Use of silica synthetic adsorbent from beach sand on the adsorption of metal ion Pb and Cu in printing waste.

The Printing waste consists of the heavy metals chrome (Cr), lead (Pb), and manganese (Mn), as well as large concentrations of volatile organic compounds (VOG). Pb and Cu contained in the printing waste released into the environment must be handled. One of them is using adsorbents as metal ion absorption contained in the waste. This study aims to utilize silica from beach sand as a natural adsorbent to absorb metal ions in liquid waste. Silica adsorbent was produced by refluxing 100 grams of beach sand with 6M HCl at 90 °C for four hours. The result of the previous process was filtered and washed until the filter was free of Cl−. Subsequently, the sand is dried at 120 °C. Each sample of sand was refluxed for four hours with 6M NaOH at a constant temperature of 80 °C, then filtered and washed. Drop by drop, HCl was added to the filter until the pH reached 12 and the solution turned white. The solution was then stored for 24 hours until the gel was formed. Afterward, the gel was separated and washed until the filtrate had no Cl. The synthesized silica was dried in an oven at 120 °C for four hours. The dried silica was utilized as an adsorbent for contact with the waste. Variables in this study included mass variations of 5 grams, 10 grams, and 15 grams and contact durations of 60, 90, and 120 minutes. The optimal metal ions absorbability from the adsorbent in this study was found in 10 grams of sample mass and a variable time of 90 minutes, with an efficiency adsorption metal cuprum of 96.60 %. [ABSTRACT FROM AUTHOR]