Abstract
A new method for the concurrent treatment of Cr(VI)-contaminated wastewater and production of the useful I2 chemical was developed. The method is based on the redox reaction between Cr(VI) and I– that occurs when an aqueous wastewater solution containing Cr(VI) and I– is frozen, producing I2 and allowing for the effective removal of Cr. The redox reaction occurs primarily because of the accumulation of Cr(VI), I–, and protons in the ice grain boundaries formed during freezing (i.e., the freeze concentration effect). This effect was verified by confocal Raman spectroscopy and the experiments varying I– concentration and pH. The reduction of Cr(VI) (20 μM) was near complete after freezing at I– concentrations ≥ 100 μM, pH ≤ 3.0, and temperatures ≤ −10 °C. The freezing method (liquid cooling vs air cooling) had little effect on the final Cr(VI) reduction efficiency but had a significant effect on the Cr(VI) reduction rate. The freezing method was also tested with Cr(VI)-contaminated electroplating wastewater samples, and simultaneous Cr(VI) reduction and I2 production proceeded rapidly in a frozen solution but was not observed in an aqueous solution. Additionally, other substances in electroplating wastewater did not reduce the rate and final efficiency of Cr(VI) reduction and I2 production. Therefore, the freezing/Cr(VI)/I– system can be considered a feasible approach to water-energy nexus technology for simultaneous I2 production and Cr(VI)-contaminated wastewater treatment.
https://pubs.acs.org/doi/10.1021/acs.est.0c05322
3DGraphic work by Scapiens.
学術雑誌の表紙絵(カバーアートカバーピクチャー)を制作するサピエンススタジオです。
提供された資料をもとにオーダーメイドで製作します。
論文誌のカバーピクチャー
科学イラスト
科学3Dイメージ
学術雑誌のカバーピクチャー制作
フィギュア
いつでもご相談歓迎します。
より多くのポートフォリオをご覧になりたい場合は、以下のリンクをクリックしてご確認ください。
サピエンスの期間限定プロモーション価格を確認したい場合は、tom@scapiens.com までご連絡ください。
ラインメッセージでも連絡可能です。