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Abstrak :
Gas merupakan salah satu bentuk produk hasil metabolisme mikroorganisme, dapat disebut sebagai biogas. Biogas berupa gas metana diketahui dapat dimanfaatkan sebagai sumber energi terbarukan. Produksi gas metana oleh bakteri terjadi pada siklus metanogenesis dengan tiga tahap yaitu, hidrolisis, asetogenesis, dan metanogenesis. Proses ini umumnya dilakukan oleh bakteri dalam lingkungan dengan kondisi anaerob. Sedimen Sungai Muara Karang dengan kondisi tercemar materi organik dan rendah oksigen berpotensi sebagai habitat mikroba anaerob dengan kemampuan metanogenesis. Kemampuan mikroba sedimen dalam produksi biogas diuji dengan menginokulasi sedimen Muara Karang pada medium Methanogen Enrichment Barker broth dengan variasi rasio C/N sumber karbon glukosa untuk mengetahui kemampuan produksi biogas. Parameter kemampuan produksi biogas oleh mikroba sedimen Muara Karang dilakukan dengan perhitungan total karbon, total nitrogen, volume biogas, chemical oxygen demand COD, dan pH. Diperoleh dua isolat yaitu, isolat I dan isolat II. Identifikasi dilakukan menggunakan VITEK 2 compact. Hasil penelitian menunjukkan rasio C/N 25:1 menghasilkan biogas terbesar, namun tidak menurunkan kadar COD dengan baik. Isolat I diidentifikasi sebagai Methylobacterium spp. dan isolat II diidentifikasi sebagai Dermacoccus nishinomiyaensis. ......Gas is one form of metabolism microorganisms products, it can be identified as biogas. Biogas in the form of methane gas can be utilized as a renewable energy source. The production of methane gas by bacteria occurs through methanogenesis with three stages namely, hydrolysis, acetogenesis, and metanogenesis. This process is generally performed by bacteria in anaerobic environment. The Muara Karang River Sediments contaminated with organic matter and low oxygen potential as anaerobic microbial habitat with metanogenesis ability. The ability of sediment microbes in biogas production is tested by inoculating Muara Karang sediment in Methanogen Enrichment Barker broth medium with variation of C N ratio with glucose as carbon source to analyze biogas production. The parameter of biogas production by Muara Karang sediment microbe is performed by calculating total carbon, total nitrogen, biogas volume, chemical oxygen demand COD, and pH. Two isolates were obtained, namely isolate I and isolate II. Isolates identified by VITEK 2 compact. The result showed that C/N 25:1 ratio produced the largest biogas, but did not lower COD level well. Isolate I was identified as Methylobacterium spp. and isolate II was identified as Dermacoccus nishinomiyaensis.

Abstrak :
Environmental condition of lake Limboto, as Gorontalo Province land mark, has stressed by sedimentation, organic pollution and development of cage system fish culture....

Abstrak :
Perubahan fisika dan kimia dalam timbunan kompos diteliti selama proses pengomposan limbah pembuatan botol yang terkontaminasi oleh gemuk (grease). Temperature awal menunjukkan peningkatan diikutioleh penurunan secara bertahap pada akhir proses pengomposan....

Abstrak :
Penelitian dilakukan pada bulan Maret--Juni 2013 di Hutan Mangrove Pancer Cengkrong, Trenggalek, Jawa Timur. Penelitian bertujuan untuk memperoleh informasi komposisi vegetasi, potensi stok karbon, produksi, laju dekomposisi dan kontribusi nutrisi serasah mangrove. Komposisi vegetasi diukur menggunakan transek kuadran. Stok karbon diestimasi dengan persamaan allometrik. Produksi serasah dihitung menggunakan perangkap serasah ukuran 1x1m2. Laju dekomposisi serasah diukur selama 56 hari dengan pengamatan 2 minggu sekali. Kontribusi serasah ke perairan diperoleh dengan menyaring serasah pada saluran air saat laut surut. Sebanyak 26 spesies telah diidentifikasi (17 mangrove sejati dan 9 mangrove asosiasi). Vegetasi pohon didominasi oleh Sonneratia alba J.E. Smith dengan kerapatan 596 pohon/ha sedangkan anakan dan semai didominasi Ceriops tagal (Perr.) C.B. Robinson (kerapatan 1.745 anakan/ha; 34.745 semai/ha). Stok karbon dan biomassa total di lokasi penelitian masing-masing 185,81 ton/ha dan 400,45 ton/ha (total serapan CO2 sebesar 681,91 ton/ha). Sebagian besar sumbangan stok karbon berasal dari S. alba, Rhizophora apiculata Blume, dan Avicennia alba Blume. Produksi serasah 1,42 g/m2/hari, tersusun atas daun 84%, organ reproduksi 9% dan ranting 7%. Potensi nutrisi serasah 0,4 gC/m2/hari dan 0,012 gN/m2/hari. Serasah dilepas ke perairan sebesar 11,15 g/m3/hari. Laju dekomposisi serasah daun paling cepat ialah R. apiculata (0,20 g/hari). Nilai nutrisi tertinggi terdapat pada S. alba dengan rasio C:N 62,90. ......Research has been conducted in March--June 2013 on the Mangrove Forest Cengkrong Pancer, Trenggalek, East Java. The objectives were to obtain information of vegetation composition, potential carbon stocks, production, decomposition rates, and nutrient contribution of mangrove litter. There were 50 quadrants on tree stations for vegetation analysis. Potential carbon stock was calculated by allometric equations. Littertrap size 1x1 m2 used to calculate litter production. Decomposition rate calculated for 56 days by once observation in two weeks. Litter contribution to waters was obtained by filtering water channel at low tide. The total of 26 species were identified (17 true mangroves and 9 association mangroves). The vegetation dominated by Sonneratia alba J.E. Smith (596 trees/ha) while the saplings and seedlings dominated by Ceriops tagal (Perr.) C.B. Robinson (1,745 saplings/ha; 34,745 seedlings/ha). Total biomass were 400.45 ton/ha and carbon stocks 185.81 ton/ha (CO2 uptake 681,91 ton/ha). The carbon stocks were donated from S. alba, Rhizophora apiculata Blume, dan Avicennia alba Blume. The production of litter was 1.42 g/m2/day consisting of leaves 84%, reproductive organs 9%, and twigs 7% respectively. The litter contained 0.4 gC/m2/day and 0.012 gN/m2/day. In addition 11.15 g/m3/day litters flow towards the waters during high tide. The fastest decomposition rate of leaf litter was R. apiculata (0.20 g/day). While the highest nutritional value from S. alba with C:N ratio of 62.90.

Abstrak :
Kenaikan timbulan sampah menyebabkan terbatasnya lahan TPA dan permasalahan pengelolaan pada lindi. Hal ini dapat diatasi dengan penerapan bioreaktor landfill yang dapat mempercepat dekomposisi sampah yang sekaligus dapat menurunkan kandungan pencemar yang ada dalam lindi. Pada penelitian ini berfokus pada kemampuan sampah bioreaktor lysimeter yang terdekomposisi berumur 3 tahun tanpa resirkulasi lindi dalam mengolah air lindi yang berasal dari TPA Cipayung. Parameter yang diukur di dalam penelitian ini adalah karakteristik sampah dan parameter kimia air lindi. Uji karakteristik sampah yang dilakukan adalah analisis ultimate yang berupa kandungan unsur karbon (C), hidrogen (H), oksigen (O), nitrogen (N), total sulfur (S), dan fosfor (P), rasio C/N, serta analisis proximate yang berupa uji kadar kelembaban, dan kadar abu, serta nilai kalori sampah. Sedangkan untuk parameter kimia lindi berupa tingkat penyisihan BOD, COD, TSS, nitrit, nitrat, dan pH. Berdasarkan simulasi pengolahan yang telah dilakukan, data analisis ultimate yang mengalami penurunan adalah unsur C dengan hasil akhir 1,38% dan N adalah 0,16%, sedangkan unsur H dan O mengalami peningkatan dengan kadar akhir sebesar 1,98% dan 12,16%. Peningkatan juga terjadi pada data analisis proximate, dimana kadar kelembaban akhir sebesar 3,4%, sedangkan kadar abu dalam sampah adalah 85,1%. Berdasarkan data analisis ultimate, nilai kalor akhir pada sampah adalah 550,599 kkal/kg dengan rasio C/N sebesar 8,625. Sedangkan untuk pengolahan lindi, sampah bioreaktor memiliki efisiensi rata-rata tingkat penyisihan lindi pada parameter BOD, COD, TSS, dan nitrit sebesar 89,26%, dan penurunan pH efluen mendekati rentang pH netral sebesar 7,2-7,8, sedangkan kenaikan konsentrasi terjadi pada parameter nitrat hingga kenaikan rata-rata sebesar 249,99%.

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Increasing in solid waste generation causing limited area of landfill and leachate management problems. These can be solved by applying the bioreactor landfill to accelerate waste decomposition that also can reduce pollutants content in the leachate. This study focused on the ability of 3-year-old decomposed waste in bioreactor lysimeter without leachate recirculation for treating the leachate from Cipayung landfill. Parameters measured in this study are the waste characteristics and leachate chemical parameters.Characteristics of waste includes ultimate analysis of element content of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), total sulphur (S) and phosphorus (P), ratio of C / N, and proximate analysis in the form of moisture content, ash content, and calorific value of the waste.As for chemical parameters of the leachate includes removal efficiencies of BOD, COD, TSS, nitrite, change of pH, and rate of nitrate increase. Based on the simulation of leachate treatment has been done, ultimate analysis data that decreased was element C with final results 1.38% and N was 0.16%, while the final results of element H and O increased by 1.98% and 12,16%. Escalation also occurred in proximate analysis data, which the final moisture content was 3.4%, while the ash content in the waste was 85.1%.Based on data from ultimate analysis, final result of calorific value of waste was 550.599 kcal/kg with C/N ratio was 8.625.As for the results of leachate treatment, bioreactor landfill has average efficiency rate of leachate removal on the BOD, COD, TSS, and nitrite parameters at rate 89,26%, and a decrease of pH occured in leachate effluent with pH range 7,2 to 7,8, while the increase occured in average of nitrates concentrations reached 249,99%.

Abstrak :
The purpose of this research is to examine the relationships of job satisfaction to organizational commitment and turnover intentions. Next, the purpose of this research is to examine whether organizational commitment related to turnover intentions. This research conducted with survey on auditors working on the big audit firms in Jakarta that affiliated to foreign audit firms (The Big Four). Unit analysis are auditors who have non-partner position i.e: junior, senior and manager that concentrated in audit services. The structural equation modeling with AMOS program is used to analized the data. The results of this research suggest that job satisfication has significant positive relationships to organizational to turnover intentions. Next, organizational commitment has significant negative relationship to turnover intentions. This result suggests that job satisfication related to turnover intentions both of direct or through organizational commitment.