This cross-sectional study, conducted in 2011, aimed to examine visual fatigue and determine the relationship between its symptoms and visual flicker value changes in 248 operators of VDTs in several occupations. The materials used in this study were a visual fatigue questionnaire of VDTs and a VFM-90.1 device. Visual fatigue was measured in two stages (prior to beginning to work and 60 min later). The data were analyzed by SPSS11.5, using descriptive statistics, paired t-test, simple and multiple linear regressions, correlation and recognition coefficients. Then regression equations of changes in flicker value depending on the changes in the main domains and the changes in final score before the questionnaire were obtained.
Paired t-test indicated significant differences in the mean score of visual fatigue symptoms and the mean score of flicker value between the two stages, respectively (P ≤ 0.001). Simple and multiple regressions of flicker value variations, for the last visual fatigue changes in questionnaire score and the four main domains of the questionnaire were obtained R2 = 0.851 and R2 = 0.853, respectively. Correlation coefficient in the above tests indicated reverse and significant relationships among flicker value changes with changes in questionnaire score and visual fatigue symptoms.
Diagnosing the first symptoms of visual fatigue could be an appropriate warning for VDTs operators in sensitive occupations to react suitably, in behavior and management, to control or treat visual fatigue and prevent errors efficiently
Wastewater treatment efficiency in stabilization ponds, Olang treatment plant, Mashhad, 2011-13
Get PDFOlang wastewater treatment facilities purifying raw urban wastewater consist of two stabilization pond modules. Both are on operation in parallel. Functioning of natural systems is influenced by different factors including ambient condition. Considering final effluent of this system discharges to Kashafrood river and sometimes is used for agricultural purposes, assessing the quality parameters in effluent was the main objective of this study. This cross-sectional study investigated some important quality parameters for both raw and treated wastewater in two years periods. Data analysis was carried out using descriptive statistics. Statistical tests were done at a significant level of 0.05. Simple linear regression analysis was used only for modeling. Raw wastewater was almost severe.
Average removal efficiency for BOD5, COD, and TSS was 81, 83, and 78% respectively. There wasn’t a meaningful relationship between the removal efficiency of mentioned parameters and input pH. Ambient temperature fluctuations were effective on BOD5, and COD reduction. SAR index didn’t show a considerable restriction on irrigation application of effluent. In 62.5% cases outlet Na content was at the extent to which restrictions were imposed.
Olang wastewater treatment plant generates an acceptable effluent relating to most of the quality parameters that were measured in this study. Considering special status of Mashhad city, it is worthy to reuse effluent in areas with a high water requirement such as agriculture
Investigation of Electrolysis Process Performance by Graphite Electrodes for De-Colorization of Phenolphthalein and Phenol Red from Aqueous Solution
Get PDFThis study elucidates the de-colorization of phenolphthalein and phenol red from aqueous solution through electrochemical oxidation technique. An electrochemical reactor had 1 liter volume that used 2 graphite electrodes. Effect of electric power voltage, inter electrode distance and electrolyte concentration was investigated in this system.
It was found that the optimum conditions for completely removal of phenolphthalein was at voltage of 48 V, retention time of 9 minutes, distance between the electrode of 5 cm, and the salt concentration of 1.5 g/l. Also completely removal of phenol red was at voltage of 48 V, retention time of 8 minutes, distance between the electrode of 5 cm, and the salt concentration of 2 g/l. Phenol red and phenolphthalein COD removal efficiency was 85 and 80 percent respectively.
The results suggest that the electrolysis process is an effective way to removal of phenolphthalein and phenol red color from effluent, because of it can completely remove the color in a short time
A survey of economic indices of plastic wastes recycling industry
Get PDFNumerous small recycling units of plastic wastes have been currently constructed heedless to study of economic indices in Iran. Pay attention to the prominent performance of the industrial sector for economic development and its priority for fortifying other sectors to implement job opportunities, survey of the economic indices beckon the stakeholders and industries owners. The main objective of this study was a survey of economic indices in small recycling unit of plastic wastes. Therefore, the practice of computing the economic indices was performed using empirical equations, professional experiences and observations in site of the industry in terms of sustainability performance. Current study had shown the indices values such as value-added percent, profit, annual income, breakeven point, value-added, output value, data value, variable cost of good unit and production costs were found 62%, 364292.6, 423451.25, 678787, 314494.4 respectively. The breakeven point about 15.93%, the time of return on investment about 1.12 (13.7 months) were represented that this industry slightly needs long time to afford the employed capital and starts making a profit
A novel method to design water spray cooling system to protect floating roof atmospheric storage tanks against fires
Get PDFHydrocarbon bulk storage tank fires are not very common, but their protection is essential due to severe consequences of such fires. Water spray cooling system is one of the most effective ways to reduce damages to a tank from a fire. Many codes and standards set requirements and recommendations to maximize the efficiency of water spray cooling systems, but these are widely different and still various interpretations and methods are employed to design such systems. This article provides a brief introduction to some possible design methods of cooling systems for protection of storage tanks against external non-contacting fires and introduces a new method namely “Linear Density Method” and compares the results from this method to the “Average Method” which is currently in common practice. The average Method determines the flow rate for each spray nozzle by dividing the total water demand by the number of spray nozzles while the Linear Density Method determines the nozzle flow rate based on the actual flow over the surface to be protected. The configuration of the system includes a one million barrel crude oil floating roof tank to be protected and which is placed one half tank diameter from a similar adjacent tank with a full surface fire. Thermal radiation and hydraulics are modeled using DNV PHAST Version 6.53 and Sunrise PIPENET Version 1.5.0.2722 software respectively. Spray nozzles used in design are manufactured by Angus Fire and PNR Nozzles companies. Schedule 40 carbon steel pipe is used for piping. The results show that the cooling system using the Linear Density Method consumes 3.55% more water than the design using the average method assuming a uniform application rate of 4.1 liters per minute. Despite higher water consumption the design based on Linear Density Method alleviates the problems associated with the Average Method and provides better protection