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Li S, Xing D, Sun C, Jin C, Zhao Y, Gao M, Guo L. Effect of light intensity and photoperiod on high-value production and nutrient removal performance with bacterial-algal coupling system. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 356:120595. [PMID: 38520851 DOI: 10.1016/j.jenvman.2024.120595] [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: 02/02/2024] [Accepted: 03/10/2024] [Indexed: 03/25/2024]
Abstract
Direct discharge of mariculture wastewater can lead to eutrophication, posing a threat to aquatic ecosystems. A novel Bacteria-Algae Coupled Reactor (BACR) offers advantages in treating mariculture wastewater, which can effectively remove pollutants while simultaneously obtaining microalgal products. However, there is limited information available on how illumination affects the cultivation of mixotrophic microalgae in this bacteria-algae coupling system. Therefore, a combined strategy of photoperiod and light intensity regulation was employed to improve the biological mariculture wastewater remediation, promote microalgae biomass accumulation, and increase the high-value product yield in this study. Optimal light conditions could effectively enhance microalgal carbohydrate, protein, lipid accumulation and photosynthetic activity, with the carbohydrate, protein and lipid contents reached 44.11, 428.57 and 399.68 mg/L, respectively. Moreover, excellent removal rates were achieved for SCOD, NH4+-N and TP, reaching 86.68%, 87.35% and 95.13% respectively. This study proposes a comprehension of BACR processes in mariculture wastewater under different light conditions.
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Affiliation(s)
- Shangzong Li
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Dongxu Xing
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Cheng Sun
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Chunji Jin
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
| | - Yangguo Zhao
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Mengchun Gao
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Liang Guo
- Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering (MEGE), Qingdao, 266100, China.
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Jia L, Xin J, Wu H, Gong S, Wu H, Zhang Z. Enhancing nitrate attenuation in groundwater via selectively applying surface agricultural practices: A novel and sustainable strategy for non-point source pollution mitigation. WATER RESEARCH 2023; 239:120052. [PMID: 37178664 DOI: 10.1016/j.watres.2023.120052] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/22/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023]
Abstract
Non-point nitrate pollution in groundwater has been accelerated by agricultural development, but sustainable nitrogen removal is a challenge because of its wide distribution and negative side effects. Surface agricultural practices (SAPs), which are demonstrably effective in driving the downward infiltration of dissolved organic carbon (DOC), have not been well explored for their potential to enhance nitrate attenuation in groundwater. Therefore, a combination of soil column and groundwater incubation experiments was performed to investigate the carbon and nitrogen responses to different SAPs (manure fertilization, lucerne planting, and straw return). The soil column experiment showed that SAPs promoted DOC and reduced nitrate leaching into groundwater, and straw treatment witnessed the highest DOC leaching flux (252.71 g m-2 yr-1) and lowest nitrate leaching flux (9.51 g m-2 yr-1). The groundwater incubation experiment showed that leachates from the straw treatment displayed the best denitrification-enhancement performance, with the highest NO3--N reduction efficiency (92.93%) and rate (1.627 mg/day), N2 selectivity (99.78%), and net nitrogen removal (0.09 mg). Furthermore, Fourier transform ion cyclotron resonance mass spectrometry confirmed that CHOS molecules with lower double bond equivalents (0-5) and larger carbon numbers (10-15) were more accessible to denitrifiers. This study provides a new path for the sustainable control of non-point source nitrate pollution.
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Affiliation(s)
- Linna Jia
- Key Lab of Marine Environment and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Jia Xin
- Key Lab of Marine Environment and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
| | - Han Wu
- Key Lab of Marine Environment and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Shuo Gong
- Key Lab of Marine Environment and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Haoran Wu
- Key Lab of Marine Environment and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Zhiyuan Zhang
- Key Lab of Marine Environment and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
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Yu J, You X, Wang Y, Jin C, Zhao Y, Guo L. Focus on the role of synthetic phytohormone for mixotrophic growth and lipid accumulation by Chlorella pyrenoidosa. CHEMOSPHERE 2022; 308:136558. [PMID: 36150488 DOI: 10.1016/j.chemosphere.2022.136558] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/26/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
Synthetic phytohormone (SP) is regarded as an attractive candidate for microalgae cultivation due to its potential for high-value microalgae biomass production. Herein, α-naphthylacetic acid (NAA), indomethacin (IN) and 2,4-dichlorophenoxyacetic acid (2,4-D) were used for the mixotrophic cultivation of Chlorella pyrenoidosa with mariculture wastewater (MW) acidogenic fermentation effluent. The growth and lipid accumulation of Chlorella pyrenoidosa added with SP were enhanced, given their high bioavailability of the nutrients. Among these three SPs, IN was optimal for Chlorella pyrenoidosa growth, with the maximum optical density of 1.81. NAA exhibited the best performance for lipid production and the proportion of lipid reached 50.24%. Furthermore, the energy of Chlorella pyrenoidosa cultured with SP preferentially allocated to lipogenesis. To understand the mechanism of lipid accumulation in Chlorella pyrenoidosa in response to SP, the enzyme activities involved in carbon metabolism were determined. The malic enzyme (ME) and acetyl-CoA carboxylase (ACCase) were positively correlated with lipid accumulation. Phosphoenolpyruvate carboxylase (PEPC) was the negative feedback enzyme for lipid synthesis. The findings could provide valuable information for regulation mechanism of lipid accumulation and value-added products recovery by microalgae.
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Affiliation(s)
- Jinghan Yu
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Xuting You
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, United States
| | - Chunji Jin
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Yangguo Zhao
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Liang Guo
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
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The Control Strategy and Kinetics of VFAs Production in an ASBR Reactor Treating Low-Strength Mariculture Wastewater. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19137858. [PMID: 35805516 PMCID: PMC9265308 DOI: 10.3390/ijerph19137858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 11/17/2022]
Abstract
As an environment-friendly wastewater treatment process, the anaerobic fermentation process has been widely used for the pretreatment of high-strength wastewater. However, it is rarely applied to treat low-strength wastewater due to low methane recovery. In this study, anaerobic fermentation treating low-strength mariculture wastewater was studied in an anaerobic sequencing batch reactor (ASBR) with a COD removal rate of 75%. Anaerobic fermentation was successfully controlled at the acidification stage by increasing COD loading. As the greenhouse gas emission decreased, the residual organics were enough for biological nutrients’ removal. Fluorescence in situ hybridization results showed that the dominant bacteria in the ASBR were acidogenic bacteria and methanogens, accounting for 39.7% and 46.5% of the total bacteria, respectively. Through the calculation processing of the experimental data, the order of the anaerobic fermentation reaction was a second-order reaction. The kinetic parameters of low-strength organic wastewater treatment were determined by using the Grau second-order substrate removal model, Stover–Kincannon model, Monod model and Haldane model. The maximum rate removal constant Umax, sludge yield coefficient Y and inhibition constant Ki were 1.157 g/(L·d), 0.153 mgVSS/mgCOD and 670 mg/L, respectively. It provided data support for the practical application of the anaerobic fermentation treating low-strength wastewater.
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Abstract
With the rapid development of intensive mariculture, lots of mariculture wastewaters containing residual feed and excrements are discharged into marinelands, leading to coastal pollution. Recently, the environmental problems caused by the discharge of mariculture wastewater have been paid much attention, as have other breeding industries in China. In fact, organic solid waste accounts for most of the pollutants and can be reduced by precipitation or filtration technologies, after which the supernatant can be easily treated by ecological methods. Some national guidelines and relevant local standards have been issued to strictly control the mariculture wastewater, but there are still few effective technologies for mariculture wastewater treatment due to its high salinity and extremely low pollutant concentration. This paper aims to propose feasible pollution control methods of mariculture wastewater according to the wastewater characteristics from different mariculture modes. For raw ammonia-based wastewater, it should be sequentially treated by precipitation, nitrification and denitrification and ecological methods, which would target solid waste, organic carbon/nitrogen and phosphorus removal, respectively. For the nitrate-based wastewater, this just needs denitrification filters and ecological methods for nitrate and phosphorus removal. After an overview of pollution control strategies for different types and scales of industrial mariculture wastewater treatment, some challenges are also mentioned.
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Application of Thermophilic Bacteria for the Treatment of Municipal Wastewaters. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2022. [DOI: 10.1007/s13369-021-06518-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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