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Huang Y, Wang J, Sun Y, Zeng W, Xia A, Zhu X, Zhu X, Liao Q. Non-immersed zigzag microalgae biofilm overcoming high turbidity and ammonia of wastewater for muti-pollutants bio-purification. WATER RESEARCH 2023; 244:120499. [PMID: 37634456 DOI: 10.1016/j.watres.2023.120499] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 08/13/2023] [Accepted: 08/17/2023] [Indexed: 08/29/2023]
Abstract
Biological treatment that utilizes microalgae technology has demonstrated outstanding efficacy in the wastewater purification and nutrients recovery. However, the high turbidity of the digested piggery wastewater (DPW) leads to serious light attenuation and the culture mode of suspended microalgae results in a huge landing area. Thus, to overcome light attenuation in DPW, a non-immersed titled zigzag microalgae biofilm was constructed by attaching it onto a porous cotton cloth. As a result, the light could directly irradiate microalgae biofilm that attached on both sides of the cotton cloth, and the microalgal biofilm area was up to 6 m2 per bioreactor landing area. When the non-immersed zigzag microalgae biofilm bioreactor (N-Z-MBP) was used to treat wastewater with an ammonia nitrogen (NH4+-N) concentration of 362 mg L-1, the NH4+-N was completely removed in just 5 days and the maximum growth rate of microalgae biofilm reached 7.02 g m-2 d-1. After 21 days of long-term sequencing batch operation for the N-Z-MBP, the biomass density of the biofilm reached 52 g m-2 and remained at this high value for the next 14 days. Most importantly, during the 35 days' running, the NH4+ -N maximum removal rate of single batch reached up to 65 mg L-1 d-1 and its concentration in the effluent was always below the discharge standard value (80 mg L-1 form GB18596-2001 of China) and total phosphorus was completely removed in each batch. Furthermore, the biomass concentration of microalgae cells in the effluent of the N-Z-MBP was almost zero, indicating that the non-submerged biofilm achieved in situ separation of microalgae from the wastewater. This work suggests that the N-Z-MBP can effectively purify DPW over a long period, providing a possible strategy to treat wastewater with high ammonia nitrogen and high turbidity.
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Affiliation(s)
- Yun Huang
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China.
| | - Jintai Wang
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China
| | - Yabo Sun
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China
| | - Weida Zeng
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China
| | - Ao Xia
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China
| | - Xianqing Zhu
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China
| | - Xun Zhu
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China
| | - Qiang Liao
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China
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Luo M, Wang C, He X, Zhan M, Yu R. Photocatalytic oxidation degradation of inhibitory fatty acids for aged Chlorella vulgaris cultivation medium recycling. Bioprocess Biosyst Eng 2022; 45:1211-1222. [PMID: 35716219 DOI: 10.1007/s00449-022-02739-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 05/28/2022] [Indexed: 11/02/2022]
Abstract
The medium used for Chlorella vulgaris cultivation exerted obvious inhibitory effects on the growth of C. vulgaris after several culture-harvest cycles. The accumulated fatty acids secreted by C. vulgaris during their growth process were expected to be the cell inhibition components. In this work, the ultraviolet-driven photocatalytic oxidation technique was applied for the degradation of microalgae cell growth inhibition components in the aged cultivation medium, and the reaction parameters were optimized. The results indicated that the photocatalytic oxidation processes using 0.5 g/L [Formula: see text] NPs as the catalyst under the aeration condition showed as high as 74.61 ± 4.60% FA degradation efficiency after 20 min illumination, and the contents of -COOH, [Formula: see text] (α) and -COO-R functional groups in the aged C. vulgaris medium were significantly reduced. In addition, the modification of the photocatalyst further improved the ability of the degradation of FA. When the modified [Formula: see text]/AC and [Formula: see text]/Ag catalysts were applied, the FA degradation rates reached as high as 92.46 ± 0.37% and 93.91 ± 1.37%, respectively. In the recycled medium treated with [Formula: see text]/AC, the cell density in the stable phase reached 96.33 ± 1.83% of that in the fresh medium as the control. In summary, the photocatalytic oxidation with the modified [Formula: see text]/AC catalyst was proposed as the efficient strategy to realize the recycling of the aged C. vulgaris cultivation medium via the degradation of the FA as the cell growth inhibitors.
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Affiliation(s)
- Moye Luo
- Department of Environmental Science and Engineering, School of Energy and Environment, Southeast University, No. 2 Sipailou Street, Nanjing, 210096, Jiangsu, China
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Chuya Wang
- Department of Environmental Science and Engineering, School of Energy and Environment, Southeast University, No. 2 Sipailou Street, Nanjing, 210096, Jiangsu, China
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Xue He
- Department of Environmental Science and Engineering, School of Energy and Environment, Southeast University, No. 2 Sipailou Street, Nanjing, 210096, Jiangsu, China
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, 210009, Jiangsu, China
| | - Manjun Zhan
- Nanjing Research Institute of Environmental Protection, Nanjing Environmental Protection Bureau, Nanjing, 210013, Jiangsu, China
| | - Ran Yu
- Department of Environmental Science and Engineering, School of Energy and Environment, Southeast University, No. 2 Sipailou Street, Nanjing, 210096, Jiangsu, China.
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, 210009, Jiangsu, China.
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Farooq W, Naqvi SR, Sajid M, Shrivastav A, Kumar K. Monitoring lipids profile, CO 2 fixation, and water recyclability for the economic viability of microalgae Chlorella vulgaris cultivation at different initial nitrogen. J Biotechnol 2022; 345:30-39. [PMID: 34995559 DOI: 10.1016/j.jbiotec.2021.12.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 12/10/2021] [Accepted: 12/31/2021] [Indexed: 12/19/2022]
Abstract
The economic viability of microalgae as a bioenergy source depends on many factors. High CO2 fixing rate, improved lipids yield, and minimum water footprint are few key parameters. This study investigates the effect of four initial nitrogen concentrations (1-, 2-, 6- and 10-mM as nitrate) on lipids yield, their classification and composition, CO2 fixation rate, and water quality for further reuse after first cultivation. The initial 6 mM nitrate was found optimum for the growth and overall lipid productivity of Chlorella vulgaris. The maximum quantum efficiency (as Fv/Fm ratio) for algae decreases along with the cell growth profile and depletion of the initial nitrate concentration. CO2 fixation rate increased initially and peaked during exponential growth and then declined for the rest of the cultivation period. A higher CO2 fixation rate was recorded at 6 mM, and an overall fixation rate of CO2 was high at 6 mM. A higher total organic carbon (TOC) is produced in recycled water at a low nitrogen concentration of 1 and 2 mM. TOC changes during the cultivation period and with each reuse of water. Water was recycled twice successfully, while growth was inhibited during the 3rd cycle. Based on all these investigations, 6 mM of initial nitrogen was found optimal at given growth conditions.
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Affiliation(s)
- Wasif Farooq
- Department of Chemical Engineering, King Fahd University of Petroleum, and minerals (KFUPM), Dhahran 31261, Saudi Arabia.
| | - Salman Raza Naqvi
- School of Chemical and Material Engineering (SCME), National University of Science and Technology (NUST), H-12, Islamabad, Pakistan
| | - Muhammad Sajid
- Department of Chemical Engineering, King Fahd University of Petroleum, and minerals (KFUPM), Dhahran 31261, Saudi Arabia
| | - Anupama Shrivastav
- Microbiology Department, Parul Institute of Applied Sciences, Parul University, Waghodia, Vadodara, India
| | - Kanhaiya Kumar
- Department of Biotechnology and Food Sciences, Norwegian University of Science and Technology (NTNU), Kjemi 3, 325, Gløshaugen, Norway
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