Judul: Penentuan Kondisi Optimum pada Proses Fenton dalam Pengolahan Limbah Tekstil
Abstrak: Textile waste from the textile industry activity increases with the textile industry activities. Textile waste has relatively high biochemical oxygen demand (BOD), color, total suspended solids (TSS), electrical conductivity, and zinc content. Therefore, waste treatment is needed. One of the waste treatments is Fenton process using Fenton reagent that is hydrogen peroxide (H2O2) and ferrous sulfate (FeSO4). Fenton reagent can oxidize and degrade organic compounds. In this study, textile waste was tested based on the influence of pH, concentration of hydrogen peroxide, and the concentration of ferrous sulfate. The largest decrease occurred in the BOD under pH 5 in combination with H2O2 concentration of 25 mg/L and the concentration of FeSO4 50 mg/L. Beside that, this combination showed significant reduction of the three other parameters, namely TSS, electrical conductivity, and zinc content.
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Judul: Pengolahan limbah cair yang mengandung logam merkuri dengan reaksi Fenton dan presipitasi sulfida
Abstrak: Discharging wastewater to water body can cause environment contamination if its quality does not meet with the corresponding quality standard. For analysis, every laboratory use various hazardous chemicals according to reference methods. This research was intended to reduce environmental contamination by reducing organic matters and metal that exists in wastewater before discharging it to the waters. Wastewater samples were oxidized using Fenton reaction with ratios of 1:10, 1:25, 1:50, and 1:100 (b/b) to reduce its organic matters level and continued by sulfide precipitation using Na2S 13% (b/v) with volumes of 7, 9, 10, 11, 15, and 20 mL in 100 mL samples to reduce its metal content level. The content of organic matters was measured by chemical oxygen demand analysis and for its metal level contents was analyzed using atomic absorption spectroscopy. The highest percentage removal of organic matter level was 92.01% from the ratio of 1:100 and for inorganic compounds reached 99.99% in various Na2S volume. The results indicated that this method could reduce organic matters and metal content level.
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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