scholarly journals Remediation of Aquaculture Wastewater Using the Microalga Chlorella sorokiniana

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3144
Author(s):  
Libardo A. Lugo ◽  
Ragnheidur I. Thorarinsdottir ◽  
Sigfus Bjornsson ◽  
Olafur P. Palsson ◽  
Hakon Skulason ◽  
...  

The aquaculture industry requires solutions to several environmental challenges in order to become sustainable, including adequate wastewater management. Aquaculture wastewater (AWW) is rich in nitrogen, phosphorus, organic carbon, and other elements essential for microalgae. Due to the potential for AWW to be used as a microalgal growth medium and the potential of Chlorella sorokiniana to remediate wastewater, the growth of this species in AWW was evaluated. The microalgal growth in AWW was compared to the growth in a modified BG11 growth medium containing similar nutrient concentrations as the AWW. The effect of pH regulation and air-lifting the cell suspension at different airflow rates was also studied. As a result, it was found that C. sorokiniana can grow successfully in AWW; however, its cultivation required pH regulation. This microalga species can reach a biomass concentration of up to 476 mg/L and a biomass productivity of 140 mg/L/day. Furthermore, up to 78% of the nitrogen, 77% of the phosphorus, 70% of the magnesium, 90% of the zinc, and 99% of the nickel contained in the AWW were assimilated by the microalgae. The results of this study show that microalga cultivation in wastewater has great potential to reduce contamination while generating economic benefits.

2021 ◽  
Author(s):  
Poone Yaqoubnejad ◽  
Hassan Aminirad ◽  
Mohsen Taghavijeloudar

Abstract The cultivation conditions of a newly isolated strain Chlorella sorokiniana pa.91 were optimized for the first time by performing sixty batch cultivation experiments at various temperatures (20, 25, 30 and 35 °C) and light intensities (1000, 3000, 4000, 5000 and 7000 Lux) in three different culture mediums of BG-11, real settled municipal wastewater (RMWW) and synthetic wastewater (SWW). Additionally, to evaluate the capability of C. sorokiniana pa.91 in CO2 bio-fixation and wastewater treatment, the microalgae was cultivated in a flat-plate photobioreactor (CO2 = 16% and 0.6 vvm aeration) under the optimal condition. The optimization results suggested that at the culture conditions of 30 °C, 4000 Lux and RMWW (COD 211 mgL-1) microalgae had the best performance in growth and biomass productivity. Maximum biomass concentration and productivity of 3.21 gL-1 and 0.31 gL-1d-1were achieved, respectively, by cultivation of C. sorokiniana pa.91 in the photobioreactor under the optimized condition. Experimental results showed that C. sorokiniana pa.91 has a high capacity of CO2 bio-fixation (0.59 mgL-1d-1) and CO2 removal rate (35.6 %). Moreover, using C. sorokiniana pa.91 could efficiently remove 74% of NH3, 93% of NO3-, 83% of PO4-3 and 76% of COD from real municipal wastewater after eight days of cultivation in the photobioreactor.


2002 ◽  
Vol 27 (2) ◽  
pp. 141-150 ◽  
Author(s):  
RUI G. CARNEIRO ◽  
PAULO MAZZAFERA ◽  
LUIZ CARLOS C.B. FERRAZ ◽  
TAKASHI MURAOKA ◽  
PAULO CESAR O. TRIVELIN

Two soybean (Glycine max) cultivars were used in this study, Ocepar 4, rated as moderately resistant to Meloidogyne incognita race 3 but susceptible to M. javanica, and 'BR 16', susceptible to both nematodes. The effect of nematodes infection on the uptake and transport of N, P and Ca to the shoot was studied in plants growing in a split root system. The upper half was inoculated with 0, 3,000, 9,000 or 27,000 eggs/plant while the lower half received 15N, 32P or 45Ca. Infected plants showed an increase of root but a decrease of shoot mass with increasing inoculum levels. In general, total endogenous nutrients increased in the roots and tended to decrease in the shoots with increasing inoculum levels. When concentrations were calculated, there was an increase in the three nutrients in the roots, and an increase of Ca but no significant variation of N and P was observed in the shoots. The total amount of 15N in the roots increased at the highest inoculum levels but 32P and 45Ca decreased. In the shoots there was a reduction of 32P and 45Ca. The specific concentrations of the labelled nutrients (abundance or radioactivity/tissue mass) also showed a decrease of 32P and 45Ca in the shoots and roots of infected plants and an increase of 15N in the shoots. Considering that overall nutrient concentrations reflect cumulative nutrient uptake and the data from labelled elements gave information at a specific moment of the infection, thus nematodes do interfere with nutrient uptake and translocation.


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 463 ◽  
Author(s):  
Ali Nawaz Kumbhar ◽  
Meilin He ◽  
Abdul Razzaque Rajper ◽  
Khalil Ahmed Memon ◽  
Muhammad Rizwan ◽  
...  

The decline in fossil fuel reserves has forced researchers to seek out alternatives to fossil fuels. Microalgae are considered to be a promising feedstock for sustainable biofuel production. Previous studies have shown that urea is an important nitrogen source for cell growth and the lipid production of microalgae. The present study investigated the effect of different concentrations of urea combined with kelp waste extract on the biomass and lipid content of Chlorella sorokiniana. The results revealed that the highest cell density, 20.36 × 107 cells−1, and maximal dry biomass, 1.70 g/L, were achieved in the presence of 0.5 g/L of urea combined with 8% kelp waste extract. Similarly, the maximum chlorophyll a, b and beta carotenoid were 10.36 mg/L, 7.05, and 3.01 mg/L, respectively. The highest quantity of carbohydrate content, 290.51 µg/mL, was achieved in the presence of 0.2 g/L of urea and 8% kelp waste extract. The highest fluorescence intensity, 40.05 × 107 cells−1, and maximum total lipid content (30%) were achieved in the presence of 0.1 g/L of urea and 8% kelp waste extract. The current study suggests that the combination of urea and kelp waste extract is the best strategy to enhance the biomass and lipid content in Chlorella sorokiniana.


2015 ◽  
Vol 52 (2) ◽  
pp. 59-70 ◽  
Author(s):  
J. Vanags ◽  
L. Kunga ◽  
K. Dubencovs ◽  
V. Galvanauskas ◽  
O. Grīgs

Abstract Optimization of the microalgae cultivation process and of the bioprocess in general traditionally starts with cultivation experiments in flasks. Then the scale-up follows, when the process from flasks is transferred into a laboratory-scale bioreactor, in which further experiments are performed before developing the process in a pilot-scale reactor. This research was done in order to scale-up the process from a 0.4 1 shake flask to a 4.0 1 laboratory-scale stirred-tank photobioreactor for the cultivation of Desmodesmus (D.) communis microalgae. First, the effect of variation in temperature (21-29 ºC) and in light intensity (200-600 μmol m-2s-1) was studied in the shake-flask experiments. It was shown that the best results (the maximum biomass concentration of 2.72 g 1-1 with a specific growth rate of 0.65 g g-1d-1) can be achieved at the cultivation temperature and light intensity being 25 °C and 300 μmol m2s-1, respectively. At the same time, D. communis cultivation under the same conditions in stirred-tank photobioreactor resulted in average volumetric productivities of biomass due to the light limitation even when the light intensity was increased during the experiment (the maximum biomass productivity 0.25 g 1-1d-1; the maximum biomass concentration 1.78 g 1-1).


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hee Su Kim ◽  
Won-Kun Park ◽  
Bongsoo Lee ◽  
Gyeongho Seon ◽  
William I. Suh ◽  
...  

AbstractThe heterotrophic cultivation of microalgae has a number of notable advantages, which include allowing high culture density levels as well as enabling the production of biomass in consistent and predictable quantities. In this study, the full potential of Chlorella sp. HS2 is explored through optimization of the parameters for its heterotrophic cultivation. First, carbon and nitrogen sources were screened in PhotobioBox. Initial screening using the Plackett-Burman design (PBD) was then adopted and the concentrations of the major nutrients (glucose, sodium nitrate, and dipotassium phosphate) were optimized via response surface methodology (RSM) with a central composite design (CCD). Upon validation of the model via flask-scale cultivation, the optimized BG11 medium was found to result in a three-fold improvement in biomass amounts, from 5.85 to 18.13 g/L, in comparison to a non-optimized BG11 medium containing 72 g/L glucose. Scaling up the cultivation to a 5-L fermenter resulted in a greatly improved biomass concentration of 35.3 g/L owing to more efficient oxygenation of the culture. In addition, phosphorus feeding fermentation was employed in an effort to address early depletion of phosphate, and a maximum biomass concentration of 42.95 g/L was achieved, with biomass productivity of 5.37 g/L/D.


Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 1351-1360 ◽  
Author(s):  
M. J. Fernández-Sanjurjo ◽  
E. Alvarez-Rodríguez ◽  
A. Núñez-Delgado ◽  
M. L. Fernández-Marcos ◽  
A. Romar-Gasalla

Abstract. The objective of this work was to study nutrients release from two compressed nitrogen–potassium–phosphorous (NPK) fertilizers. In the Lourizán Forest Center, tablet-type controlled-release fertilizers (CRF) were prepared by compressing various mixtures of fertilizers without covers or binders. We used soil columns (50 cm long and 7.3 cm inner diameter) that were filled with soil from the surface layer (0–20 cm) of an A horizon corresponding to a Cambic Umbrisol. Tablets of two slow-release NPK fertilizers (11–18–11 or 8–8–16) were placed into the soil (within the first 3 cm), and then water was percolated through the columns in a saturated regime for 80 days. Percolates were analyzed for N, P, K+, Ca2+ and Mg2+. These elements were also determined in soil and fertilizer tablets at the end of the trials. Nutrient concentrations were high in the first leachates and reached a steady state when 1426 mm of water had been percolated, which is equivalent to approximately 1.5 years of rainfall in this geographic area. In the whole trial, both tablets lost more than 80% of their initial N, P and K contents. However, K+, Ca2+ and Mg2+ were the most leached, whereas N and P were lost in leachates to a lesser extent. Nutrient release was slower from the tablet with a composition of 8–8–16 than from the 11–18–11 fertilizer. In view of that, the 8–8–16 tablet can be considered more adequate for crops with a nutrient demand sustained over time. At the end of the trial, the effects of these fertilizers on soil chemical parameters were still evident, with a significant increase of pH, available Ca2+, Mg2+, K+, P and effective cation exchange capacity (eCEC) in the fertilized columns, as well as a significant decrease in exchangeable Al3+, reaching values < 0.08 cmol (+) kg−1.


2020 ◽  
Vol 12 (6) ◽  
pp. 2224
Author(s):  
Jie Shi ◽  
Qian Leng ◽  
Junying Zhu ◽  
Huiwang Gao ◽  
Xinyu Guo ◽  
...  

A marine ecosystem box model was developed to reproduce the seasonal variations nutrient concentrations and phytoplankton biomasses in Jiaozhou Bay (JZB) of China. Then, by removing each of the external sources of nutrients (river input, aquaculture, wastewater discharge, and atmospheric deposition) in the model calculation, we quantitatively estimated its influences on nutrient structure and the phytoplankton community. Removing the river input of nutrients enhanced silicate (SIL) limitation to diatoms (DIA) and decreased the ratio of DIA to flagellates (FLA); removing the aquaculture input of nutrients decreased FLA biomass because it provided less dissolved inorganic nitrogen (DIN) but more dissolved inorganic phosphate (DIP) as compared to the Redfield ratio; removing the wastewater input of nutrients changed the DIN concentration dramatically, but had a relatively weaker impact on the phytoplankton community than removing the aquaculture input; removing atmospheric deposition had a negligible influence on the model results. Based on these results, we suppose that the change in the external nutrients sources in the past several decades can explain the long-term variations in nutrient structure and phytoplankton community. Actually, the simulations for the 1960s, 1980s, and 2000s in JZB demonstrated the shift of limiting nutrients from DIP to SIL. A reasonable scenario for this is the decrease in riverine SIL and increase in DIP from aquaculture that has reduced DIA biomass, promoted the growth of FLA, and led to the miniaturization of the phytoplankton.


1997 ◽  
Vol 13 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Nicholas C. Songwe ◽  
F. E. Fasehun ◽  
D. U. U. Okali

ABSTRACTThe variations in macronutrient concentrations of the leaves of Terminalia superba and Pycanthus angolensis were studied and the concentrations of nutrients in leaves before abscission were compared with those after abscission. The amounts of nutrients returned to the forest floor were also computed from litter fall data at the start of maximum annual fall in the Reserve. With the exception of potassium in Pycanthus angolensis, there were significant variations in the nutrient concentrations of the two species with the time of year. With increasing leaf age the concentration of nitrogen, phosphorus, potassium and magnesium declined in Terminalia superba while magnesium concentration decreased in Pycanthus angolensis leaves. Furthermore, calcium showed an increasing concentration in Terminalia superba with increase in leaf age. The concentrations of nitrogen, phosphorus and potassium decreased before leaf fall. Estimated losses in nitrogen phosphorus and potassium before abscission were 44, 53 and 50%, respectively, whereas generally there was an increase (40%) in the concentration of calcium at leaf fall. Magnesium did not follow a definite pattern. The return of calcium through litter fall to the forest floor was the greatest of all the major elements. The distribution and variation of foliar nutrient concentrations in the leaves of Terminalia superba and Pycanthus angolensis and the importance of the amount of litter and the concentration of the various nutrients in the influencing soil fertility are discussed.


Author(s):  
Ravina Pawar ◽  
A. K. Singh ◽  
K. P. Raverkar ◽  
Chiranjeev Kumawat ◽  
Johnson Lakra

An investigation was undertaken to study the effect of micronutrients and sea weed sap on nutrient availability and leaf nutrient concentrations of mango cv. Dashehari in the year 2014-2015. The experiment was conducted in a randomized block design with three replications and ten treatments consisting of various concentrations and combinations of micronutrients, sea weed sap along with recommended dose of fertilizers in sub-tropical region of GBPUA&T, Pantnagar, Uttarakhand, India. The highest available soil nitrogen, phosphorus, potassium (195.51, 74.30 & 218.79 kg ha-1), B, Zn, Fe, Cu and Mn (1.41, 0.85, 16.78, 3.21 and 25.50 ppm) after harvest were observed with the application of RDF + IIHR Mango Special @ 5 g/l (2 sprays at two months before flowering and marble stage). RDF + IIHR Mango Special also increased the nitrogen, phosphorus, potassium (1.88, 0.99, 0.83 %); B, Zn, Fe, Cu and Mn (18.17, 69.29, 199.49, 48.89 and 84.40 ppm) in leaves of mango cv. Dashehari. Foliar application of sea weed sap @ 10% (2 sprays at panicle emergence and marble stage) + RDF + ZnSO4 @ 200 g + CuSO4 @ 100 g + Boric acid @ 100 g (soil application) per plant in basin after harvest, also resulted in enhanced status of nutrients in plants and soil over various treatments followed to RDF + IIHR Mango Special @ 5 g/l foliar application.


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