Page 226 - Materials Chemistry, Second Edition

Green and Eco-Friendly Materials for Removal of Phosphorus 207

TABLE 10.1 (CONTINUED)
Natural Adsorbents for Phosphorus Removal

Adsorption
−1
Adsorbents P Conc.(mg L ) Capacity(mg g ) Reference
−1
Shellsand 0–480 9.6 Adam et al. (2007)
Wollastonite – 0.467–1.8 Gustafsson et al. (2008)
Polonite 5.30 mg dm −3 – Gustafsson et al. (2008)
Peat 4.9 0.081 Koiv et al. (2010)
Phoslock – 9.5–10.5 Haghseresht et al. (2009)
Lanthanum(III) 5 14 Kuroki et al. (2014)
modified
bentonite
Red soil 20 0.998 Rout et al. (2015)

exact mechanism during the phytoremediation was assimilation and sorption dur-
ing the removal of phosphorus. Zirconium(IV) immobilized orange waste gel from
a widely available biomass was investigated for its possible use in the removal of
phosphorus from aqueous solution. When the adsorption capacity was compared
with that of synthetic materials, it was four times higher than for zirconium ferrite.
At low pH, about 85% removal was attained in fixed bed column studies (Biswas
et al., 2008). Posidonia oceanica fibers, found abundantly in the coastal zones of the
Mediterranean basin, were investigated for the removal of phosphorus from wastewa-
ter by Wahab and his research team, who proposed a sustainable approach for using
the plant waste in agricultural fields as a substitute for chemical fertilizers. A dual
strategy was chosen, in which the plant assisted in the removal of orthophosphate from
wastewater and phosphorus-loaded plant species were used as fertilizer and compost
(Wahab et al., 2011a). Batch experimentation was performed on synthetic and second-
ary effluent using Posidonia oceanic fibers, and the effects of several parameters were
studied. Eighty percent phosphorus removal was obtained from synthetic solution. An
important phenomenon was noted with secondary effluent, in which competition was
seen between sulfate and phosphorus for adsorption sites. The authors found that a
continuous reactor was more beneficial than a column (Wahab et al., 2011b). A green
alga, Neochloris oleoabundans, was used for the treatment of phosphorus from syn-
thetic and real municipal wastewater. Additionally, the biomass had great potential to
be used as biofuel (Wang and Lan, 2011). Greenhouse effluent also contained a large
amount of phosphorus, which was a big challenge for researchers.
Gastropod shell, a green and eco-friendly natural material, was employed in a
column reactor to decontaminate wastewater from aquaculture. It also assisted in
recovering phosphorus and can be reused as a soil conditioner, which is better than a
fertilizer. Chemisorption was found to be the dominating driving force while elimi-
nating phosphorus from waste water. About 73.32% phosphorus was removed with a
maximum uptake of 185.8 mg g . Phosphate was precipitated by a thermally treated
−1
calcium mineral derived from gastropod shell, which resulted in high phosphate
recovery (Oladoja et al., 2015). African land snail shell was tested for its ability to