Arsenic Removal from Drinking Water by Iron–Copper Mixed Hydroxide Precipitate

This study aimed to model arsenic (As V) removal from water using iron–copper mixed hydroxide precipitate (IC-HP) via adsorption. IC-HP, synthesized through coprecipitation, exhibited a rough and porous surface with a point of zero charge (PZC) value of 7.8. Response surface methodology (RSM) with Doehlert’s design (DD) matrix was employed for efficient model development and better performance analysis. DD reduces experimental runs with low-error output. In the four factors DD matrix, pH, contact time, adsorbent dose, and initial As(V) concentration were all considered. Contact time and adsorbent dose have a positive effect on arsenic removal performance. DD model identified pH as the most influential factor, followed by adsorbent dose and contact time in arsenic removal. By optimization process, optimal conditions of factors were found to be pH 4.83, contact time of 75.44 min, adsorbent dose of 0.83 gm/L, and initial arsenic concentration of 98.83 ppb. At optimum conditions, 97.71% arsenic removal was achieved, with a well-fitted model (R2 = 0.9843) and a maximum error of ±3.17%.