School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, PR China.
Ecotoxicol Environ Saf. 2021 Jan 1;207:111546. doi: 10.1016/j.ecoenv.2020.111546. Epub 2020 Oct 30.
Degradation solutions containing atrazine need to be further purified before they are discharged into the aquatic environment. With the objectives of evaluating removal capacity of the microalga Chlorella sp. toward atrazine in degradation solutions and toxicity of the degradation products, we investigated the removal efficiency (RE) and bioaccumulation of atrazine in the microalgae after an 8 d exposure to diluted degraded solutions containing 40 μg/L and 80 μg/L of atrazine as well as degradation products in the present study. Moreover, pure atrazine solutions with similar concentrations were simultaneously inoculated with the microalgae in order to distinguish the influence of the products. The photocatalytic degradation results showed that 31.4% of atrazine was degraded after 60 min, and three degradation products, desisopropyl-atrazine (DIA), desethyl-atrazine (DEA), and desethyl-desisopropyl-atrazine (DEIA) were detected. After an 8-d exposure, 83.0% and 64.3% of atrazine were removed from the degraded solutions containing 40 μg/L and 80 μg/L of atrazine, respectively. In comparison with the control, i.e., pure atrazine solution with equal concentration, Chlorella sp. in the degraded atrazine solution showed lower RE and growth rate. The photosynthetic parameters, especially performance index (PI), clearly displayed the differences between treatments. The values of PI of Chlorella sp. cultured in degradation atrazine for 8 days were significantly lower (P < 0.01) than that in the corresponding pure atrazine, suggesting potential inhibitory effect of degradation products on the microalgae. Atrazine and the degradation products inhibited algal photosynthesis via depressed light absorption and electron transport, and reduced utilization of light energy via energy dissipation. Our results demonstrated that microalgae Chlorella sp. had an encouraging atrazine removal potential and the degradation products of atrazine may inhibit algal growth and removal capability. This study may be useful for the application of microalgae in herbicide wastewater treatment and understanding algal removal of atrazine in natural aquatic environment.
含莠去津的降解溶液在排放到水生环境之前需要进一步净化。本研究的目的是评估微藻小球藻对降解溶液中莠去津的去除能力以及降解产物的毒性，我们研究了在 8d 暴露于含有 40μg/L 和 80μg/L 莠去津以及降解产物的稀释降解溶液后，微藻对莠去津的去除效率（RE）和生物累积。此外，还同时在含有相似浓度的纯莠去津溶液中接种微藻，以区分产物的影响。光催化降解结果表明，60min 后莠去津降解了 31.4%，检测到三种降解产物：异丙基去莠津（DIA）、去乙基莠去津（DEA）和去乙基异丙基去莠津（DEIA）。8d 暴露后，分别从含 40μg/L 和 80μg/L 莠去津的降解溶液中去除了 83.0%和 64.3%的莠去津。与对照（即等浓度的纯莠去津溶液）相比，在降解莠去津溶液中培养的小球藻的 RE 和生长速率较低。光合参数，特别是性能指数（PI），清楚地显示了处理之间的差异。在 8d 培养在降解莠去津中的小球藻的 PI 值明显低于（P<0.01）相应的纯莠去津，表明降解产物对微藻可能有抑制作用。莠去津和降解产物通过抑制光吸收和电子传递来抑制藻类光合作用，并通过能量耗散来降低光能的利用。研究结果表明，微藻小球藻对莠去津具有令人鼓舞的去除潜力，莠去津的降解产物可能会抑制藻类生长和去除能力。本研究可为微藻在除草剂废水处理中的应用以及理解藻类在自然水生态环境中对莠去津的去除提供参考。
