Showing 9 results for Washing
Volume 4, Issue 1 (1-2002)
Abstract
The increasing production and use of fossil fuels increase the probability of soil source contamination by oil and petroleum products, and pose a hazard to life. There are over 43,000 chemical contaminated sites in Canada and USA, with 2,200 of them classified as high risk. In the US, over $10 billion are spent annually on the cleanup of contaminated sites. The primary objective of this study was to develop and test an innovative in situ soil washing system that could extract contaminants from the soil, quickly and effectively, without causing any threat to water sources. We proposed the use of an organic solvent in our system that is not only lighter than water but is also immiscible with water. It was in-troduced into the soil profile from below using a system of horizontal, underground per-forated pipes, and collected from the soil surface. Since the solvent was being introduced from the bottom, it “wete” the soil completely and thus removed the contaminant effec-tively. To understand and evaluate the performance of the system for remediation, a pre-liminary experiment was performed using two stainless steel columns (1m long x 0.2m di-ameter) packed with two diesel fuel contaminated soils (fresh and old contamination). The proposed technique is innovative, unique and very fast for the remediation of diesel fuel contaminated soils. It is the first study of its kind employing a subirrigation system for de-livering organic solvents (lighter than water and immiscible in water) for in situ soil wash-ing. Some preliminary applications of the system to diesel fuel contaminated sand soils have proved very promising for both fresh and old contaminated sites. The method could be equally suited for other contaminants also.
Hojat Mirsadeghi, , , ,
Volume 4, Issue 1 (6-2015)
Abstract
Fish egg is an important source of polyunsaturated fatty acids, protein, minerals and vitamins. These are produced in the form of smoked, salted and then consumed. Initial preparations for washing eggs can have an important role on the finished product. To increase the strength of the egg membrane, waste removal, connective tissue and broken shells, fish eggs obtained after washing with different methods are carried out. In this study, three treatments have been utilized including, non-boiled water, boiled water cooled to3 to 5 °C, boiled water to 40 °C. Afterward, the two groups were prepared with 1.5% salt and no salt. Results of chemical, microbial and sensory tests were assessed on days 0, 12 and 24. It was shown that, cooled boiled water with a temperature of 3 to 5 °C with 1.5% salt and boiled water with a temperature of 40 °C with 1.5% salt gave the best and Non-boiled water with ambient temperature devoid of salt had the worst chemical andmicrobial results. In addition, cold boiled water with temperatures 3 to 5 °C with 1.5% salt showed the best sensorial results. Boiled water with a temperature of 40 °C and non-boiled water without salt had the lowest sensorial results.
Volume 14, Issue 63 (6-2016)
Abstract
Regarding to the necessity of vegetable consumption, it is necessary to examine the extent to which the nutrient content of vegetables changes during different processes. In this study the effect of various procedures; washing, blanching and six-month storage was evaluated on total phenolic, vitamin C, ash and mineral content and antioxidant activity. Two methods using boiled water or steam for blanching and domestic and semi-industrial for freezing were applied. The results showed that washing did not have any significant effect on vitamin C and total phenolic content, antioxidant activity and firmness in pepper while blanching caused a considerable reduction in these parameters as vitamin C reduced from 1498.6 in fresh pepper to 1025.4 in the samples blanched by boiled water and 392.2 mg/ 100 g db in pepper blanched by steam. Antioxidant activity also reduced from 70.5% in fresh pepper to 58.6% and 57.1% in the samples blanched by boiled water and steam, respectively. The findings revealed that washing and the type of freezing did not have any significant effect on amount of vitamin C, phenolic compounds, antioxidant activity and stiffness whereas blanching showed a significant effect.
Volume 15, Issue 85 (3-2019)
Abstract
One of the problems with the consumption of fresh vegetables is the possibility of contamination with pathogenic bacteria. Washing fresh vegetables plays an important role in reducing the microbial population and increasing the safety of these products. Electrolyzed water has been considered as a new disinfectant in recent years. It is antiseptic, inexpensive and safe that affects different species of bacteria, fungi and viruses. In this study, the use of various types of washing water has been studied on the reduction of Shigella Flexneri population in lettuce. Types of water used include drinking water, acidified drinking water, chlorinated deionized water with chlorine concentrations of 50 and 25 mg / L, neutralized electrolyzed water, acidified electrolyzed water with a chlorine concentration of 50 and 25 mg / L were studied at different washing times (60 and 180 seconds) and different washing temperatures (4 and 25 °C). The results of this study showed that electrolysis of water had the most efficiency in reducing the microbial load of lettuce (72%) and the acidification of electrolyzed water increased its disinfection efficiency (75%). In addition, the study of lettuce microbial population during 1 to 4 days showed that the growth rate of microbial growth in lettuce samples was slower than other washing methods.
Volume 16, Issue 87 (5-2019)
Abstract
In this study, the effect of different treatments including method 1- homogenized by-product (BP-FPI), method 2- washing of homogenized by-product by distilled water (WBP-FPI), method 3- washing of homogenized by-product by CaCl2-citric acid (CaCi-BPFPI), method 4- CaCl2-citric acid treated –washing by distilled water (CaCi-W- BPFPI), method 5- washing by distilled water- CaCl2-citric acid treatment (W-CaCi-BPFPI) on composition of protein isolate from rainbow trout (Oncorhynchus mykiss) by-product were investigated. Washing by distilled water (method 2) and distilled water + combination of CaCl2 + citric acid (method 5) had significant effect on heme iron and phospholipid (P < 0.05). Washing methods influenced protein yield and the lowest yield (9.4%) was obtained using method 5 (P < 0.05). Washing-derived proteins were lighter in color compared with that obtained from by-product. Method 1 resulted in higher redness (9.36) while that obtained with method 5 showed the lowest redness (1.19) (P < 0.05). Protein hydrolysate produced from method 5 protein isolate had high antioxidant activity in a dose-dependent manner. Additionally, the presence of small peptides in hydrolysate contributed to its anti-diabetic activities. Results indicated that washing by distilled water (method 2) or combined with CaCl2 + citric acid (method 5) is necessary for production of protein isolate from rainbow trout processing by-product.
Volume 16, Issue 89 (7-2019)
Abstract
In this study, the effect of water and Sodium diacetate solutions on reduction of pollutions in Mazafati rutab was investigated. Date branches were washed at the last stage of Khalal by spraying of pure water and Sodium diacetate solution (4000 ppm). Total microbial and fungal counts were determined before washing as well as two, three and four weeks after washing of the fruits on tree. Mazafati rutab samples were packed after harvest and stored in cold room and also at ambient temperature for 6 months. The results showed that surface and microbial pollutions significantly (P<0.05) decreased after washing of the fruits with pure water and Sodium diacetate solution. Total microbial and fungal counts gradually increased during stage of fruit maturity. Rotting rate was significantly (P<0.05) high in the dates treated with Sodium diacetate at harvest time. The moisture content of the dates decreased but total soluble solids (TSS) increased during storage at ambient temperature. In all treatments, pH content decreased and percent acidity (as lactic acid) increased during storage. Total microbial counts in the dates treated with Sodium diacetate was significantly (P<0.05) lower than other treatments during storage. The results indicated that washing of Mazafati date bunches at the last stage of Khalal by spraying of pure water can be effective in reduction of surface pollutions on the fruits. Mazafati rutab should be stored in cold rooms to prevent the activity of microorganisms and pests and increase the storage life.
Volume 17, Issue 4 (11-2017)
Abstract
Remediation of contaminated soil by heavy metals is an important environmental issue which attracted many attentions and was evaluated by several methods. It is highly desirable to apply suitable remedial methods to reduce the risk of heavy metal contamination in soils. Development of new low-cost, efficient and environmental friendly remediation technologies is the main goal of the recent research activities in environmental science and technology. Using nanotechnology in removal of environmental pollutions is of modern and applicable methods. One of the early generations of nanoscale technologies in the field of environment is the use of iron nanoparticles as a ground for sorption of pollutants. These nanoparticles are nontoxic, inexpensive, and very strong absorbents.The aim of this study was to assess the effects of cadmium removal by soil washing with iron (III) oxide nano particles (Fe3O4), stabilized with Polyacrylic Acid (PAA) as nanofluid, on physicochemical characteristics of nanofluid and soil in two defined systems including batch and continuous flow configurations. For this purpose, after complete removal of Cd from the soil in both systems under the optimized conditions, the effects of removal on the physicochemical characteristics of soil and nanofluid including pH, electrical conductivity, and total dissolved solid were assessed. The results of XRD and SEM of soil samples and also zeta potential and size distribution of nanofluid, before and after the removal were investigated. To ensure the absence of other pollutants and elimination of any interaction between soil pollutants, the soil was prepared with clean standard materials and afterwards it was contaminated with cadmium solution prepared by cadmium nitrate. The optimum conditions for cadmium removal in the batch system was as follows: nanofluid concentration=500 ppm, pH=6.5, contact time=24 hr and the ratio of contaminated soil mass (gr) to nanofluid volume (mL) =1:150 . completely Cd removal in continouse flow configuration obtained in the following conditions: nanofluid concentration=500 ppm, pH=6.5, contact time=24 hr, and the flow rate =0.5 mL/min. Cadmium content in the nanofluid after remediation was determined with UV spectrophotometer by using APDC complexes in Tween 80 media. As per the results of this study, pH of the soil samples in the both batch and continuous flow configuration increased from 7.8 to 8.55 and 8.35 respectively. pH of nanofluid increased from 6.5 to 6.8 in the continuous flow configuration and 7.59 in the batch system. EC and TDS of the nanofluid decreased from 1.66 mS/cm and 1110 mg/L to 1.049 mS/cm and 699 mg/L in the continuous flow configuration and these parameters also reached respectively to 0.952 mS/cm and 635 mg/L in the batch system. Soil washing using Fe3O4 nanoparticle did not changed remarkably EC and TDS of the contaminated soil. Nanoparticles size with highest frequency in nanofluid before removal was 205 nmand after Cd removal reached to 23 nm and 29 nm in the continuous flow configuration and batch system respectively, which was an indication of the sorption of nanoparticles with grater size to the soil during the soil washing process. Zeta potential values of influent and effluent of nanofluid from continuous flow configuration and batch system were -61.5, -51.3, and -37.4 mV respectively. The structural changes of soil samples after removal in the both systems were assessed by XRD and SEM tests which confiremed the sorption of nanoparticles through the soil washing.
Volume 18, Issue 118 (12-2021)
Abstract
The methods used to maintain the quality of eggs during the storage period are mainly based on inactivating microorganisms and preventing mass exchanges. In order to investigate the effect of water washing and shell coating using active nanocomposite coating based on 2% carboxymethyl cellulose containing 3.5% nanoclay and 2% marjoram extract on internal quality and egg shell, an experiment with 4 treatments including control (unwashed and uncoated), washed and uncoated, unwashed and coated, washed and coated and 3 replicates during a 4-week storage period at ambient temperature (25±2oC) with weekly evaluation the studied parameters were performed. At the end of the storage period, the highest values of HU (49.71±0.15), YI (0.32±0.00) and the lowest values of WL percentage (3.07±0.02), albumen pH (8.59±0.02), TBARS (0.125±0.03 mg MDA/Kg) and TVC (2.75±0.05 log cfu/ml) were observed in coated eggs (P<0.05). In the evaluation of yolk color indices, coated eggs had significantly (P<0.05) higher values of b* (57.24), a* (-7.72) and lower value of L* (45/51). Regardless of the coating, egg washing had no significant effect on the evaluated parameters. Therefore, the use of active nanocomposite coating of carboxymethyl cellulose - nano montmorillonite - marjoram extract with barrier, antioxidant and antimicrobial properties is recommended to increase the shelf life of eggs at ambient temperature for 4 weeks.
Volume 19, Issue 126 (8-2022)
Abstract
In this research a validated and effective method was developed for simultaneous analysis of 60 pesticides in rice, using liquid chromatography-mass spectrometry (LC-MS/MS), then, the effects of washing and heating processes on residues of studied pesticides were investigated. Extraction was performed by the original QuEChERS method. The pesticides were analyzed simultaneously in a single run with a multiple reaction monitoring (MRM) method. The validation study was performed based on the SANTE 2019 guideline. The method was tested to assess for linearity, trueness, precision, specificity, limit of quantification (LOQ) and limit of detection (LOD). The results showed that the calibration curves for all studied compounds were linear with a coefficient of determination (R2) ranged between 0.984 - 1.000. The mean recoveries obtained for three fortification levels (25, 250, 1000 ng/g) were 76.4 - 110.2 % with satisfactory precision (RSD ranged between 2.8 – 16.7%.
After analysis of treated rice samples with investigated pesticides, the results indicated that both of washing and heating processes, in individual and combinational cases, significantly reduced the amounts of studied pesticides.