DingYuhao,ChengCheng,XiaoHuan,et al.Purification Efficiency of Rainwater by Bioretention Facility with Biochar-Chalcopyrite Composite Substrate[J].China Water & Wastewater,2026,42(17):123-130.
Purification Efficiency of Rainwater by Bioretention Facility with Biochar-Chalcopyrite Composite Substrate
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第42卷
Number:
第17期
Page:
123-130
Column:
Date of publication:
2026-09-01
- Keywords:
- bioretention facility; rainwater runoff; chalcopyrite; biochar; sulfur autotrophic denitrification
- Abstract:
- To enhance the purification performance of bioretention facilities for rainwater treatment, biochar-chalcopyrite was selected as a composite substrate. The pollutants leaching and adsorption characteristics of biochar and chalcopyrite were investigated, and the pollutants removal efficiencies of the bioretention facility packed with this composite substrate were evaluated. The results showed that chalcopyrite-mediated sulfur autotrophic denitrification played an important role in the nitrogen removal process. The addition of an appropriate amount of biochar prevented the formation of a metal coating layer on the chalcopyrite surface, thereby significantly improving total nitrogen removal efficiency. Under the condition of 10% chalcopyrite addition in all treatments, the experimental group amended with 10% biochar achieved a total nitrogen removal rate of (39.8±1.3)% during a 5-day drought period, which was 12.3% higher than that of the treatment without biochar addition. Furthermore, the phosphorus content of the substrate was identified as a critical factor affecting phosphorus removal performance. Since biochar acted as a phosphorus leaching source, its incorporation into the submerged zone did not exert a positive effect on PO43--P removal. In contrast, chalcopyrite exhibited strong adsorption capacity for PO43--P without phosphorus leaching, thus significantly enhancing the phosphorus removal efficiency of the facility and showing promise as a potential phosphorus-removing substrate.
Last Update:
2026-09-01