###### Abstract  
This study presents the development and evaluation of an innovative modular ecological transition zone system for riparian restoration. Through systematic optimization, we developed a C25-grade ecological concrete module (100 mm \(\times\) 100 mm \(\times\) 100 mm) with a specialized cavity design (\(\varphi\)61 mm \(\times\) H60 mm) that achieves optimal balance between structural integrity (20-30 MPa compressive strength) and environmental functionality (>15% porosity, >1 \(\times\) 10\({}^{-4}\) cm s\({}^{-1}\) permeability). The module incorporates precisely calibrated proportions of cement (378 kg m\({}^{-3}\)), reinforcing agent (12 kg m\({}^{-3}\)), aggregate (1650 kg m\({}^{-3}\)), and water (137 L m\({}^{-3}\)), creating a robust platform for environmental remediation. The system was evaluated at two scales: module-scale experiments in 25 L containers (833:1 mL g\({}^{-1}\) ratio) and kinetic studies (10:1 mL g\({}^{-1}\) ratio), revealing a sophisticated three-phase removal process. The initial rapid surface adsorption phase (0-4 h) achieved removal rates of 0.28-0.42 mg g\({}^{-1}\) h\({}^{-1}\), followed by pore diffusion (4-24 h) and chemical fixation phases, with removal patterns effectively modeled using a modified pseudo-second-order equation. The system demonstrated exceptional heavy metal removal capabilities across varying concentration ranges, achieving removal efficiencies of 95.6% for Pb\({}^{2+}\) ions, 92.3% for Cd\({}^{2+}\) ions, 84.2% for Cr\({}^{3+}\) ions, 89.7% for Cu\({}^{2+}\) ions, and 84.8% for Zn\({}^{2+}\) ions under optimal conditions. Performance remained robust across two orders of magnitude in concentration ranges, with removal efficiencies maintaining above 80% at both experimental scales. The modular design's cost-effectiveness is demonstrated through material costs of USD 45-60 m\({}^{-3}\), with operational costs 40-60% lower than conventional systems. This research provides a practical, cost-effective solution for riparian zone restoration, combining structural durability with efficient pollutant removal capabilities while maintaining consistent performance across varying environmental conditions. ecological concrete; modular design; heavy metal removal; riparian restoration licenses/by/4.0/. 2025, 15, 3721. 2025 15 3721.  
limits for heavy metals [2], monitoring data from major river systems shows widespread contamination. [PERSON] et al. (2018) reported that 42% of monitored sites exceeded the standard limit of 0.005 mg L\({}^{-1}\) for cadmium (Cd), while 35% exceeded the 0.01 mg L\({}^{-1}\) threshold for lead (Pb) [3]. The situation is particularly severe in industrial zones, where [PERSON] et al. (2022) documented chromium (Cr) and zinc (Zn) levels reaching up to 10 times the permitted standards of 0.05 mg L\({}^{-1}\) in riparian sediments [4]. The environmental and health implications of this contamination are substantial. Long-term ecological monitoring has revealed a 30-50% decline in aquatic biodiversity in heavily contaminated riparian zones over the past decade [5]. Moreover, these pollutants can accumulate in the food chain, with studies showing elevated heavy metal concentrations in fish and aquatic plants commonly consumed by humans [6]. Economic assessments indicate that water pollution-related health costs exceed USD 50 billion annually in developing countries alone [7]. Conventional remediation approaches, including chemical precipitation, ion exchange, and adsorption, have shown limited success in addressing this complex challenge. While these methods can achieve removal efficiencies of 60-85% for individual metals, their effectiveness dramatically decreases when dealing with mixed metal contamination [8]. Field studies have shown that traditional treatment systems struggle to maintain consistent performance under variable pollutant loads, with efficiency dropping by up to 40% during peak contamination events [9].