Table 2. Data of Wastewater Treatment Processes Using ZnO/Biochar Systems.
| material | feedstock | pyrolysis temp (°C) | surface area (m2/g) | pollution | initial pollution concentration (mg/dm3) | applied dose (g/dm3) | adsorption capacity (mg/g) | degradation method | removal eficiency (%) | ref |
|---|---|---|---|---|---|---|---|---|---|---|
| ZnO/biochar | crayfish shell | 600 | 236.9 | trichloroacetic acid | 50 | 2.0 | 8.6 | adsorption | (56) | |
| ZnO/biochar | camphor tree leaves | 650 | 915.0 | ciprofloxacin | 30–300 | 0.5 | 449.4 | adsorption | (55) | |
| ZnO/biochar | wheat husks and paper sludge | 500 | 183.4 | gemifloxacin | 20 | 1.5 | catalysis | 83.7 | (52) | |
| ZnO/biochar | bamboo | Methylene Blue | 20 | 2.0 | 0.823 mg/kg | adsorption + photocatalysis (UV) | 83.9 | (58) | ||
| ZnO/CMC/biochar | bamboo | Methylene Blue | 20 | 2.0 | 17.01 g/kg | adsorption + photocatalysis (UV) | 10.9 | (58) | ||
| ZnO/biochar | Corchorus capsularis | 700 | 62.2 | Methylene Blue | 20–100 | 0.5 | adsorption + photoatalysis (UV) | 99.0 | (17) | |
| ZnO/biochar | sewage sludge | 450 | 15.5 | Acid Orange 7 | 20 | 0.9 | 0.9 | photo-oxidative process (persulfate oxidation) | 93.8 | (53) |
| ZnO/biochar | bamboo shoot shell | 550 | 282.2 | ReO4– | 20–180 | 3.0 | 24.5 | adsorption | (50) | |
| ZnO/biochar | bamboo shoot shell | 550 | 282.2 | ReO4– | 120–180 | 3.0 | 25.9 | adsorption | (54) | |
| ZnO/ZnS/biochar | corn stover (Zn contaminated) | 600 | 397.4 | Pb(II) | 400 | 2.0 | 135.8 | adsorption | 35.1 | (57) |
| Cu(II) | 91.2 | 39.0 | ||||||||
| Cr(VI) | 24.5 | 21.3 | ||||||||
| ZnO-betaine- biochar | commercial biochar | 100.0 | PO4– | 10 | 3.0 | 265.5 | adsorption | 100.0 | (59) |