TiO2/Kaolin composite as low-cost adsorbent for procion red removal from aqueous solution: kinetics, equilibrium, and thermodynamic studies

ABSTRACT. Procion red is one of the most utilized textile dyes by numerous textile factories worldwide. Unfortunately, it has a detrimental effect on the ecosystem whenever it was released into the environment as textile wastewater. In this work, the removal of procion red from aqueous solution has been conducted by adsorption with modified natural kaolin as a low-cost adsorbent. Kaolin was systematically modified by thermal activation then followed by acid activation in different acid concentration. Activated kaolin sample was then mixed with TiO2 to produce TiO2/Kaolin composite. Activated kaolin and TiO2/Kaolin composite were characterized using X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). Various operational variables that affect the adsorption process were taken into consideration, including the effect of initial pH, contact time, initial dye concentration, and temperature. The adsorption parameters of kinetics, isotherm, and thermodynamics were also studied according to the most common model established. The results showed that the procion red adsorption was pH-dependent and reached equilibrium at 90 min. The kinetics study was revealed that the adsorption process was better demonstrated by the pseudo-first-order rather than the pseudo-second-order model. The adsorption isotherm investigation showed that the adsorption process was followed both Langmuir and Freundlich model with qe reached 158 mg/g, and the adsorption process was predicted in favorable condition. The thermodynamic study revealed that the adsorption process is spontaneous with endothermic nature. According to the results, it can be considered that the TiO2/Kaolin composite adsorbent has better adsorption capability to the procion red.               KEY WORDS: Activated kaolin, TiO2, Composite, Adsorption, Procion red Bull. Chem. Soc. Ethiop. 2019, 33(3), 437-450.DOI: https://dx.doi.org/10.4314/bcse.v33i3.

Penerapan Metode Drills Berbasis Multimedia Untukmeningkatkanhasil Belajar Siswa pada Mata Pelajaran IPS Terpadu Kelas VIII SMPN 2 Banda Aceh

Penelitian ini tentang penerapan metode drills berbasis multimedia untukmeningkatkanhasil belajar siswa padamata pelajaran IPS Terpadu kelas VIII SMPN 2 Banda Aceh. Penelitian ini bertujuan untuk mengetahui; (1) Peningkatan hasil belajar siswa; (2) Aktivitas guru dan siswa; (3) Keterampilan guru; dan (4) Respon siswa terhadap penerapan metode drills berbasis multimedia. Subjek dalam penelitian ini adalah siswa kelas VIII-5 SMPN 2 Banda Aceh yang terdiri atas 30siswa. Pengumpulan data dilakukan dengan menggunakan tes hasil belajar siswa, lembar pengamatan aktivitas guru dan siswa, lembar pengamatan keterampilan guru dalam mengelola pembelajaran, dan angket respon siswaterhadap penerapan metode drills berbasis multimedia yang telah dilaksanakan. Analisis data menggunakan statistik deskriptif persentase. Hasil penelitian diperoleh bahwa; (1) Persentase ketuntasan individual pada siklus I yaitu63persendanpadasiklus II 80 persen. Secara klasikal, persentase ketuntasan pada siklus I yaitu 60 persendanpadasiklus II menjadi 90 persen; (2) Aktivitas guru dan siswa dikatakan meningkat dari siklus I sampai dengan siklus II; (3) Keterampilan guru pada siklus I diperoleh skor 2,45 dengan kategori sedang danpadasiklus II denganskor3,48dikategorikanbaik; (4) Respon siswa terhadap penerapanmetode drills berbasis multimedia dapat dikatakan positif.Ini terbukti bahwa siswa dapat memahami materi yang disajikan guru terhadap penerapanmetode drills berbasis multimedia

Pengaruh Budaya Organisasi Dan Motivasi Kerja Terhadap Kepuasan Kerja Dan Kinerja Perawat (Studi Pada Perawat Di Ruang Rawat Inap Pada Rumah Sakit Umum Daerah (RSUD) H. Hanafie Muara Bungo - Jambi)

Penelitian bertujuan untuk menganalisis dan menjelaskan pengaruh budaya organisasi dan motivasi kerja terhadap kepuasan kerja dan kinerja perawat. Penelitian ini termasuk penelitian explanatory research. Tehnik sampel dengan menggunakan tehnik Proportional Random Sampling (tehnik sampel proposional) besarnya ditetapkan berdasarkan rumus Slovin sebesar 74 dari 277 tenaga perawat Rumah Sakit Umum Daerah (RSUD) H. Hanafie Muara Bungo. Metode pengumpulan data menggunakan kuesioner. Analisa data menggunakan analisis jalur (Path Analisys). Hasil penelitian bahwa budaya organisasi berpengaruh tidak signifikan terhadap kepuasan kerja, budaya organisasi berpengaruh signifikan terhadap kinerja perawat, motivasi kerja berpengaruh signifikan terhadap kepuasan kerja, motivasi kerja berpengaruh signifikan terhadap kinerja perawat, dan kepuasan kerja berpengaruh tidak signifikan terhadap kinerja perawat. Kata Kunci: Budaya Organisasi, Motivasi Kerja, Kepuasan Kerja dan Kinerja Perawat. The purpose of this study to analyze and explain the influence of organizational culture and work motivation on job satisfaction and nurse performance. This research includes explanatory research. Sampling technique using proportional random sampling as determined by Slovin formula 74 of 277 nurses Regional General Hospital H. Hanafie Muara Bungo. Methods of data collection using questionnaires. Data analysis using path analysis. Research results effect the organizational culture is not significant on job satisfaction, organizational culture significant influence on nurse performance, work motivation significant effect on job satisfaction, work motivation significant influence on nurse performance, and the job satisfaction is not a significant influence on nurse performance

Pengaruh Individu dan Organisasi terhadap Disiplin Kerja (Studi pada PT. Bank “X” Cabang “Y” Malang)

Work discipline is the condition desired by organization. Work discipline will never be happened automatically, but should be shaped by many factors, both individual and organizational factors. Employee that discipline in their work will give optimal result that supports achievement of company's goals. PT. Bank “X” Branch “Y” Malang is a stated-owned corporation and has strategic position in supporting national development. In order to make its function functioned properly, so that PT Bank “X” Branch “Y” Malang has to enhance its organization performance. Organization performance was significantly affected by employee work discipline, while personnel management has heavy duty in creating high-level discipline. This research was explanatory research, with employee of PT. Bank “X” Branch “Y” Malang as the analysis unit. Stratified random sampling technique was used in taking sample, while questionnaire was used to collect data from 50 employees. Variable measurement used in this research was the Likert scale. Data analysis used descriptive and inferential methods. The results showed that: (1) descriptive analysis resulted that variables of employee need (X1), employee capability (X2), work training (X3), compensation type (X4), close-monitoring (X5) and employee's work discipline (Y) were perceived by employees properly and occurred as desired. (2) By completely, there was significant influence between independent variables on dependent variable. (3) Partially, variables of employee need (X1), employee work capability (X2), work training (X3), compensation type (X4) and close-monitoring (X5) significantly affected variable of employee work discipline (Y). (4) Regression test result showed that variable of compensation type (X4) has dominant contribution, namely 19,90 percents, on employee work discipline (Y), if been compared with other variables. Variables of compensation type (X4) have dominant contribution in this research. So that there are many things that should be considered by company, namely: 1) variabel of compensation type (X4) essentially on items of incentive giving and amount of insurance guarantee that should be more considered and enhanced because variable of compensation type (X4) had dominant contribution on employee work discipline, of course, and without ignoring other variables. (2) Employee work discipline have shown a properly condition so that should be maintained even enhanced in order to give more maximal value-added for the company

Measuring water sorption isotherm of mortar containing chloride

The water sorption isotherm of materials is of great importance to predict their durability. Many different methods are used in the literature to measure this water sorption isotherm. Chloride present in concrete elements/structures e.g. in marine exposure, can change the water sorption of the material. In this paper, the water sorption isotherm of a standard mortar with and without chloride is measured with a hygroscopic method. The chloride penetration into the sample is obtained by the vacuum saturation method. Subsequently the sample is placed in a glass vessel and dried. By injecting a known amount of water into the vessel, the water evaporates and is partly adsorbed by the sample until an equilibrium state is reached. With the known amount of the injected water into the vessel, the humidity inside the vessel and the volume of the vessel, one point of the adsorption isotherm is determined. For measuring the next point, more water is injected into the vessel. More points are measured in the same manner until the sample is saturated and with this the adsorption isotherm is completed. Afterwards, the measurement of the desorption isotherm starts with blowing dry air with a known flow, humidity and duration into the vessel. After reaching equilibrium, the first point of the desorption curve is measured. The next point is measured by blowing more dry air into the vessel. This continues until the sample is completely dry and with it the desorption isotherm is also completed

Synthesis and anti-mycobacterial evaluation of some new isonicotinylhydrazide analogues

AbstractThe synthesis of some new 3,4-disubstituted thiazolylideneisonicotinohydrazide derivatives 3a–k, 2-substituted thiazolidinylisonicotinamide derivatives 4a–d and pyrrolylisonicotinamide derivatives 5, 6 and 7 is described. The resulted compounds are evaluated for their in vitro antitubercular activity. The minimum inhibitory concentration (MIC) of compound 3g showed comparable in vitro activity to isoniazid against Mycobacterium tuberculosis H37Ra 7131 strain in concentration 9.77μg/mL

Pengaruh Pelatihan Dan Promosi Terhadap Motivasi Dan Kinerja Karyawan (Studi Pada Karyawan Pt.pln (Persero) Area Kendari)

Tujuan penelitian ini adalah untuk mengetahui dan menjelaskan pengaruh pelatihan terhadap motivasi, pengaruh pelatihan terhadap kinerja karyawan, pengaruh promosi terhadap motivasi, pengaruh promosi terhadap kinerja karyawan dan pengaruh motivasi terhadap kinerja karyawan. Penelitian ini menggunakan pendekatan kuantitatif dengan menggunakan metode survei (explanatory research) dan menggunakan analisis path. Hasil penelitian ini menyatakan pelatihan berpengaruh signifikan dan positif terhadap motivasi, promosi berpengaruh signifikan dan positif terhadap motivasi, promosi berpengaruh signifikan dan positif terhadap kinerja karyawan, motivasi berpengaruh signifikan dan positif terhadap kinerja karyawan. Namun, pelatihan berpengaruh tidak signifikan dan positif terhadap kinerja karyawan