Recycling of Wastewater Contaminated With Cationic Dyes Using Nonporous Silica Extracted From Rice Husk

‌the world-wide production of dyes generates wastewaters contaminated with toxic materials which makes the environmental pollution# textile, paper and pulp mills, tanneries, distilleries, and food industries discharge colored wastewaters# the carcinogenicity and toxicity of dyes necessitate the wastewater treatment# silica based materials are one the most important adsorbents employed in industrial applications# this material is produced in nano scale with nano-porous structure# in the present study, the rice husk which is well-known as an agricultural waste was used to synthesize silica adsorbent and the effect of processing factors such as sodium hydroxide, gelation ph and ageing time on dye removal efficiency were investigated based on designed experiments# the optimal conditions for the effective synthesis of silica were determined as: sodium hydroxide concentration: 0#5 mol#l-1, ph: 9 and ageing time:12 h