Immobilization and in-situ biodegradation of microcystins using engineered biofiltration for drinking water production

使用工程生物过滤对微囊藻毒素进行固定化和原位生物降解用于饮用水生产

• 批准号: 2128480
• 负责人: Chenyang Jiang
• 金额: $ 33.54万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2128480&HistoricalAwards=false
• 关键词: Immobilization; situ; biodegradation; microcystins; using

Harmful algal blooms (HABs) in surface waters are caused by massive growth of algae often with associated toxins called ‘cyanotoxins’ produced by cyanobacteria. HABs threaten the Nation’s water supplies and cost millions of dollars per year in responses and lost revenue. Microcystin is the most common cyanotoxin produced by cyanobacteria blooms in freshwater lakes. Microcystin is highly toxic to humans and animals, and large concentrations have resulted in the temporary shutdown of an entire municipal drinking water system. Despite large investments in HAB mitigation, cyanotoxins continue to be a great challenge for safe drinking water production. The goal of this project is to address this challenge through the development of novel engineered nanomaterials to remove microcystin from drinking water and break it down to non-toxic products. The engineered nanomaterials will be fabricated using biochar (charcoal produced from plants) with specific modified surfaces to trap microcystin and remove it from water. Special bacteria then degrade the toxins trapped on the surface in a microscale bioreactor. Successful development of this ‘trap and destroy’ technology has potential to transform our ability to remove cyanotoxins from drinking water. Additional societal benefits result from the training of graduate students in multidisciplinary science to enhance the Nation’s STEM workforce.The goal of this research project is to develop new three-dimensional net-like functional hydrogel-biochar composite materials to selectively capture and degrade microcystin in drinking water. This goal will be achieved through four specific objectives to: i) develop materials for selective microcystin adsorption through complementary pore size, ion exchange, and π-π electron donor-acceptor interactions; ii) optimize microcystin uptake kinetics through strong electrostatic interactions or ion exchange with positively charged quaternary ammonium groups; iii) encapsulate microcystin-degrading bacterial consortia into functional biomaterials to enable in situ biodegradation of microcystin; and iv) remove clogging and regenerate adsorbent binding sites in the biofiltration system through a chemically enhanced backwash. Novel advances in this research include the synthesis of a new cationic poly(diallyldimethylammonium-co-styrene)-grafted cellulose nanofibril and biochar composite, elucidation of microcystin adsorption/biodegradation mechanisms using Thomas, Adams-Bohart, and CXTFIT models, and sorption site characterization using density functional theory. The viability and function of microcystin-degrading bacteria encapsulated in biomaterial composites will be evaluated by coupling scanning electron microscope and culturing methods. Reverse transcriptase quantitative PCR, 16S rRNA gene sequencing, and metagenomics analysis will be used to develop genotypic insight into microcystin degradation mechanisms. Successful completion of this research will help advance water treatment technologies by integrating novel targeted biodegradation with new functional nanomaterials as an effective water treatment technology. Societal benefits will result from effective and low-cost treatment technology for microcystin removal to protect the Nation’s drinking water supplies from HABs.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.

地表水中的有害藻华（HABs）是由藻类大量生长引起的，通常伴随着由蓝藻产生的称为“蓝藻毒素”的相关毒素。有害藻华威胁着国家的水供应，每年花费数百万美元用于应对和损失收入。微囊藻毒素是淡水湖中最常见的蓝藻毒素。微囊藻毒素对人类和动物都有剧毒，高浓度的微囊藻毒素曾导致整个市政饮用水系统暂时关闭。尽管在减少有害藻华方面进行了大量投资，但蓝藻毒素仍然是安全饮用水生产的一大挑战。该项目的目标是通过开发新型工程纳米材料来解决这一挑战，以去除饮用水中的微囊藻毒素并将其分解为无毒产品。这种工程纳米材料将使用生物炭（植物产生的木炭）制造，其表面经过特殊修饰，可以捕获微囊藻毒素并将其从水中去除。然后，特殊的细菌在微型生物反应器中降解滞留在表面的毒素。这种“诱捕和破坏”技术的成功开发有可能改变我们从饮用水中去除蓝藻毒素的能力。多学科科学研究生的培训带来了额外的社会效益，以增强国家的STEM劳动力。本研究项目的目标是开发新的三维网状功能水凝胶-生物炭复合材料，以选择性捕获和降解饮用水中的微囊藻毒素。这一目标将通过四个具体目标来实现：i)通过互补孔径、离子交换和π-π电子供体-受体相互作用来开发选择性微囊藻毒素吸附的材料；Ii)通过强静电相互作用或与带正电的季铵基离子交换优化微囊藻毒素摄取动力学；Iii)将微囊藻毒素降解菌群封装到功能性生物材料中，以实现微囊藻毒素的原位生物降解；iv)通过化学强化反冲洗去除生物过滤系统中的堵塞和再生吸附剂结合位点。本研究的新进展包括合成一种新的阳离子聚（二烯基二甲胺-co-苯乙烯）接枝纤维素纳米纤维和生物炭复合材料，利用Thomas、Adams-Bohart和CXTFIT模型阐明微囊藻毒素的吸附/生物降解机制，以及利用密度泛函数理论表征吸附位点。微囊藻毒素降解细菌被包裹在生物材料复合材料中，其生存能力和功能将通过扫描电镜和培养相结合的方法进行评估。逆转录酶定量PCR、16S rRNA基因测序和宏基因组学分析将用于开发微囊藻毒素降解机制的基因型洞察。这项研究的成功完成将有助于将新型靶向生物降解与新型功能纳米材料作为一种有效的水处理技术相结合，从而推动水处理技术的发展。有效和低成本的微囊藻毒素去除处理技术将产生社会效益，以保护国家的饮用水供应免受有害藻华的影响。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

项目成果

Modeled and measured SARS-CoV-2 virus in septic tank systems for wastewater surveillance

对化粪池系统中的 SARS-CoV-2 病毒进行建模和测量，用于废水监测

• DOI: 10.2166/wh.2023.128
• 发表时间: 2023
• 期刊: Journal of Water and Health
• 影响因子: 2.3
• 作者: Li, Dong;Quon, Hunter;Ervin, Jared;Jiang, Sunny;Rosso, Diego;Van De Werfhorst, Laurie C.;Steets, Brandon;Holden, Patricia A.
• 通讯作者: Holden, Patricia A.