Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605021
The digestate from anaerobic digestion of food waste is separated into solid residue and liquid filtrate. The filtrate retains high nutrient and carbon content, making it a viable resource for recovery. This study prepared biochar from food waste digestate residue and employed it as an electrode active material in a flow-electrode capacitive deionization (FCDI) system, with activated carbon as a control, to assess nitrogen and phosphorus removal from kitchen waste biogas slurry. ZnCl₂ modification significantly enhanced the biochar's specific surface area, adsorption capacity, capacitance, and conductivity. The optimal mass fraction of modified biochar in the electrode liquid was 7.5%. In simulated digestate, the FCDI system achieved removal efficiencies of 47.7% for NH₄⁺-N and 55.2% for reactive phosphorus (RP) over 12 hours. Performance ranking of electrode materials was activated carbon > ZnCl₂-modified biochar > unmodified biochar. In continuous operation with actual anaerobic digestion filtrate, maximum removal efficiencies were 32.2% for NH₄⁺-N and 26.2% for RP. The reduced performance in real digestate is attributed to organic foulants such as peptides and amino acids, which block ion-exchange membrane channels, increase membrane resistance, and impede ion transfer and charge transport, thereby diminishing deionization efficiency.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3768-8
Damping materials are critical for mitigating vibrations and noise across various frequencies by converting mechanical energy into thermal energy. However, achieving a simultaneous high damping capacity and high toughness remains a formidable challenge. Here, we report a supramolecular polymer (SMP) that integrates high damping and toughness through the synergistic action of dynamic hydrogen bonds and side-chain relaxation. The polymer exhibits exceptional mechanical properties: a Young's modulus of 47.08 MPa, elongation at break of 605%, and toughness of 15.24 MJ m−3. The dynamic hydrogen bonds confer dual responsiveness to strain rate and temperature, with a 6.7-fold variation in Young's modulus under different stretching rates and a five-order-of-magnitude change in storage modulus across a temperature range. Under mechanical force, the interpenetrating side chains undergo mutual friction, enabling repetitive energy dissipation. This mechanism yields superior damping ability with a loss factor (tanδ) of 1.6 at 1 Hz, demonstrating outstanding performance in vibration absorption and noise reduction. The material's design offers a promising strategy for developing high-performance damping materials that balance energy dissipation and mechanical robustness, suitable for applications in wearable electronics, protective equipment, and structural vibration control.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026030202
High nitrogen (N) inputs, low N use efficiency, and substantial greenhouse gas emissions constrain sustainable double-cropping rice production in the middle and lower reaches of the Yangtze River. To evaluate whether humic acid urea (HAU) can reconcile yield stability with N reduction and carbon mitigation, a field experiment was conducted in a double-cropping rice system. Five treatments were established: conventional urea at the recommended N rate (U), HAU at the recommended N rate (HAU), conventional urea with a 20% reduction in N input (U-20), HAU with a 20% reduction in N input (HAU-20), and a no-N control (CK). Rice yield, N uptake and utilization, and the full life-cycle carbon footprint were quantified. Results showed that HAU significantly increased double-cropping rice yield by 6.46% (early rice) and 8.76% (late rice) compared to U (P < 0.05). HAU-20 maintained yield equivalent to U, while U-20 significantly reduced yield. HAU-20 significantly improved nitrogen fertilizer apparent utilization rate, agronomic efficiency, and partial factor productivity. Specifically, apparent utilization rate increased by 9.24 percentage points (early rice) and 7.80 percentage points (late rice); agronomic efficiency increased by 18.51% and 26.69%, and partial factor productivity by 22.79% and 25.58% for early and late rice, respectively (P < 0.05). Life-cycle carbon footprint was significantly reduced by 26.25% (early rice) and 40.38% (late rice) under HAU-20 compared to U, with per-unit product carbon footprint reduced by 0.22 t CO2-eq·t−1 and 0.86 t CO2-eq·t−1, respectively. The reduction was primarily attributed to decreased CH4 and N2O emissions: early rice CH4 and N2O cumulative emissions decreased by 28.92% and 44.34%, and late rice by 44.46% and 63.85% (P < 0.05). In conclusion, HAU with 20% N reduction sustains yield, enhances N use efficiency, and significantly lowers carbon footprint, offering a viable path for green and low-carbon double-cropping rice production.