JWSS - Journal of Water and Soil Science

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Aqueous extraction of gum from flaxseed was optimized using Response Surface Methodology (RSM). In this study the effect of temperature (45-100 °C), pH (3-7) and water/seed ratio (4-24), on the dependent variables including: yield, protein and apparent viscosity of extracted gum were investigated. The results showed that temperature and pH are two major effective factors on yield and quality of extracted gum (purity and apparent viscosity), whereas water/seed ratio had minor effects. The optimized conditions of extraction were as follows: temperature 85- 90 ^oC pH 6.5- 7.0 and water/seed ratio 14. Apparent viscosities of extracted gums were determined and the effect of extraction conditions on rheological properties of flaxseed gum was investigated.

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Nowadays, Inulin, due to its nutritional properties, is widely being used all over the world. Artichoke tuber is one of its major industrial extraction sources. Therefore, in the present study we initially aimed to determine total carbohydrate, inulin, reducing sugars as well as dry matter contents of an Iranian artichoke. Thereafter, we focused on the optimization of aqueous extraction of inulin in the presence and absence of direct and indirect ultrasonic waves at various combinations of extraction time, temperature and solvent:solid ratio using Box-Behnken design and response surface methodology (RSM). Based on the experiments, the dry matter and total carbohydrate contents of Iranian artichoke were 6.7 and 3.9%, respectively. We also found that an empirical model developed by RSM could satisfactorily describe relationship between independent parameters and the yield of total carbohydrate as well as inulin. Furthermore, our findings revealed that optimal aqueous extraction of inulin could be achieved at 80ºC, for a duration of 5 min at a solvent:solid ratio of 1:5. Moreover, a direct relation was seen between the yield of extraction and the power as well as frequency of ultrasonic waves where with increasing latter variables, duration of extraction process and inulin yield considerably reduced and increased, respectively.

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The objective of current study was to perform screening experiment, (phase zero of response surface methodology) the analysis of salinity and water tensions for spring wheat in Mashhad region and derive water production functions. The experiment was performed in the Research Field of Agricultural Faculty of Ferdowsi University of Mashhad in 2009-2010. Two water sources were selected: saline water (10 dS/m) and water without salinity limitation (0.5 dS/m). A single replicate factorial experiment with four variables and water requirements in different growth stages, was done with each variable having two levels, 20% and 100% of water requirements. The central points of experiment area with two replications were added for estimating the curvature in the fitted response surface. The results showed the water requirements in heading and flowering were the most important variables. The fitted water production functions estimated the yield of saline and non saline plots with correlation coefficients equalsing 0.95 and 0.99. In general, the obtained results proved the efficiency of the screening experiment in identifying the relative importance of variables and excluding the ineffective variables

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As the industry expands and water resources decline, attention has increasingly focused on the treatment and recycling of wastewater generated by various industrial processes. Adsorption using cost-effective and readily available adsorbents is a simple and low-cost method for wastewater treatment in various industrial sectors. In this study, clinoptilolite natural zeolite (CNZ) was employed for the removal of two dye pollutants: cationic methylene blue and disperse red 60. To evaluate the efficiency of CNZ, four variables, pH, contact time, adsorbent dosage, and initial dye concentration, were investigated using response surface methodology. Based on the results obtained from batch experiments, the maximum removal efficiencies of methylene blue and disperse red 60 by CNZ were 98.9% and 78.7%, respectively. These optimal removal percentages were achieved under the following conditions: a contact time of 120 minutes, an initial dye concentration of 50 mg/L, an adsorbent dosage of 20 g/L, and a pH of 10 for methylene blue and a pH of 4 for disperse red 60. The pseudo-second-order kinetic model, with an R² value greater than 0.90, exhibited the best fit for the adsorption of both dyes from aqueous solutions. Furthermore, the extent of dye adsorption exhibited a better correlation with the Langmuir (Disperse Red 60) and the Freundlich (Methylene Blue) adsorption isotherms. Results of column experiments demonstrated that the maximum adsorption capacities for Methylene Blue and Disperse Red 60 were 97.7 and 45.9 mg/g, respectively. The results revealed the high potential of CNZ as a sorbent for cationic dye pollutants from industrial wastewaters.

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