Judul: Evaluasi dan Desain Peningkatan Kapasitas Instalasi Pengolahan Air Minum di PT. Krakatau Tirta Industri
Abstrak: PT. Krakatau Tirta Industri (PT KTI) has a rule as supplier of Cilegon Municipality’s water needs. Considering the demand for water supply continues to grow, PT. KTI intends to increase its capacity up to 2500 liters/sec. This study aims to evaluate current condition of water treatment plant of PT. KTI, and to review the increasing of installation capacity by process and design aspects. The study is conducted in two stages, namely collecting primary and secondary data and analyzing process and design calculations. Water treatment plant at PT. KTI are bar screen, sand trap, coagulation, flocculation, sedimentation, filtration, and disinfection. Bar screen unit was designed with 40 pieces bar and width of 6 mm. Sand trap unit has minimum height of 4.30 m. Three pumps must have an efficiency of 90%. If the efficiency doesn’t reach that value, then the addition of at least one pump unit is needed. Coagulation unit design is carried out by hydraulic jump and mechanical mixing. Flocculation unit design is done by changing the impeller rotation to 32 rpm. On sedimentation units, plate settlers as much as 891 pieces is designed with inter-plate distance of 0.05 m and height of 1 m. Conclusions of this study are almost all units have parameters that don’t meet the design criteria, and design takes on the unit bar screen, and accelator.
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Judul: Evalusi Pemberian Dosis Koagulan Aluminium Sulfat Cair dan Bubuk Pada Sistem Dosing Koagulan di Instalasi Pengolahan Air Minum PT. Krakatau Tirta Industri
Abstrak: Surface water before being used for particular purposes must be processed first in order to be viable consumed. One of the worth attempts is by building a water treatment such as the installation of Water Treatment Plant that been practiced by PT. Krakatau Tirta Industri, Cilegon. One of the processes is coagulation using aluminium sulfate powder and liquid as the coagulant. This research purpose is to find the optimum dose of aluminium sulfate (liquid) at PT. KTI by comparing the quality and the production cost. The methods including several stages such as preparation phase, data collection, data processing and analysis and presentation of results. The optimum dose for powder using is 60 ppm and for liquid is 100 ppm. The production cost of aluminium sulfate (liquid) using wet alumina is Rp 6.491.838,36 and the cost of goods is Rp 1.131,17/ kg and for dry alumina the production cost is Rp 8.829.278,36 and the cost of goods is Rp 1.538,46/ kg the cost are cheaper than the aluminium sulfate powder cost of goods Rp 1.760/ kg. As resulted from the sensitivity test, the most sensitive variable from the cost of goods is sulfate acid for wet alumina and dry alumina for aluminium sulfate that using dry alumina as the raw material.
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Judul: Mitochondrial DNA Gene Organization and Phylogenetic Relationship of Naja siamensis
Abstrak: Naja siamensis is one of Asiatic cobra in the Family of Elapidae, known as a cryptic snake. It has many morphological variations that lead to misidentification. Misidentification can cause the wrong concept in developing antivenom types due to high snakebite cases occur in Thailand. Thus, an accurate species identification using a molecular approach is crucially required. Mitochondrial DNA has been used widely in snake molecular studies. These studies were aimed to determine the arrangement of the N. siamensis partial mitochondrial genes using reptile-oriented primers and to reveal the phylogenetic relationship among other species of Asian cobra. DNA extraction was carried out based on the standard DNA salting-out protocol and was conducted by bioinformatics analysis using BLASTn and MEGA 6 software. Gene annotation was performed against N. kaouthia complete genome. A total of 3121 bp of N. siamensis mtDNA genes were sequenced consisting of partial of six regions: 16S rRNA, ND1, tRNA-Ile, CRII region, tRNA-Leu, tRNA-Gln, and COI genes. The mtDNA gene organization of N. siamensis was predicted to has a similar pattern with the common Elapidae mtDNA gene organization. This study showed that there is a monophyletic form in Naja genus and N. kaouthia is the closest species with N. siamensis based on partial 16S rRNA and ND1 gene.
Keyword: 16S rRNA, Elapidae, ND1, phylogenetic relationship