20 research outputs found
Investigation of Electrolysis Process Performance by Graphite Electrodes for De-Colorization of Phenolphthalein and Phenol Red from Aqueous Solution
This 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
Nonionizing Electromagnetic Irradiations; Biological Interactions, Human Safety
Human is usually exposed to environmental radiation from natural and man-made sources. Therefore, it is important to investigate the effects of exposure to environmental radiation, partly related to understanding and protecting against the risk of exposure to environmental radiation with beneficial and adverse impacts on human life. The rapid development of technologies causes a dramatic enhancement of radiation in the human environment. In this study, we address the biological effects caused by different fractions of non-ionizing electromagnetic irradiation to humans and describe possible approaches for minimizing adverse health effects initiated by radiation. The main focus was on biological mechanisms initiated by irradiation and represented protection, and safety approaches to prevent health disorders
Predicting needlestick and sharps injuries and determining preventive strategies using a Bayesian network approach in Tehran, Iran
OBJECTIVES Recent studies have shown that the rate of needlestick and sharps injuries (NSIs) is unacceptably high in Iranian hospitals. The aim of the present study was to use a systematic approach to predict and reduce these injuries. METHODS This cross-sectional study was conducted in 5 hospitals in Tehran, Iran. Eleven variables thought to affect NSIs were categorized based on the Human Factors Analysis and Classification System (HFACS) framework and modeled using a Bayesian network. A self-administered validated questionnaire was used to collect the required data. In total, 343 cases were used to train the model and 50 cases were used to test the model. Model performance was assessed using various indices. Finally, using predictive reasoning, several intervention strategies for reducing NSIs were recommended. RESULTS The Bayesian network HFACS model was able to predict 86% of new cases correctly. The analyses showed that safety motivation and fatigue were the most important contributors to NSIs. Supervisors’ attitude toward safety and working hours per week were the most important factors in the unsafe supervision category. Management commitment and staffing were the most important organizational-level factors affecting NSIs. Finally, promising intervention strategies for reducing NSIs were identified and discussed. CONCLUSIONS To reduce NSIs, both management commitment and sufficient staffing are necessary. Supervisors should encourage nurses to engage in safe behavior. Excessive working hours result in fatigue and increase the risk of NSIs
Systematic review of pre-clinical and clinical devices for magnetic resonance-guided radiofrequency hyperthermia
Clinical trials have demonstrated the therapeutic benefits of adding radiofrequency (RF) hyperthermia (HT) as an adjuvant to radio- and chemotherapy. However, maximum utilization of these benefits is hampered by the current inability to maintain the temperature within the desired range. RF HT treatment quality is usually monitored by invasive temperature sensors, which provide limited data sampling and are prone to infection risks. Magnetic resonance (MR) temperature imaging has been developed to overcome these hurdles by allowing noninvasive 3D temperature monitoring in the target and normal tissues. To exploit this feature, several approaches for inserting the RF heating devices into the MR scanner have been proposed over the years. In this review, we summarize the status quo in MR-guided RF HT devices and analyze trends in these hybrid hardware configurations. In addition, we discuss the various approaches, extract best practices and identify gaps regarding the experimental validation procedures for MR - RF HT, aimed at converging to a common standard in this process
Advanced oxidation of formaldehyde in the aqueous solutions using UVC/S2O82- process: Degradation and mineralization
Background: As a human carcinogen, formaldehyde is a toxic chemical imposing adverse effects on
public health and environment. Due to its high reactivity, colorless nature, sustainability, purity in
commercial forms, and low prices, the production and consumption of this compound has expanded
vastly in industries.
Methods: In this study, a UVC photoreactor with a total volume of 120 mL was used and operated
in a rotary mode. To determine the residual concentration, high-performance liquid chromatography
(HPLC) device was applied whose detector was set at a wavelength of 355 nm and equipped with C18
column (with dimensions of 25 × 4.6 mm i.d, and particle size of 5 μm). Total organic carbon (TOC)
was determined using a TOC analyzer.
Results: The optimal condition in this study was obtained at pH=3 and formaldehyde concentration
of 350 mg, so that the removal of formaldehyde and TOC was 98.2% and 95.1%, respectively, after 35
minutes reaction time. The formaldehyde removal efficiency was assessed in the presence of methanol
(MeOH), tert-butyl alcohol (TBA), and salicylic acid (SA) scavengers, and it was indicated that SO4
•-
radicals were the most effective factors in formaldehyde destruction. By increasing the concentrations
of MeOH, TBA, and SA to 2.5 g/L, the degradation efficiency of formaldehyde dropped from 98.02%
to 69.78%, 64.68%, and 45.14%, respectively, at 35 minutes reaction time. The removal of formaldehyde
in the presence of nitrate was significantly reduced and it had a significant effect on the removal of
formaldehyde.
Conclusion: In this study, the removal of formaldehyde was investigated in the presence of various
anions including bicarbonate, carbonate, chloride, sulfate, and nitrate. According to the results, the
UVC/S2O8
2- process is a convenient and cost-effective method for the removal of formaldehyde.
Keywords: Formaldehyde, Advanced oxidation, Bicarbonates, Carbonates, Sulfates, Nitrate
Data on health risk assessment of fluoride in water distribution network of Iranshahr, Iran
The main of this data was determine the concentrations and health risks of fluoride in 66 drinking water samples collected from villages of the Iranshahr city, Sistan and Baluchestan Province in Iran. Fluoride concentration was measured by the standard SPADNS method. Data indicated that fluoride concentration in drinking water ranged from 0.25 to 1.72 mg L−1 and average of fluoride concentration was 0.27 mg L−1. The mean estimated daily intake (EDI) values for fluoride in different groups of infants, children, teenagers and adults were 0.0021, 0.0151, 0.0107 and 0.0086 mg/kg, respectively. Also, risk assessment data indicated that hazard quotient (HQ) value of groundwater samples is more than 1 in 6% of groundwater samples in age groups of children and teenagers. Keywords: Drinking water, Fluoride, Risk assessment, Iranshahr, Ira