Judul: Effectivity of activated charcoal as adsorbent for wastewater treatment
Abstrak: The main purpose of this research was to study the optimum condition for production activated charcoal in a retort with 100 kg capacity and to apply the best activated charcoal as adsorbent for wastewater treatment. The raw materials used in this research were wood sawdust, mangium wood (Acacia mangium) and coconut shell. The charcoal was activated using the condition : activating temperature at 700 ºC continued by steaming with H2O for 1, 2, 3 hours and without steaming as a control. In Order to improve the qualities of the activated charcoal, further activation was conducted using H3PO4 solution at 5 % concentration. The possible changes in structure were evaluated using Infrared Spectrophotometry, X-ray Difraction and Scanning Electron Microscope. The results showed that the best quality of activated charcoal was achieved by Acacia mangium by soaking in H3PO4 5 % solution without steaming. The yield of activated charcoal was 40,54 %; moisture content 5,25 %; ash content 2,31 %; volatile matter 7,01 %; fixed carbon 90,69 %. Adsorptive capacity of iodine was 657,20 mg/g; metanol 7,13 %; CCl4 8,39 %; CHCl3 13,24 %; formaldehida 6,57 % and benzene 7,13 %. Degree of crystalinity 58,23 %; height of aromatic layers (Lc) 4,02 nm; width of aromatic layers (La) 4,22 nm; number of aromatic layers (N) 10,84 and distance of aromatic layers (d) 0,21 nm with pore diameter of 0,14 – 0,35 μm. The best concentration of activated charcoal as adsorbent for domestic wastewater treatment was 1 % concentration. It decreased Biological Oxygen Demand (BOD) 98,03 %; Total Suspended Solid 97,66 %; oil and grease 76,92 % and pH value increased 6,15 %. For hospital wastewater treatment, the best condition was achieved using activated charcoal at 2 % concentration. It could decreased pH value 17,50 %; Total Suspended Solid 93,06 %; ammonia 76,09 %, phosphat 33,06 % and coliform bacteri 90 %. BOD and Chemical Oxygen Demand (COD) increased 330,79 % and 135,91 %. The best concentration of activated charcoal as adsorbent for nicel coated industry wastewater treatment was 1 % concentration. It decrease Total Suspended Solid 84,72 %; Cr 39,50 %; Cu 66,67 %; Zn 91,50 %; Ni 73,75 % and Cd 71,43 %. pH value increase 242,84 %, but Pb value was not changed.
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Judul: Pemanfaatan Karbon Aktif dengan Aktivator H3PO4 dari Limbah Padat Agar sebagai Penjerap pada Limbah Cair Industri Penyamakan Kulit
Abstrak: Agar solid waste can be used as an adsorbent in the form of activated carbon. The study aims were to determine the best concentration of H3PO4 and activation time on the processing of activated carbon and the effectiveness of activated carbon as an adsorbent in the tanning industry wastewater. The activation step of activated carbon was carried out with H3PO4 concentration of 10; 20; 30% and the time activation of 15; 20; 25 hours. The best activation treatment was obtained on 10% H3PO4 concentration and 15 hours activation time with activated carbons yield of 93.42%, moisture content of 10.59%, ash content of 65.91%, absorption of iodine of 1090.80 mg/g, volatile matter of 21.60% dan fixed carbon of 12.35%. The best activated carbon was applied to the tanning industry wastewater with contact time of 0.5; 1; 1.5; 2 hours and activated carbon concentrations of 0; 1; 2; 3%. Application treatment with contact time of 0.5 hours and 3% activated carbon concentration decreased the value of Cr from 4371.21 ppm to 3572.76 ppm, treatment with contact time of 1 hours and 3% activated carbon concentration decreased the value of BOD, COD from 1216.10 mg/L, 17753.33 mg/L to 438.21 mg/L, 11770.00 mg/L respectively, however it did not affect the pH value.
Keyword: adsorbent, agar solid waste, wastewater, activated carbon, H3PO4

Judul: Studi kasus migran pedagang kaki lima di pasar Senen, Jakarta Pusat
Abstrak: Sejak Jakarta menjadi ibukota negara RI, Jakarta tidak pernah sepi dari arus migrasi penduduk. Masuknya para migran ke Jakarta disebabkan karena pertumbuhan fisik yang nyata, yaitu dari pembangunan gedung perkantoran, fasilitas hiburan dan lainnya, memberi daya tarik bagi orang bukan penduduk Jakarta. Termasuk di antara migran adalah kaum golongan kecil yang berasal dari kalangan sirkuit bawah desa. Alasan utama migrasi di sirkuit bawah, yaitu khususnya yang akhirnya bekerja sebagai pedagang kaki lima di Pasar Senen ini pindah ke Jakarta, adalahJakarta menawarkan kesempatan kerja bagi siapa saja yang mau bekerja. Karena di desa tak ada pekerjaan yang dapat menampung golongan muda, kaum migran meninggalkan desa menuju Jakarta. Pola migrasi masuk ke Jakarta tidak dipengaruhi oleh kemungkinan golongan muda mampir di kota-kota kecil sebelum tiba di Jakarta. Keberanian dan tekad bulat meninggalkan desa asal didorong pula oleh sumber cerita tentang Jakarta (saudara/kenalan) yang juga mengalami bahwa setiba di Jakarta mereka akan langsung bekerja. Pendidikan rendah, tidak memiliki ketrampilan, orang petani/buruh tani, merupakan bagian kecil latar tua belakang sosial migran pedagang kaki lima. Memperoleh pekerjaan apa saja asal halal pada mulanya, tempat tinggal dimana saja, modal kecil dan pendapatan harian yang rendah juga mewarnai hidup para migran pedagang kaki lima di Jakarta. Namun sekalipun demikian mereka tetap hidup, bahkan dapat mengirim uang ke desa asal, pulang ke desa minimum setahun sekali dan sedikit-sedikit mampumenabung. Bekerja sebagai pedagang kaki lima sudah ditekuni selama lebih dari lima tahun bahkan ada yang lebih dari tujuh tahun. Inipun dimulai setelah minimum selama dua tahun migran mengerjakan apa saja di Pasar Senen: yang penting dapat uang dan bisa hidup di Jakarta. Bahkan modal membuka usaha kaki lima diperoleh dari selama bekerja mula-mula itu. untuk pengumpulan upah Sekalipun terdapat kenaikan tingkat kehidupan sosial di kota dibandingkan dari desa, kaum migran pedagang lima di Pasar Senen ini tetap berada bawah kota. di kaki bawah sirkuit Ikatan-ikatan baru di kota hampir tidak terjadi kecuali ikatan-ikatan kedaerahan yang terus dipertahankan.
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