Current available methods for water desalination are energy intensive, expensive, and not feasible for small-scale applications. As an alternative, hydrogels and hydrogel composites may be utilized both as draw agent and semi-permeable membrane to desalinate water via forward osmosis. In this study, a non-toxic, biodegradable, and low-cost hydrogel composite is prepared by adding activated carbon (AC) as filler to a 3:1 blend of sodium carboxymethyl cellulose (NaCMC) and hydroxyethyl cellulose (HEC), with citric acid as crosslinking agent. A one factor-at-a-time (OFAT) analysis was performed to correlate the crosslinker concentration, crosslinking duration, and AC content to the swelling and desalination efficiency of the CMC/HEC/AC hydrogel composite. Results showed that the swelling of the hydrogel varies directly with the crosslinking duration but varies inversely with the crosslinking concentration. The experiments also showed that the addition of AC as filler significantly improves the desalination efficiency of the hydrogel composite; however, it was also observed that efficiency is reduced if the AC content is excessive.

• hydrogel,
• composite,
• desalination,
• activated carbon,
• cellulose

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