Zeinab Salari1, Zeynab Bayat2 , Shima Dabaghi 3,* , and Fatemeh Salahshoori Niaei4
1 Department of Agricultural Biotechnology, Faculty of Agriculture, University of Shahid Bahonar, Kerman, Iran
2 Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
3 Department of Chemical Engineering, Faculty of Engineering, University of Shahid Bahonar, Kerman, Iran
4 Department of Biology, Faculty of Sciences, Naein Branch, Islamic Azad University, Isfahan, Iran * Corresponding author: Shima Dabaghi, Department of Chemical Engineering, Faculty of Engineering, University of Shahid Bahonar, Kerman, Iran Email: sh_dabaghi@eng.uk.ac.ir
Abstract:
Introduction: Increasing the concentration of Boron in drinking water, wastewater, and irrigation have negative effects on the human environment. This pollution can be partially removed by the application of phytoremediation technologies using algae or aquatic plants. The aim of the current study was to determine the biosorption capacity of the algae Spirogyra sp. for Boron from industrial wastewater and examine the best elimination conditions using different parameters. Materials and Methods: In this study, 100 g of fresh algal biomass was collected from the industrial wastewater of a copper mine located in Kerman, Iran. At first, algae was selected among various algal species concerning abundance and resistance ability to high concentrations of Boron. Then, removal of Boron by the algal was examined in terms of algae biomass levels (2 and 4 gr), incubation time intervals (2, 12. 24. 48, and 72 hours), and different concentrations of Boron (5, 10, 15, 25, and 100 ppm) on the were examined. The experiment was factorial with a completely randomized design framework and three replications. Results: The results presented that the elimination of Boron from industrial wastewater was performed by biomass of algae Spirogyra sp. The maximum Boron absorption was achieved at concentrations of 5 ppm and an incubation time of 12 hours. The absorption of Boron was higher in 4 gr than in 2 gr of algae biomass treatment. Conclusion: It can be concluded that algae Spirogyra sp. has a strong potential for boron removal in industrial wastewater containing boron ions.
1.Introduction
Boron is a paradoxical contaminant used for wastewater. From a health standpoint, it is a micronutrient for many plants and animals at low levels, while it is a poison at higher levels1,2. Exposure to large amounts of Boron (B) over short periods of time can affect the stomach, intestines, liver, kidney, and brain and can eventually lead to death3. The excessive amount of B in the cultivated soils can lead to B toxicity, and consequently inhibition of nitrate reduction and increased ammonium assimilation in tomato plants, accompanied by the loss of leaf biomass and disorders in organic nitrogen metabolism4. The WHO limit for Boron is set at 0.3 ppm for drinking water; however, there is some speculation that this limit can be increased to 2.4 ppm. Thus, it has been left to state and regional regulatory agencies to set limits on boron discharge in waste water5. Boron is diffused to the environment mainly in discharged industrial wastewater, including manufacturing facilities of heat-resistant materials, storage and distribution of solar energy systems, catalysts, ceramics, and glass6. Since B removal from industrial wastewaters has received interest among scholars, some methods, including adsorption– flocculation, electrocoagulation, reverse osmosis, precipitation, ion-exchange, use of B-selective resins, and some biological materials (such as duckweeds) have been tried7-10. Phytoremediation is defined as a process of decontaminating soil and aquatic systems by using plants, fungi, or algae to absorb heavy metals. Recently, aquatic plants, especially micro and macro algae, have received much attention as they can absorb metals and take up toxic elements from the environment or lessen their detrimental effects11,12. The algae can be considered ideal candidates for the selective elimination and concentration of heavy metals due to its high tolerance to heavy metals, ability to grow both autotrophically and heterotrophically, large surface area/volume ratios, phototaxy, phytochelatin expression, and potential for genetic manipulation13,14. In recent years, several species of the algae, namely Chlorophyta and Cyanophyta, have been utilized to absorb and accumulate Arsenic and Boron ions from their environment into their bodies15-17. The current study aimed to determine the biosorption of capacity of the algae Spirogyra sp for B from industrial wastewater and examine the best elimination conditions using different parameters.
