New Separation Material Obtained from Waste Rapeseed Cake for Copper(II) and Zinc(II) Removal from the Industrial Wastewater

Abstract

Rapeseed cake biochar was produced by pyrolysis at 973.15 K for 2 h, in anoxic conditions. Porous structure, specific surface area and die composition of waste rapeseed cake were studied. The specific surface area of rapeseed cake biochar was 166.99 m2·g−1, which exceeded most other biochars reported, which made it an attractive material during wastewater treatment. The SEM study of the material demonstrated a large number of pores formed on the cell wall, with a pore volume Vp = 0.08 cm3·g−1. The results indicate lower aromaticity and increased polarity of the tested material. The observed H/C ratio of 0.29 is similar for activated carbons. Furthermore, sorption properties of the obtained carbon material in relation to copper(II), zinc(II) and arsenic(III) ions were also studied. Moreover, the impact of parameters such as: sorption time, temperature, adsorbate concentration, sorbent mass and solution pH on the efficiency of the adsorption process of the studied cations was also examined. Sorption studies revealed that the sorbent can be successfully used for the separation of Cu(II) and Zn(II) from technological wastewaters. Rapeseed cake biochar exhibits superior Cu(II) adsorption capacity (52.2 mg·g−1) with a short equilibrium time (6 h). The experimental data collected show a high selectivity of the obtained carbon material relative to copper(II) and zinc(II) ions in the presence of arsenic(III) ions.

Turning Food Protein Waste into Sustainable Technologies

“…Yet, there are a few reports on applying food waste and byproducts containing proteins directly for water purification. − For instance, functionalized soy waste biomass after oil extraction was employed for removing Pb, Cu, and Ni from water. Compared to other adsorbents, however, the obtained adsorption capacities were lower .…”

“…Although the adsorption capacities for Cu and Zn increased slightly, the carbonization process at high temperatures cannot be considered to be sustainable due to the high carbon footprint. 606 In another work, human hair, dog hair, chicken feathers, and degreased wool as four typical waste keratin fibers were used directly as adsorbents for the simultaneous removal of eight metal ions (Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb) from water. 614 The removal performance efficiency was in the order of degreased wool > chicken feathers > human hair > dog hair.…”

“…It was also pyrolyzed at 700 °C to form a biochar adsorbent. Although the adsorption capacities for Cu and Zn increased slightly, the carbonization process at high temperatures cannot be considered to be sustainable due to the high carbon footprint …”

Removal of Heavy Metal Ions from One- and Two-Component Solutions via Adsorption on N-Doped Activated Carbon

“…As far as copper species are concerned, in the solutions of pH close to 6, the dominant species are Cu 2+ ions, whereas in the pH range between 6 and 10, cationic species like CuOH + and Cu(OH) 2 2+ are observed [29]. At higher pH values (7)(8)(9)(10)(11)(12), precipitation of copper(II) hydroxide takes place, while at pH above 9, anionic forms, i.e., Cu(OH) 3 − and Cu(OH) 4 2− , are also possible. In our experiment, the initial water solutions of pH higher than 6 grew increasingly turbid with increasing pH; moreover, in the neutral and basic environments, a sediment appeared on the bottom of the flask.…”

“…Phosphorus-enriched carbon materials show excellent cation-exchanging properties. In turn, nitrogen-doped activated carbons are very effective in H 2 S, SO 2 , CO 2 , NO 2 , or VOCs' removal from gas stream as well as in the removal of copper and lead ions, amines, phenol, and its derivatives' adsorption from aqueous solutions [10][11][12][13][14].…”