Jurnal Kejuruteraan SI 1(4) 2018: 59-64 http://dx.doi.org/10.17576/jkukm-2018-si1(4)-08 Synthesis of Mesoporous Silica for Ammonia Adsorption in Aqueous Solution (Sintesis Silika Mesoliang untuk Penjerapan Ammonia dalam Larutan Akues) Rabiatul Adawiyyah Arifn a , Hassimi Abu Hasan a,b* , Nur Hidayatul Nazirah Kamarudin a,b , Nur ‘Izzati Ismail b a Chemical Engineering Programme, b Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia ABSTRACT In this work, mesoporous silica (MSN) was synthesized and tested for ammonia adsorption. The synthesized MSN was characterized using the Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Brunauer–Emmett–Teller (BET). In the ammonia adsorption experimental, the mass of MSN was varied at 0.5, 1.0, 1.5, 2.0 and 2. 5 g. The data of ammonia uptake by MSN was plotted using Langmuir and Freundlich isotherms, while the kinetic adsorptions were determined using pseudo-frst order and pseudo-second order kinetics. The results showed the MSN structural was hexagonal form and particle size of 70 to 150 nm. Characterization using FTIR shows the MSN contained various chemical functional groups. The adsorption of ammonia rest resulted with a high percentage of ammonia removal. At 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 g of MSN, the highest adsorption uptake at 5 minutes were 0.79, 0.42, 0.31, 0.21, 0.17 and 0.12 mg/g, respectively. The adsorption data were ftted to the isotherm and kinetic models to predict the mechanism and kinetic characteristics of the adsorption process. The Freundlich isotherm model shows the highest correlation with the Freunclidh (K F ) and adsorption constant (n) of 6.78 and 0.39 mg/g, respectively. For the kinetic modeling, the data of ammonia adsorption process were well ftted to the pseudo-second order with coeffcient determination (R 2 ) value of 0.9992. These results indicated the potential for a new application of MSN as an effective adsorbent for ammonia removal and it can be applied in the water treatment processes. Keywords: Mesoporous silica; ammonia adsorption; water treatment; isotherms model; kinetic model ABSTRAK Dalam kajian ini, silika mesoliang (MSN) telah disintesis dan diuji untuk penjerapan ammonia. Pencirian terhadap MSN dilakukan dengan menggunakan Spektroskopi Transformasian Fourier Inframerah (FTIR), Mikroskop Elektron Pengimbas (SEM), Mikroskop Elektron Pancaran (TEM), dan Brunauer-Emmett-Teller (BET). Dalam uji kaji penjerapan ammonia, jisim MSN diubah pada 0.5, 1.0, 1.5, 2.0 dan 2. 5 g. Data pengambilan ammonia oleh MSN telah diplot menggunakan isoterma Langmuir dan Freundlich, sementara kinetik penjerapan telah ditentukan dengan menggunakan kinetik urutan pseudo- pertama dan kinetik urutan pseudo-kedua. Keputusan menunjukkan struktur MSN adalah berbentuk heksagon dengan saiz partikel antara 70 – 150 nm. Pencirian melalui FTIR pula menunjukkan MSN mempunyai pelbagai kumpulan kimia berfungsi. Saiz liang MSN yang besar telah menghasilkan peratusan penyingkiran ammonia yang tinggi. Pada jisim MSN sebanyak 0.5, 1.0, 1.5, 2.0, 2.5 dan 3.0 g, penjerapan ammonia tertinggi pada 5 minit pertama masing-masing adalah 0.79, 0.42, 0.31, 0.21, 0.17 and 0.12 mg/g. Data penjerapan diplot pada model isoterma dan kinetik untuk meramalkan mekanisme dan ciri-ciri kinetik proses penjerapan ammonia. Model isoterma Freundlich menunjukkan korelasi tertinggi dengan pemalar Freunclidh (K F ) dan penjerapan (n) masing-masing sebanyak 6.78 dan 0.39 mg/g. Pemodelan kinetik menunjukkan data penjerapan ammonia berpadanan dengan pesanan pseudo-kedua dengan nilai penentuan koefsien (R 2 ) sebanyak 0.9992. Ini menunjukkan potensi aplikasi MSN sebagai penjerap berkesan untuk penyingkiran ammonia dan boleh diaplikasikan dalam proses rawatan air. Kata kunci: Mesoliang silika; penjerapan ammonia; rawatan air; model isoterma; model kinetik INTRODUCTION Water is a natural resources that very important not only for human but also for animals and plants. Water have several uses not only use for drinking but for another daily routine such as using for bath, cooking and industrial purposes (Abu Hasan et al. 2011). Nowadays, the sources for clean water remain decreasing because several resources have been polluted with the industrial effuent discharges. Failure to get a clean water for drinking will cause bad impact for long term. One of the mostly chemical compound with highly concentration presents in river water is ammonia (Ahammed & Davra 2010) discharged by industrial activities. The Ministry of Health, Malaysia has regulated the minimum limits of ammonia that only can be presents in the treated water is not exceed 1.5 mg/L (Abu Hasan et al. 2011). JK 30 SI1(4) Bab 8.indd 59 12/4/2018 10:14:48 AM