Judul: Performance of Chitosan and Ulva sp. Based Bio-Adsorbent to Reduce Heavy Metal Level in Liquid Waste
Abstrak: Pencemaran air ialah permasalahan global yang harus dihadapi oleh masyarakat selama beberapa dekade terakhir. Salah satu opsi yang sudah diakui sebagai cara dalam mengurangi kadar logam berat di perairan ialah adsorpsi. Material biologi yang dapat digunakan sebagai Bio-adsorben dalam usaha mengurangi pencemaran logam berat salah satunya adalah alga hijau Ulva sp. dan kitosan. Penelitian ini bertujuan untuk menentukan pengaruh Ulva pada karakteristik bio-adsorben serta mengukur kemampuan Chitosan-Ulva beads sebagai adsorben untuk menurunkan kadar logam berat pada larutan Pb dan Cd dengan perlakuan perbedaan rasio kitosan:Ulva U1 (1:0); U2 (1:0,1) dan U3 (1:0,5). Rasio Chitosan-Ulva beads paling bagus dalam menurunkan kadar logam berat Pb maupun Cd ialah beads U3. Diameter Chitosan-Ulva beads yang dibuat berkisar antara 2,98 – 3,7 mm. Nilai swelling gel Chitosan-Ulva beads paling tinggi diperoleh pada U3 pada waktu 3 jam setelah perendaman. Persen fraksi gel Chitosan-Ulva beads paling tinggi terdapat pada perlakuan U3. Pengaruh rasio Ulva berpengaruh pada nilai swelling gel, fraksi gel, serta kemampuan menyerap logam berat Chitosan-Ulva beads., Water pollution is a global problem that we had to deal with over the past few decades. One option that has been recognized as a way to reduce heavy metal levels in waters is adsorption. Biological materials that can be used as bio-adsorbents in an effort to reduce heavy metal pollution include green algae Ulva sp. and chitosan. This study aims to determine the effect of Ulva on bio-adsorbent characteristics and measure the ability of Chitosan-Ulva beads as an adsorbent to reduce heavy metal levels in Pb and Cd solutions with different chitosan:Ulva ratios U1 (1:0); U2 (1:0.1) and U3 (1:0.5). The best Chitosan-Ulva beads ratio in reducing Pb and Cd heavy metal levels is U3 beads. The diameter of Chitosan-Ulva beads made ranged from 2.98 - 3.7 mm. The highest swelling gel value of Chitosan-Ulva beads was obtained in U3 at 3 hours after immersion. Percent fraction of Chitosan-Ulva beads gel was highest in U3 treatment. The effect of Ulva ratio affects the swelling gel value, gel fraction, and heavy metal absorbing ability of Chitosan-Ulva beads.
Keyword: adsorbent, chitosan, heavy metal, ulva

Judul: Efektifitas Kitosan dan Biofilter Eceng Gondok (Eichornia crassipes (Mart) Solm) dan Kijing Taiwan (Anodonta woodiana) Sebagai Adsorben pada Pengolahan Limbah yang Mengandung Logam Hg, Cd dan Pb
Abstrak: Environmental problems need attention, because many activities in residential, agriculture, mining, and industry sectors can produce waste water that is discharged into the environment. Waste processing was generated by various sectors must be processed before being discharged into the environment. Various kinds of methods are used to process the waste. One of the methods can do developed for the waste processing which contains Hg, Cd and Pb Metals is done waste absorption method by chitosan solution then followed by biofilter of mussel Anodonta woodiana and water hyacinth. Chitosan solution can absorb Pb metals for 46,65%, Hg for 78,64%, and Cd for 53,52%. The use of biofilter can decrease Pb levels of waste for 98,05%, Hg for 98,88%, and Cd for 97,86%. The use of these biomaterials has three types of these biomaterials. These are easy to find in the environment, so these can be used more optimal in the process of waste processing.
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Judul: Karakteristik Barisan Eksak Pendek HomR(N, ) dan HomR( ,N)
Abstrak: Module merupakan generaIisasi dari ruang ve}ctor, dimana pada ruang vektor skalar-skalamya berasal dati suatu lapangan (field) sedangkan pada module skaJar-skalamya merupalam unsur-unsur dan suatu ring R dengan unsur satuan. Dari suatu grup komutatif yang unsur-unsumya dipadukan dengan unsur-unsur dart suatu ring R, maka akan mengbastlk.an yang namanya R-module. Himpunan seroua fungsi homomorfisma yang memetakan dati R-module M ke R-module N dinotasikan sebagai HomiM,N), dimana HomiM,N) juga merupakan suatu R-module.
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