International Journal for Research in Applied Science & Engineering Technology (IJRASET) ISSN: 2321-9653; IC Value: 45.98; SJ Impact Factor: 7.538 Volume 10 Issue IX Sep 2022- Available at www.ijraset.com There are many metals on which studies are carried out like: As(V), Cd, Co, Cr (III), Cr(VI), Cu, Hg, Ni, Pb and Zn [44], Cu, Pb(II), Zn(II), Ni(II) [43], selenium [75]. [76] showed that the amount of Pb ions adsorbed per unit mass of Rice Husk is more than the other ions with this trend: Pb > Hg > Cd > Cu > Co > Mn > Zn > Ni. [77] Showed Pb adsorption was higher than Hg (10.86 and 3.23 mg/g, respectively). [114] showed that metallic ion adsorption by activated carbon with maximum adsorption in the order Cd(II) > Cu(II) > Zn(II) > Hg(II). The maximum adsorption capacity for each metal ion from previous works has been summarized in table:1. The values of referenced adsorption capacity should be considered as values under explicit conditions but not as maximal adsorption limits [44]. Table:1 shows that the adsorption of metal Pb is more effective than for other metals by Rice Husk modified adsorbents. Table-I The adsorption capacity for metal ion S.no. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. Adsorbate As(V) Co (II) Cr (III) Cr (VI) Hg Zn Cu Pb Zn(II) Ni(II) Ar(V) Cu(II) Pb(II) Cd(II) As(III) Se(IV) Capacity (mg/g) 615.11 0.32 1.90 164.31 66.66 30.80 31.85 120.48 35.3 26.6 90.7% 112.43 207.50 164.31 1.22 40.92 Reference [78] [79] [79] [78] [80] [81] [82] [83] [84] [85] [86] [87] [88] [89] [90] [75] Table:2 shows some of the dyes that have been effectively removed by the Rice Husk or modified Rice Husk made bioadsobant. It is clearly showing that Rice Husk has the highest capacity for adsorbing two dyes that are safranine and methylene blue. [91] Shown order of effectiveness of adsorption process by various treatments Glutradehyde < methanol < ethanol < NaOH < NH4OH < boiling < native < Triton X- 100 < heat treated < CTAB < MgSO4 < CaCl2.H2O < NaCl < HNO3 < H2SO4 < HCl. Boiling of Rice Husk showed zero effect on the biosorption capacity of the biomass. [92] Shown enhancement of sorption capacity after modification of biomass with HCl, H2SO4, and HNO3 acids. Table-II Adsorption Capacity for Dyes S.no. 1. 2. 3. 4. 5. 6. 7. 8 9. 10 Adsorbate Acid yellow 36 Methylene Blue Indigo carmine Crystal Voilet Acid yellow 17 Basic Green 4 Basic Red 2 Basic Blue 9 Safranine Direct Orange26 Capacity (mg/g) 86.9 1450-1950 4.86 (95%) 44.87 12.98 (97.97%) 511 838 312 838.00 19.96 Reference [93] [94] [95] [96] [97] [98] [99] [99] [99] [100] ©IJRASET: All Rights are Reserved | SJ Impact Factor 7.538 | ISRA Journal Impact Factor 7.894 | 597