Synthesis of Copper Nanoparticles from Cu2+-Spiked Wastewater via Adsorptive Separation and Subsequent Chemical Reduction

Abstract

Copper in ionic form (Cu2+) should be removed from wastewater because of its harmful effects on human health. Meanwhile, Cu-metal nanoparticles (Cu0 NPs) are widely used in various applications such as catalysts, optical materials, sensors, and antibacterial agents. Here, we demonstrated the recovery of Cu2+ from wastewater and its subsequent transformation into Cu0 NPs, a value-added product, via continuous adsorption followed by chemical reduction by hydrazine. To separate and enrich Cu2+ from wastewater, a biosorbent that exhibits excellent selectivity and adsorption capacity toward Cu2+, i.e., polyethyleneimine-grafted cellulose nanofibril aerogel (PEI@CNF), was packed into a column and used to treat 20 mg/L Cu2+ wastewater at a flow rate of 5 mL/min. The Cu2+ adsorption reached equilibrium at 72 h, and the Cu2+-saturated column was eluted using 0.1 M of HCl. After five consecutive elutions of Cu2+ from the adsorbent column, a Cu2+-enriched solution with a concentration of 3212 mg/L was obtained. The recovered Cu2+ concentrate was chemically reduced to obtain Cu0 NPs by reaction with hydrazine as a reductant in the presence of sodium dodecyl sulfate (SDS) as a stabilizer. The solution pH and hydrazine/Cu2+ ratio strongly affected the reduction efficiency of Cu2+ ions. When 0.1 M of SDS was used, spherical 50–100 nm Cu0 NPs were obtained. The results demonstrate that Cu2+-spiked wastewater can be converted into Cu0 NPs as a value-added product via adsorption followed by chemical reduction.

Features of Copper and Gold Nanoparticle Translocation in Petroselinum crispum Segments

“…Such a complicated dependence between the concentration of NPs used for watering and the obtained response reaction may be caused by the aggregation ability of NPs; however, this needs to be studied separately, and it was not an objective of the present study. It is known that the effects of different NPs on plant systems are determined by several factors, such as the chemical nature of the particles, their size, and reactivity, but the most important is the nanoparticle concentration, which comes into contact with the plant [36,37]. Depending on the combinations of the mentioned factors but also on the plant species, the effects of nanoparticles can be either inhibitory or stimulating [50].…”

“…To ensure that the data obtained in the present study were comparable with literature values, the effects of the same concentrations of CuNPs and AuNPs on the Petroselinum crispum were investigated. In addition, the effects of low concentrations (1 and 5 mg/L), which are far more likely to be present in wastewater, were studied [37]. For the experiments, initial NP solutions were diluted with distillate water to obtain solutions with the following concentrations: 1, 5, 10, 50, and 100 mg/L.…”

Latent Benefits and Toxicity Risks Transmission Chain of High Dietary Copper along the Livestock–Environment–Plant–Human Health Axis and Microbial Homeostasis: A Review

“…Thus, methods modification and use of composites, polymers, and NPs to adsorb excess Cu in water have become a research hot spot. The adsorbed Cu can also be made into NP materials to promote sustainable utilization. , …”

“…The adsorbed Cu can also be made into NP materials to promote sustainable utilization. 109,110 4. COPPER AND PLANTS 4.1.…”