Access to clean and safe water is a critical challenge in many parts of the world due to harmful contaminants such as arsenic in water sources that affect millions worldwide. This article explores how iron oxide nanoparticles can remove arsenic from water and discusses the importance of water analysis and sustainable solutions.
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Sustainable Water Management
Creating sustainable water management systems that are both ecologically and economically viable is essential since access to clean and safe water is a basic human right.
One of the key elements of sustainable water management is developing and implementing effective water treatment technologies designed to remove contaminants from water sources in a cost-effective and environmentally sustainable manner. However, before implementing these technologies, it is essential to have a complete picture of several water quality-determining parameters via different water analysis techniques.
Importance of Water Analysis
Water analysis is an essential component of water management and critical for ensuring drinking water's safety and quality. It involves the measurement of biological, chemical, and physical parameters in water samples, including pH, total dissolved solids, turbidity, dissolved oxygen, temperature and various contaminants such as viruses and bacteria.
Water analysis is vital for several reasons since it helps identify and determine the concentration of potential contaminants, which is critical for ensuring that water is safe for human consumption. Moreover, water analysis helps monitor the effectiveness of water treatment processes, understand the overall quality of water resources and identify any long-term trends or changes in water quality.
General Water Analysis Techniques
Water analysis can involve several techniques, including colorimetric tests, which are simple and inexpensive tests used to measure the concentration of a particular hazardous substance, spectroscopy involving light to measure the properties of water samples, and chromatography, which is a more complex technique used to separate and identify individual components in water samples.
Arsenic Pollution of Water Supplies
A severe issue that may result in various health issues, such as skin lesions, cancer, and cardiovascular illness, is arsenic pollution of water supplies caused by natural geological processes and human activities like mining and agriculture.
Several methods can be used to remove arsenic from water, including activated alumina and reverse osmosis. These effectively remove arsenic from water but can be expensive and require specialized equipment, making them less practical in developing countries.
Iron Oxide Nanoparticles for Arsenic Removal from Water
Iron oxide nanoparticles offer a promising sustainable solution to arsenic contamination in water sources since their high surface area and reactivity make them effective at adsorbing and removing arsenic. Iron oxide nanoparticles work by adsorbing arsenic onto their surface, which is then removed from the water through filtration.
Iron Oxide Nanoparticles Modified Rice Husk Ash Adsorbent
In a 2023 study, researchers used rice husk ash (RHA) and iron oxide nanoparticles to fabricate a low-cost and highly efficient adsorbent for arsenic removal from water. Researchers used N2 adsorption–desorption, EDX, SEM, and FTIR to characterize the physicochemical properties of iron oxide-modified RHA adsorbent.
The manufactured adsorbent was turned into a purification cartridge with a 100 mL/min flow rate and tested on a groundwater sample with a 40 ppm arsenic contamination. On average, 98% of the metal-containing arsenic was removed, and several adsorption parameters, including metal concentration, adsorbent dosage, time, and pH, were also optimized.
MCNTs Modified with Iron Oxide Nanoparticles for Arsenic Removal
In a study published in 2011, researchers demonstrated arsenic removal from water using multi-walled carbon nanotubes (MCNTs) modified with iron oxide nanoparticles. The study showed that MCNTs alone have poor efficiency in eliminating arsenic from water by conventional adsorption mechanisms; however, when these are modified with iron oxide nanoparticles, the efficiency increases from 11% to 77.5%.
Plant Leaves Used for Cost-effective Iron Oxide Nanoparticles Synthesis
A study published in 2020 used leaf extracts from five different plant species as a reducing agent for iron oxide nanoparticle synthesis for arsenic adsorption and compared their adsorption capacities via comparative analysis.
The green synthesis method was used to synthesize iron nanoparticles using five plants, including eucalyptus leaves (Eucalyptus globulus), pomegranate leaves (Punica granatum), green tea leaves (C. sinensis), oak tree leaves (Quercus virginiana), and black tea leaves (Camellia sinensis).
The maximum arsenic adsorption capability was shown by eucalyptus leaf nanoparticles, which had a value of 39.84 mg/g, followed by Oaktree leaf nanoparticles, with a value of 32.05 mg/g.
Iron oxide nanoparticles provide a sustainable solution for water purification since not only are they effective at removing arsenic, but they are also relatively easy to synthesize and modify, making them a cost-effective and scalable solution for developing countries as well as being environmentally sustainable, as they do not produce any harmful byproducts or generate waste.
However, it is important to note that using iron oxide nanoparticles for water treatment is not a silver bullet solution to the problem of arsenic contamination. Therefore it is essential to continue developing and implementing a range of sustainable water management strategies, including source water protection, water conservation, and public education.
References and Further Reading
Bhat, A., Hara, T. O., Tian, F., & Singh, B. (2023). Review of analytical techniques for arsenic detection and determination in drinking water. Environmental Science: Advances. doi.org/10.1039/D2VA00218C
Javed, K., Mahmood, S., Ammar, M., Abbas, N., Shah, M. Y., Ahmed, T., & Mustafa, G. (2023). Rice husk ash adsorbent modified by iron oxide with excellent adsorption capacity for arsenic removal from water. International Journal of Environmental Science and Technology. doi.org/10.1007/s13762-022-04390-7
Kamath, V., Chandra, P., & Jeppu, G. P. (2020). Comparative study of using five different leaf extracts in the green synthesis of iron oxide nanoparticles for removal of arsenic from water. International journal of phytoremediation. doi.org/10.1080/15226514.2020.1765139
Tawabini, B. S., Al-Khaldi, S. F., Khaled, M. M., & Atieh, M. A. (2011). Removal of arsenic from water by iron oxide nanoparticles impregnated on carbon nanotubes. Journal of Environmental Science and Health, Part A. doi.org/10.1080/10934529.2011.535389