Page 228 - Materials Chemistry, Second Edition

Green and Eco-Friendly Materials for Removal of Phosphorus 209

TABLE 10.2 (CONTINUED)
Biosorbents for Phosphorus Removal

P Conc. Adsorption
−1
−1
Biosorbents (mg L ) Capacity(mg g ) Reference
Shell of African land 25–300 222.22 Oladoja et al. (2012)
snail
Palm surface fibers 50 26.05 Ismail (2012)
Granular date stones 50 26.66 Ismail (2012)
Modified coconut shell – 200 De Lima et al. (2012)
fibers
Iron loaded soybean 25 4.785 Nguyen et al. (2013)
milk residues (okara)
Apple peels – 20.35 Mallampati and Valiyaveettil
(2013)
Peanut shell biochar – 6.79 Jung et al. (2015)
Fruit (Citrus limetta) – 0.9585 Yadav et al. (2015)
juice residue
Ferric oxide loaded – 0.963 Ren et al. (2015)
cotton stalk biochar
Wheat straw biochar – 2.47–16.58 Li et al. (2016)
Modified rice husk – 21 Seliem et al. (2016)
composite
Activated rice husk ash – 0.89 Mor et al. (2016)
Engineering waste egg – 248.73 Chen et al. (2016)
shell
Water hyacinth magnetic – 5.07 Cai et al. (2017)
biochar

10.3 PHOSPHORUS RECYCLING
The foremost step during the recycling of phosphorus is the recovery of phosphorus
from the adsorbed material. In some treatments, phosphorus was recovered from
adsorbent material by a thermal method, which involved a large investment, thereby
increasing the treatment cost. Hence, for easier recovery and recycling of phospho-
rus, natural biodegradable materials have attracted attention. Moreover, the loaded
materials can be used as fertilizers, compost, or soil conditioners. Recycling lowers
the environmental risk by reducing the burden on the limited sources of phosphorus.
The depletion of phosphorus ores is occurring at an exponential rate, and recycling
and recovery are in the limelight for the scientific community. Also, the recycling
and recovery of phosphorus from sludge further fulfills the concept of zero genera-
tion of solid waste and lowers the burden on available natural resources. Several
technologies are employed for recovery, which have certain limitations due to the
cost of recovery and the difficulty of the processes (Hukari et al., 2016). Sewage
sludge from municipal wastes contains large amounts of phosphorus. But generally,
along with phosphorus, it also includes heavy metals and other pollutants. A ther-
mochemical treatment is adopted for recovering phosphorus from sewage sludge