Judul: Pengolahan limbah cair praktikum analisis kualitatif logam berat menggunakan polialuminium klorida sebagai koagulan
Abstrak: Research activity in laboratory often use substances containing heavy metals. One of them is qualitative analysis for chloride and spot test for measuring the existence of heavy metals on the samples. This wastewater contains various chemicals especially heavy metals and acidic substances. It appears with low pH value and high concentration of dye and heavy metals. Waste storage containers also need handling. Based on observation, polypropylene bottle became dark-colored after it kept heavy metal waste for 2 years. In this research, wastewater samples were treated with coagulation process to obtain optimum condition for polyaluminum chloride (PAC) and to identify polypropylene bottle using scanning electron microscope and energy dispersive spectrometer. Samples were coagulated using PAC at concentrations 500, 600, 700, 800 mg/L, and pH 7, 8, 9, 10. Parameters observed were pH, color, and Cr, Ni, and Pb heavy metal content. The result showed that the highest Cr reduction was 97.99% at coagulation pH 10 and PAC concentration of 700 mg/L. Polypropylene bottle showed carbon content lowering in all 3 sampled bottles, whereas contents of all other elements were relatively not affected.
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Judul: Efektivitas Campuran Poli(Aluminium Klorida) (PAC) dan Aluminium Sulfat (Tawas) sebagai Koagulan dalam Pengolahan Air Bersih
Abstrak: Poly(aluminum chloride) (PAC) and aluminum sulfate (alum) are commonly used coagulants for water treatment. This study aimed to determine the effective coagulant dose of PAC and alum mixture Cisadane river water treatment. Coagulant mixture ratio used were 100:0, 75:25, 50:50, 25:75, and 0:100 with low and high levels of water turbidity. In addition to turbidity, effectiveness in decreasing the Fe, Mn, and organic substances contents were also studied. PAC was more effective in decreasing the levels of turbidity (88.29%), Fe (76.03%), Mn (75.57%), and organic substances contents (41.74%) compared to the other coagulant mixtures. In terms of cost, 75:25 ratio of PAC-alum coagulant mixture was more efficient under condition of high turbidity level.
Keyword: alum, aluminum sulfate, poly(aluminum chloride), PAC, turbidity

Judul: Karakteristik Anatomi Skelet Kepala Buaya senyulong (Tomistoma schlegelii).
Abstrak: Buaya sepit atau senyulong (Tomistoma schlegelii) merupakan jenis buaya asli Indonesia yang berhabitat di sungai-sungai Sumatera, Kalimantan, dan juga pedalaman Sulawesi. Salah satu ciri khas buaya senyulong adalah bentuk moncong yang runcing dan sempit, namun hingga saat ini informasi mengenai struktur skelet kepala buaya senyulong sangat terbatas. Penelitian ini bertujuan untuk mempelajari karakteristik anatomi skelet kepala buaya senyulong yang dikatikan dengan fungsi dan perilakunya. Penelitian dilakukan secara eksploratif dengan melakukan pengamatan, pencatatan, dan pengambilan gambar dari skelet kepala buaya senyulong. Skelet kepala berukuran panjang 70 cm, lebar 29 cm, dan tingggi 17 cm dengan permukaan kasar pada os nasale, os frontale, os maxilla, os mandibula, os lacrimale, os jugale. Jumlah gigi pada buaya ini sebanyak 78 buah, terdiri dari 4 buah gigi premaxila, 16 buah gigi maxila, dan 19 buah gigi mandibula. Pada regio orbitalis ditemukan dua pasang fenestrae temporales yang berkembang baik. Fenestra supratemporale merupakan lubang oval yang membentang di sepanjang os parietale. Fenestra infratemporale berbentuk segitiga dan dibatasi oleh os squamosum, os postorbitale, os jugulare, dan os quadratum. Os mandibula hewan ini mempunyai symphysis mandibularis yang panjang yaitu garis yang melintang di corpus mandibulae. Secara fungsional ukuran symphysis mandibularis berkaitan dengan adaptasi hewan terhadap diet makan.
Keyword: kepala, moncong, Tomistoma schlegelii