In this research, the potential of chitosan to be used as a coagulant to treat coal wastewater was investigated, in comparison to a conventional coagulant, i.e: Al2(SO4)3 or aluminum sulfate, and Poly Aluminium Chloride (PAC). The parameters being studied were turbidity, pH, TDS, and TSS. The result of this research showed that chitosan worked as a more efficient coagulant to treat coal wastewater compared to alum and PAC, in terms of the needed dose of application. The optimum dose of chitosan was 20 mg/L that gave a 100% decrease in turbidity and TSS. On the other hand, a dose of 120 mg/L of alum was needed to have an optimum result, where the turbidity and TSS were decreased up to 100%. When PAC was used as a coagulant, the optimum dose was 120 ppm that reduced turbidity and TSS to 99.50% and 99.58%, respectively. Coagulation by chitosan, alum, and PAC were all influenced by pH, where the optimum pH for all three coagulants was within a range of neutral pH.

ABSTRAKSintesis dan karakterisasi gamma alumina (γ-Al 2 O 3 ) dari kaolin asal Tatakan, Kalimantan Selatan berdasarkan variasi temperatur kalsinasi telah dilakukan. Gamma alumina (γ-Al 2 O 3 ) diperoleh dengan metode sol-gel. Polyethylene glycol 6000 digunakan sebagai template pembentuk pori, presipitasi dilakukan dengan penambahan NH 4 OH 2,6 M hingga pH larutan 8-9 untuk memperoleh Al(OH) 3 . Kalsinasi dilakukan pada temperatur 500, 600, 700 dan 800 0 C. Gamma alumina (γ-Al 2 O 3 ) hasil kalsinasi kemudian di analisis menggunakan Fourier Transform Infrared (FTIR) dan X-Ray Diftraction (XRD). Hasil analisis karakterisasi FTIR menunjukkan pada masing-masing variasi temperatur terbentuknya kerangka gamma alumina (γ-Al 2 O 3 ) dan hasil XRD menunjukkan fasa alumina yang terbentuk adalah gamma alumina (γ-Al 2 O 3 ). Struktur terbaik dari gamma alumina (γ-Al 2 O 3 ) berdasarkan kekristalannya yaitu pada temperatur kalsinasi 700 0 C dengan nilai 2θ = 46,06; 60,07 dan 66,93.Kata kunci : kaolin, gamma alumina, kalsinasi. SYNTHESIS AND CHARACTERIZATION GAMMA ALUMINA (γ-Al 2 O 3 ) FROM KAOLIN OF TATAKAN, SOUTH KALIMANTAN BASED ON TEMPERATURE VARIATION OF CALCINATION ABSTRACTSynthesis and characterization gamma alumina (γ-Al 2 O 3 ) from kaolin of Tatakan, South Kalimantan with variation on their calcination temperature has been done. In this research, gamma alumina (γ-Al 2 O 3 ) was made by sol-gel method. Polyethylene glycol was utilized as a template of forming pore, precipitation was done by addition of 2.6 M NH 4 OH until pH 8-9 to obtain Al(OH) 3 . Calcination was carried out at various temperature, i.e. 500, 600, 700 and 800 0 C. Gamma alumina (γ-Al 2 O 3 ) obtained from the calcination process was then analyzed using FTIR (Fourier Transform Infrared) Spectroscopy and XRD (XRay Difraction) method. The FTIR result showed that at each variation of temperature, the structural backbone of gamma alumina (γ-Al 2 O 3 ) has already started to form, which is in line with the result of XRD analysis that indicated that the alumina phase being formed was gamma alumina (γ-Al 2 O 3 ). The best structure of gamma alumina (γ-Al 2 O 3 ) based on its crystallinity was obtained at the calcination temperature 700 0 C, where its values of 2θ were 46,06; 60,07 dan 66,93.

<p><em>This research aims to synthezise the superporous adsorbent from chitosan using glutaraldehyde as a cross linker, NaHCO₃ as a porogen, and polyvinyl alcohol (PVA) as a reinforcing agent. Generally, the reaction of adsorbent synthesis was carried out through four steps: (1) the addition of PVA to the chitosan solution, (2) the addition of porogen, (3) the crosslinking of chitosan, and (4) the releasing of porogen. The obtained adsorbents were characterized by Fourier Transform Infra Red (FTIR) Spectroscopy, photograph of Digital Microscope (DM), and Scanning Electron Microscopy (SEM) to measure the porosity. The adsorbent was then be applied to adsorb of HA for adsorption capacity determination. The results showed that the addition of PVA and porogen during adsorbent synthesis has produced adsorbent with more compact and flexible physical properties and greater porosity. The adsorption test showed that the adsorption capacity of KPG is 33.07 mg/g. However, if the amount of used adsorbent is larger (based on the chitosan mass 1 g), the capacity adsorption of KPG is 141.74 mg/g. The initial concentration of HA contained in peat water was 45.64 mg/L, KPG can adsorb of HA as much as 95%.</em></p>

The bioplastic synthesis of alginate in this study has been carried out using nanocellulose from sago fronds as a filler. Bioplastic synthesis uses different nanocellulose concentrations, namely 0%; 0.2%; 0.4%; and 0.6% (w / w). This study aims to see how the characteristics of bioplastics with the addition of nanocellulose. The resulting bioplastics were analyzed for moisture content, solubility, thickness, transmission rate, and transparency. The results of the research on the addition of nanocellulose concentrations show that nanocellulose can improve the characteristics of bioplastics in the form of thickness, transparency, moisture content, solubility, and water vapor transmission. Abstrak: Sintesis bioplastik dari alginat dalam penelitian ini telah dilakukan dengan menggunakan nanoselulosa dari pelepah sagu sebagai pengisi. Sintesis bioplastik menggunakan konsentrasi nanoselulosa yang berbeda beda yaitu  0%; 0,2%; 0,4%; dan 0,6% (b/b). Penelitian ini bertujuan untuk melihat bagaimana karakteristik bioplastik dengan  adanya penambahan nanoselulosa. Bioplastik yang dihasilkan dianalisis kadar air, kelarutan, ketebalan, laju transmisi dan transparansi. Hasil penelitian penambahan konsentrasi nanoselulosa menunjukkan bahwa  nanoselulosa dapat memperbaiki karakteristik dari bioplastik berupa ketebalan, transparansi, kadar air, kelarutan dan transmisi uap air.

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