scholarly journals Cultivation of the Acidophilic Microalgae Galdieria phlegrea with Wastewater: Process Yields

Author(s):  
Maria Rosa di Cicco ◽  
Maria Palmieri ◽  
Simona Altieri ◽  
Claudia Ciniglia ◽  
Carmine Lubritto

Algal based wastewater treatment offers the opportunity to recover, in the form of biomass, the nutrients and internal chemical energy of wastewater. Recently, there has been a growing interest in the use of extremophilic microalgae, as they can easily adapt to difficult and often pollutant-rich environments. The thermo-acidophilic microalga Galdieria phlegrea is a species of recent discovery and great metabolic versatility, but it has still been poorly studied. Here, G. phlegrea was cultivated using raw municipal wastewater in 1 L Erlenmeyer flasks with 700 mL working volume at 37 °C for up to nine days. During the cultivation phase, biomass growth, phycocyanin content, ammonium and phosphate removal from the wastewater, lipid fraction, total carbon and nitrogen in the biomass, and variation in δ13C and δ15N isotopic ratios (a novel analytical contribution in these experiments) were monitored. Results indicated that G. phlegrea was able to grow in raw effluent, where it removed more than 50% ammonium and 20% phosphate in 24 h; total lipid content was in the range of 11–22%, while average C-N content was of 45% and 6%, respectively; isotopic analyses proved to be a useful support in identifying C and N metabolic pathways from effluent to biomass. Overall, G. phlegrea showed consistent performance with similar Cyanidiophyceae and is a potentially viable candidate for municipal wastewater valorization from a circular economy perspective.

1994 ◽  
Vol 30 (6) ◽  
pp. 237-246 ◽  
Author(s):  
A. Carucci ◽  
M. Majone ◽  
R. Ramadori ◽  
S. Rossetti

This paper describes a lab-scale experimentation carried out to study enhanced biological phosphate removal (EBPR) in a sequencing batch reactor (SBR). The synthetic feed used was based on peptone and glucose as organic substrate to simulate the readily biodegradable fraction of a municipal wastewater (Wentzel et al., 1991). The experimental work was divided into two runs, each characterized by different operating conditions. The phosphorus removal efficiency was considerably higher in the absence of competition for organic substrate between P-accumulating and denitrifying bacteria. The activated sludge consisted mainly of peculiar microorganisms recently described by Cech and Hartman (1990) and called “G bacteria”. The results obtained seem to be inconsistent with the general assumption that the G bacteria are characterized by anaerobic substrate uptake not connected with any polyphosphate metabolism. Supplementary anaerobic batch tests utilizing glucose, peptone and acetate as organic substrates show that the role of acetate in the biochemical mechanisms promoting EBPR may not be so essential as it has been assumed till now.


2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Nicole R. Gay ◽  
Elizabeth Fleming ◽  
Julia Oh

Cloacibacterium normanense is a Gram-negative bacterium recovered from untreated human wastewater. Given its high abundance in wastewater and its apparent absence in human stool, it may contribute to biological phosphate removal. Here, we perform a whole-genome sequence of C. normanense NRS-1(T) and examine particular features of this draft genome.


2020 ◽  
Vol 17 (2) ◽  
pp. 946-949
Author(s):  
Samaneh Alijantabar Aghouzi ◽  
Thomas S. Y. Choong ◽  
M. I. Aida Isma

This study elucidates the performance of sequencing batch reactor for nutrient removal from municipal wastewater. The removal of COD, ammonia nitrogen and phosphorus were investigated. The SBR with a working volume of 5 L was operated for 6 hours, with 5 min fill, 30 min settle and 5 min effluent withdrawal. The remaining time in each cycle was 90 min anaerobic phase, 130 min anoxic phase and 110 min aerobic phase. The experiment was repeated with a longer aeration time of 180 min resulting to prolong the duration cycle. In the aerobic phase, dissolved oxygen was kept in the range of more than 2 mg/L. During batch operation, the system attained stability and had a removal efficiency for ammonia nitrogen, COD and phosphorus of 51.36%, 83.33% and 99.53%, respectively. Extending the aeration period improved ammonia nitrogen removal to 54.27%. It should be noted that the stability of the granular biomass agglomerates highly depending on the bacterial consortia. The particle size of sludge reduced from 60.26 μm to 39.00 μm in 60 days. It was observed that degranulation process and biomass loss was unavoidable.


2015 ◽  
Vol 773-774 ◽  
pp. 1173-1177
Author(s):  
Mohd Afindy Abd Kadir ◽  
Ab Aziz Abdul Latiff ◽  
Zawawi Daud

. A combined laboratory-scale system UASB-DFAF and HUASB-DFAF was operated for treating Municipal wastewater at six hydraulic retention times (HRT) of 45.08, 30.06, 22.54, 18.03, 15.03, 12.88 h. COD removal efficiency in range from 72% to 82% in UASB, while in HUASB range from 84 to 89% with decrease of HRT. There are several method have been developed to represent biodegration of municipal sewerage in a combined treatment system. The Monod, Grou second-order and first order model have been used to analyze this studies. The combined of HUASB reactor, 5.41 L working volume, followed by DFAF reactor, having a working volume 2.67L were analyzed. The kinetic parameters were determined through line regression using experimental data. The predicted COD concentration was calculated using the kinetic constant. The kinetic models applied for this study were Grou second-order, followed by first order method and Monod method.


2021 ◽  
Author(s):  
Moritz Mainka ◽  
Laura Summerauer ◽  
Daniel Wasner ◽  
Gina Garland ◽  
Marco Griepentrog ◽  
...  

Abstract. A central question in carbon research is how stabilization mechanisms in soil change over time with soil development and how this is reflected in qualitative changes of soil organic matter (SOM). To address this matter, we assessed the influence of soil geochemistry on bulk SOM composition along a soil chronosequence in California, USA spanning 3 million years. This was done by combining data on soil mineralogy and texture from previous studies with additional measurements on total carbon (C), stable isotope values (δ13C and δ15N), and spectral information derived from Diffuse Reflectance Infrared Fourier-Transform Spectroscopy (DRIFTS). To assess qualitative shifts in bulk SOM, we analysed the peak areas of simple plant-derived (S-POM), complex plant-derived (C-POM), and predominantly microbially derived OM (MOM) and their changes in abundance across soils varying several millennia to millions of years in weathering and soil development. We observed that SOM became increasingly stabilized and microbially-derived (lower C : N ratio, increasing δ13C and δ15N) as soil weathering progresses. Peak areas of S-POM (i.e. aliphatic root exudates) did not change over time, while peak areas of C-POM (lignin) and MOM (components of microbial cell walls (amides, quinones, and ketones)) increased over time and depth and were closely related to clay content and pedogenic iron oxides. Hence, our study suggests that with progressing soil development, SOM composition co-varies with changes in the mineral matrix. Our study indicates that a discrimination in favour of structurally more complex OM compounds (C-POM, MOM) gains importance as the mineral soil matrix becomes increasingly weathered.


Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1094
Author(s):  
Marco Chiappero ◽  
Francesca Cillerai ◽  
Franco Berruti ◽  
Ondřej Mašek ◽  
Silvia Fiore

Biochar (BC) recently gained attention as an additive for anaerobic digestion (AD). This work aims at a critical analysis of the effect of six BCs, with different physical and chemical properties, on the AD of mixed wastewater sludge at 37 °C, comparing their influence on methane production and AD kinetics. AD batch tests were performed at the laboratory scale operating 48 reactors (0.25 L working volume) for 28 days with the addition of 10 g L−1 of BC. Most reactors supplemented with BCs exhibited higher (up to 22%) methane yields than the control reactors (0.15 Nm3 kgVS−1). The modified Gompertz model provided maximum methane production rate values, and in all reactors the lag-phase was equal to zero days, indicating a good adaptation of the inoculum to the substrate. The potential correlations between BCs’ properties and AD performance were assessed using principal component analysis (PCA). The PCA results showed a reasonable correlation between methane production and the BCs’ O–C and H–C molar ratios, and volatile matter, and between biogas production and BCs’ pore volume, specific surface area, and fixed and total carbon. In conclusion, the physic-chemical properties of BC (specifically, hydrophobicity and morphology) showed a key role in improving the AD of mixed wastewater sludge.


2020 ◽  
Vol 48 (4) ◽  
pp. 552-569 ◽  
Author(s):  
Paloma G. Juárez-Camargo ◽  
Atahualpa Sosa-López ◽  
Yassir Edén Torres-Rojas ◽  
Edgar Fernando Mendoza-Franco ◽  
Sergio Aguiñiga García

The study of the feeding habits variability (spatial and temporal scales) allows us to evaluate the trophic interactions between species, thus, the short and long-term effects of the removal of different species by the presence of different phenomena. In this study, we carried out stable isotope (δ13C and δ15N) and stomach content analyses to infer the trophic linkages between two snapper species (Lutjanus synagris and Lutjanus griseus) captured in the littoral of Campeche, Mexico. In total, 781 specimens were collected (528 L. synagris and 253 L. griseus) and based on relative importance index [%PSIRI] both snapper species consumed based on the prey-specific index of relative importance (PSIRI), Penaeidae family (PSIRI = 23.41%) was the most important species in the diet of Lutjanus synagris, while Callinectes sapidus (PSIRI = 21.45%) was the primary prey of Lutjanus griseus. The isotopic analyses indicated that both snapper species feed in the coastal-marine (δ15N: 10.6 to 12.1‰ and δ13C: -15.7 to -12.7‰); however, according to PERMANOVA, low diet similarity was found between snapper species (R = 0.07, P < 0.01), also, significant differences was detected in the δ15N and δ13C values between L. synagris, and L. griseus. Therefore, despite both snapper species presents similar trophic positions (L. synagris: 4.2 ± 0.2; L. griseus: 3.9 ± 0.1) and feeding behavior (according to SIBER = opportunistic predators), a low trophic overlap was observed, probably associated with the differential use of habitat in the coastal zone; where L. synagris is ecologically fed in areas of seagrass, while L. griseus is probably intermittent between pasture and mangrove areas, therefore, the role of each species is crucial in the dynamics of coastal-marine ecosystems as predators and potential structuring of the populations of their prey.


2020 ◽  
Vol 13 ◽  
pp. 117862212096965
Author(s):  
Yohannis Fetene ◽  
Taffere Addis

Phosphorous from municipal and industrial wastewater is the main cause of eutrophication of rivers and lakes, because effluent quality from conventional secondary wastewater treatment plants does not meet the discharge standard that demands further treatment. Therefore, we investigated pumice as a potential low-cost adsorbent for the tertiary treatment of phosphate from municipal wastewater. The phosphate adsorption process reached equilibrium after 60 minutes contact time and achieved a removal efficiency of 94.4% ± 0.7% for an adsorbent dose of 10 g/L in 3 mg/L phosphate solution. The highest phosphate removal was recorded at pH 7. The experimental data best fitted with the Redlich-Peterson isotherm and the pseudo-second-order kinetic models. The coexisting anions decreased phosphate adsorption in the order of mixture >SO42– > HCO3− > NO3− > Cl− > CO3−. Pumice removed 95% ± 0.2% of phosphate from effluents of the secondary treatment unit of a municipal wastewater treatment plant. Furthermore, effective regeneration of saturated pumice was possible with a 0.2 M NaOH solution. Therefore, pumice could be a technically workable low-cost reusable adsorbent for phosphate removal from wastewater as a tertiary treatment to curb eutrophication of surface waters. However, further column adsorption study is recommended for a continuous flow system to optimize process design variables and scale up for field applications.


2000 ◽  
Vol 42 (12) ◽  
pp. 33-48 ◽  
Author(s):  
H. Ødegaard

Advanced compact wastewater treatment processes are being looked for by cities all over the world as effluent standards are becoming more stringent and land available for treatment plants more scarce. In this paper it is demonstrated that a very substantial portion of the pollutants in municipal wastewater appears as particulate and colloidal matter. Pre-coagulation, therefore, gives very efficient pre-treatment that results in considerable saving in the total space required by the plant, especially when combined with a biofilm process for the removal of the soluble matter. A new biofilm process for this purpose is described. The moving bed biofilm process is based on plastic carriers, that move in the reactor, on which biomass attach and grow. The carriers are kept withinthe reactor by a sieve arrangement and biomass that is sloughing off the carriers is separated before effluent discharge. In addition to combining the moving bed biofilm process with pre-coagulation, the paper discusses also the use of a high-rate moving bed process combined with coagulation directly after the biofilm reactor in order to enhance separability. This results in very compact treatment plants for secondary treatment and possibly phosphate removal.


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