SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4138-5
Electrocoagulation (EC) has emerged as a promising electrochemical technology for wastewater treatment, offering distinct advantages over conventional chemical coagulation and membrane processes. This review systematically summarizes recent advancements in EC, focusing on the underlying mechanisms, key operating parameters, and diverse technical applications. The EC process involves three stages: electrolytic oxidation and in-situ coagulant formation, destabilization of contaminants, and floc formation. Unlike chemical coagulation, EC requires no external chemical additives, and process control is achieved by adjusting current density, voltage, or electrode materials, enabling adaptation to varying wastewater qualities. The review highlights the influence of dissolved organic matter (DOM) on EC efficiency, as clarified by Luo et al. (Water Research, 2025). Furthermore, it discusses reactor design innovations, including continuous-flow and cascade-type configurations, and the role of current waveforms in mitigating electrode passivation. The integration of EC with membrane bioreactors and forward osmosis is also examined, demonstrating enhanced treatment performance and fouling mitigation. Key challenges, such as energy consumption and electrode scaling, are addressed, along with future research directions. This comprehensive analysis provides a critical framework for optimizing EC systems and scaling them for industrial wastewater treatment, emphasizing the need for holistic reactor design and process integration to achieve sustainable water reuse.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025111302
High-concentration chloride ions (Cl−) in industrial wastewater cause severe corrosion and environmental hazards. Conventional removal methods suffer from low efficiency, high cost, and difficulty in product recovery. This study fabricated porous metallic bismuth-based blocks (Bi-PM) via 3D printing, combining chemical precipitation with additive manufacturing. Systematic evaluation of Cl− removal under varying pH and light irradiation revealed that at pH 0.1 and 0.5, dark-condition efficiencies were 53.6% and 31.0%, respectively, increasing to 69.3% and 38.1% under light. Radical trapping identified photogenerated holes as the primary active species, oxidizing metallic Bi to release Bi3+ and enhance precipitation. At pH 0.5, Bi-PM exhibited balanced efficiency and structural stability; over five cycles, average removal efficiency was 25% in darkness versus 41.2% under light, with superior stability under illumination. XRD and SEM confirmed abundant BiOCl formation on the surface under light, mitigating Bi loss. This approach ensures high chloride removal while minimizing material degradation, offering a novel pathway for industrial wastewater treatment.
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.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3726-3
Olfactory displays remain the least commercialized modality in immersive virtual reality (VR) despite olfaction's disproportionate influence on emotion, memory consolidation, and hazard detection. This review classifies reported olfactory display mechanisms into airflow-based, atomization-based, and heating-based architectures, detailing their electrical characteristics, scent delivery latency, and residual odor management. Stationary, portable, and wearable form factors are systematically compared, with emphasis on structural configurations and operational constraints. Recent noninvasive electrical stimulation approaches for inducing olfactory percepts—including transethmoid olfactory bulb stimulation, subdural electrode activation of the olfactory tract, and direct orbitofrontal cortex stimulation—are examined alongside their clinical evidence base. The analysis identifies a persistent trade-off between scent switching speed and device miniaturization: airflow systems achieve rapid clearing but require bulky pumps and long transmission paths, while atomization and heating approaches reduce form factor at the cost of thermal management and nozzle clogging. Driven by flexible electronics, MEMS, and AI, the field is converging toward flexible, wearable, miniaturized, and intelligent olfactory displays. However, quantitative benchmarks for scent delivery latency, cross-contamination rates, and long-term reliability remain sparse, impeding standardization and commercial translation. This review consolidates the empirical foundation needed to prioritize engineering efforts and establish performance metrics for next-generation olfactory interfaces.