Photosynthetic bacteria (PSB) wastewater treatment is a novel technology for wastewater purification and resources recovery but is restricted by low efficiency. This paper applied zero-valent iron nanoparticles (Fe⁰ NPs) to enhance its performance. Results showed that 20 mg/L Fe⁰ NPs under light-anaerobic condition significantly increased the PSB biomass production and wastewater chemical oxygen demand removal by 122% and 164.3%, and shortened the time required for wastewater purification by 33%; these effects were far more better than the addition of Fe²⁺. The mechanism was because the addition of Fe⁰ NPs promoted the intracellular ATP content and pigments (carotenoid and bacteriochlorophyll) contents, and up-regulated dehydrogenase and succinate dehydrogenase activity; the increase rate reached 38.7%, 39.6%, 22.0%, 23.9% and 218.2%, respectively.

光合细菌（PSB）废水处理是一种用于废水净化和资源回收的新技术，但效率低下。本文应用零价铁纳米颗粒（Fe ⁰ NPs）来增强其性能。结果表明，在轻度厌氧条件下20 mg / L Fe ⁰ NPs可使PSB生物量生产和废水化学需氧量去除分别提高122％和164.3％，并将废水净化所需的时间缩短33％。这些效果远优于添加Fe ²⁺。其机理是因为添加了Fe ⁰NPs促进了细胞内ATP含量和色素（类胡萝卜素和叶绿素）的含量，并上调了脱氢酶和琥珀酸脱氢酶的活性。增长率分别达到38.7％，39.6％，22.0％，23.9％和218.2％。