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Zhou X, Liu H, Fan X, Xu X, Gao Y, Bi X, Cheng L, Huang S, Zhao F, Yang T. Innovative inbuilt moving bed biofilm reactor for nitrogen removal applied in household aquarium. Front Microbiol 2024; 15:1373119. [PMID: 38694801 PMCID: PMC11062409 DOI: 10.3389/fmicb.2024.1373119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/27/2024] [Indexed: 05/04/2024] Open
Abstract
An innovative inbuilt moving bed biofilm reactor (MBBR) was created to protect fish from nitrogen in a household aquarium. During the 90 experimental days, the ammonia nitrogen (NH4+-N) concentration in the aquarium with the inbuilt MBBR was always below 0.5 mg/L, which would not threaten the fish. Concurrently, nitrite and nitrate nitrogen concentrations were always below 0.05 mg/L and 4.5 mg/L, respectively. However, the blank contrast aquarium accumulated 1.985 mg/L NH4+-N on the 16th day, which caused the fish to die. The suspended biofilms could achieve the specific NH4+-N removal rate of 45.43 g/m3/d. Biofilms presented sparsely with filamentous structures and showed certain degrees of roughness. The bacterial communities of the suspended biofilms and the sediment were statistically different (p < 0.05), reflected in denitrifying and nitrifying bacteria. In particular, the relative abundance of Nitrospira reached 1.4%, while the genus was barely found in sediments. The suspended biofilms showed potentials for nitrification function with the predicted sequence numbers of ammonia monooxygenase [1.14.99.39] and hydroxylamine dehydrogenase [EC:1.7.2.6] of 220 and 221, while the values of the sediment were only 5 and 1. This study created an efficient NH4+-N removal inbuilt MBBR for household aquariums and explored its mechanism to afford a basis for its utilization.
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Affiliation(s)
| | | | | | | | | | - Xuejun Bi
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, Qingdao University of Technology, Qingdao, China
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Yan H, Zhang T, Yang Y, Li J, Liu Y, Qu D, Feng L, Zhang L. Occurrence of iodinated contrast media (ICM) in water environments and their control strategies with a particular focus on iodinated by-products formation: A comprehensive review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119931. [PMID: 38154220 DOI: 10.1016/j.jenvman.2023.119931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/03/2023] [Accepted: 12/23/2023] [Indexed: 12/30/2023]
Abstract
Iodinated contrast media (ICM), one of the pharmaceutical and personal care products (PPCPs), are frequently detected in various water bodies due to the strong biochemical stability and recalcitrance to conventional water treatment. Additionally, ICM pose a risk of forming iodinated by-products that can be detrimental to the aquatic ecosystem. Consequently, effectively removing ICM from aqueous environments is a significant concern for environmental researchers. This article provides a comprehensive review of the structural characteristics of ICM, their primary source (e.g., domestic and hospital wastewater), detected concentrations in water environments, and ecological health hazards associated with them. The current wastewater treatment technologies for ICM control are also reviewed in detail with the aim of providing a reference for future research. Prior researches have demonstrated that traditional treatment processes (such as physical adsorption, biochemical method and chemical oxidation method) have inadequate efficiencies in the removal of ICM. Currently, the application of advanced oxidation processes to remove ICM has become extensive, but there are some issues like poor deiodination efficiency and the risk of forming toxic intermediates or iodinated by-products. Conversely, reduction technologies have a high deiodination rate, enabling the targeted removal of ICM. But the subsequent treatment issues related to iodine (such as I- and OI-) are often underestimated, potentially generating iodinated by-products during the subsequent treatment processes. Hence, we proposed using combined reduction-oxidation technologies to remove ICM and achieved synchronous control of iodinated by-products. In the future, it is recommended to study the degradation efficiency of ICM and the control efficiency of iodinated by-products by combining different reduction and oxidation processes.
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Affiliation(s)
- Hao Yan
- Beijing Key Lab for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Tao Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yi Yang
- University of Science and Technology of China, Anhui 230026, China
| | - Juan Li
- Advanced Interdisciplinary Institute of Environment and Ecology, Beijing Normal University, Zhuhai 519087, China
| | - Yongze Liu
- Beijing Key Lab for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Dan Qu
- Beijing Key Lab for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Li Feng
- Beijing Key Lab for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Liqiu Zhang
- Beijing Key Lab for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
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Zheng Y, Ren Y, Yang J, Huang Y, Liu Y. Rational design of electrocatalytic system to selective transform nitrate to nitrogen. CHEMOSPHERE 2023; 341:140016. [PMID: 37652250 DOI: 10.1016/j.chemosphere.2023.140016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/02/2023] [Accepted: 08/28/2023] [Indexed: 09/02/2023]
Abstract
Nitrate (NO3-) is one of the most common pollutants in natural bodies of water and as such threatens both human health and the safety of aquatic environment. There are efficient electrochemical techniques to directly remove NO3-, but inexpensive, selective and electrocatalytic strategies to eliminate NO3- by converting it into benign nitrogen (N2) remain challenging. This work studied Cu particles that were formed directly on a Ni foam (Cu-NF) and evaluated their electrocatalytic NO3- reduction performance. The use of carbon nanotubes (CNT) functionalized with titanium suboxides (TiSO) as the anode facilitated the generation of active chlorine species that had a key role in the removal of NH4+. An electrochemical system that integrated a Cu-NF cathode with a TiSO-CNT anode could remove 88.5% of NO3- with a >99% N2 selectivity when operated over 6 h (4.1 × 10-4 h-1) at a potential of -1.2 V vs Ag/AgCl. Because the chloride ions are very common in natural sources of water, this technique offers a sustainable and environmentally friendly approach for the removal of NO3- from contaminated water sources.
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Affiliation(s)
- Yiqing Zheng
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Yifan Ren
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Jianping Yang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, China
| | - Yingping Huang
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, 443002, China
| | - Yanbiao Liu
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
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