1
|
Depth optimization of inclined thin layer photobioreactor for efficient microalgae cultivation in high turbidity digestate. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
2
|
In-situ remediation of nitrogen and phosphorus of beverage industry by potential strains Bacillus sp. (BK1) and Aspergillus sp. (BK2). Sci Rep 2021; 11:12243. [PMID: 34112820 PMCID: PMC8192750 DOI: 10.1038/s41598-021-91539-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 05/19/2021] [Indexed: 12/03/2022] Open
Abstract
The bioremediation of beverage (treated and untreated) effluent was investigated in the current study by using the potential strains of Bacillus sp. (BK1) and Aspergillus sp. (BK2). Effluent was collected from the beverage industry (initial concentration of nitrogen were 3200 ± 0.5 mg/L and 4400 ± 0.6 mg/L whereas phosphorus were 4400 ± 2 mg/L and 2600 ± 1 mg/L in treated and untreated effluent correspondingly). Further, the BK1 and BK2 exhibited high removal competence after 1 week of incubation; BK1 removed phosphorus 99.95 ± 0.7% and BK2 95.69 ± 1% in treated effluent while nitrogen removed about 99.90 ± 0.4% by BK1 and 81.25 ± 0.8% by BK2 (initial concentration of phosphorus 4400 ± 2 mg/L and nitrogen 3200 ± 0.5 mg/L). Next, in the untreated effluent BK1 removed 99.81 ± 1% and BK2 99.85 ± 0.8% of phosphorus while removed nitrogen 99.93 ± 0.5% by BK1 and 99.95 ± 1.2% by BK2 correspondingly, (initial concentration of phosphorus 2600 ± 1 mg/L and nitrogen 4400 ± 0.6 mg/L). The physiochemical composition of sample such as pH, total carbohydrates, total proteins, total solids of treated and untreated effluent were also analysed before and after treatment of both the samples. BK1 and BK2 increased the pH by 8.94 ± 0.3 and 9.5 ± 0.4 correspondingly in treated effluent whereas 6.34 ± 0.5 and 7.5 ± 0.2 correspondingly in untreated effluent (initial pH of treated and untreated effluent 7.07 ± 0.8 and 4.85 ± 0.3 correspondingly). Total Carbohydrates removed about 17,440 ± 4.6 mg/L and 10,680 ± 3.2 mg/L by BK1 and BK2 correspondingly in treated effluent whereas 18,050 ± 3.5 mg/L and 18,340 ± 2.3 mg/L correspondingly in untreated effluent (initial concentration of treated and untreated effluent 25,780 ± 1.6 mg/L and 35,000 ± 1.5 mg/L correspondingly) while BK1 and BK2 removed total proteins by 30.336 ± 4.6 mg/L and 40.417 ± 2.3 mg/L correspondingly in treated effluent whereas 18.929 ± 1.2 mg/L and 17.526 ± 0.8 mg/L correspondingly in untreated effluent (initial concentration of treated and untreated effluent 49.225 ± 1.5 mg/L and 20.565 ± 1 mg/L correspondingly). Next, total solids removed by BK1 and BK2 2.5 ± 0.3 mg/L and 1.6 ± 0.6 mg/L correspondingly in treated effluent whereas 5.5 ± 0.8 mg/L and 4.6 ± 0.6 mg/L in untreated effluent (initial concentration of treated and untreated effluent 5.6 ± 1.5 mg/L and 9.48 ± 1.2 mg/L correspondingly). Both the strains BK1 and BK2 are highly efficient in the nitrogen and phosphorus removal therefore this strain may be applied for the potential remediation.
Collapse
|
3
|
Nithiya EM, Fenila F, Vasumathi KK, Premalatha M. Cultivation of scenedesmus sp. using optimized minimal nutrients and flocculants - a potential platform for mass cultivation. ENVIRONMENTAL TECHNOLOGY 2020; 41:1284-1297. [PMID: 30281403 DOI: 10.1080/09593330.2018.1531939] [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: 09/12/2017] [Accepted: 09/22/2018] [Indexed: 06/08/2023]
Abstract
A major constraint in the microalgal technology is the economics involved in cultivation and harvesting. This work is focussed on the optimization of nutrients for cultivation and harvesting using 'Scenedesmus sp'. Response surface methodology (RSM) using 'Face centered central composite design' (FCCD) available in Design expert 10.0.4 was used to develop the regression model for optimization of nutrients and flocculation conditions. The optimum nutrient conditions were 500 ppm of urea, 250 ppm of potassium dihydrogen phosphate and 1000 ppm of potassium hydrogen carbonate under artificial light conditions and 500 ppm of urea and 2000 ppm of potassium hydrogen carbonate under sunlight conditions. The optimum conditions were predicted using the model and compared with experimental data. The model has an R2 value of 0.9769 and 0.9798 for artificial light and sunlight conditions, respectively. In the case of harvesting studies, 98% flocculation efficiency was obtained for a combination of pH 10.4, temperature 45°C, 200 mg/l of leaf powder of Cassia auriculata. The model has an R2 value of 0.9989. The present studies indicated that cultivation of Scenedesmus sp. with the optimized nutrients and harvesting conditions facilitate a platform for energy efficient mass cultivation.
Collapse
Affiliation(s)
- E M Nithiya
- Algal Research and Biotechnology Lab, Department of Energy and Environment (DEE), National Institute of Technology (NIT), Tiruchirappalli, Tamil Nadu, India
| | - F Fenila
- Algal Research and Biotechnology Lab, Department of Energy and Environment (DEE), National Institute of Technology (NIT), Tiruchirappalli, Tamil Nadu, India
| | - K K Vasumathi
- Algal Research and Biotechnology Lab, Department of Energy and Environment (DEE), National Institute of Technology (NIT), Tiruchirappalli, Tamil Nadu, India
| | - M Premalatha
- Algal Research and Biotechnology Lab, Department of Energy and Environment (DEE), National Institute of Technology (NIT), Tiruchirappalli, Tamil Nadu, India
| |
Collapse
|
4
|
Li K, Liu Q, Fang F, Luo R, Lu Q, Zhou W, Huo S, Cheng P, Liu J, Addy M, Chen P, Chen D, Ruan R. Microalgae-based wastewater treatment for nutrients recovery: A review. BIORESOURCE TECHNOLOGY 2019; 291:121934. [PMID: 31395401 DOI: 10.1016/j.biortech.2019.121934] [Citation(s) in RCA: 227] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/27/2019] [Accepted: 07/29/2019] [Indexed: 05/05/2023]
Abstract
The water resource crisis and concerns with environmental pollution are pushing for upgrading of conventional wastewater treatment process. Microalgae-based wastewater treatment process has shown many advantages that can meet the new demand for improved wastewater treatment. However, considering the issues related to the complexity of wastewater characteristics and adaptability of microalgae species, and the challenges to the design and optimization of treatment processes in order to achieve higher removal efficiencies with lower costs, further exploration and research are still needed. This review provides an overview of microalgae strains commonly used for wastewater treatment, physical and chemical properties of various wastewaters and their suitability for algae cultivation, factors affecting algae growth, nutrient assimilation/removal and biomass productivity. The design and operation of microalgae-based wastewater treatment processes are also discussed. Moreover, the issues and limitations of microalgae-based wastewater treatment are also discussed and suggestions are proposed for the further research and development.
Collapse
Affiliation(s)
- Kun Li
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China; Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55112, USA
| | - Qiang Liu
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China
| | - Fan Fang
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China
| | - Ruihuan Luo
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China
| | - Qian Lu
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China
| | - Wenguang Zhou
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China
| | - Shuhao Huo
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Pengfei Cheng
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, China
| | - Junzhi Liu
- College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316022, China
| | - Min Addy
- Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55112, USA
| | - Paul Chen
- Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55112, USA
| | - Dongjie Chen
- Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55112, USA
| | - Roger Ruan
- Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55112, USA.
| |
Collapse
|
5
|
Liu S, Elvira P, Wang Y, Wang W. Growth and Nutrient Utilization of Green Algae in Batch and Semicontinuous Autotrophic Cultivation Under High CO2 Concentration. Appl Biochem Biotechnol 2019; 188:836-853. [DOI: 10.1007/s12010-018-02940-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/30/2018] [Indexed: 11/29/2022]
|
6
|
Huy M, Kumar G, Kim HW, Kim SH. Photoautotrophic cultivation of mixed microalgae consortia using various organic waste streams towards remediation and resource recovery. BIORESOURCE TECHNOLOGY 2018; 247:576-581. [PMID: 28982087 DOI: 10.1016/j.biortech.2017.09.108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 06/07/2023]
Abstract
In this study, mixed microalgae consortia was cultivated using digestate (D), animal manure (AM) and textile wastewater (TW) as growth medium providing mainly N (nitrogen) and P (phosphorous) sources without any extra nutrient addition. The corresponding total nitrogen (TN) and total phosphorous (TP, PO3-P) concentrations were noted as 323 and 21 for AM, 481 and 31 for TW and 747 and 55mg/L for D, respectively. After a cultivation period of 13days, P were completely removed (100%), however, N was still remain and attained the removal rate of 70.1, 72.3 and 16.7% for TW, AM and D, respectively. The peak growth rate and biomass production of 0.419d-1 and 0.4g/L (in terms of volatile solids, VS) was achieved using TW as growth medium.
Collapse
Affiliation(s)
- Menghour Huy
- Department of Environmental Engineering, Daegu University, Gyeongsan, Geoungbuk 38453, Republic of Korea
| | - Gopalakrishnan Kumar
- Department of Environmental Engineering, Daegu University, Gyeongsan, Geoungbuk 38453, Republic of Korea
| | - Hyun-Woo Kim
- Department of Environmental Engineering, Chonbuk National University, Jeonju, Jeonbuk 54896, Republic of Korea
| | - Sang-Hyoun Kim
- Department of Environmental Engineering, Daegu University, Gyeongsan, Geoungbuk 38453, Republic of Korea; Sustainable Environmental Process Research Institute, Daegu University, Gyeongsan, Gyeongbuk 38453, South Korea.
| |
Collapse
|
7
|
Anbalagan A, Schwede S, Lindberg CF, Nehrenheim E. Influence of iron precipitated condition and light intensity on microalgae activated sludge based wastewater remediation. CHEMOSPHERE 2017; 168:1523-1530. [PMID: 27939662 DOI: 10.1016/j.chemosphere.2016.11.161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 06/06/2023]
Abstract
The indigenous microalgae-activated sludge (MAAS) process during remediation of municipal wastewater was investigated by studying the influence of iron flocculation step and light intensity. In addition, availability of total phosphorous (P) and photosynthetic activity was examined in fed-batch and batch mode under northern climatic conditions and limited lighting. This was followed by a semi-continuous operation with 4 d of hydraulic retention time and mean cell residence time of 6.75 d in a photo-bioreactor (PBR) with varying P availability. The fed-batch condition showed that P concentrations of 3-4 mg L-1 were effective for photosynthetic chl. a development in iron flocculated conditions. In the PBR, the oxygen evolution rate increased with increase in the concentration of MAAS (from 258 to 573 mg TSS L-1) at higher surface photosynthetic active radiation (250 and 500 μmol m-2 s-1). Additionally, the rate approached a saturation phase at low MAAS (110 mg L-1) with higher light intensities. Semi-continuous operation with luxury P uptake and effective P condition showed stable average total nitrogen removal of 88 and 92% respectively, with residual concentrations of 3.77 and 2.21 mg L-1. The corresponding average P removal was 68 and 59% with residual concentrations of 2.32 and 1.75 mg L-1. The semi-continuous operation produced a rapidly settleable MAAS under iron flocculated condition with a settling velocity of 92-106 m h-1 and sludge volume index of 31-43 ml g-1 in the studied cases.
Collapse
Affiliation(s)
- Anbarasan Anbalagan
- Department of Energy, Building and Environment, Mälardalen University, SE-721 23, Västerås, Sweden.
| | - Sebastian Schwede
- Department of Energy, Building and Environment, Mälardalen University, SE-721 23, Västerås, Sweden
| | - Carl-Fredrik Lindberg
- Department of Energy, Building and Environment, Mälardalen University, SE-721 23, Västerås, Sweden; ABB AB, Corporate Research, SE-721 28, Västerås, Sweden
| | - Emma Nehrenheim
- Department of Energy, Building and Environment, Mälardalen University, SE-721 23, Västerås, Sweden
| |
Collapse
|
8
|
de Farias Silva CE, Sforza E. Carbohydrate productivity in continuous reactor under nitrogen limitation: Effect of light and residence time on nutrient uptake in Chlorella vulgaris. Process Biochem 2016. [DOI: 10.1016/j.procbio.2016.09.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
9
|
Effect of specific light supply rate on photosynthetic efficiency of Nannochloropsis salina in a continuous flat plate photobioreactor. Appl Microbiol Biotechnol 2015; 99:8309-18. [DOI: 10.1007/s00253-015-6876-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 07/16/2015] [Accepted: 07/18/2015] [Indexed: 12/31/2022]
|
10
|
Implication of Industrial Waste for Biomass and Lipid Production in Chlorella minutissima Under Autotrophic, Heterotrophic, and Mixotrophic Grown Conditions. Appl Biochem Biotechnol 2015; 176:1581-95. [DOI: 10.1007/s12010-015-1663-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/07/2015] [Indexed: 11/26/2022]
|
11
|
Saeid A, Chojnacka K. Toward production of microalgae in photobioreactors under temperate climate. Chem Eng Res Des 2015. [DOI: 10.1016/j.cherd.2014.06.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
12
|
Ruiz J, Arbib Z, Álvarez-Díaz P, Garrido-Pérez C, Barragán J, Perales J. Influence of light presence and biomass concentration on nutrient kinetic removal from urban wastewater by Scenedesmus obliquus. J Biotechnol 2014; 178:32-7. [DOI: 10.1016/j.jbiotec.2014.03.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/27/2014] [Accepted: 03/03/2014] [Indexed: 10/25/2022]
|
13
|
Xue S, Zhang Q, Wu X, Yan C, Cong W. A novel photobioreactor structure using optical fibers as inner light source to fulfill flashing light effects of microalgae. BIORESOURCE TECHNOLOGY 2013; 138:141-147. [PMID: 23612173 DOI: 10.1016/j.biortech.2013.03.156] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 03/20/2013] [Accepted: 03/22/2013] [Indexed: 06/02/2023]
Abstract
In this work, a novel photobioreactor structure using optical fibers being fixed vertically to culture flow direction as inner light source was proposed to fulfill flashing light effects (FLE) of microalgae, so as to obtain high light efficiency. Three types of optical-fiber photobioreactor fulfilling FLE of microalgae, i.e. air-driven panel, pump-driven panel and stirred tank type, were proposed and a 130 L airlift panel one was practically constructed on which both cold (light profile, liquid velocity) and hot model tests were carried out. Results demonstrated that it could produce uniformed light/dark frequencies being over 10 Hz and microalgae productivity increased by 43% and 38% for Spirulina platensis and Scenedesmus dimorphus respectively, compared with the control. This suggested the structure to be a viable and promising option for future photobioreactors.
Collapse
Affiliation(s)
- Shengzhang Xue
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | | | | | | | | |
Collapse
|
14
|
Ruiz J, Arbib Z, Alvarez-Díaz PD, Garrido-Pérez C, Barragán J, Perales JA. Photobiotreatment model (PhBT): a kinetic model for microalgae biomass growth and nutrient removal in wastewater. ENVIRONMENTAL TECHNOLOGY 2013; 34:979-991. [PMID: 23837349 DOI: 10.1080/09593330.2012.724451] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This article proposes a kinetic model for wastewater photobiotreatment with microalgae (the PhBT model). The PhBT model for nutrient uptake, coupled with the Verhulst growth model, is a simple and useful tool to describe batch experiments of nutrient removal by microalgae. The model has been validated with experiments of Chlorella vulgaris (C. vulgaris) grown in wastewater and different synthetic media. The model provided information about nitrogen and phosphorus limitation and their luxury uptake during the test. Productivity observed in synthetic medium (0.17 g SS L(-1) d(-1)) was similar to that obtained in nutrient enriched wastewater (0.15 g SS L(-1) d(-1)). Biomass productivity of this alga in wastewater and the efficient nutrient removal suggested that C. vulgaris could be cultured in wastewater for biomass production while nutrients are reduced from this stream.
Collapse
Affiliation(s)
- J Ruiz
- Department of Environmental Technology, Centro Andaluz de Ciencia y Tecnología Marinas (CACYTMAR), Campus de Excelencia Internacional del Mar (CEIMAR), University of Cádiz, Cádiz, Spain.
| | | | | | | | | | | |
Collapse
|
15
|
Kim TH, Lee Y, Han SH, Hwang SJ. The effects of wavelength and wavelength mixing ratios on microalgae growth and nitrogen, phosphorus removal using Scenedesmus sp. for wastewater treatment. BIORESOURCE TECHNOLOGY 2013; 130:75-80. [PMID: 23306113 DOI: 10.1016/j.biortech.2012.11.134] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 11/26/2012] [Accepted: 11/28/2012] [Indexed: 06/01/2023]
Abstract
In wastewater treatment using microalgae, the effects of wavelength and wavelength mixing ratio on microalgae growth and removal of nitrogen and phosphorus were evaluated using LEDs (white light, 670nm, 450nm, and 525nm). Microalgae production rates were enhanced by a maximum of 45% with 400-700nm white light compared to that of a single wavelength. The phosphorus removal rate was as high as 90% with blue light. When red light and blue light were mixed and supplied, the microalgae production rate was about 50% higher than the rate of the culture with white light. Nitrogen and phosphorus removal rates were as high as approximately 15mg/L/day at a wavelength mixing ratio of 7 (red light):3 (blue light) and 2.1mg/L/day at a wavelength mixing ratio of 5 (red light):5 (blue light).
Collapse
Affiliation(s)
- Tae-Hyeong Kim
- Department of Environmental Science and Engineering, Center for Environmental Studies, Kyung Hee University, Seochon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, Republic of Korea
| | | | | | | |
Collapse
|
16
|
Ruiz J, Álvarez-Díaz PD, Arbib Z, Garrido-Pérez C, Barragán J, Perales JA. Performance of a flat panel reactor in the continuous culture of microalgae in urban wastewater: prediction from a batch experiment. BIORESOURCE TECHNOLOGY 2013; 127:456-463. [PMID: 23138070 DOI: 10.1016/j.biortech.2012.09.103] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 09/23/2012] [Accepted: 09/26/2012] [Indexed: 06/01/2023]
Abstract
A laboratory-scale flat panel photobioreactor was operated for the continuous growth of Scenedesmus obliquus and consequent removal of nutrients in wastewater. This study develops a simple model by which biomass values in continuous operation can be predicted from kinetic growth parameters obtained from a shorter batch experiment. Based on this study, biomass concentrations and productivities in continuous operation can be successfully predicted as a function of the specific hydraulic retention time (HRT) assumed. Considerable biomass production and nutrient uptake from wastewater were achieved in the experiment. Optimum operating conditions for the reactor depend on the particular objective: the maximization of biomass production and carbon dioxide biofixation involves a HRT of 2 μ(-1) (specific growth rate), whereas efficient nutrient removal involves a HRT as close as possible to μ(-1) (as long as discharges comply fully with the parameters set); alternatively biomass intended for biodiesel or biogas production would involve a HRT > 2 μ(-1).
Collapse
Affiliation(s)
- J Ruiz
- Department of Environmental Technology, Centro Andaluz de Ciencia y Tecnología Marinas, University of Cádiz, Campus Universitario de Puerto Real, 11510 Puerto Real, Cádiz, Spain.
| | | | | | | | | | | |
Collapse
|
17
|
Powell N, Shilton AN, Pratt S, Chisti Y. Factors influencing luxury uptake of phosphorus by microalgae in waste stabilization ponds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:5958-62. [PMID: 18767651 DOI: 10.1021/es703118s] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Phosphorus removal in waste stabilization ponds (WSP) is highly variable, but the reasons for this are not well understood. Luxury uptake of phosphorus by microalgae has been studied in natural systems such as lakes but not under the conditions found in WSP. This work reports on the effects of phosphate concentration, light intensity, and temperature on luxury uptake of phosphorus by WSP microalgae in continuous culture bioreactors. Increasing temperature had a statistically significant "positive effect" on intracellular acid-insoluble polyphosphate concentration. It is likely that elevated temperature increased the rate of polyphosphate accumulation, but because the biomass was not starved of phosphate, the stored acid-insoluble polyphosphate was not utilized. Increasing light intensity had no effect on acid-insoluble polyphosphate but had a "negative effect" on the acid-soluble polyphosphate. A possible explanation for this is that the faster growth rate at high light intensity results in this form of polyphosphate being utilized by the cells for synthesis of cellular constituents at a rate that exceeds replenishment. The variability in the phosphorus content of the microalgal biomass shows that with this new understanding ofthe luxury uptake mechanism there is the potential to optimize WSP for biological phosphorus removal.
Collapse
Affiliation(s)
- Nicola Powell
- Centre for Environmental Technology and Engineering, Massey University, Private Bag 11-222, Palmerston North, New Zealand.
| | | | | | | |
Collapse
|