جستجوی مقالات مرتبط با کلیدواژه "سیتریک اسید" در نشریات گروه "آب و خاک"

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.