The production capacity of Indonesia’s paper industry is expected to continously increase causing more wastewater generated. The wastewater of paper industry that has been treated in biological Wastewater Treatment Plant (WWTP) is commonly discharged to the environment and may still contain organic materials and nutrients such as nitrogen and fosfor that have not been utilized. An alternative of wastewater utilization is in algae cutivation. The Spirulina platensis is one of blue-green microalgae types containing high protein and widely used as food and fish feed ingredients. This study was conducted to identify S. platensis growth in effluent of paper industry as medium. The wastewater with the percentages of 0%, 25%, 50%, 75% and 100% were used as media to grow microalgae S. platensis. During cultivation,the medium pH and biomass production were analyzed, while proximate analysis were also done after havesting. Results showed that S. platensis microalgae grown in 100% wastewater medium yielded the highest biomass among all other treatments at 4-days of cultivation, about 25% higher than that in control medium. The biomass produced contains about 60% protein which is nearly equal to that reported from other countries .Keywords : microalgae, Spirulina platensis, effluent, paper industry ABSTRAKKapasitas produksi industri kertas di Indonesia diperkirakan akan terus meningkat menyebabkan peningkatan air limbah yang dihasilkan. Air limbah industri kertas yang telah diolah pada Instalasi Pengolahan Air Limbah (IPAL) biologi pada umumnya langsung dibuang ke lingkungan dan masih mengandung materi organik serta unsur hara seperti nitrogen dan fosfor yang belum termanfaatkan. Salah satu alternatif pemanfaatan air limbah tersebut adalah budidaya alga. Spirulina platensis merupakan salah satu jenis mikroalga hijau kebiruan yang mengandung protein tinggi dan banyak digunakan sebagai bahan pangan dan pakan ikan. Penelitian ini dilakukan untuk mengetahui pertumbuhan S. platensis pada efluen industri kertas sebagai medium. Efluen dengan persentase perlakuan 0%, 25%, 50%, 75% dan 100% digunakan sebagai medium tumbuh S. platensis. Selama kultivasi alga, dilakukan pengamatan terhadap pH medium dan pengukuran produksi biomassa sedangkan analisa proksimat dilakukan setelah pemanenan kultur. Hasil menunjukkan bahwa kultur S. platensis pada medium air limbah 100% menghasilkan produksi biomassa paling tinggi pada hari ke-4 kultivasi, yaitu sekitar 25% lebih tinggi dibandingkan medium kontrol. Biomassa S. platensis yang dibudidayakan dalam media air limbah terolah industri kertas mengandung 60% protein yang hampir setara dengan yang dihasilkan negara lain.Kata kunci : mikroalga, Spirulina platensis, efluen, industri kertas
Pencarian jalur terpendek pada masjid – masjid di kota Samarinda sangat diperlukan oleh ustadz, kyai maupun ulama yang ingin mengadakan safari dakwah. Selain itu juga diperlukan oleh instansi terkait seperti kementerian agama yang ingin melakukan kunjungan dengan tujuan pendataan masjid. Algoritma greedy bekerja dengan menccari titik bobot yang terkecil dengan menghitung jalur yang dilewati dan tergantung dari bobot tahapan yang telah dilewati serta bobot pada tahap itu sendiri. Penelitian ini menguji algoritma greedy pada 7 masjid di tengah kota Samarinda yang sering dikunjungi untuk safari dakwah maupun aktivitas lainya.
The paper-recycling process of paper mills generates reject waste in the region of 525% of its raw material, depending on the recovered fiber quality and process used in the mill. We carried out an assessment of the paper industry's reject waste pellets (RWP) as a boiler fuel. Reject waste was identified by means of sorting. The pelletizing of paper mills' reject waste is a solidification process, as it is easier to store, handle, and transport solid waste. We analyzed the approximate calorific value and the sulphur content of reject waste pellets. The results showed that the components of reject waste are largely comprised of 51% fibers and 49% plastic. The plastic components of are dominated by the high density poly ethylene (HDPE) plastic type. RWP contains a lot of organic matter and has a high calorific value and low sulphur content, which gives it the potential of being used as fuel. Utilization of 10% RWP mixed with 90% coal as boiler fuel could reduce CO 2 gas as greenhouse gas (GHG) emissions by about 9%.
Penelitian tingkat pencemaran emisi boiler berbahan bakar batubara telah dilakukan pada industri tekstil dikabupaten Bandung sebanyak 14 industri dan di wilayah Cimahi sebanyak 10 industri. Parameter yang diujimeliputi partikulat, SO2, NOx, opasitas, dan CO2. Parameter partikulat diukur menggunakan metoda gravimetri,parameter NOx diukur menggunakan metoda chemiluminescence, dan parameter SO2 diukur menggunakan metodanon-dispersive infra red (NDIR). Hasil menunjukkan di wilayah Kabupaten Bandung masih terdapat 4 perusahaantidak memenuhi persyaratan kadar partikulatnya, tetapi nilai rata-ratanya sudah memenuhi persyaratan yaitu sebesar148 mg/m3. Di wilayah Cimahi masih terdapat 3 perusahaan tidak memenuhi persyaratan kadar partikulatnya, dannilai rata-ratanya sebesar 311 mg/m3 masih diatas persyaratan. Wilayah Kabupaten Bandung ada 5 perusahaan yangemisi sulfur dioksida masih tinggi, dengan rata-rata emisi sulfur dioksida sebesar 763 mg/m3 yang berarti belummemenuhi persyaratan. Wilayah Cimahi ada 4 perusahaan yang kadar sulfur dioksida masih tinggi, tetapiperhitungan rata-rata sebesar 602 mg/m3 sudah memenuhi persyaratan. Kualitas emisi udara dengan parameterNO2 dan opasitasnya pada wilayah Kabupaten Bandung dan wilayah Cimahi sudah baik. Emisi gas CO2 yangdikeluarkan oleh industri tekstil di wilayah Kabupaten Bandung adalah 0,05 – 0,22 kg/m3 , dan di wilayah Cimahiadalah 0,07 – 0,31 kg/m3. Wilayah Kabupaten Bandung dan wilayah Cimahi mengkontribusi emisi gas rumah kaca(GRK) masing-masing sebesar 3,5 juta ton CO2-eq./tahun dan 1,3 juta ton CO2-eq./tahun.
Solid waste of paper mill hydrapulper reject (HR) has a relatively high plastic content, with around 45-49% composition of the total HR. About 99% of the plastic has the catagory of High Density Polyethylene (HDPE). HDPE is a type of Polyethylene (PE) plastic which has high recyclability and may be reformed at high temperature. This study tries to discribe the potential of producing particleboards derived from HR using a hot-press method. Molded HR was being hot-pressed at a presssure of 25 kgf/cm2for 5 – 15 minutes of residence time, with a variation of of the amount of HR from 150-500 gram, and variations in hot-press temperature of 150-180°C. The resulting product is then analyzed for parameters of moisture content, density, water absorption, thickness swelling, and internal bond compared to SNI 03-2105-2006 and JIS A 5908-2003. The results showed that most of the samples were relatively accepted to the SNI. The best results are obtained at HR weight of 250 gram with 165 and 180°C pressing temperature, and pressing time more than 10 minutes. The addition of HDPE pellets shows an increment of density and decrement of moisture content of particleboard, while the addition of MA shows some decrements of moisture content and water absoption of particleboard.
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