1.1 BACKGROUND STUDY
Wastewater in the textile , plastic, paper and cosmetics industry is a major threat to the environment. The volume of wastewater produced starts from different processes throughout from the pretreatments to the final treatment. The contents found in the wastewater are complex, having inorganic and organic compound chemicals in it and aquatic lives are at risk. Some of these wastes have even caused mutation in genetic coding of the marine organisms(Gao, Qin et al. 2013) .The dyes released causes allergic reaction on skins and to a certain extent, some have been even found to be carcinogenic in nature. Sunlight is blocked from being penetrated into the water bodies due to the concentration of the dyes. This causes a disturbance in …show more content…
It was found to be an adsorbent of vapor and gases in canisters. The method of producing silica gel was patented in 1918 by Walter A. Patrick , a chemical professor at John Hopkins University.
2.2.2 SYNTHESIS OF SILICA GEL
a) USING KAOLIN BY-PRODUCT
The synthesis process (D. Brahmia 2014) was carried out in two steps namely, (1)Metasilicate sol preparation and (2) Metasilicate destabilization with acid. In the first step, a mixture of sodium carbonate and sand were heated to 1000°C to form silicate. Sodium silicate formed in this study was prepared with different molar ratios, n, ranging from 1 to 4 as shown in Equation (2.1). The result obtained was generally in the ratio of three SiO2 molecules to one molecule of Na2CO3 producing three molecules of sodium silicate and carbon dioxide gas released, shown as equation (2.2).
Equation (2.1) n = SiO2 / Na2O
Equation (2.2) 3SiO2 +Na2CO3 (3SiO2 , Na2O) + CO2 The result obtained was close to 3.3 : 1 (Brahmi, Merabet et al.