Vetiver and Dictyosphaerium sp. co-culture for the removal of nutrients and ecological inactivation of pathogens in swine wastewater

Publication date: Available online 17 May 2019Source: Journal of Advanced ResearchAuthor(s): Wang Xinjie, Ni Xin, Cheng Qilu, Xu Ligen, Zhao Yuhua, Zhou QifaAbstractSwine wastewater poses chemical and biological risks because it contains high concentrations of ammonia and diverse species of pathogens. We developed a vetiver-Dictyosphaerium sp. co-culture for the rapid removal of ammonia and the effective inactivation of pathogens. Plants and microalgae benefited mutually and co-utilized the nutrients in the wastewater in the co-culture. The pathogens were inactivated by reactive oxygen species that were released by the microalgae as well as the supersaturated concentrations of dissolved oxygen in the enclosed bioreactor. In a greenhouse experiment, the time required for wastewater NH4-N to decrease from 102 mg·L-1 to 5 mg·L-1 was 65.5 days, 34.2 days, and 13.3 days in the plant culture, the algal culture, and the plant-algal co-culture, respectively. Among the 35 detected genera of bacteria, the operational taxonomic units for 31 tended to decrease with culture time in the plant-algal co-culture. Additionally, certain bacteria (e.g., Escherichia spp.) were completely removed by day 9 or 15, and the aerobic phototrophic bacterium Erythromicrobium spp. became most abundant on day 15 in the plant-algal co-culture. Important positive interactions that were observed between plants and microalgae included co-utilization of the nutrients, wastewater acidification through plant roo...
Source: Journal of Advanced Research - Category: Research Source Type: research