سنتز نانوذرات دو فلزي Fe-Ni و بررسي كارايي آن در حذف رنگ‌زاي 14AR از محلول‌هاي آبي

Synthesis of Bimetallic Nanoparticles Fe-Ni and Investigation of their Performance in AR14 Dye Removal from Aqueous Solutions

در اين پژوهش پس از ساخت نانوذرات دو فلزي آهن- نيكل به روش رسوب دهي شيميايي نمك آهن توسط احياكننده‌ي قوي سديم بورهيدريد توسط روشي ساده و قابل اجرا، كيفيت آن ها با استفاده از روش هاي XRD و SEM تعيين شده است. كه مطابق آن ها، اندازه‌ي نانوذرات سنتزشده در محدوده‌ي 200-30 نانومتر بوده است. سپس از آن ها براي حذف رنگ‌زاي 14AR، در سيستم دوغابي استفاده و پارامترهاي موثر در حذف اين رنگ‌زا بهينه شده است. در ادامه، براي شناسايي ساير عوامل مداخله‌كننده، آزمايش هاي شاهد در شرايط بهينه انجام شده است. مطابق آزمايش‌هاي انجام‌شده، شرايط بهينه‌ي زماني به دست آمده است كه از نانوذرات تازه ساخته‌شده با غلظت نانوذرات برابرgr/L 05/0 استفاده شده است، در زماني كه غلظت اوليه‌ي رنگ‌زا، mg/L 200 و pH مساوي 5/7 و دما حدود 2±25 درجه‌ي سانتي‌گراد بوده است. راندمان حذف در شرايط بهينه پس از 2، 30، و 240 دقيقه به ترتيب به 39/79 ،52/90، و 42/94 درصد رسيده است.

According to studies, nearly 15 percent of synthetic dyes enter wastewater during production and consumption operations annually, which is very dangerous and causes many problems for the environment. Thus, removing these compounds is mandatory. NZVI can be used in detoxification of many environmental pollutants, as a reducing agent and catalyst. In order to develop the technology of NZVI, bimetallic nanoparticles are prepared by deposition of a noble metal, such as nickel, over iron nanoparticles. In this study, as a simple and applicable method in the laboratory, bimetallic nanoparticles, Fe-Ni, were made using the method of chemical deposition of iron chloride (FeCl3.6H2O) by a strong reducer, sodium bohr hydride (NaBH4), under nitrogen gas. To ensure the size and nature of the nanoparticles, SEM and XRD experiments were performed. Then, the nanoparticles were used in a slurry system to remove the azo dye (ccid red 14). To achieve optimum conditions during the experiments, the parameters of the dye initial concentration, nanoparticle dosage, pH, elapsed time from creation to implementation of the nanoparticles, shaking speed and temperature were investigated. Then, to identify other effective factors, a control experiment was performed under the optimal conditions and it was found that ethanol, nickel, and light do not have any effect on dye removal. The reducer, however, was able to remove the dye completely. Also, the use of nickel with 3 wt% iron increased dye removal efficiency by 14.65%. According to the survey conducted, optimal conditions were obtained when the tests were performed at temperatures of 25±2 0C with newly synthesized nanoparticles that have 0.05 gr/L concentration with an initial concentration of dye equal to 200 mg/L and pH of 7.5 and a beginning mixer time of two minutes. These nanoparticles had very high activity, so, removal efficiency after 2, 30 and 240 minutes, was 79.39, 90.52 and 94.42 percent, respectively. Finally, LC-Mass experiments indicated that after 4 hours of reaction, the azo band in the dye was broken.