Production of redox-active-reactive filter material from charcoal

Abstract

The surficial and textural features of a pyrogenic carbonaceous material (charcoal) was modulated with acidic Piranha solution (i.e., 1:3 30% H2O2 to H2SO4) to produce a redox-active adsorbent for the simultaneous adsorption and reduction of Cr(VI) in groundwater sample. The optimal modification time of 60 s is required to transform the raw charcoal to an efficacious redox-active adsorbent (MCh). The MCh surface was imbued with electron donor moieties that is required for the direct conversion of the adsorbed Cr(VI) to Cr(III). The rate parameters for Cr(VI) adsorption by the MCh were initial concentration dependent. The GW system variables had minimal influence on the performance of the MCh, which showed that the MCh is capable of effective performance within broad process variables. The direct conversion of Cr(VI) to Cr(III) on the MCh surface was affirmed. The treatment of Cr(VI) contaminated GW in a microcosm real-life system was highly effective over the period of study (40 hours). The residual Cr(VI) concentration in the hourly sample collection ranged between undetectable (i.e.,<0.01), at the inception, to 1.77 mg/L at the 40th hour. The pH values of the treated water were not vitiated, and the EC (μs cm− 1) values continually reduced over time.

Keywords

• Groundwater
• Redox-active
• Cr(VI) reduction
• Piranha solution
• Charcoal
• Pyrogenic material