Isolasi dan Karakterisasi Silika Dari Diatom Laut Ambon Navicula sp. TAD Menggunakan Variasi Larutan Asam

Abstract

Diatoms are microalgae with cell walls made of silica with nano-sized pores known as frustules. Silica can be applied in various fields, including silica as a catalyst matrix for the purification and separation of substances, heavy metal adsorption, biosensors, drug delivery, and photocatalysts. This study aims to isolate and characterize silica by washing with an acid solution from the diatoms in the deep waters of Ambon Bay, namely Navicula sp. Navicula sp. TAD cell cultivation was carried out to obtain biomass cultivated in a modified medium for seven days. Harvesting obtained Navicula sp. TAD wet biomass of 90.799 g with wet biomass productivity of 1.090 g ml-1 day-1. Isolation of silica from Navicula sp. TAD biomass was carried out by washing nitric acid, hydrochloric acid, and sulfuric acid to obtain silica of 7.650 ± 0.071, 4.550 ± 0.35, and 6.800 ± 0.707 g, respectively. Characteristics of silica characterized by SEM/EDX showed that the nanoporous structure of the frustule biosilica surface could be seen clearly and was composed of silicon and oxygen, indicating that the biosilica had been purified from organic impurities.