Investigation and Optimization of Reactive Red 195 Dye Removal Performance from Aqueous Solution Using Hemp Seed Oil Cake as a Low-Cost Adsorbent under Different Parametric Conditions

The effluent discharge of synthetic dyes, notably azo dyes such as the anionic dye Reactive Red 
195 (RR195), in textile effluents constitutes a significant environmental and public health risk. 
This is attributed to their inherent toxicity, environmental persistence, and potential carcinogenicity. 
The assessment of hemp seed oil cake (HSOC), a sustainable and inexpensive agricultural by
product, as a novel effective adsorbent for the sequestration of the reactive azo dye RR195 from 
aqueous media was investigated. The influence of critical operational parameters on adsorption 
performance was systematically examined through a series of batch experiments. The investigation 
established the following optimal conditions for maximum sequestration: an initial dye 
concentration of 40 mg/L, an adsorbent dosage of 1.5 g, a temperature of 50°C, a solution pH of 
4, and a contact time of 120 minutes under agitation at 100 rpm. The experimental data 
demonstrated that unmodified HSOC is a highly efficient, renewable, and cost-effective adsorbent, 
representing its potential as a promising green technology for advanced textile effluent remediation.