Judul: Pemanfaatan ganggang mikro sebagai bioindikator perairan yang tercemar
Abstrak: This study aimed to determine the sensitivity of some freshwater microalgae from Indonesia to the heavy metal contaminants (Hg, Cd, As and Pb) and pesticides. Result of the selection of ten isolates of microalgae grown in BG 11 medium obtained three strains which have the fastest growth rate: ICBB 9111, ICBB ICBB 9113 and 9114. Third is selected microalgae strains were identified as: Synechoccus sp. ICBB 9111 (originally there in Mt Salak, Bogor), Chlamydomonas sp. ICBB 9113 (paddy field of Ciomas - Bogor) and Chlorella vulgaris ICBB 9114 (origin Telaga Warna, Puncak, Bogor). To test the sensitivity of microalgae to heavy metals, three selected bacteria are grown in a medium containing heavy metals Cd, Hg, As and Pb at a concentration of 1.25 ppm, 2.50 ppm, 5.00 ppm and 10.00 ppm. Observation of the optical density (OD) performed on the first 30 minutes up to 96 hours. Based on visual observations obtained during this period that two strains of micro-algae growth stalled. Both strains of microalgae are Synechococcus sp. ICBB 9111 and Chlamydomonas sp. ICBB 9113. In contrast to Chlorella vulgaris ICBB 9114 still survive, especially in the medium containing metal ions Cd and Pb, whereas in medium containing Hg and As these strains are not able to survive. The next stage of research is the analysis of metal content, which is not absorbed by the micro algae biomass. From the analysis found that Hg and As are almost entirely absorbed by algae and micro-media content in each of the remaining <0.001 ppm and <0,002 ppm. Whereas for Cd and Pb only a small portion is absorbed by microalgae. Based on the results of the durability of each micro algae in media containing different heavy metals. ICBB Chlorella vulgaris strain 9114 has the durability and adaptability to heavy metals higher than the strain Chlamydomonas sp. ICBB 9113. While Synechococcus sp. ICBB 9111 had the highest sensitivity of all four metals tested. In addition to heavy metals tested, three strains were also tested sensitivity to the herbicide; isoprophylamine glyphosate and paraquat dichloride and insecticide ; buthylphenylmethylcarbamate (BPMC) and deltamethrin with variations of the following concentrations: 5ppm, 10ppm, 20ppm and 40ppm. Microalgae growth observations showed that all three strains are able to survive up to 24 hours in media containing pesticides tested. After 24 hours, the three began to show signs of decline. At the 96-hour observation of all micro algae die. The amount of pesticide concentrations ranged from 10-20ppm concentration which is critical to the durability and adaptability of microalgae. Of the overall treatment and observation can be drawn a conclusion that some micro algae have tolerance to pollutants (heavy metals or pesticides) that enter the aquatic environment. Adsorption capacity and adaptation of micro algae can be used as bio-indicators in monitoring and evaluation of marine environmental impacts of the heavy metal pollutants and pesticides.
Keyword: 

Judul: Pemanfaatan mikroalga laut Scenedesmus sp. sebagai penyerap bahan kimia berbahaya dalam air limbah Industri
Abstrak: Pencemaran perairan akibat kegiatan industri, baik sektor pertanian, makanan, minuman maupun mesin berat, memberikan dampak buruk bagi lingkungan perairan baik perairan hulu maupun perairan pesisir. Limbah industri dikategorikan dalam dua kelompok yaitu limbah influent dan limbah effluent. Apabila limbah tersebut dibuang ke perairan umum dapat mengubah komposisi alami parameter fisika, kimia dan biologi perairan tersebut. Salah satu tipe pencemaran laut akibat limbah industri adalah pencemaran logam berat. Dalam upaya meminimalisir dampak pencemaran yang akan ditimbulkan, salah satu metode yang saat ini berkembang adalah bioremediasi, yaitu dengan memanfaatkan mikroorganisme untuk mengurangi kandungan bahan pencemar, baik zat berbahaya ataupun logam berat yang terdapat dalam limbah tersebut. Mikroalga merupakan mikroorganisme tumbuhan air yang memiliki potensi yang dapat dikembangkan. Salah satu spesies mikroalga potensial untuk dikembangkan adalah Scenedesmus sp. Scenedesmus sp. merupakan spesies mikroalga bersifat kosmopolitan dan memiliki laju pertumbuhan yang tinggi. Kenyataan tersebut menjadi dasar digunakannya mikroalga laut Scenedesmus sp. sebagai penyerap bahan kimia berbahaya, terutama Cr dan Cu yang terkandung dalam air limbah industri. Tujuan penelitian ini adalah membandingkan pola pertumbuhan mikroalga laut Scenedesmus sp. yang dikultivasi pada limbah influent dan effluent dan melihat pengaruh mikroalga tersebut terhadap logam berat kromium (Cr) dan tembaga (Cu). Penelitian dimulai pada tanggal 23 Maret 2010 sampai dengan 5 Juli 2010 di Surfactant And Bioenergy Research Center (SBRC) LPPM IPB Baranangsiang, Bogor. Penelitian terbagi menjadi empat tahap. Tahap pertama merupakan tahap persiapan penelitian. Tahap kedua merupakan tahap kultivasi Scenedesmus sp. yang dilakukan sebanyak tiga kali ulangan pada setiap perlakuan selama sepuluh hari. Tahap ketiga merupakan tahap analisis kualitas air pada limbah yang digunakan sebagai media kultivasi. Metode yang digunakan adalah metode kultivasi mikroalga laut.
Keyword: 

Judul: Konstruksi Hukum Grup Kurva Eliptik Atas F3m
Abstrak: Elliptic curves upon F3m can be divided in two cases, i.e. supersingular and nonsupersingular case. Based on group laws on elliptic curves, a new arithmetic upon F3m can be formulated as an addition process of two random points on the curve. This addition process can then be applied to the ElGamal algorithm.
Keyword: