ThesisOpen AccessMetadata saja
2026•
Chlorella vulgaris merupakan salah satu jenis fitoplankton yang banyak dimanfaatkan dalam berbagai bidang, potensi tersebut dapat dikembangkan dengan budidaya Chlorella vulgaris. Pertumbuhan Chlorella ini sangat dipengaruhi oleh ketersediaan nutrien, salah satunya ion magnesium (Mg2+) yang berperan penting dalam pembentukan klorofil guna porses fotosintesis. Penelitian ini bertujuan untuk menganalisis pertumbuhan Chlorella vulgaris dengan penambahan ion magnesium (Mg2+) pada media kultur. Penelitian ini dilakukan selama 7 hari dengan lima perlakuan konsentrasi ion Mg2+, yaitu 0 ppm; 0,4 ppm; 0,8 ppm; 1,2 ppm; dan 1,6 ppm, masing-masing dua ulangan. Parameter kualitas air yang diukur suhu, salinitas dan, pH. Hasil penelitian menunjukkan bahwa perlakuan penambahan ion Mg2+ 0,4 ppm memberikan pertumbuhan tertinggi sebanyak 24.720 × 10⁴ sel/mL pada hari ke-6 pengamatan, sedangkan laju pertumbuhan spesifik tertinggi pada perlakuan penambahan ion Mg2+ 1,6 ppm sebesar 2.59 sel/mL hingga 7 hari pengamatan. Berdasarkan hasil tersebut dapat disimpulkan penambahan ion Mg2+ mampu memberikan pertumbuhan Chlorella vulgaris. Chlorella vulgaris is a phytoplankton species widely utilized in various sectors, including aquaculture, biotechnology, and environmental management. Its production potential can be optimized through the cultivation of C. vulgaris. The growth of C. vulgaris is strongly influenced by nutrient availability, particularly magnesium ions (Mg²⁺), which play a crucial role in chlorophyll formation for the photosynthesis process. This study aimed to analyze the growth of Chlorella vulgaris with the addition of magnesium ions (Mg²⁺) in the culture media. The experiment was conducted over seven days using five treatments of Mg²⁺ concentrations: 0 ppm, 0.4 ppm, 0.8 ppm, 1.2 ppm, and 1.6 ppm, each with two replications. Water quality parameters measured included temperature, salinity, and pH. The results showed that the treatment with the addition of 0.4 ppm Mg²⁺ yielded the highest growth, reaching 24,720 × 10⁴ cells/mL on the sixth day of observation. Meanwhile, the highest specific growth rate was recorded in the 1.6 ppm Mg²⁺ treatment, reaching 2.59 cells/mL over the seven-day observation period. Based on these results, it can be concluded that the addition of Mg²⁺ ions enhances the growth of Chlorella vulgaris.
ThesisOpen AccessMetadata saja
2022•Skripsi, Thesis, Disertasi, dan Tugas Akhir
The existence of mangrove forests is one of the ecosystem building blocks in the Mangrove Conservation Area in Tarakan City. The rapid development in Tarakan City has caused the loss or reduction of the mangrove forest area. This study aims to analyze the community structure and density of mangroves in the Mangrove and Crab Conservation Area, Pamusian Village, Tarakan City. This research was conducted in November-December 2020 in the Mangrove and Crab Conservation Area, Pamusian Village, Tarakan City. The sampling method used is purposive sampling method. Observations were made at 3 (three) station points and each station consisted of 3 plots with a size of 10m x 10m for trees, 5m x 5m for tillers and 1m x 1m for seedlings. This study uses data analysis of mangrove vegetation including species density, relative density, species frequency, relative frequency, species cover or dominance, relative dominance, significant value index and Community Structure. The types of mangroves found in the Mangrove and Crab Conservation Area, Pamusian Village, Tarakan City are Avicennia alba, Avicennia marina, Lumnitzera racemosa, Rhizophora apiculata, Rhizophora mucronata, Sonneratia alba, Xylocarpus granatum and Nypa fruticants. Species density values ranged from 1.800 – 9.333, species frequency values ranged from 16-25, species dominance values were 1.775.745 and important value index values ranged from 200 - 300%. The structure of the mangrove and crab conservation area, pamusian sub-district, Tarakan city is very dense.
ThesisOpen AccessMetadata saja
2021•Skripsi, Thesis, Disertasi, dan Tugas Akhir
Mangrove forest is one of the mangrove crab habitats which is used as a spawning and rearing area. The purpose of the study was to analyze the relationship between mangrove density and the abundance of mangrove crabs in the Mangrove and Crab Conservation Area, Pamusian Village, Tarakan City. The sampling method used is purposive sampling method. carried out at 3 (three) station points and each station consists of 3 plots. In each plot, 2 folding traps were installed. The results showed that the highest density of mangrove species was from the mangrove species Rhizophora mucronata, while the lowest density was from the mangrove species Lumnitzera racemosa. The highest abundance of mangrove crabs was at station 3 and the lowest was at station 2. The correlation between mangrove density and mangrove crab (Scylla serrata) was found to have a tree-level correlation with an R2 value of 0.626 (Strong), tiller level with an R2 value of 0.041 (Very weak). and the seedling level with an R2 value of 0.227 (very weak). The effect of mangrove density on mangrove crabs using a simple linear regression test of 0.65 which means that the relationship between mangroves and mangrove crabs is quite strong, namely 65% while 35% is influenced by other factors.
ThesisOpen AccessMetadata saja
2021•Skripsi, Thesis, Disertasi, dan Tugas Akhir
.The presence of plastic waste is increasing along with the increasing population in the city of Tarakan, which reaches 48 tons per day. Plastic waste that is difficult to decompose causes problems of waste accumulation, so efforts are needed to process plastic waste into a useful product. One of them is by utilizing plastic waste as raw material for making paving blocks. This study sought to find an alternative method of making paving blocks with plastic waste raw materials, which might have better characteristic values than conventional paving blocks. Based on the results of the research, the method of manufacture that had the best characteristic value was Method III, with a melting time of 60 minutes, and using gradual cooling. In this method, variations in the composition of the mixture were also given, namely III.A with a composition of 100% plastic waste, and III.B with a composition of 65% plastic waste and 35% sand. Based on the tests carried out, the composition III.B gave the best characteristic value, with a density value of 1.176 gr/cm3, the absorption value reached 1.183% and the compressive strength value was 17.397 Mpa. Based on the analysis, the plastic paving made by method III.B was 99.36% qualified according to the category C paving quality in SNI 03-0691-1996, which was used for pedestrians.
