Defluoridation efficiency of a green composite reactive material derived from lateritic soil and gastropod shell

Tuning charcoal to functional reactive filter materials for groundwater defluoridation

“…Over the pH PZC value, the adsorbent surface is negatively charged, and repels the fluoride (F − ) ions, while below the pH PZC value, the surface becomes positively charged and attracts the F − ions via the electrostatic attraction. 14,18 In the case of the MC that exhibited a very low pH PZC , the possibility of fluoride removal via electrostatic attraction is not feasible. Therefore, the removal of fluoride by the MC must have occurred via other modes of interaction, whose underlying mechanism is highly dependent on the initial solution pH value, as exemplified in Fig.…”

“…17,28,29 Some other adsorption-based defluoridation processes that have shown a better fit to the pseudo-second-order kinetic equations have also been reported. 15,[17][18][19][20][21]24…”

“…Amongst the commonly used point-of-use water treatment system is the water filter system, which uses a reactive phase as the filter material. A few of the materials that have been investigated as reactive materials for potable water defluoridation included γ-Al 2 O 3 /γ-Fe 2 O 3 nanocomposite, 15 calcined gastropod shell, 16 watermelon rind biochar, 17 lateritic soil–gastropod shell composite, 18 hollow tubular alumina, 19 granular anionic clay composite, 20 aluminum infused diatomaceous earth, 21 layer double hydroxides, 22,23 and calcium aluminate–diatomaceous earth composite. 24 In this study, we aimed at boosting the surface oxides of raw charcoal, to prepare an affordable and efficacious functional reactive filter material for groundwater defluoridation.…”

Novel Mesoporous Lignin-Calcium for Efficiently Scavenging Cationic Dyes from Dyestuff Effluent

“…The effect of pH was estimated over a pH range of 2–12. Scientifically, adsorbate concentration variation of solution generated by pH should be taken into consideration, as well as pH changing by addition of adsorbent. , Hence, in this study, both the initial concentration of MB solution with different pH values and the equilibrium pH value of the solution were also assessed. We have found that the addition of adsorbent LC caused a minor pH change, which could be ignored.…”