Evaluating the effectiveness of ecological restoration of hard bank rivers: a case study from Shedu river port, China

The main aim of this study was to evaluate the performance of ecological restoration of hard bank rivers at the Shedu river port in Yixing city, China. The pre-fabricated porous concrete templates were covered on the hard bank surface in order to reduce the negative impact of hard bank on the river water quality. The results showed that the microbial community, population, and the water purification ability of biofilm were affected by the seasonal changes. The biofilm growing on the surface of the porous concrete templates showed the highest population (3.27 × 10⁷ cell cm⁻²) and a healthy microbial community structure during the autumn season. The chemical oxygen demand (COD), NH₃-N, NO₃-N, total nitrogen (TN), and total phosphorus (TP) removal during the autumn season was 48.6, 39.8, 40.2, 42.6 and 35.8%, respectively. During the one-year experimental period, biomass (0.3794 ± 0.0040 g) of Barnyard grass grew on the porous concrete templates. A total of seven insects and two faunal species were also observed on the porous concrete templates. The good results from this study showed that the pre-fabricated porous concrete templates are very efficient for river water purification.