Search

Selective capture of radioactive 99TcO 4 - from highly alkaline nuclear waste is highly desirable for environmental remediation and waste disposal. However, the combined features of adsorbents with excellent chemical stability and high capture selectivity for 99TcO 4 - have not yet been achieved. Herein, we report an ultra-stable 3D pyridinium salt-based polymeric network (TMP-TBPM) nanotrap with remarkable radiation, acid and base stability for selective capture of ReO 4 - via hydrophobic engineering and steric hindrance, a non-radioactive surrogate of 99TcO 4 -. The batch capture experiments show that TMP-TBPM has high capture capacity (918.7 mg g−1) and fast sorption kinetics (94.3 % removal in 2 min), which can be attributed to the high density of pyridinium salt-based units on the highly accessible pore channels of 3D interconnected low-density skeleton. In addition, the introduction of abundant alkyl and tetraphenylmethane units into the 3D framework not only greatly enhanced the hydrophobicity and stability of TMP-TBPM, but also significantly improved the affinity toward 99TcO 4 -/ReO 4 -, enabling reversible and selective capture of 99TcO 4 -/ReO 4 - even under highly alkaline conditions. This study exhibits the great potential of 3D pyridinium salt-based polymeric network nanotrap for 99TcO 4 -/ReO 4 - capture from highly alkaline nuclear waste, providing a new strategy to construct high-performance cationic polymeric sorbents for radioactive wastewater treatment. [Display omitted] • Robust 3D pyridinium salt-based polymeric network for selective capture of ReO 4 −. • The first example of 3D pyridinium salt-based polymeric network for ReO 4 - capture. • TMP-TBPM has excellent capture performance and high selectivity for 99TcO 4 -/ReO 4 -. • TMP-TBPM can selectively and reversibly capture 99TcO 4 -/ReO 4 - under alkaline conditions. [ABSTRACT FROM AUTHOR]

Three-stage operation system (3S A–C system) combining adsorption and CDI is efficient in recovering liquid fertilizers from wastewater and is a promising technology for simultaneously addressing nutrient crises and environmental pollution. • Hydrogel adsorbents have good separation ability for metal cation and anion. • Hydrogel adsorbents showed little removal of nutrients. • 3S A–C system was presented for nutrient recovery and wastewater treatment. • Plants using recovered liquid fertilizers revealed excellent values. The recovery of nitrogen (N) and phosphorus (P) from wastewater is of great importance in addressing the global nutrient crisis. The limitations of existing methods require the development of effective technology. Here, two different hydrogel adsorbents were fabricated with good separation ability for metal cation (M+) and metal anion (M−) but showed little removal of nutrients. Based on the materials, a novel three-stage operation system combining adsorption and capacitive deionization (CDI) technology was presented for nutrient recovery and wastewater treatment. In the first two stages, mixed metals in wastewater were successfully separated (Cu2+: 144.6 mg/g; Cr 2 O 7 2−: 167.0 mg/g), and nutrients were retained (N and P < 1 mg/g). In the third stage, the residual trace metal ions in the solution were removed (2.0 mg/L to N/A), and the nutrients were enriched through electroadsorption and desorption processes by CDI. Plants using recovered liquid fertilizers revealed similar values for height, root length, and chlorophyll compared with those obtained using actual fertilizers. The results indicated that this novel three-stage operation system (3S A–C system) combining adsorption and CDI is efficient in recovering liquid fertilizers from wastewater and is a promising technology for simultaneously addressing nutrient crises and environmental pollution. [ABSTRACT FROM AUTHOR]