Showing 8 results for Color
A Maleki,
Volume 3, Issue 2 (7-2010)
Abstract
Backgrounds and Objectives: Carcinogenic and mutagenic potential of some azo dyes as a category of common dyes in different types of industries has been reported. The degradation of one commercially available dyestuff [C.I. Reactive Red 198 (RR 198)] by means of ultraviolet radiation (UV), ultrasonic irradiation (US), UV/H2O2 and US/H2O2 processes was investigated.
Materials and Methods: Photolysis process was accomplished in a laboratory-scale batch photoreactor equipped with an 55W immersed-type low-pressure mercury vapour lamp (UVC) and sonication in a sonoreactor with low frequency (42 kHz) plate type transducer at 170W of acoustic power with emphasis on the effect of various parameters on decolouration and degradation efficiency.
Results: Initial results showed that, color removal efficiencies by US and US/H2O2 processes were negligible. Almost complete disappearance of RR 198 (20 mg/L) in UV/H2O2 process was possible to achieve after 10 min of irradiation. It is found that lower pH and lower concentration of dye favor the dye degradation. Hence any increase in initial dye concentration results in decreased decolouration rates. Also, the experimental results indicated that the kinetics of sono-oxidation and photo-oxidation processes fit well by pseudo-first order kinetics and first order reaction kinetics, respectively.
Conclusion: It is concluded that UV/H2O2 reaction was more effective than other reactions in bleaching and the reaction rate was sensitive to the operational parameters and increased with increasing H2O2 concentration up to 15 mM.
Kazem Naddafi, Mehran Mohammadian Fazli, Ali Reza Mesdaghinia, Simin Nasseri, Mahnaz Mazaheri Assadi, Masoud Yunesian,
Volume 5, Issue 2 (10-2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Environmental pollution and health risks of dyestuffs
extensively are caused by many industries. Nonbiodegradability of dyes is
important so that different methods are studied for removing them. The use of
white rot fungi is promising technique in this regard. Therefore, objective of
this work is to investigate Rimazol Brilliant Blue Royal decolorization by
immobilized Ganoderma sp. in sodium alginate from aqueous solution.
Material and Methods: This is an experimental study. First, the nutritional, environmental, and
operational conditions of decolorization process were optimized. Then,
efficiency of immobilized fungal cells was investigated. Experimental designs
were provided using fractional factorial methods and quadratic model was fitted
on decolorization data by MiniTab software.
Results: Our findings
showed that type and concentration of carbon source, temperature, and pH were
the most important factors affecting decolorization and statistically
significant. Optimal conditions to 95.3 percent color removal were: glycerol as
carbon source at 19.14 g/L temperature, 27 oC and initial pH, 6.26. Moreover,
decolorization efficiency increased from 75 percent up to 95 percent by improving
process and fungal immobilization.
Conclusion: Ganoderma
fungus has suitable potential to decolorization. Besides, optimization and cell
immobilization can improve its capability. Application of experimental design
to research methodology is important because of decreasing in experiments and
saving resources. It is suggested to use these potentials in environmental
pollution control.
Mehrnoosh Mohammadi, Alireza Riyahi Bakhtiari, Saber Khodabandeh,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objectives: Development of cosmetics industry has increased the affinity to use these products by people especially women for makeup and toilet. Due to the presence of metals such as lead and cadmium as preservative and colored element in these products, concentrations of these metals in sunscreen cosmetics, lipstick and hair color were determined. Materials and Methods: Different brands of cosmetics were analyzed to determine Cd and Pb concentration (in µg/kg dry weight) using graphite furnace atomic absorption (AA-670). Results: We found that generally mean concentration of Cd was lower than Pb. There was no significant difference of Cd level between different brands of sunscreen and lipstick (p>0.05), whereas, a significant difference of Pb between the brands studied was observed (p<0.05). No significant difference was obtained between concentration of Cd and Pb in various brands of hair color (p>0.05). Conclusion: Though levels of Pb and Cd in selected brands of cosmetics were lower than standard limits, their low concentration in compared with the results of previous research works could induce serious hazards on human health and the possibility of occurrence or exacerbation of disease including allergy, inflammation, skin diseases, cancer and so on. Hence, preparation and use of these products must be done according to current standards.
M. Arbabi, M.a. Ahmadi, M. Sedehi,
Volume 7, Issue 3 (5-2014)
Abstract
Background and Objectives: Bakery’s yeast industry wastewater contains various pollutants and is generally characterized with high chemical oxygen demand (COD), dark color, high-nitrogen and sulfate and non-biodegradable organic pollutants. Having persistent soluble colored compounds (called melanoidins), effluent from yeast industry is a major source of water and soil pollution. The aim of this study was to evaluate advanced oxidation efficiency using Fenton process for COD and color removal from bakery’s yeast wastewater. Materials and Methods: This was an experimental- laboratory scale study. In this study, the effect of time and Fenton concentrations were tested for COD and color removal from bakery’s yeast wastewater. The sample used for this study was yeast effluent from Separator 2 with initial concentrations of COD and color of 5300 mg/L and 6950 pt-co respectively. In order to obtain the optimum operating conditions of the process, Taguchi analysis method was used. Experiments were carried out in five stages of the time in the range of 15, 30, 45, 60 and 75 min with various concentrations of hydrogen peroxide (e.g., 0.02, 0.04, 0.06, 0.08, and 0.1 molar) and concentrations of Fe2+ (e.g., 0.01, 0.02, 0.03, 0.04, and 0.05 molar) at pH = 3. Jar test method was used to determine the best operating conditions including: reaction time, dosages of hydrogen peroxide and Fe2+. Results: According to Taguchi method and SN-ratio analysis, the best H2O2/Fe2+ dosages were 0.08/0.04 molar at pH 3 and in reaction time of 30 min for removal of COD and color. For these conditions, the maximum COD and color removal efficiencies were 63 and 69 percent respectively. Based on the results, with increasing reaction time, there was no perceptible change in the removal efficiency. Conclusion: It can be concluded that Fenton’s oxidation method can be used successfully, as an alternative option to the design and choice of color and COD removal from strength industrial wastewaters e.g., bakery’s yeast industry.
F Khalili, A.h Mahvi, S Nasseri, M Yunesian, B Djahed, M Yaseri,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objectives: Chemical hair color are one of the most widely used cosmetics. The presence of heavy metals in these products can affect the health of consumers. Unlike other cosmetics, no study has been conducted on the heavy metal levels in the synthetic chemical hair colors. This study determined the concentration of heavy metals in these products and the risk assessment of non-carcinogenic effects by these elements were calculated.
Material and Method: 32 samples of chemical hair color from eight brands (3 local and 5 imported ones) and four most used colors were collected from the markets in Tehran. The concentration of cadmium, lead, and barium was determined using ICP-MS. The information required to assess exposure risk was gathered through a questionnaire distributed among citizens of Tehran. The assessment of exposure was conducted using Mont Carlo method and non-carcinogenic risk was determined using the index of Hazard Quotient. .
Results: Barium concentration measured was 0.86 mg/kg and concentrations of Cadmium and Lead were 0.45 and 185.34 µg/kg respectively. Among the elements, Pb with Hazard Quotient equals to 7.46×10-4 had the most risk and cadmium with Hazard Quotient equals to 3.57×10-5 had the lowest risk. Moreover, the Iranian brand and blond had the highest risk among the samples.
Conclusion: Based on the index of Hazard Quotient, heavy metals in the studied samples had no risk for consumers of these products.
S Torbati,
Volume 9, Issue 4 (3-2017)
Abstract
Background and Objective: Malachite green dye is used in many industries including textile industries. Disposal of wastewaters containing the dye to the environment, can lead to many environmental problems. Currently, many physico-chemical approaches are used for wastewater treatment. Because of limitations and difficulties of these methods, biological treatment is considered as an economic and effective treatment method. The aim of the present study was to study the feasibility of phytoremediation of malachite green dye using watercress and investigate the effect of some environmental factors in removal efficiency.
Materials and Methods: After collection, the plants were kept in the laboratory, and they were treated with different concentrations of malachite green. During the experiments, decolorization extent was determined by UV-Vis spectrophotometry. Intermediate compounds generated during the biodegradation of the pollutant were identified using GC-MS method.
Results: After 7 days, the ability of watercress in removal and biodegradation of 10 mg/L of malachite green solution was more than 90%. Five intermediate compounds were identified in the biodegradation pathway of the pollutant. It was also found that increasing dye concentration up to 20 mg/L led to the increase of the plant photosynthetic pigment contents and activities of antioxidant enzymes.
Conclusion: Our results showed that watercress has high ability in the dye removal of malachite green. The reusability of the plant for decolorization confirmed the biological degradation process. Moreover, an increase in the plant biomass, temperature and pH led to the increased decolorization efficiency.
Mohammad Hossein Fekri, Samaneh Soleymani, Maryam Razavi Mehr, Fatemeh Saki,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: Due to the presence of industrial pollutants in water sources, it is necessary to treat wastewater, especially colored wastewater. This study aims to treat wastewater containing methyl orange dye using nano mesopore SBA-16.
Materials and Methods: In this study, the effect of different parameters (pH, concentration of methyl orange, amount of adsorbent, temperature, and contact time) on the absorption of methyl orange by nanocomposite prepared with the help of Design of Experiment 7 software and Response Surface Method (RSM) was investigated.
Results: The maximum amount of pollutant removal by the adsorbent was obtained under optimal conditions of pH = 4.07, temperature 50 °C, contact time 35 minutes, initial concentration of adsorbent 10 mg/L, and amount of adsorbent 0.04 g. Also, the findings showed that the absorption behavior is most consistent with the Langmuir isotherm and the absorption process is exothermic and spontaneous at low temperatures.
Conclusion: In optimal conditions, the SBA-16 adsorbent was able to remove 98.60 % of methyl orange from the aqueous solution and the maximum adsorption capacity (qmax) for the removal of methyl orange pollutant was 37.73 mg/g. Considering the high potential of nano mesopore SBA-16 in removing methyl orange pigment, it can be considered a suitable candidate for removing colored pollutants and treating wastewater from textile factories.
Mehrdad Salami, Reza Saeedi, Ahmadreza Yazdanbakhsh, Maryam Heydari, Azita Mohagheghian, Mehrnoosh Abtahi,
Volume 18, Issue 4 (3-2026)
Abstract
Background and Objective: Despite their high nutritional value, fruits and vegetables may pose a risk to public health due to nitrate accumulation. This study aimed to assess the health risks associated with dietary exposure to nitrates present in fruits and vegetables sold in produce markets of Shahre-Rey.
Materials and Methods: In this cross-sectional study, samples of apples, oranges, potatoes, onions, and both greenhouse- and field-grown tomatoes and cucumbers (n = 13, 12, 22, 18, 24, and 32, respectively) were collected during autumn and winter 2023 and spring and summer 2024. Nitrate concentrations were measured using a spectrophotometric method. The non-carcinogenic hazard quotient (HQ) was calculated based on the measured nitrate levels. In addition, using GBD data, the contribution of nitrate to the disease burden of colorectal cancer was estimated through YLL (Years of Life Lost), YLD (Years Lived with Disability), and DALY (Disability-Adjusted Life Years) indices.
Results: The mean nitrate concentration varied significantly across the products, with the highest level found in field cucumbers (294.06 mg/kg) and the lowest in apples (51.99 mg/kg). In some products, nitrate levels exceeded the permissible limits set by the Iranian national standard. The highest non-carcinogenic risk was observed in potatoes, with a mean HQ of 0.231. Potatoes also had the highest incidence rate of colorectal cancer (2.02 per 100,000 population), the greatest DALY (23.15), and the highest nitrate-related mortality. The mean DALY attributed to nitrate exposure was estimated at 107.38 for potatoes, 94.87 for onions, and 12.10 for greenhouse cucumbers.
Conclusion: Certain agricultural products, particularly potatoes and onions, are significant sources of dietary nitrate exposure and may contribute to an increased risk of colorectal cancer. Continuous monitoring and management of nitrate levels in these products are essential.
