| Acid mine drainage sludge (AMDS) |
The maximum removal efficiencies of As on AMDS under a pH of 7.0 |
58.5 |
19.7 |
142
|
| Aluminum-based adsorbent (ABA) and coal mine drainage sludge coated polyurethane (CMDS-PU) |
The adsorbents were efficient at pH range (3–10) |
|
10–31 |
143
|
| Magnetic bio-sludge (MS) containing activated sludge and magnetite (Fe3O4) nanoparticles |
MS featured a macroporous structure with a surface area of 78 m2 g−1 and a pore volume of 0.53 cm3 g−1, pH 2.6 at 25 °C |
|
18.5 |
144
|
| Goethite and calcite |
The adsorption of AsV is highest under acidic pH conditions, while AsIII achieves maximum adsorption at neutral to slightly basic pH levels |
66.9 |
21.5 |
145
|
| Fe-based backwashing sludge (FBBS) |
At pH 7 to pH 10, the removal of As V was enhanced with an increase in ion strength (0.01–1 M NaNO3) |
59.7 |
43.32 |
146
|
| Red mud-modified biochar produced from rice straw |
pH of 2 for As V and pH of 10 for AsIII
|
0.52 |
5.923 |
147
|
| Biochar prepared from pinewood and natural hematite |
γ-Fe2O3 particles on the carbon surface served as sorption sites, pH of 7 |
|
0.429 |
148
|
| Agrowaste derived biochars |
Impregnate ZnO on biochar derived from agricultural residual biomass, pH of 6.00–6.50 |
|
25.9 |
149
|
| Waste rocks |
Particle size of 45–75 μm, mole ratio of 1.6 for OH− to modification salts, aging time of 72 h, liquid/solid ratio of 63, 25 °C. pH of 7 |
|
5.99 |
150
|
