1
|
Wang C, Qi WK, Zhang SJ, Du TY, Zhang L, Peng YZ. Continuous self-circulating up-flow granular sludge fluidized bed process treating low-strength real municipal wastewater at high hydraulic loads. BIORESOURCE TECHNOLOGY 2024; 414:131618. [PMID: 39396578 DOI: 10.1016/j.biortech.2024.131618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2024] [Revised: 10/08/2024] [Accepted: 10/08/2024] [Indexed: 10/15/2024]
Abstract
Conditions conducive to aerobic granular sludge (AGS) growth and maintenance are very difficult to realize in continuous-flow biological treatment processes. This study conducted a continuous-flow self-circulating up-flow granular sludge fluidized bed (Zier process) treating real urban wastewater approximately one year. The substantial self-circulating multiple times (RSCMT, 8-15 times) and up-flow velocity (8-15 m/h) generated by aeration, the only power equipment in Zier process, facilitated pollutant removal, particle granulation and stabilization. With hydraulic retention time of 5 h, RSCMT of 9.3-14.4 times and chemical oxygen demand (COD)/total nitrogen (TN) ratio of 5.9 ± 1.0, the effluent COD, ammonia nitrogen and TN were 28.6 ± 7.7, 1.1 ± 1.2, and 13.3 ± 1.7 mg/L, respectively. The median particle size was 150-250 μm and effluent suspended solids concentration was 33.4 ± 14.5 mg/L. It is unnecessary to set up sludge reflux which simplifies the subsequent mud-water separation facilities. The Zier process provides a new process structure for implementation of continuous-flow AGS process.
Collapse
Affiliation(s)
- Cong Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China; Beijing Drainage Group Co., Ltd., Beijing 100044, PR China
| | - Wei-Kang Qi
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Shu-Jun Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China; Beijing Drainage Group Co., Ltd., Beijing 100044, PR China
| | - Tian-Yuan Du
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Liang Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Yong-Zhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
| |
Collapse
|
2
|
Shi W, Tang Y, Liu Y, Fan J, Huang S, Guo Y, Zhang B, Lens PNL. Deciphering the role of micro/nano-hydroxyapatite in aerobic granular sludge system: Effects on treatment performance and enhancement mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 366:121850. [PMID: 39018842 DOI: 10.1016/j.jenvman.2024.121850] [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: 01/11/2024] [Revised: 05/26/2024] [Accepted: 07/12/2024] [Indexed: 07/19/2024]
Abstract
Hydroxyapatite (HAP), a mineral nucleus identified within aerobic granular sludge (AGS), plays a vital role in enhancing the AGS systems. However, the microscopic mechanism underlying their roles remains largely unexplored. Herein, a systematic investigation was carried out to elucidate the impact and enhanced mechanisms associated with HAP of different sizes, i.e. micro-HAP (mHAP) and nano-HAP (nHAP), on the aerobic granulation, nutrient removal and microbial diversity of AGS. Results showed that the presence of nHAP and mHAP significantly shortened the granulation process to 15 and 20 days, respectively. This might be ascribed to the fact that the large specific surface area of nHAP aggregates was conducive to microbial adhesion, biomass accumulation and sludge granulation. Compared with mHAP, the granules with nHAP showed better settlement performance, mechanical strength and larger diameter. The X-ray diffraction (XRD) and Raman spectrometer analysis confirmed the presence of HAP within the granules, which was found to stimulate the secretion of extracellular polymeric substance, improve the compactness of granule structure and suppress the growth of filamentous bacteria, thereby contributing to a stable AGS system. The presence of HAP, especially nHAP, effectively enriched the functional microorganisms, such as nitrifying and denitrifying bacteria (e.g. Candidatus_Competibacter) and phosphorus accumulating organisms (e.g. Flavobacterium), leading to the improved nutrient removal efficiencies (COD > 96%, TN > 76%, and TP > 74%). Further analysis revealed the up-regulation of functional enzymes (e.g. nitrite oxidoreductase and polyphosphate kinase) involved in nutrient metabolism, underlying the inherent mechanisms for the excellent nutrient removal. This study deepens the understanding of granulation mechanisms from the perspective of mineral cores, and proposes an economically feasible strategy for rapid initiation and stabilization of AGS reactors.
Collapse
Affiliation(s)
- Wenxin Shi
- College of Environment and Ecology, Chongqing University, Chongqing, 400044, China
| | - Yi Tang
- College of Environment and Ecology, Chongqing University, Chongqing, 400044, China
| | - Yi Liu
- College of Environment and Ecology, Chongqing University, Chongqing, 400044, China
| | - Jiawei Fan
- College of Environment and Ecology, Chongqing University, Chongqing, 400044, China
| | - Shuchang Huang
- College of Environment and Ecology, Chongqing University, Chongqing, 400044, China
| | - Yuan Guo
- State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an, 710048, China
| | - Bing Zhang
- College of Environment and Ecology, Chongqing University, Chongqing, 400044, China.
| | - Piet N L Lens
- UNESCO-IHE, Institute for Water Education, Westvest 7, 2601, DA, Delft, the Netherlands
| |
Collapse
|
3
|
Liu S, Wang Q, Liang J, Li J, Shao Z, Han Y, Arslan M, El-Din MG, Li Z, Chen C. The potential effects of N-Acyl homoserine lactones on aerobic sludge granulation during phenolic wastewater treatment. ENVIRONMENTAL RESEARCH 2024; 251:118654. [PMID: 38485076 DOI: 10.1016/j.envres.2024.118654] [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: 11/30/2023] [Revised: 02/20/2024] [Accepted: 03/05/2024] [Indexed: 03/20/2024]
Abstract
The formation of aerobic granular sludge (AGS) is relatively difficult during the treatment of refractory wastewater, which generally shows small granular sizes and poor stability. The formation of AGS is regulated by N-Acyl homoserine lactones (AHLs)-mediated quorum sensing (QS). However, the potential role of AHLs in AGS formation under the toxic stress of refractory pollutants and the heterogeneity in the distribution and function of AHLs across different aggregates are not well understood. This study investigated the potential effects of AHLs on the formation of AGS during phenolic wastewater treatment. The distribution and succession of AHLs across varying granular sizes and development stages of AGS were investigated. Results showed that AGS was successfully formed in 13 days with an average granular size of 335 ± 39 μm and phenol removal efficiency of >99%. The levels of AHLs initially increased and then decreased. C4-HSL and 3-oxo-C10-HSL were enriched in large granules, suggesting they may play a pivotal role in regulating the concentration and composition of extracellular polymeric substances (EPS). The content of EPS constantly increased to 149.4 mg/gVSS, and protein (PN) was enriched in small and large granules. Luteococcus was the dominant genus constituting up to 62% after the granulation process, and exhibited a strong association with C4-HSL. AHLs might also regulate the bacterial community responsible for EPS production, and pollutant removal, and facilitate the proliferation of slow-growing microorganisms, thereby enhancing the formation of AGS. The synthesis and dynamics of AHLs were mainly governed by AHLs-producing bacterial strains of Rhodobacter and Pseudomonas, and AHLs-quenching strains of Flavobacterium and Comamonas. C4-HSL and 3-oxo-C10-HSL might be the major contributors to promoting sludge granulation under phenol stress and play critical roles in large granules. These findings enhance our understanding of the roles that AHLs play in sludge granulation under toxic conditions.
Collapse
Affiliation(s)
- Shasha Liu
- State Key Laboratory of Petroleum Pollution Control, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China
| | - Qinghong Wang
- State Key Laboratory of Petroleum Pollution Control, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China
| | - Jiahao Liang
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Key Laboratory of Petrochemical Pollution Control of Guangdong Higher Education Institutes, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China
| | - Jin Li
- State Key Laboratory of Petroleum Pollution Control, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China
| | - Zhiguo Shao
- State Key Laboratory of Petroleum Pollution Control, CNPC Research Institute of Safety and Environmental Technology, Beijing, 102200, China
| | - Yehua Han
- State Key Laboratory of Petroleum Pollution Control, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China
| | - Muhammad Arslan
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Mohamed Gamal El-Din
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Zhuoyu Li
- State Key Laboratory of Petroleum Pollution Control, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China.
| | - Chunmao Chen
- State Key Laboratory of Petroleum Pollution Control, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China
| |
Collapse
|
4
|
Chen X, Gong Y, Li Z, Guo Y, Zhang H, Hu B, Yang W, Cao Y, Mu R. Key function of Kouleothrix in stable formation of filamentous aerobic granular sludge at low superficial gas velocity with polymeric substrates. BIORESOURCE TECHNOLOGY 2024; 397:130466. [PMID: 38373501 DOI: 10.1016/j.biortech.2024.130466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 01/29/2024] [Accepted: 02/16/2024] [Indexed: 02/21/2024]
Abstract
Forming and maintaining stable aerobic granular sludge (AGS) at a low superficial gas velocity (SGV) is challenging, particularly with polymeric substrates. This study cultivated filamentous aerobic granular sludge (FAGS) with filamentous Kouleothrix (Type 1851) at low SGV (0.15 cm/s) utilizing mixed acetate-soluble starch. Within approximately 260 days, notable increases in the relative abundance of Kouleothrix (from 4 % to 10 %) and Ca. Competibacter (from 1 % to 26 %) were observed through 16S rRNA gene analysis. Metagenomic analysis revealed increased expression of functional genes involved in volatile fatty acid (VFA) production (e.g., ackA and pta) and polyhydroxyalkanoate synthesis (e.g., phbB and phbC). Kouleothrix acted as a skeleton for bacterial attachment and was the key fermenting bacteria promoting granulation and maintaining granule stability. This study provides insight into the formation of FAGS with low-energy and non-VFA substrates.
Collapse
Affiliation(s)
- Xi Chen
- School of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an 710048, China.
| | - Yanzhe Gong
- School of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an 710048, China
| | - Zhihua Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Yingming Guo
- School of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an 710048, China
| | - Hongjiang Zhang
- North China Electric Power Research Institute Co., Ltd, Beijing 100045, China
| | - Bin Hu
- School of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an 710048, China
| | - Wenhao Yang
- School of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an 710048, China
| | - Yinhuan Cao
- School of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an 710048, China
| | - Ruihua Mu
- School of Environmental and Chemical Engineering, Xi'an Polytechnic University, Xi'an 710048, China
| |
Collapse
|
5
|
Wang Y, Zhang Z, Wang X, Guo H, Zhu T, Ni BJ, Liu Y. Percarbonate-strengthened ferrate pretreatment for enhancing short-chain fatty acids production from sewage sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166771. [PMID: 37660812 DOI: 10.1016/j.scitotenv.2023.166771] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 08/20/2023] [Accepted: 08/31/2023] [Indexed: 09/05/2023]
Abstract
Sewage sludge management poses a pressing environmental challenge, demanding the implementation of sustainable solutions to facilitate resource recovery. Short-chain fatty acids (SCFAs) serve as valuable chemicals and renewable energy sources, underscoring the importance of maximizing their production to achieve sustainable waste management. Therefore, this study proposes a novel and green strategy, i.e., percarbonate-strengthened ferrate pretreatment to enhance SCFAs synthesis from sewage sludge, because percarbonate could activate ferrate oxidation through providing (bi) carbonate and hydrogen peroxide. Results show that percarbonate largely reduces the required ferrate dosage for fermentation improvement, and their combination exhibits obvious synergistic effects on SCFAs accumulation and sludge reduction. Under the optimal pretreatment conditions, SCFAs production is promoted to 3670.2 mg COD/L, representing a remarkable increase of 5512.4 %, 156.0 % or 395.1 % compared to the control, percarbonate alone or ferrate alone, respectively. Mechanism explorations demonstrate that percarbonate-strengthened ferrate pretreatment significantly enhances sludge solubilization, elevates substrate biodegradability, and alters the physiochemical properties of sludge to favor organics fermentation. The synergistic effects on solid organics release and sludge properties can be attributed to the combined mechanisms of enhanced oxidation and alkaline hydrolysis. Further investigations on metabolic pathways reveal that the combination substantially improves key enzyme activities associated with hydrolysis and SCFAs formation, while severely inhibits that of SCFAs consumption. These findings are further supported by the functional genes coding relevant enzymes. Moreover, the combination alters microbial structures and compositions, leading to the screening and enrichment of key microbes that facilitate SCFAs accumulation. This innovative strategy holds significant promise in advancing sewage sludge management towards a more circular and resource-efficient paradigm.
Collapse
Affiliation(s)
- Yufen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Zixin Zhang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Xiaomin Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Haixiao Guo
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Tingting Zhu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Bing-Jie Ni
- School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Yiwen Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
| |
Collapse
|
6
|
Rosas-Echeverría K, Fall C, Gutiérrez-Segura E, Romero-Camacho MP, Ba KM. Mechanisms of persistence and impact of ordinary heterotrophic organisms in aerobic granular sludge. BIORESOURCE TECHNOLOGY 2023:129346. [PMID: 37336447 DOI: 10.1016/j.biortech.2023.129346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/08/2023] [Accepted: 06/16/2023] [Indexed: 06/21/2023]
Abstract
The stability of granules, contaminant removal and microbial structure of an aerobic granular sludge (AGS) process were investigated with a focus on ordinary heterotrophic organisms (OHOs). Long-term stable granules and high removals of COD (97 %), NH4+ (98 %), P (85 %) and total N (77 %) were achieved. Sequencing analyses identified 6.6 % of phosphorus-accumulating organisms in the sludge, concordant with the observed bio-P removal capacity. However, OHOs were the most abundant bacteria in the sludge (70-93 %) without resulting in unstable aggregates. Under current dogmas of microbial competition in activated sludge, it seemed contradictory that OHOs could persist in the long term in the AGS where COD was depleted beginning in the anaerobic phase. Microbial analyses showed that OHOs could survive in granules by micropredation, proteolysis, fermentation and EPS consumption. Heterotrophic-nitrification/ aerobic-denitrification was an active pathway in the AGS. These findings contribute to a better understanding of microbial competition in AGS and its stability.
Collapse
Affiliation(s)
- K Rosas-Echeverría
- Universidad Autónoma del Estado de México, Facultad de Química, Col Ciprés, C.P. 50120, Toluca, Mexico
| | - C Fall
- Universidad Autónoma del Estado de México (UAEM), Instituto Interamericano de Ciencias y Tecnología del Agua (IITCA), Carr. Toluca-Ixtlahuaca, km. 14.5, C.P. 50120, San Cayetano, Toluca, Mexico.
| | - E Gutiérrez-Segura
- Universidad Autónoma del Estado de México, Facultad de Química, Col Ciprés, C.P. 50120, Toluca, Mexico
| | - M P Romero-Camacho
- Universidad Autónoma del Estado de México (UAEM), Instituto Interamericano de Ciencias y Tecnología del Agua (IITCA), Carr. Toluca-Ixtlahuaca, km. 14.5, C.P. 50120, San Cayetano, Toluca, Mexico
| | - K M Ba
- Universidad Autónoma del Estado de México (UAEM), Instituto Interamericano de Ciencias y Tecnología del Agua (IITCA), Carr. Toluca-Ixtlahuaca, km. 14.5, C.P. 50120, San Cayetano, Toluca, Mexico
| |
Collapse
|