جستجوی مقالات مرتبط با کلیدواژه "صنایع نساجی" در نشریات گروه "پزشکی"

The presence of many synthetic dyes in aqueous solutions can cause carcinogenesis and mutagenicity and affect human health. Reactive Red 198 is one of the types of azo dyes with complex structure, toxic, carcinogenicity, mutagenicity properties, and tolerable in the environment, which is discharged to the environment through the sewage of textile industries. This study was performed to determine the mineralization of 198 reactive red dyes by the hybrid advanced oxidation process UV/US/H2O2/O3 from colored wastewater using central composite design.

In this descriptive-analytical study several factors affecting on dye mineralization process including the presence of ozone gas and ultraviolet rays (UV) as well as the initial dye concentration, Ultrasound (US), contact time, pH, and hydrogen peroxide were investigated. Experimental design and optimization were performed by design of experiment software using central composite design and its optimal conditions were determined.

The maximum dye degradation efficiency of 100% was performed under optimal conditions including initial dye concentration of 200 mg/L, reaction time of 34 minutes, hydrogen peroxide concentration of 27 mg/L and pH=9 in the presence of ozone gas flow, ultraviolet rays and ultrasonic waves. Also, the influence of factors on dye removal including ozone, UV, initial dye concentration, US, contact time, pH, and peroxide were  58.8%, 19.3%, 2.3%, 1.5%, 1.1%, 0.6 %and 0.2 % ,respectively.

UV/US/H2O2/O3 hybrid process with advantages such as performance and high speed can be recommended for wastewater treatment in various industries.

Dyes are one of the main pollutants in textile wastewater and due to their molecular structures, they are usually toxic, carcinogen and persistent in the environment. Therefore, the aim of present work was to compare the efficiency of LECA and coral limestone to remove Methylene Blue aqueous solution from synthetic wastewater.
This work is a basic-applied study in which, LECA and coral limestone were used as efficient adsorbents for removal of Methylene Blue aqueous solution. The parameters studied included absorbent weight, contact time, dye concentration and solution pH. As well, data acquired from equilibrium constant were evaluated using various isotherm and kinetic models.
The results of the experiments showed that absorption of Dye by both absorptions was increased by increasing the pH, contact time and adsorbent dosage. By increasing the concentration of dye from 50 mg/l to 100 and 150 mg/l, the removal efficiency of organic matter and color has been reduced. The results showed that constant equilibrium data obeyed both isotherm models, With the difference that Langmuir isotherm model showed a higher correlation coefficient in the use of calcareous coral absorber (R2= 1) and higher LECA absorption coefficient (R2= 0.999) in using Frendlich model. Also checking the data showed that kinetics of methylene blue removal is followed by both kinetic models that in this case, the second-order kinetic equation showed a higher correlation coefficient (R2.870).
According to the results, it was determined that coral limestone has higher efficiency than LECA in removal of Methylene Blue aqueous solution. The use of these adsorbents due to rapid sedimentation and lack of effective residual in the wastewater can be easier to use than other adsorbents.

Macro-ergonomic risk assessment is one of risk assessment method that has been used for identification occupational hazard that human exposed with it in workplaces. One of macro-ergonomic risk assessment is relative stress index (RSI) which Able to identify risk factors associated with the incidence of occupational hazards in the work environment. The aim of present study was macro-ergonomic risk assessment with relative stress index in textile industry. This study was conducted base on Census method among 154 workers in textile industry in Isfahan that work in three shifts. Risk assessment based on relative stress index divided in three main sections; job description, checklist and RSI. For computation this method, different equations has been defended that by their computation was performing. The final values for the RSI are a scale between zero to 10 where zero implies on dangerous, insecure no efficient and number 10 indicated safe, secure and being efficient. ANOVA test showed that among six categories in this study, hand work and sensory in different shifts among textile industry had significant relationships with occupational hazard (P<0.05). Also posture with mean 6.19±0.11 and manual material handling with mean 9.14±0.41 had lowest and highest score, respectively Based on the findings of the study, the posture at work and hand work were the most influential factor in the incidence of Occupational hazards among workers in the textile industry. So keep a good posture and reducing the level of hand work activity during each shift can have a significant impact in reducing occupational hazards.

Basic and reactive dyes such as basic violet16 and Reactive Red 120 have most common in different industries such as textile, leather and food industry. The degradation of basic violet and Reactive Red 120 by means of UV/H2O2 processes was investigated in the current study.

photolysis process was accomplished in a laboratory-scale batch photoreactor equipped with an 55 W immersed-type low-pressure mercury vapor lamp(UVC) with emphasis on the effect of various parameters on decolouration and degradation efficiency.

The results showed that radiation of UV alone cannot remove dyes completely and needs to accompany with UV/H2O2 process for getting best results. According to the obtained results, the removal efficiency increased with increasing H2O2concentration until especial concentration of H2O2and decreasing the initial dye concentration. Mean while, the electrical energy (EE/O) for decolorization of solution was calculated.Concclusion: It is concluded that the application of UV/H2O2 process for degradation of basic violet 16 and reactive red 120 was suitable and have a high removal efficiency.

Çhemical dyes used in textile industries involve some potential risks including carcinogenic and mutagenic effects in human. Furthermore، penetration of different dyes into surface and groundwater is a source of color in water reservoirs. This study aims at investigating the removal efficiency of yellow 3 and disperse yellow 3 reactive dyes by combined ÇÂÇ-SBR system.

This experimental study was conducted on a batch scale and two SBR reactors were used. Wastewater samples used in this study were synthetic (ÇÔD=1800). Âfter setting up the reactors، yellow 3 and disperse yellow 3 reactive dyes were injected to the system and its removal efficiency was investigated during different reaction times. Âfter determining the SBR system efficiency in dye and ÇÔD removal، GÂÇ-SBR system efficiency was examined.

During 24 hours of reactions، the efficiency of SBR and GÂÇ-SBR systems in the removal of reactive yellow3 dye was 58% and 72%، while for disperse yellow 3 it was 85 and 91%، respectively. Âlso، during 14 hours of reaction، the efficiency of SBR and GÂÇ-SBR systems for ÇÔD removal was 98 and 98. 5%، respectively. Çonclusion: The efficiency of GÂÇ-SBR system in the removal of reactive yellow 3 and disperse yellow 3 dyes was higher than that of the SBR system. However، their difference was insignificant regarding the ÇÔD removal. Ôverall، increase in the reaction time led to increase in the efficiency of systems and in a specific time of the reaction، their removal efficiency became uniform.

Backgrounds and Reactive dyestuff has potential of toxicity, carcinogenesis and mutagenesis for mammals and aquatic organisms. The current physical and chemical methods such as adsorption, coagulation, precipitation, filtration and. .. can been used for removing of dyestuff. Biological treatment which is effective and economic for decontamination of dyestuff wastewaters was preferred because of limitation and difficulty of physicochemical methods. In order to investigate the trend of pollution reduction of color compounds, ability of Remazol Black-B dyestuff removal from aqueous medium by bacterial consortium under anoxic conditions was studied. The mix culture of bacteria from textile industries activated sludge was enriched in luria broth medium containing RB-B dyestuff as a carbon source. Then biodegradation was assessed in 4 batch reactors. Microbial population of bacterial and decolorization quantities of samples were detected by MPN and UV-Vis spectrophotometer. Decolorization efficiency by the bacterial consortium was obtained more than 99% for 50 and 250 mg/L concentrations in 72 and 144 h (3 and 6 days) respectively, while for the initial concentration of 500 mg/L was 98.1in 240 h (10 days) of biodegradation period. Dyestuff reduction rate after completed removal was about 0.69, 1.74,2 mg/L/h for initial concentration of 50, 250, 500 mg/L respectively. Results showed that Alcaligenes denitrificans and Alcaligenes xylosoxidans bacteria which were isolated from activated sludge have good potential of RB-B dyestuff removal and this removal is depending on primary concentration of dye. Removal efficiency increased as primary concentration went up.

Background and

Researches in the field of positive and negative affect have shown mixed results. While some have argued that positive and negative affects are two ends of a single construct، others suggested that these two concepts are independent from each other. Previous studies also support the idea that negative affect had a positive relationship with pain. According to theoretical frameworks، the aim of current research was to investigate the role of positive affect in the relationship between stress and pain، and negative affect in women with chronic pain، and possible implications of positive affect as an important psychological resource that a patient may use for coping efforts during periods of pain.

104 women in textile and carpet weaving industry suffering from osteoarthritis and fibromyalgia were participated in the survey and completed the initial assessments for demographic data and personality characteristics. They subsequently completed 10 to 12 weekly interviews regarding pain، stress، negative and positive affect. After completion of the survey using cross sectional method، data were analyzed via hierarchical multilevel modeling.

Findings showed that weekly increases in pain and stress could predict negative affect elevations. Higher weekly positive affect as well as higher average positive affect، weather directly and indirectly in interaction with pain and stress، resulted in lower levels of negative affect. In addition، increases in weekly negative affect and higher average negative affect، related to greater levels of pain in subsequent weeks. In contrast، higher levels of overall positive affect predicted lower levels of pain in subsequent weeks.

The current study emphasized that when individuals encounter pain or stress، positive and negative affects are not independent and therefore showed important role of positive affect in reducing negative affect related to pain and stress، which could be helpful for patients to bear pain and reducing the resulted tension.