نوع مقاله : پژوهشی
نویسندگان
1 دانشکده فنی و مهندسی- گروه مهندسی عمران - دانشگاه خوارزمی
2 دانشجوی کارشناسی ارشد مهندسی عمران- محیط زیست، دانشکدة فنی و مهندسی، دانشگاه خوارزمی
3 استاد گروه شیمی تجزیه، دانشکده علوم پایه، دانشگاه آزاد اسلامی واحد تهران مرکز
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
A group of water-source pollutants whose concentration and distribution were either negligible or undiscovered in the past, yet can leave undesirable effects on the environment and living organism are called emerging chemical pollutants, such as pharmaceutical compounds. Developing effective and efficient methods for removing this group of pollutants can be a great step for persevering the environment. This study presents a practical and economical method of synthesizing nano silica-gel dendrimers with the aim of absorbing Rifampicin. Our method begins by the conversion of the silica-gel core to a dendrimer, followed by the addition of branches (chemical functional groups) to the said core, resultingly creating an inexpensive and environment-friendly absorbent. In addition to trapping pollutant particles within its branches, this absorbent is also capable of forming hydrogenic and Van der Waals bonds with antibiotic molecules. The FESEM, TGA, XRD, and FTIR methods of analysis were used to determine the morphology and structure of the absorbent. Furthermore, the absorption rate of Rifampicin was studied across various in vitro conditions, such as various temperatures and detention time. The results suggest that the synthesized nanoparticles -with an average diameter of 47 nm- share a homogenous net-like structure and include the desired functional groups. The absorption process is further facilitated due to the formation of hydrogenic and Van der Waals bonds between the hydroxyl groups present in the absorbate and the functional groups on the surface of the nano-absorbent. A maximum elimination ratio of 85% was achieved at 38.57 C, given a 20-minute detention time at a pH of 5. Additionally, studying the experiment’s isotherm showed that the suggested Langmuir system has a better compatibility with in vitro conditions compared to the Freundlich, and Temkin models, yielding a maximum absorption capacity of 131 mg/g with R2=0.9941, and confirming the absorption process to be monolayered and homogenous. Kinetical examination of the experiment proved that a pseudo-second-order kinetic model can properly describe the process of Rifampicin absorption with R2=0.994, proving the absorption process to be chemical. Lastly, reduction and reabsorption of the nano-absorbent was attempted and achieved via a process comprised of ten consecutive cycles of washing with methanol, resulting in absorption rates of up to 60%; which speaks of this absorbent’s commendable reabsorption performance. Therefore, it could be concluded that the nano silica-gel dendrimer nano absorbent as a high-performance, environment-friendly, and recyclable solution, shows a great potential in the development of water and wastewater treatment.
کلیدواژهها [English]
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