A report on arsenic removal from water via adsorption of an arsenomolybdate complex on S–CuFe 2 O 4 adsorbents

Drinking ground water in many areas of Pakistan is contaminated by dissolved arsenic. The consumption of arsenic-contaminated water causes many carcinogenic diseases. Hence, this work aims to estimate and eliminate arsenic from ground water used for drinking purposes in the Layyah District (Punjab – PK). For the purpose, water samples were collected from selected areas of the aforementioned district, and average arsenic concentration was estimated to be 95 ppb. Thereafter, to remove dissolved arsenic contents (As 3+ and As 5+ ), sulphur-doped copper ferrite, i.e. , S–CuFe 2 O 4 adsorbent, was developed via a hydrothermal approach. To justify its effectiveness, structural morphology of the adsorbent was evaluated via XRD, FT-IR, Raman and AFM analysis, whereas its stability was investigated via TGA analysis. Its purity and chemical compositions were determined using SEM, EDX and XPS techniques. Magnetic properties of S–CuFe 2 O 4 were examined via VSM. The results indicated that spinel cubic morphology of S–CuFe 2 O 4 facilitates the effective adsorption of arsenic contents. For complete elimination, arsenic contents were first converted to an arsenomolybdate complex (AMC) and then removed from water via adsorption on S–CuFe 2 O 4 . The adsorption was found to be spontaneous with Δ G = −13.51 kJ mol −1 , and adsorption kinetics for the AMC were well fitted by pseudo second order with a correlation coefficient ( R 2 ) of 0.99997. Adsorption isotherm and electrostatic interaction between S–CuFe 2 O 4 and AMC were confirmed and revealed using Langmuir and Temkin models with R 2 = 0.97021 and R 2 = 0.87431, respectively. Results suggested that one gram of S–CuFe 2 O 4 is enough to deliver 275 gal of arsenic free water.