جستجوی مقالات مرتبط با کلیدواژه "سیتریک اسید" در نشریات گروه "کشاورزی"

Phytoremediation is an important method for refining heavy metals, but the main limitation is the low bioavailability of the metals. Chelating agents, by releasing heavy metals from the soil solid phase, can increase their uptake by the plants. In this research, the effects of some chelating agents on the phytoremediation of Vicia faba in a calcareous soil contaminated with Cd were investigated. A factorial experiment was conducted based on a completely randomized design with three replications in the greenhouse of Razi University. The factors included Cd at four levels (0, 5, 10, and 15 mg kg-1 soil as CdCl2), and three chelating agents including ethylene di-amine tetra acetic acid (EDTA), citric acid (CA), and oxalic acid (OA), at two levels (4 and 8 mmol kg-1). The results showed that the highest Cd concentration in the root and shoot (39.90 and 27 mg kg-1, respectively) was obtained at 15 mg kg-1 of Cd and 8 mmol kg-1 of EDTA, CA, and OA. The highest values of transfer factor (0.67) and biological accumulation factor (5.65) were obtained at the highest level of Cd pollution and 8 mmol kg-1 of chelating agents. This indicates that firstly, cadmium was mainly accumulated in the root and was less transferred to the shoot. Secondly, it shows the potential of bean in phytoremediation and Cd uptake. Also, the amounts of the measured factors with citric and oxalic acid were not much different from EDTA, and therefore, these two environmentally friendly natural chelating agents could be used instead of EDTA.

The rapid growth of the world's population in recent decades has led to growing problems in terms of water supply and agricultural resources, and limited water resources are one of the major problems in the agricultural sector. The treated urban and industrial wastewater, which its pollution load is reduced by adding amendments, can be a suitable way to provide plant water and nutritional requirements. Thus, this research aimed to investigate the effect of different amendments on soil properties irrigated with wastewater from Bu-Ali industrial region in the Hamadan province.

For this study, treated wastewater was collected from Bu-Ali Industrial town, Hamadan Province. The greenhouse experiment in the Bu Ali Sina University was conducted in a completely randomized design with three replicates with loamy soil irrigated with wastewater. In this research, nine treatments including citric acid, compost, manure, gypsum, composite treatments (gypsum+ manure, gypsum+ compost, citric acid+ manure, citric acid+ compost), and control (27 sample) were used to investigate the effect of these amendments on some chemical properties. Soil properties were measured before and after the application of treatments. These properties included pH, electrical conductivity, cation exchange capacity, organic matter, total phosphorus, and available phosphorus and heavy metal concentrations such as lead, nickel, cadmium, and micronutrient such as zinc, copper, iron, and manganese were also measured.

The results showed that the applied wastewater was considered to be unsuitable water with large quantities of sodium. The application of various amendments such as compost, manure, and citric acid in soil irrigated with wastewater can significantly reduce soil salinity (from 2.53 in the control treatment until 2.16 in the compost treatment). The effect of amendments on some chemical properties revealed that the addition of different amendments to the soil irrigated with wastewater resulted in significant changes in pH, electrical conductivity, cation exchange capacity, organic matter, carbonate equivalent calcium, Ca, Mg, and Na cations, total phosphorus, and Olsen phosphorus. The lowest total copper content was observed in the control treatment with an average of 13.84 mg kg-1, whereas the highest content of this element was seen in the treatment of 50% gypsum + 50% compost with an average of 14.93 mg kg-1.

Furthermore, the total and available concentration of heavy metals (Pb, Ni and Cd) in soil treated by amendments was mostly higher than the control soil. However, their values were lower than those in the soil and therefore, it had no adverse effect on the soil in this respect. There is also no problem with other soil characteristics such as salinity. In general, the results demonstrated that the use of these amendments can be a useful way to reduce pollution levels and the absorption of heavy metals in the plant.

In the present study, the functional properties of medium-density fiber board made with formaldehyde urea resin as a control with MDF made with chitosan and carboxylic acids were investigated and compared. Various compounds including chitosan acetate solution, chitosan acetate –butane tetra carboxylic acid solution, chitosan acetate -citric acid solution and citric acid solution were investigated. The chemical structure of specimens was investigated by infrared spectroscopy (FTIR). The results of spectroscopy clearly showed the difference in the use of different compounds. The formation of cross-links between cellulose chains and carboxylic acids was confirmed, as well as the formation of hydrogen bonds between chitosan and lignin. Specimens made with the combination of acetate chitosan-BTCA showed better dimensional stability. Also, the internal bonding of MDF specimens made with chitosan acetate solution was higher than controls. Boards made of Chitosan acetate -BTCA compound can be considered as a successful substitute for urea-formaldehyde adhesive due to its better dimensional stability and good internal bonding.

Loquat is a non-climacteric fruit and is very perishable during storage. In the present study, effects of times (0, 7, 14, 21, 28 and 35 + 2 days), packaging (polystyrene and polystyrene/polyethylene dishes) and antioxidants (ascorbic acid 1 and 2%, citric acid 0.5 and 1% and sodium hexametaphosphate 0.5 and 1%) were investigated. These treatments were selected for control of enzymatic browning and storage life of loquat fruits. Treated fruits were stored at 5°C for up to 35 days and 2 days shelf life at 25°C. Results showed that the lowest fruit weight loss (4.34%) was observed in hexametaphosphate 0.5% treated with 2 layers packaging. The treatment of ascorbic acid 2% + citric acid 1% + sodium hexametaphosphate 1% caused lowest browning index. The highest contents of vitamin C, total phenol, total flavonoid and antioxidant activity were observed in fruits treated with ascorbic acid 2%. Overall, it was revealed that ascorbic acid 2% was the most effective treatment to maintain the quality of loquat fruit during storage.

The aim of this study was to investigate the effect of different amendments on soil properties, mass and accumulation of elements in corn (Zea mays) grown on irrigated soil with wastewater of Bu-Ali industrial region. The green house experiment was conducted with treatments of Gypsum, Citric Acid, farmyard manure and compost separately and as complex, in a completely randomized design with four replicates in Bu-Ali Sina University at 2013. Obtained results showed that the applied different amendments under wastewater irrigated, changed significantly chemical characteristics in the studied soil i.e. pH, EC, CEC, organic matter, CCE, soluble cations. The results also showed that the applied different amendments increased significantly dry and wet mass of corn, in which the maximum and minimum (350.50 and 42.75mg/kg respectively) was in farmyard manure treatment and those amount (74.87 and 10.54mg/kg respectively) observed for control treatment. Applied amendments on irrigated soil with wastewater was effected on heavy metal concentration of shoot corn plants, however it was much less than background in which was not adverse effect on plants. But on root corn plant concentration of Zn and Cd was above background in which was adverse effect on plants. The results showed that maximum and minimum heavy metal concentration in corn plant (root + aerial part) was related to Fe and Cd, respectively. The application of amendments (particularly compost and farmyard manure) and wastewater in soil coincidently, not only increased dry and wet mass of corn via nutrition of plant but also prevented salt and sodic conditions in soil for longer time.

Since the waste of agricultural and horticultural products is high, appropriate methods should be used to produce products with high quality and shelf life for export. In Iran a great part of fruits and vegetables are dried conventionally and farmer use So2 gas for preservation and color stability of dried apricots, but this gas is allergic and carcinogenic and effort to find suitable substitutes for this substance would be an efficient method to the health of the society. So, in this study 3 apricot varieties were selected to evaluate the drying quality and to determine the so2 replacement methods. The selected varieties (Noori, Khaybei 2 and Nasiri) were treated with citric acid, (0.3%), ascorbic acid (0.3%), sodium meta bisulfate (0.4%) and a 50% mixture of ascorbic and citric before drying and then were compared with control samples(without any treatment). After drying, the characteristics such as Brix, pH, moisture contents, browning index, acidity and organoleptic properties were evaluated. Results showing that the effect of variety on moisture, browning, pH, acidity and organoleptic properties were significant (P

The effects of hormonical, chemical and physical treatments were studied on seed germination of seeds of Eremurus olgae. The ripening seeds were collected from National Botanical Garden of Iran. Seeds were treated under physical stimulator pretreatments including soaking seeds in the water for 24-48h, cutting seeds top, making abrasion on seed cortex, subjecting to light for 24h, 12h and absolute darkness and chemical stimulator like sodium hypochloride, citric acid and gibberellic acid in different densities for finding the appropriate methods of seed germination and dormancy breaking were applied. The results showed that the most suitable pretreatment and treatment were soaking seeds in water for 24-48h, removing seed cortex, cutting seed top, temperature 10-15°C, white light, 24h (4500-5000 lux) and treating in gibberrelic acid (0.08 Molar) for 45 minutes in 1-3 weeks makes the germination percentage (80%), germination speed 1.6, seed vigor 13.65 and treating in citric acid (30 mg/lit) with germination percentage (70%), germination speed (1.27) and seed vigor (7.3). The results showed some important differences comparing to controls.