Judul: Pemanfaatan limbah kaleng sebagai bahan dasar koagulan berbasis aluminium
Abstrak: Wastes of canned drink were found abundantly in the environment. Utilization of this waste can increase the value of the waste. This type of can has been tested previously and showed the aluminum contents of 1.41–16.04%. The aluminium content indicates its potential to be used as raw material for aluminum-based coagulant. The synthesis method used for producing coagulant was partial hydrolysis using HCl 33% with various polymerization times of 24 and 48 hours and components of 5 and 10%, giving 4 kinds of synthetic coagulant. The synthetic coagulants characterized based on SNI 06-3822-1995 showed that the results did not meet the requirements of SNI-quality. The peaks of infrared absorption on the synthetic coagulants were 3518.16, 1631.78, and 1168.86 cm-1 and almost resemble the commercial polyaluminium chloride which are 3452.58, 1627.92, and 3070.68 cm-1. Performance test of the coagulant on some textile industry wastewater had been tested at pH 6, 7, 8, and 9. The most effective performance from each coagulant was shown at pH 9. Coagulation of the waste cans made by partial hydrolysis method using HCl was able to reduce turbidity of more than 95%.
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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: Revisi marga Ptychopyxis miquel (Euphorbiaceae) di kawasan Malesia
Abstrak: Ptychopyxis adalah salah satu marga dari 317 marga yang termasuk ke dalam suku Euphorbiaceae. pertama kali dipublikasikan oleh Miquel (1860). Marga ini Marga ini pernah dimasukkan kedalam marga lain, yaitu Podadenia, Mallotus dan Clarorivinia. Fakta tersebut menunjukkan bahwa batasan marga Ptychopyxis belum cukup mantap. Persebaran marga ini menurut Van Welzen (1993) jumpai di Thailand, Indochina dan kawasan Malesia, di seluruhnya ada 23 jenis dan 10 jenis diantaranya terdapat di kawasan Malesia. Marga ini umum berperawakan pohon dan berumah dua, tumbuh di hutan hujan dataran rendah sampai pada ketinggian 1500 m dpl. Penelitian taksonomi yang komprehensif tentang marga ini telah dilakukan oleh Airy Shaw pada tahun 1960; sejak saat itu belum ada penelitian taksonomi yang lebih kompre- hensif, khususnya untuk kawasan Malesia. Kini dengan bertambahnya jumlah spesimen koleksi baru, maka tepatlah kiranya dilakukan revisi marga. Tujuan penelitian ini adalah untuk memberikan batasan marga serta jenis-jenisnya yang termasuk dalam Ptychopyxis selain itu diteliti pula hubungan kekerabatan antar jenis dan keterangan-keterangan..dst
Keyword: Herbarium Bogoriense, Podadenia, Mallotus, Clarorivinia