Assessing the impacts of COVID-19 pandemic on the environment: A correlation or causation?

The outbreak of the COVID-19 pandemic has severely impacted human lives, human activities, and the world economy. In response to curb its spread, pandemic risk reduction measures such as mass lockdowns, extensive travel bans, and mass quarantine were imposed globally. While the imposition of these measures has negatively impacted the world economy, its impacts on the environment could be described as a gain, as the ecosystem appears to be given a rebirth. During the mass lockdown (February to April 2020), air pollution worldwide has dropped significantly precisely, with a decline in the emission and concentration of pollutants. The emission of CO2 globally declined by 8.8% during the first half of 2020. Additionally, both surface and underground water quality have been improved due to reduced industrial activities. Also, there has been an increase in carbon sink due to the decline in global bush fires. In a nutshell, the study recommends that as the world economy recovers from the impact of COVID-19, world leaders and policymakers should focus on measures that improve the environment and the ecosystem, such as the adoption of the green economy, production and use of fuel cells cars instead of gasoline cars and treating industrial effluents to WHO recommended levels before discharging them into water bodies.&nbsp;</p

EDTA-Cross-Linked β‑Cyclodextrin: An Environmentally Friendly Bifunctional Adsorbent for Simultaneous Adsorption of Metals and Cationic Dyes

The discharge of metals and dyes poses a serious threat to public health and the environment. What is worse, these two hazardous pollutants are often found to coexist in industrial wastewaters, making the treatment more challenging. Herein, we report an EDTA-cross-linked β-cyclodextrin (EDTA-β-CD) bifunctional adsorbent, which was fabricated by an easy and green approach through the polycondensation reaction of β-cyclodextrin with EDTA as a cross-linker, for simultaneous adsorption of metals and dyes. In this setting, cyclodextrin cavities are expected to capture dye molecules through the formation of inclusion complexes and EDTA units as the adsorption sites for metals. The adsorbent was characterized by FT-IR, elemental analysis, SEM, EDX, ζ-potential, and TGA. In a monocomponent system, the adsorption behaviors showed a monolayer adsorption capacity of 1.241 and 1.106 mmol g^–1 for Cu­(II) and Cd­(II), respectively, and a heterogeneous adsorption capacity of 0.262, 0.169, and 0.280 mmol g^–1 for Methylene Blue, Safranin O, and Crystal Violet, respectively. Interestingly, the Cu­(II)–dye binary experiments showed adsorption enhancement of Cu­(II), but no significant effect on dyes. The simultaneous adsorption mechanism was further confirmed by FT-IR, thermodynamic study, and elemental mapping. Overall, its facile and green fabrication, efficient sorption performance, and excellent reusability indicate that EDTA-β-CD has potential for practical applications in integrative and efficient treatment of coexistenting toxic pollutants

Green Synthesis of Magnetic EDTA- and/or DTPA-Cross-Linked Chitosan Adsorbents for Highly Efficient Removal of Metals

The present paper describes a green and economic approach to explore EDTA/DTPA-functionalized magnetic chitosan as adsorbents for the removal of aqueous metal ions, such as Cd­(II), Pb­(II), Co­(II), and Ni­(II). EDTA and DTPA play roles not only as cross-linkers but also as functional groups in chelating metal ions. The morphology, structure, and property of the magnetic adsorbents were characterized by SEM, TEM, XRD, EDS, FT-IR, TGA, and VSM techniques. Their adsorption properties for the removal of metal ions by varying experimental conditions were also investigated. The kinetic results revealed that the transportation of adsorbates from the bulk phase to the exterior surface of adsorbents was the rate-controlling step. The obtained maximum adsorption capacities of magnetic adsorbents for the metal ions ranged from 0.878 to 1.561 mmol g^–1. Bi-Langmuir and Sips isotherm models fitting well to the experimental data revealed the surface heterogeneity of the adsorbents. More significantly, the resulting EDTA-/DTPA-cross-linked magnetic chitosan adsorbents had selectivity to Cu, Pb, Zn, Fe, and Ni from a practical industrial effluent. Furthermore, their good reusability and convenient magnetic separation makes them viable alternatives for real wastewater treatment