scholarly journals Comparative Performances of Microalgal-Bacterial Co-Cultivation to Bioremediate Synthetic and Municipal Wastewaters Whilst Producing Biodiesel Sustainably

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1427
Author(s):  
Wai Hong Leong ◽  
Kunlanan Kiatkittipong ◽  
Worapon Kiatkittipong ◽  
Yoke Wang Cheng ◽  
Man Kee Lam ◽  
...  

The potentiality of a microalgal-bacterial culture system was explored in bioremediating wastewater while generating biomass for biodiesel production. A pre-determined optimal activated sludge and microalgal ratio was adopted and cultivation performance was evaluated in both synthetic and municipal wastewater media for nitrogen removal along with biomass and lipid generation for biodiesel production. The microalgal-bacterial consortium grown in the municipal wastewater medium produced higher biomass and lipid yields than those in the synthetic wastewater medium. The presence of trace elements in the municipal wastewater medium, e.g., iron and copper, contributed to the upsurge of biomass, thereby leading to higher lipid productivity. Both the microbial cultures in the synthetic and municipal wastewater media demonstrated similar total nitrogen removal efficiencies above 97%. However, the nitrification and assimilation rates were relatively higher for the microbial culture in the municipal wastewater medium, corresponding to the higher microbial biomass growth. Accordingly, the feasibility of the microalgal-bacterial consortium for bioremediating real municipal wastewaters was attested in this study by virtue of higher biomass and lipid production. The assessment of fatty acid methyl esters (FAME) composition showed the mixed microbial biomasses comprised 80–93% C16 to C18 FAME species, signifying efficient fuel combustion properties for quality biodiesel requirements.

1994 ◽  
Vol 29 (10-11) ◽  
pp. 431-438 ◽  
Author(s):  
Y. Watanabe ◽  
D. Y. Bang ◽  
K. Itoh ◽  
K. Matsui

This paper concerns simultaneous nitrification and denitrification in a completely mixed bio-reactor with partially and fully submerged rotating biological contactors. The bio-reactor is designed to cause the nitrification and denitrification in partially and fully submerged biofilms, respectively. An experimental investigation was made into the effect of organic material and ratio of influent organic carbon to ammonia nitrogen concentrations(C/N ratio) on the efficiency of simultaneous nitrification and denitrification in the bio-reactor. Settled municipal wastewater and synthetic wastewater containing ammonia nitrogen and organic material such as acetate, ethylene-glycol, phenol and poly-vinyl-alcohol(PVA) were fed into the experimental units. A biofilm dominated by nitrifiers developed on the partially submerged contactors, while a biofilm dominated by heterotrophs developed on the fully submerged contactors. A micro-aerobic environment was formed and biological denitrification occurred in the submerged biofilm. In the municipal wastewater treatment where the influent C/N ratio was around 3.5, the maximum nitrogen removal efficiency was about 60 %. Acetate and ethlene-glycol were effectively used as the organic source of the denitrification. The ability to aerobically degrade PVA was induced by phenol. Once the bacteria inhibiting the biofilm gained the ability to degrade PVA, PVA became an effective organic source of the denitrification.


2022 ◽  
Vol 11 (1) ◽  
pp. e37411125049
Author(s):  
Glalber Luiz da Rocha Ferreira ◽  
José Daniel Gonçalves Vieira ◽  
Emmanuel Bezerra D’Alessandro

Fungi are a promising alternative source of oil to produce biodiesel, still very little known. The identification of a species with desirable characteristics is a fundamental component to achieve the economic viability of the process. The study aimed to carry out the evaluation of the fungus Aspergillus terreus in different culture media and different temperatures, the production of fungal biomass and in line with obtaining the profile of methyl esters of fatty acids. The fungal biomass revealed that in the NBRIP medium at both a temperature of 29 ºC and 36 ºC, it resulted in a great potential in the production of saturated fatty acids (SFA), which have excellent combustion properties, reaching values of 35.89 and 34,89%, respectively. For most species, the fuel would need to be mixed to make up culture conditions to be optimized and achieve the correct lipid profile, so that the fungal fuel meets European biodiesel production standards (EN 14214). Aspergillus terreus from iron ore tailings proved to be a promising microbial biomass as an energy source in the production of biodiesel.


2018 ◽  
Vol 78 (1) ◽  
pp. 174-182 ◽  
Author(s):  
P. Foladori ◽  
S. Petrini ◽  
M. Nessenzia ◽  
G. Andreottola

Abstract The optimization of total nitrogen removal from municipal wastewater was investigated in a laboratory-scale photo-sequencing batch reactor (PSBR) operated with a mixed microalgal–bacterial consortium spontaneously acclimatized to real wastewater. No external aeration was provided in the PSBR to reduce energy consumption: oxygen was only supplied by the microalgal photosynthesis. The enhancement of total nitrogen removal was achieved through: (1) feeding of wastewater in the dark phase to provide readily biodegradable COD when oxygen was not produced, promoting denitrification; (2) intermittent use of the mixer to favor simultaneous nitrification–denitrification inside the dense flocs and to achieve 41% energy saving with respect to continuous mixing. Efficient COD removal (86 ± 2%) was observed, obtaining average effluent concentrations of 37 mg/L and 22 mg/L of total COD and soluble COD, respectively. TKN removal was 97 ± 3%, with an average effluent concentration of 0.5 ± 0.7 mg NH4+-N/L. Assimilation of nitrogen by heterotrophic bacteria accounted only for 20% of TKN removal, whilst the major part of TKN was nitrified. In particular, the nitrification rate was 1.9 mgN L−1 h−1 (specific rate 2.4 mgN gTSS−1 h−1), measured with dissolved oxygen near zero, when the oxygen demand was higher than the oxygen produced by photosynthesis. Total nitrogen of 6.3 ± 4.4 mgN/L was measured in the effluent after PSBR optimization.


2013 ◽  
Vol 12 (12) ◽  
pp. 2371-2383
Author(s):  
Krishnaswamy Usharani ◽  
Perumalsamy Lakshmanaperumalsamy ◽  
Muthusamy Muthukumar

2019 ◽  
Author(s):  
Chem Int

Biodiesel produced by transesterification process from vegetable oils or animal fats is viewed as a promising renewable energy source. Now a day’s diminishing of petroleum reserves in the ground and increasing environmental pollution prevention and regulations have made searching for renewable oxygenated energy sources from biomasses. Biodiesel is non-toxic, renewable, biodegradable, environmentally benign, energy efficient and diesel substituent fuel used in diesel engine which contributes minimal amount of global warming gases such as CO, CO2, SO2, NOX, unburned hydrocarbons, and particulate matters. The chemical composition of the biodiesel was examined by help of GC-MS and five fatty acid methyl esters such as methyl palmitate, methyl stearate, methyl oleate, methyl linoleate and methyl linoleneate were identified. The variables that affect the amount of biodiesel such as methanol/oil molar ratio, mass weight of catalyst and temperature were studied. In addition to this the physicochemical properties of the biodiesel such as (density, kinematic viscosity, iodine value high heating value, flash point, acidic value, saponification value, carbon residue, peroxide value and ester content) were determined and its corresponding values were 87 Kg/m3, 5.63 Mm2/s, 39.56 g I/100g oil, 42.22 MJ/Kg, 132oC, 0.12 mgKOH/g, 209.72 mgKOH/g, 0.04%wt, 12.63 meq/kg, and 92.67 wt% respectively. The results of the present study showed that all physicochemical properties lie within the ASTM and EN biodiesel standards. Therefore, mango seed oil methyl ester could be used as an alternative to diesel engine.


2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.


2004 ◽  
Vol 39 (4) ◽  
pp. 319-330 ◽  
Author(s):  
Sandra Kok

Abstract Under the Government of Canada's Great Lakes Program, the Great Lakes Sustainability Fund and its predecessor programs (the Great Lakes Cleanup Fund and the Great Lakes 2000 Cleanup Fund) were established to implement cleanup actions and strategies that would contribute to the restoration of beneficial uses in environmentally degraded areas (known as Areas of Concern) in the Great Lakes basin. The Great Lakes Sustainability Fund is administered by Environment Canada on behalf of eight Government of Canada departments. Contributing to impaired beneficial uses are municipal wastewaters generated from the urban centres in the Great Lakes Areas of Concern. These municipal wastewaters include treated sewage and wetweather discharges of combined sewer overflows and stormwater runoff. This paper provides an overview of the Municipal Wastewater Program of the federal government's Great Lakes Sustainability Fund and highlights the progress made to date under the program towards wet-weather flow management and the Program's role in developing and demonstrating sustainable approaches and technologies in the Great Lakes Areas of Concern.


1996 ◽  
Vol 34 (5-6) ◽  
pp. 163-171 ◽  
Author(s):  
Celal F. Gökçay ◽  
Ulku Yetis

Biomass yield of microorganisms is important in applied microbiology since it is the ultimate factor determining the amount of product produced regardless of whether product is growth-linked or not. In the case of environmental microbiology the opposite is true and minimizing the biomass produced, or the sludge in the relevant jargon, often is the prime goal. In this paper, a unique means of manipulating the microbial biomass yield of a heterogeneous culture to fulfil either of the two goals is presented. 5.0 mgl−1 Ni(II) in the feed composition to a completely mixed, once- through, activated sludge was found to induce the observed biomass yield of the microbial culture developed from sewage. As compared with the base-line study without Ni(II), where the reactor received synthetic wastewater only, true biomass yield was found to have increased along with the increased decay constant with the net effect of lowering observed biomass yield drastically at lower dilution rates and increasing it over that observed in the base-line study at higher dilution rates. At 10.0 mgl−1 influent Ni(II) concentration the culture conditions almost reverted back to the base- line study and at 25 mgl−1 Ni(II) concentration a truly steady-state condition could not be attained.


2018 ◽  
Vol 9 (1) ◽  
pp. 133-139
Author(s):  
Waleed S. Mohammed ◽  
Ahmed H. El-Shazly ◽  
Marwa F. Elkady ◽  
Masahiro Ohshima

Introduction: The utilization of biodiesel as an alternative fuel is turning out to be progressively famous these days because of worldwide energy deficiency. The enthusiasm for utilizing Jatropha as a non-edible oil feedstock is quickly developing. The performance of the base catalyzed methanolysis reaction could be improved by a continuous process through a microreactor in view of the high mass transfer coefficient of this technique. Materials & Methods: Nanozirconium tungstovanadate, which was synthetized using sol-gel preparation method, was utilized in a complementary step for biodiesel production process. The prepared material has an average diameter of 0.066 &µm. Results: First, the NaOH catalyzed methanolysis of Jatropha oil was investigated in a continuous microreactor, and the efficient mixing over different mixers and its impact on the biodiesel yield were studied under varied conditions. Second, the effect of adding the nanocatalyst as a second stage was investigated. Conclusion: The maximum percentage of produced methyl esters from Jatropha oil was 98.1% using a methanol/Jatropha oil molar ratio of 11 within 94 s using 1% NaOH at 60 &°C. The same maximum conversion ratio was recorded with the nanocatalyst via only 0.3% NaOH.


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