The impact of Acorus calamus on the removal of cadmium-sulfamethoxazole combined pollution in wetlands and its physiological and biochemical responses

Cadmium (Cd) and sulfamethoxazole (SMX) have attracted extensive attention due to their high detection frequency and high concentration in water bodies. In order to explore the remediation potential of Acorus calamus on Cd-sulfamethoxazole (Cd-SMX) pollution, a greenhouse simulation experiment was conducted to study the removal effect of Acorus calamus on the combined pollution of Cd (initial mass concentration 0.5 mg/L) and SMX (initial mass concentration 5 mg/L) and the physiological response of Acorus calamus to Cd-SMX pollution stress. The results showed that within the 28-day cultivation period, Acorus calamus planting significantly enhanced the removal effect of Cd-SMX in wetlands (p < 0.05). After planting Acorus calamus, the degradation rate of SMX increased by 18.34%, and the removal rate of Cd increased by 29.87% (28 days). There were no significant differences in leaf fresh weight, plant height and root length, MDA, SOD and POD contents of Acorus calamus under Cd-SMX stress compared with the blank control group (P > 0.05), indicating that Acorus calamus has good tolerance to Cd-SMX pollution. Chlorophyll content was significantly positively correlated with Cd and SMX content in the environment, indicating that Cd and SMX at the experimental concentrations can promote plant photosynthesis; Cd and SMX content in Acorus calamus roots was significantly higher than that in leaves, indicating that Acorus calamus has a strong retention effect on Cd and SMX. In summary, under the experimental concentrations, Acorus calamus showed good growth potential and had a certain tolerance to Cd-SMX pollution.