Huiqun Shi, Xiaoyi Ren, Ruili Yang, Jinsong Wang, Huaihao Xu, Xinqing Liao, Yaoyin Lou, Shaohua Chen, Xin Ye, Xiaojun Wang
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引用次数: 0
Abstract
Anaerobic ammonium oxidation (anammox) process is a highly effective and economic technology for nitrogen removal from wastewater. However, the slow growth of anammox bacteria and sludge flotation often hinder its field application. Ion adsorption and crystal precipitation can potentially promote the sludge granulation and hence address the above issues. This study investigated two approaches to support anammox granulation through Mg2+ adsorption and magnesium ammonium phosphate (MAP) precipitation. Mg2+ addition improved the specific anammox activity (SAA) by 4.09 to 4.75-fold compared to MAP-mediated ones, which could be explained by the upregulations of nitrogen and inorganic carbon metabolisms. The active extracellular polymeric substances generation at metabolites level may also favor the granulation in Mg2+-mediated anammox. However, sludge loss halted the continuous size increase of sludge. Differently, MAP promoted granulation by physically increasing the granular density, which allowed for a greater retention of sludge within the reactor. However, the co-growth of MAP precipitates with anammox may lead to mass transfer limitations, resulting in down-regulated gene expressions and metabolites in inorganic carbon metabolism, which negatively impacted the SAA. Overall, both strategies achieved comparable nitrogen removal capacities. Nevertheless, the co-growth of MAP and anammox was promising for effectively mitigating sludge flotation. Our study provided strategies and omics-based evidences for anammox granulation and activity variations, benefiting anammox practical applications.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.