Engineered Biofiltration Processes for Microcystin Removal in Drinking Water: A Structured Enzyme-Kinetic Modeling Approach

有害的藻华是由藻类生长引起的，藻类生长产生一种称为微囊藻毒素的毒素。微囊藻毒素与肝癌有关，很难使用传统的饮用水处理方法进行治疗。本项目研究生物过滤（“生物过滤”）在饮用水处理过程中去除微囊藻毒素。生物过滤依赖于砂滤器中的天然细菌群落来降解微囊藻毒素。本研究主要针对高变环境下的饮用水处理厂，建立稳定的生物过滤处理系统。该项目将开发模型来预测生物过滤处理行为，目标是使生物过滤成为一种有效的处理工艺，以保护国家的饮用水供应。该教育计划将培养学生在跨学科的科学和工程，以提高科学文献和国家的技术技能。该项目的目标是开发一个预测性的理解的环境和操作因素的微生物群落动态和微囊藻毒素生物降解在生物过滤系统。具体目标是：1）定量和比较悬浮和固定化微囊藻毒素降解菌群（MC-DBC）在工程反应器中的稳态生长特性; 2）确定提高这些反应器系统中水性和生物膜MC-DBC的活性和稳定性的环境和水力条件; 3）研究和比较每个MC-DBC内的微生物群落结构和功能，以获得对MC-DBC内微生物群落相互作用的整体理解。这项研究将联合收割机培养和遗传微生物学研究与命运和运输的数值模拟相结合，以优化生物过滤系统中藻类毒素去除的管理。各种营养条件对MC-DBC生长和降解动力学的影响将直接通知生物刺激实践，以改善有害藻华期间的生物降解动力学。将实验观察结果与机械数值模型的发展相结合，将突出酶诱导动力学、酶稀释或酶调节对生物过滤效率的相对重要性。数值模型模拟将通过评估在广泛的操作条件下去除藻类毒素的可行性和处理能力来提高我们设计生物过滤系统的能力。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Harmful algal blooms are caused by the growth of algae that produce a toxin known as microcystin. Microcystin is linked to liver cancer and is difficult to treat using conventional drinking water treatment practices. This project investigates biological filtration ("biofiltration") to remove microcystin during drinking water treatment. Biofiltration relies on natural communities of bacteria in sand filters to degrade microcystin. This research focuses on establishing a stable biofiltration treatment system under the highly variable environment of a drinking water treatment plant. The project will develop models to predict biofiltration treatment behavior with the goal of making biofiltration an effective treatment process to protect the Nation's drinking water supply. The educational program will train students in cross-disciplinary science and engineering to improve the scientific literature and the technological skills of the Nation.The goal of this project is to develop a predictive understanding of the environmental and operational factors governing microbial community dynamics and microcystin biodegradation in biofiltration systems. The specific objectives are to: 1) quantify and compare the steady-state growth characteristics of suspended and immobilized microcystin-degrading bacterial consortia (MC-DBC) in engineered reactors; 2) define environmental and hydraulic conditions that enhance the activity and stability of the aqueous and biofilm MC-DBC in these reactor systems; and 3) investigate and compare the microbial community structure and function within each MC-DBC to gain a holistic understanding of the microbial community interactions within MC-DBC. This research will combine culture based and genetic microbiological investigations with numerical simulations of fate and transport to optimize management of algal toxin removal in biofiltration systems. The effects of various nutrient conditions on the growth and degradation kinetics of MC-DBC will directly inform biostimulation practices to improve biodegradation kinetics during harmful algal bloom periods. Integration of experimental observations with the development of a mechanistic numerical model will highlight the relative importance of enzyme induction kinetics, enzyme dilution, or enzyme regulation to biofiltration efficiency. The numerical model simulations will advance our ability to design biofiltration systems by assessing the feasibility and treatment capability of algal toxin removal over a wide range of operating conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.