Abstract This study aimed to identify low‐cost substrates for constructed wetlands (CWs) and enhance their treatment performance. Waste red bricks and concrete were selected and modified using acid (HCl) and alkali (NaOH) treatments to promote the resource utilization of construction and demolition waste (CDW). The results indicated that both materials exhibited rapid initial adsorption, with an adsorption equilibrium contact time of 36 h and an optimal dosage of 5.5 g/100 mL. After NaOH modification (0.5 mol/L), both substrates demonstrated substantially higher removal efficiencies than the acid‐modified or unmodified materials. Specifically, NaOH‐modified red bricks showed superior removal efficiencies for TN (82%), NH 4 + ‐N (90%), COD (86%), and TP (93%) compared to modified concrete (77%, 80%, 74%, and 79%, respectively). Brunauer Emmett Teller (BET), X‐ray diffraction (XRD), and inductively coupled plasma optical emission spectrometry (ICP‐OES) analyses revealed that NaOH treatment increased the specific surface area and pore volume of the materials, while causing only minor changes in elemental composition. Simulated constructed wetland experiments indicated that a 6:4 mixture of red bricks and concrete achieved satisfactory pollutant removal while minimizing economic cost. This study demonstrates the feasibility of converting CDW into efficient and low‐cost substrates for CWs, offering a promising pathway for its resource utilization.
Li et al. (Thu,) studied this question.