نوع مقاله : مقاله کامل علمی - پژوهشی
نویسندگان
1 دانشگاه ازاد اسلامی اصفهان
2 isfahan
3 دانشگاه ازاد نجف اباد
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives: The accumulation of inorganic pollutants, particularly phosphate and nitrate, in aquatic ecosystems leads to eutrophication and poses significant risks to human health. The present study aimed to develop a sustainable and cost-effective silica-biochar nanocomposite, synthesized from silica nanoparticles and rice husk-derived biochar, for the efficient removal of nutrients from wastewater.
Materials and Methods: Batch experiments were conducted to investigate the effects of pH, adsorbent dosage, contact time, and initial pollutant concentration on adsorption performance. The pH was adjusted to values of 2, 4, 6, 8, and 10. Contact times were set at 5, 10, 20, 40, 80, and 160 minutes. Adsorbent dosages of 0.5, 1, 2, and 4 mg/L were applied, while the initial concentration of each pollutant was fixed at 5 mg/L.
Findings: Maximum removal efficiency was achieved at pH 2, using 4 mg/L of the nanocomposite and an initial concentration of 5 mg/L for both pollutants. After 80 minutes, removal efficiencies reached 89.6% for phosphate and 87.5% for nitrate(p < 0.05). Fourier-transform infrared(FTIR) spectroscopy confirmed the presence of a heterogeneous surface containing functional groups(–OH, –COOH, Si–OH) as well as chemical interactions such as hydrogen bonding, which enhanced the adsorption capacity. X-ray diffraction(XRD) revealed an amorphous structure, contributing to a high specific surface area of 312.5 m²/g. The Langmuir isotherm model provided the best fit to the experimental data(R² > 0.95), indicating monolayer adsorption.
Conclusion: This bio-based adsorbent, derived from agricultural waste(rice husk), offers a cost-effective and environmentally friendly solution for wastewater treatment and holds potential for industrial applications aimed at mitigating nutrient pollution.
کلیدواژهها [English]
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