Judul: Desain Tata Letak Ruang dan Fasilitas Produksi Rumah  Pengomposan di PT Tanjungenim Lestari
Abstrak: Industri pulp and paper di Indonesia menghasilkan limbah berupa sludge yang berasal dari Instalasi Pengolahan Air Limbah (IPAL) dan abu sisa pembakaran boiler yang saat ini belum dimanfaatkan secara optimal. Salah satu alternatif penanganan dan pemanfaatan limbah tersebut yaitu dengan proses pengomposan. Proyek ini bertujuan untuk memanfaatkan limbah sludge dan boiler ash dari PT. Tanjungenim Lestari Pulp and Paper untuk dijadikan produk kompos dan menganalisis kualitas mutu kompos yang dihasilkan. Tujuan penelitian ini adalah merancang fasilitas bangunan rumah kompos. Hasil perancangan tata letak dilakukan dengan membuat desain 2D dan 3D dari usulan tata letak yang terpilih menggunakan bantuan software BPLAN90. Tata letak usulan yang terpilih merupakan salah satu dari 12 iterasi Algoritma BLOCPLAN. Layout yang terpilih yaitu layout usulan iterasi 7 dengan total luas area kerja 11236 m2 , total jarak penanganan bahan pada layout iterasi yang terpilih adalah sebesar 1457,72 m, dan nilai efektivitas tata letak sebesar 0,69. Desain 2D dan 3D dibuat dengan bantuan software SketchUp. Kata kunci: BLOCPLAN, IPAL, Kompos, Sludge, Tata Letak, The pulp and paper industry in Indonesia produces waste in the form of sludge originating from the Wastewater Treatment Plant (WWTP) and ash remaining from boiler combustion which has not been utilized optimally. One alternative handling and utilization of this waste is the composting process. This project aims to utilize sludge and boiler ash waste from PT. Tanjungenim Lestari Pulp and Paper to be used as compost products and to analyze the quality of the compost produced. The purpose of this research is to design compost housing facilities. The results of the layout design are carried out by making 2D and 3D designs from the selected layout proposals using the help of BPLAN90 software. The selected proposed layout is one of 12 iterations of the BLOCPLAN Algorithm. The selected layout is the iteration proposed layout 7 with a total working area of 11236 m2, the total material handling distance in the selected iteration layout is 1457.72 m, and the layout effectiveness value is 0.69. 2D and 3D designs are made with the help of SketchUp software. Keywords: BLOCPLAN, Composting, Layout, Sludge, WWTP
Keyword: BLOCPLAN, IPAL, Kompos, Sludge, Tata letak

Judul: Co-Composting Process Engineering Design of Sludge, Boiler Ash, and Dregs at PT Tanjungenim Lestari Pulp and Paper using Aerated Static Pile Method
Abstrak: PT Tanjungenim Lestari Pulp and Paper menghasilkan limbah padat berupa sludge (30 ton/hari), abu ketel (33,7 ton/hari), dan dregs (3 ton/hari). Limbah yang dihasilkan ini belum diolah dengan baik. Sanitary landfill yang menjadi penanganan limbah saat ini tidak tepat untuk diterapkan ke depannya. Cocomposting dapat menjadi solusi terbaik untuk mereduksi limbah dalam jumlah besar berdasarkan kandungan organik pada bahan dan mengubahnya menjadi produk bernilai tambah. Penelitian ini bertujuan untuk merancang proses co-composting berupa campuran sludge:abu:dregs (2:1:1) dengan metode Aerated Static Pile (ASP). Pengomposan dilakukan pada skala 500 kg dengan menggunakan laju aerasi 0,4 L/menit.kg bahan. Kualitas produk kompos yang dihasilkan lalu dibandingkan dengan baku mutu pada SNI-7847:2012. Dari pengomposan yang telah dilakukan selama 32 hari, diperoleh produk kompos dengan suhu 28?, pH 5,75, kadar air 44,12%, dan rasio C/N sebesar 17,43. Berdasarkan parameter fisik, produk kompos memiliki warna dan bau khas dregs. Berdasarkan parameter kimia, produk kompos kurang memenuhi baku mutu pH dan c-organik. Produk kompos memenuhi baku mutu parameter biologi dan logam berat. Produk kompos yang dihasilkan belum memenuhi baku mutu warna, bau, dan pH, sehingga desain proses pengomposan yang dilakukan belum bisa menjadi acuan untuk peningkatan skala pengomposan., PT Tanjungenim Lestari Pulp and Paper produces solid waste such as sludge (30 tons/day), boiler ash (33.7 tons/day), and dregs (3 tons/day). These wastes are currently not well managed. The sanitary landfill currently used for waste disposal is not suitable for future application. Co-composting could provide the best solution to reduce large quantities of waste based on the organic content of the materials and convert them into value-added products. This research aims to design a cocomposting process using a mixture of sludge:ash:dregs (2:1:1) with the Aerated Static Pile (ASP) method. Composting was conducted on a 500 kg scale with aeration flow rate of 0.4 L/minute.kg of material. The compost product quality was compared to quality standards of SNI-7847:2012. After 32 days of composting, the compost product had a temperature of 28?, pH of 5.75, moisture content of 44.12%, and C/N ratio of 17.43. Based on physical parameters, the compost product had the characteristic color and odor of dregs. Based on chemical parameters, the compost product didn’t meet the quality standards for pH and c-organic. Compost product met quality standards of biology and heavy metal parameters. The compost product did not accord the quality standards for color, odor, and pH, indicating that the composting process design conducted cannot yet serve as a reference for scaling up composting operations.
Keyword: Boiler ash, co-composting, sludge, dregs, process design

Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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