Optimization of batch electrocoagulation process using Box-Behnken experimental design for the treatment of crude vegetable oil refinery wastewater

The performance of the batch electrocoagulation process for the treatment of real crude vegetable oil refinery wastewater with high COD using sacrificial aluminum anode was explored in this research. Effects of operating factors such as electrolysis time (0–60 min), applied voltage (10–20 V) and electrode spacing (2–4 cm) on the COD removal were investigated. Mathematical model relating these key operating factors and the COD removal was developed using Box-Behnken design. 3-D response surface plots showed that the COD removal significantly increased with increase in electrolysis time and applied voltage till the optimum value. COD removal decreased, when very short or excessive electrode spacing was fixed. Experimental COD removal of 70.8% was attained at the optimized conditions and observed to be in reasonable agreement with the prediction by the Box-Behnken design

Adsorption and desorption characteristics of crystal violet in bottom ash column

This study described adsorption of Crystal Violet (CV) by bottom ash in fixed-bed column mode. Equilibrium of adsorption was studied in batch mode for finding adsorption capacity of bottom ash. In fixed bed column adsorption, the effects of bed height, feed flow rate, and initial concentration were studied by assessing breakthrough curve. The slope of the breakthrough curve decreased with increasing bed height. The breakthrough time and exhaustion time were decreased with increasing influent CV concentration and flow rates. The effect of bed depth, flow rate and CV concentration on the adsorption column design parameters were analyzed. Bed depth service time (BDST) model was applied for analysis of crystal violet adsorption in the column. The adsorption capacity of bottom ash was calculated at 10% breakthrough point for different flow rates and concentrations. Desorption studies reveals that recovery of CV from bottom ash was effective by using CH3COOH than H2SO4, NaOH, HCl and NaCl solutions