Removing Iron Ions Contaminants from Groundwater Using Modified Nano-Hydroxyapatite by Nano Manganese Oxide

Recent advancement of nano-biochar for the remediation of heavy metals and emerging contaminants: Mechanism, adsorption kinetic model, plant growth and development

Even though researches have shown that biochar can improve soil-health and plant-growth even in harsh environments and get rid of harmful heavy metals and new contaminants, it is still not sustainable, affordable, or effective enough. Therefore, scientists are required to develop nanomaterials in order to preserve numerous aquatic and terrestrial species. The carbonaceous chemical known as nano-biochar (N-BC) can be used to get rid of metal contamination and emerging contaminants. However, techniques to reduce hetero-aggregation and agglomeration of nano-biochar are needed that lead to the emergence of emerging nano-biochar (EN-BC) in order to maximise its capacity for adsorption of nano-biochar. To address concerns in regards to the expanding human population and sustain a healthy community, it is imperative to address the problems associated with toxic heavy metals, emerging contaminants, and other abiotic stressors that are threatening agricultural development. Nano-biochar can provide an effective solution for removal of emerging contaminants, toxic heavy metals, and non-degradable substance. This review provides the detailed functional mechanistic and kinetics of nano-biochar, its effectiveness in promoting plant growth, and soil health under abiotic stress. Nonetheless, this review paper has comprehensively illustrated various adsorption study models that will be employed in future research.

Conversions of Cement bypass waste to Nano-hydroxyapatite exploited in water purification.. [DOI: 10.21203/rs.3.rs-1871491/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The goal of this study is to convert cement bypass dust into a usable product called hydroxyapatite. Four hydroxyapatites’ samples (Kiln-HA1- Kiln-HA4) were successfully prepared in nano-scale (14.8–25.7 nm). The specific surface areas of all of the samples examined were high: Kiln-HA3 (161.5 m2/g) > Kiln-HA1 (130.2 m2/g) > Kiln-HA2 (81.9 m2/g) > Kiln-HA4 (54.1 m2/g).Tested nano- hydroxyapatite successfully removed Fe3+ and Mn2+ as pollutants from water with efficiencies of up to 95% for both Fe and Mn ions. The maximum adsorption capacities (qmax) of nano hydroxyapatite varied from 147 to 175 mg.g− 1 for adsorbed Fe (III), while were wide ranged from 204 to 344 mg.g− 1 for adsorbed Mn (II).Hydroxyapatite-selectivity for removing Mn and Fe ions in mixed solutions was as follows: Fe3+> Cu2+>Mn2+. In multiple cycles, the investigated materials were able to remove Fe and Mn ions without regeneration. The overall cost of producing 100 grams of hydroxyapatite from cement bypass waste is less than other calcium source which was 184 EGP/100g (9.32 €/100g).

Snail Based Carbonated-Hydroxyapatite Material as Adsorbents for Water Iron (II)

Carbonated hydroxyapatite (CHAp) adsorbent material was prepared from Achatina achatina snail shells and phosphate-containing solution using a wet chemical deposition method. The CHAp adsorbent material was investigated to adsorb aqua Fe(II) complex; [Fe(H₂O)₆]²⁺ from simulated iron contaminated water for potential iron remediation application. The CHAp was characterized before and after adsorption using infrared (IR) and Raman spectroscopy. The IR and the Raman data revealed that the carbonate functional groups of the CHAp adsorbent material through asymmetric orientation in water bonded strongly to the aqua Fe(II) complex adsorbate. The adsorption behaviour of the adsorbate onto the CHAp adsorbent correlated well to pseudo-second-order kinetics model, non-linear Langmuir and Freundlich model at room temperature of a concentration (20–100 mg L⁻¹) and contact time of 180 min. The Langmuir model estimated the maximum adsorption capacity to be 45.87 mg g⁻¹ whereas Freundlich model indicated an S-type isotherm curvature which supported the spectroscopy revelation.