Judul: Kajian Pustaka Silika Gel Asal Sekam Padi sebagai Adsorben Logam Berat
Abstrak: Meningkatnya kemajuan industri, pencemaran akibat limbah yang mengandung logam berat juga meningkat. Penanggulangan logam berat dengan proses adsorpsi yang memanfaatkan sekam padi sebagai adsorben. Sekam padi memiliki kandungan silika yang cukup tinggi. Kajian literatur ini bertujuan mengetahui potensi silika asal sekam padi sebagai adsorben logam berat melalui perlakukan yang berbeda. Sintesis silika menggunakan metode sol gel. Untuk meningkatkan kapasitas adsorpsi dilakukan penambahan aktivator asam bertujuan menghilangkan pengotor pada permukaan Selain itu, dilakukan modifikasi pada permukaan silika yang berhasil meningkatkan keasaman permukaan dan penambahan gugus fungsi baru yang dapat meningkatkan keaktifan pembentukan ikatan dengan logam berat. Hasil aktivasi dan modifikasi didukung dengan analisis gugus fungsi, permukaan, dan komposisi adsorben. Selain itu, dilakukan optimasi beberapa parameter adsorpsi berupa pH yang akan menghasilkan kapasitas adsorpsi maksimum., As the industrial sector grows, contamination from industrial waste that contains heavy metals is also increasing. One of the methods to remove heavy metals from industrial waste is the adsorption process by utilizing agricultural waste in the form of rice husks as adsorbent. Rice husk has high silica components. This literature review aims to determine the potential of silica from rice husks as an adsorbent of heavy metals through several different treatments. Silica synthesis using the sol-gel method. To improve the adsorption capacity, acid activation was carried out to remove impurities on the surface and modification of the silica surface. The modifications made were successful in increasing surface acidity and the addition of new functional groups which could increase the activity of bond formation with heavy metals. The results of activation and modification are supported by analysis of functional groups, surface, and composition of the adsorbent. In addition, the optimization of several.
Keyword: adsorbent, adsorption, heavy metals, rice husk, silica gel

Judul: Kajian Pustaka Pemanfaatan Limbah Baglog sebagai Adsorben Logam Berat
Abstrak: Limbah industri mengandung berbagai senyawa kimia berbahaya seperti logam berat yang dapat mencemari lingkungan sehingga perlu disisihkan. Adsorpsi merupakan salah satu metode yang banyak digunakan karena lebih efisien dan ekonomis. Limbah baglog merupakan sisa budi daya jamur yang telah dilaporkan memiliki sifat sebagai adsorben. Kajian pustaka ini bertujuan menentukan pemanfaatan limbah baglog sebagai adsorben logam berat dengan perlakuan yang berbeda. Dalam kajian pustaka ini, metode adsorpsi menggunakan adsorben limbah baglog tanpa aktivasi kimia, dengan aktivasi kimia, dan pengarangan (biochar). Hasilnya menunjukkan bahwa adsorben limbah baglog tanpa aktivasi kimia mampu menjerap Fe, Mn, Ni, Cu, Pb, Zn, dan Cd dengan rentang kapasitas adsorpsi 0,0724–0,769 mmol/g. Adsorben limbah baglog dengan aktivasi kimia mampu menjerap Cr, Cd, dan Pb dengan kapasitas adsorpsi 0,167–0,971 mmol/g dan adsorben limbah baglog dengan bentuk pengarangan menjerap Cd, Pb, Cu, dan Zn dengan kapasitas adsorpsi 0,417–1,92 mmol/g., Industrial waste contains various hazardous chemical compounds such as heavy metals that can cause environmental pollution that must be removed. Adsorption is one of the methods widely used because it is more efficient and economical. Spent mushroom substrates are the residue of mushroom cultivation (baglog) that have to been reported as adsorbents. This literature review aims to determine the utilization of the baglog substrates as heavy metal adsorbents with different treatments. In this literature review, the adsorption method used the baglog adsorbents without chemical activation, with chemical activation, and biochar. The results showed that the baglog substrates adsorbent without chemical activation could adsorb Fe, Mn, Ni, Cu, Pb, Zn, and Cd with an adsorption capacity range of 0.0724–0.769 mmol/g. The baglog adsorbent with chemical activation could adsorb Cr, Cd, and Pb with adsorption capacity of 0.167–0.971 mmol/g, and that of adsorbent in the form of biochar could adsorb Cd, Pb, Cu, and Zn with adsorption capacity of 0.417–1.92 mmol/g.
Keyword: adsorben, adsorpsi, limbah baglog, logam berat

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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