Judul: Design of Wastewater Treatment Plant for Frozen Cilok Production Process at PT Karya Baru Kita
Abstrak: Air limbah industri makanan yang tidak ditangani dengan tepat dapat mencemari lingkungan. Penelitian ini bertujuan untuk merancang Instalasi Pengolahan Air Limbah (IPAL) untuk mengelola 1,5 m³ limbah cair per hari dari produksi cilok beku di PT Karya Baru Kita. IPAL yang dirancang mencakup beberapa tahap pengolahan secara batch, dengan unit-unit yang dirancang yaitu bak penampungan awal, tangki koagulasi-aerasi, bak aerasi, bak sedimentasi, dan bak pengeringan lumpur dengan waktu proses untuk setiap unit berturut-turut adalah 1 hari, 35 menit, 1 hari, 1 hari, dan pengeringan lumpur dengan ketebalan 40 cm diasumsikan memakan waktu 15 hari. Rancangan ini mampu menurunkan parameter Chemical Oxygen Demand (COD) hingga 99% dan Total Suspended Solids (TSS) sebesar 82%, memenuhi baku mutu yang berlaku. Analisis finansial menunjukkan bahwa penerapan IPAL ini memiliki perkiraan biaya operasional sebesar Rp3.815.325 per bulan. Perhitungan biaya ini sudah memperhitungkan peningkatan skala produksi perusahaan, sehingga dapat menjadi solusi jangka panjang yang efektif dan efisien bagi perusahaan yang sedang berkembang pesat dalam mengelola limbah cairnya., The discharge of untreated wastewater from the food industry significantly pollutes waterways, reducing oxygen levels and harming aquatic life. This study aims to design a wastewater treatment plant (WWTP) specifically tailored for treating 1.5 m³ per day of wastewater generated from frozen cilok production, an Indonesian street food. The designed WWTP includes several stages and units of batch processing, namely equalization tank, coagulation-aeration tank, aeration tank, sedimentation tank, and sludge drying bed with process times for each unit respectively being 1 day, 35 minutes, 1 day, 1 day, and 15 days to dry sludge with a thickness of 40 cm. This design is able to reduce Chemical Oxygen Demand (COD) parameters by up to 99% and Total Suspended Solids (TSS) by 82%, meeting applicable quality standards. Financial analysis shows that implementing this WWTP has an estimated operational cost of IDR 3,815,325 per month. This cost calculation takes into account the increase in the company's production scale, therefore proving that it can be an effective and efficient long-term solution for the company that is growing rapidly in managing their wastewater.
Keyword: Cilok, Food industry wastewater, Wastewater treatment plant (WWTP)

Judul: Rancangan Instalasi Pengolahan Air limbah Industri dengan proses biologis Biological nutrient removal
Abstrak: Kegiatan industri yang menghasilkan limbah cair, berpotensi menimbulkan pencemaran air di lingkungan apabila tidak diolah dengan sesuai. Penelitian ini bertujuan menganalisis dan mengidentifikasi karakteristik limbah cair PT. W, membuat rancangan unit IPAL yang sesuai, serta menganalisis efektivitas penggunaan mikroba pada pengolahan biologis biological nutrient removal. Metode pengujian serta baku mutu yang digunakan adalah SNI pengujian air limbah, Peraturan Menteri Negara Lingkungan Hidup Nomor 03 Tahun 2010, dan Keputusan Gubernur DKI Jakarta No. 582 Tahun 2005. Hasil analisis menunjukkan bahwa nilai Total Suspended Solids (TSS), amonia (NH3), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Sulfida (S), minyak dan lemak serta fecal coliform melampaui baku mutu sehingga perlu diolah lebih lanjut. Rancangan unit IPAL yang digunakan adalah bak ekualisasi, bak penampung, bar screen, grit chamber, sedimentasi primer, biological nutrient removal, clarifier, desinfeksi, sludge thickener, sludge digester, dan sludge drying bed. Biological nutrient removal merupakan unit pengolahan biologis suspended growth yang dipilih karena unit dapat dirancang untuk menurunkan nilai BOD, TSS, dan NH3 menjadi 10 mg/l, 10 mg/l, dan 1 mg/l. Tingkat efektivitas penggunaan mikroorganisme dalam unit ini dapat diketahui dari persen penurunan nilai parameter pencemar., Industrial activities that produces waste water, causes water pollution if it not treated properly. The research objectives were to analyze and identify PT. W wastewater characteristic, to design an appropriate WWTP of PT. W and analyze the effectiveness of microorganism at biological process biological nutrient removal. The method used was based on SNI of wastewater analyzing, Regulation of Minister of the Environment Number 03/2010, and DKI Jakarta‘s Governor Regulation Number 582/2005. Result of the analysis showed TSS, NH3, S, BOD, COD, oil and grease, and fecal coliform exceeded the threshold. The units that used are equalization tank, bar screen, grit chamber, primary sedimentation, biological nutrient removal (BNR), clarifier, disinfection, sludge thickener, sludge digester, and sludge drying bed. Biological nutrient removal is suspended growth biological process were chosen because it could remove BOD, TSS, and NH3 concentration into 10 mg/l, 10 mg/l, and 1 mg/l. The effectivity of microorganism uses can be known by percent removal of indicator concentrations.
Keyword: air limbah, biological nutrient removal, IPAL

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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