Phosphorous Ratio Research Articles

High-Quality White Laser Diode Fabricated by Laser-Driven Tricolor PiG Film-on-Sapphire

Phosphor-converted white laser diode (WLD) is considered as a promising light source in next-generation high-brightness lighting. However, the WLD suffers from low optical quality in luminous efficacy and color rendering. In this work, we fabricated a high-quality WLD by a blue laser-driven a tricolor phosphor-in-glass (PiG) film-on-sapphire (PIGS). The tricolor PiGS was prepared by sintering a green/yellow/red phosphor glass film on a sapphire substrate. The optical quality of tricolor PiGS-WLDs were optimized by adjusting the phosphor ratio. At the phosphor ratio of 9:6:1, the PiGS-WLD achieves high optical quality with a luminous flux of 362.1 lm, a color rendering index (CRI) of 80.3, and a correlated color temperature (CCT) of 4590 K at a laser power of 2.4 W. The PiGS-WLD has the highest luminous efficacy of 154.5 lm/W at 3.15 W. Furthermore, the PiGS-WLD displays excellent color stability with small CCT and CRI deviation under various laser powers and continuous excitation. The surface temperature of PiGS-WLD is stable at 104 °C due to the high thermal conductivity of sapphire substrate. Therefore, this study provides a stable and high-quality laser-driven white light source for high-brightness lighting and display.

Immobilization of strontium aluminate nanoparticles onto plasma-pretreated nonwoven polypropylene fibers by screen-printing toward photochromic textiles

Polypropylene fibers have been applied in various fields, such as automotives, plastic furniture, medical devices, and food packaging. Polypropylene fibers are characterized by low-cost, high flexural and impact strength, as well as high resistant to chemicals, moisture, fade, electricity and fatigue. However, polypropylene fiber is inherently resistant to stain because they have no active dyeing sites on their surface. Therefore, it has been impossible to dye polypropylene fibers after extrusion. In the current study, we introduce a novel strategy toward the production of photoluminescent nonwoven polypropylene fabrics by plasma-assisted screen-printing with rare-earth doped strontium aluminate nanoparticles. Aqueous-based phosphor-binder printing paste was applied directly onto nonwoven polypropylene textiles. The superhydrophobic properties of the phosphor-printed nonwoven polypropylene textile substrates were enhanced with increasing the phosphor ratio in the printing paste. Both of ultraviolet protection and antibacterial activity of the phosphor-printed nonwoven polypropylene fabrics were also considered. The produced colorless photoluminescent layer displayed an emission band at 515 nm after being excited at 371 nm. The phosphor-printed fabrics exhibited various colorimetric shades, including off-white beneath daylight and green beneath ultraviolet lamp, as proved by photoluminescence spectra and CIE Lab properties. The comfortability was inspected by testing both of air-permeability and bend length to indicate good flexibility and breathability. The phosphor nanoparticles were studied for their morphological properties to display diameters of 4–9 nm. The spectroscopic findings of the phosphor-printed nonwoven polypropylene were explored. The colorfastness was studied to indicate high durability. The phosphor-printed fabrics showed good reversibility and fatigue-resistance.

Photoluminescent and photochromic smart window from recycled polyester reinforced with cellulose nanocrystals.

Smart windows with long-persistent phosphorescence, ultraviolet (UV) light protection, high transparency, and high rigidity were developed by easily immobilizing varying ratios of lanthanide-activated aluminate phosphor nanoscale particles within a composite of recycled polyester/cellulose nanocrystals (RPET/CNC). Cellulose nanocrystals were prepared from rice straw waste. Cellulose nanocrystals were used at low concentration as both crosslinker and drier to improve both transparency and hardness. The phosphor nanoscale particles must be distributed into the recycled polyester/cellulose nanocrystals composite bulk without agglomeration to produce transparent RPET/CNC substrates. Photoluminescence characteristics were also studied using spectroscopic profiles of excitation/emission and decay/lifetime. The hardness efficiency was also examined. This transparent recycled polyester waste/cellulose nanocrystals nanocomposite smart window has been shown to change colour under UV light to strong green and to greenish-yellow when it is dark, as proved by Commission Internationale de l'éclairage (CIE) laboratory colour parameters. It was found that the afterglow RPET/CNC smart window had phosphorescence intensities of 428, 493, and 523 nm upon excitation at 368 nm. There was evidence of improved UV shielding, photostability, and hydrophobic activity. In the presence of a low phosphor ratio, the luminescent RPET/CNC substrates showed quick and reversible fluorescence photochromic activity when exposed to UV radiation.

Effects of Nitrogen and Phosphorus Concentrations on the Growth and Lipid Accumulation of Microalgae Scenedesmus obliquus

In the study, Scenedesmus obliquus green algae was cultivated under laboratory conditions at 21±2°C, 16:8 (light:dark) photoperiod and continuous aeration in different nitrogen and phosphorus ratio nutrient medium and its growth was determined. Dry weight, cell density (optical density) and chlorophyll a and b were used to determine the growth of the algae. The best growth was determined in the group consisting of 30 ml NaNO3+10 ml PO4. The amount of biomass obtained was determined as 1.549 gL-1 in this group. The lowest values were the group containing 5 ml NaNO3+5 ml PO4. With the decrease in the amount of nitrogen in the medium, an increase in the amount of carotene and a decrease in the amount of chl a and b were detected. The highest lipid values were determined as 36.7% in the group containing 5 ml NaNO3+5 ml PO4 and 36.2% in the group containing 5 ml NaNO3+10 ml PO4.

우유무기질을 첨가하여 제조한 칼슘 강화 요구르트의 품질 특성

This study was conducted to evaluate the potential use of milk mineral (MM) as the calcium source for the production of calcium-fortified yogurt. MM was composed of 83% minerals, 7.5% lactose, 3.3% protein, and < 1% fat. Calcium (Ca) content in MM was about 46%; calcium: phosphorous ratio was 1.28:1. The aqueous solubility of Ca increased with the decrease in pH; the solubility at pH 4 and 5 was 98% and 53%, respectively. Ca-fortified yogurt with up to 200 mg Ca/100 mL did not show significant differences in acid production and number of viable cells; however, the viscosity increased significantly (p<0.05) with the increase in Ca levels. Microstructure analysis of Ca-fortified yogurt using confocal scanning laser microscopy indicated that the protein network became denser with increasing fortification with MM. There was no significant difference in the sensory quality between the control and Ca-fortified yogurts. Therefore, MM could be used for the production of Ca-fortified yoghurt without compromising the quality characteristics of yogurt.

Influence of down-shifting particle’s size on monocrystalline silicon solar cells

The potential cerium doped yttrium aluminum garnet (YAG:Ce3+) phosphor particles of different sizes are mixed with ethylene-vinyl acetate (EVA) to make luminescent downshifting films, which are then utilized for packaging monocrystalline silicon solar cells. The luminescence of YAG:Ce particles with the different diameters (3–5 µm, 5–8 µm, 8–10 µm, 10–15 µm, 15–20 µm, and 20–30 µm), the transmission of the down-shifting EVA films with the phosphor particles and performance of the packaged solar cells have been investigated. Experimental results show that the particles with 15–20 µm have the highest luminescent intensity. When the mass ratio of phosphors to EVA is fixed, the films with 20–30 µm have the highest transmission. The most significant increase in solar cell conversion efficiency after packaging is due to the downshifting EVA films with 15–20 µm particles. This research could be useful in the selection of downshifting phosphors for solar cells in the future.

Simple preparation of novel photochromic polyvinyl alcohol/carboxymethyl cellulose security barcode incorporated with lanthanide-doped aluminate for anticounterfeiting applications.

Forgery and low-quality products pose a danger to society. Therefore, there are increasing demands for the production of easy-to-recognize and difficult-to-copy anticounterfeiting materials. Products with smart photochromic and fluorescence properties can change colour and emission spectra responding to a light source. In this context, we devised a straightforward preparation of a luminescent polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) nanocomposite to function as a transparent labelling film. The lanthanide-doped aluminate (LdA) was prepared in the nanoparticle form to indicate diameters of 35-115 nm. Different ratios of the LdA were physically dispersed in the PVA/CMC nanocomposite label film to provide photochromic, ultraviolet protection, antimicrobial activity, and hydrophobic properties. Fluorescence peaks were detected at 365 and 519 nm to indicate a colour change to green. As a result of increasing the phosphor ratio, improved superhydrophobic activity was achieved as the contact angle was increased from 126.1° to 146.0° without affecting the film's original physical and mechanical properties. Both ultraviolet (UV) light protection and antibacterial activity were also investigated. The films showed a quick and reversible photochromic response without fatigue. The current strategy reported the development of a photochromic smart label that is transparent, cost effective, and flexible. As a result, numerous anticounterfeiting products can benefit from the current label for a better market. LdA-loaded PVA/CMC films demonstrated antibacterial activity between poor, good, very good, and outstanding as the percentage of LdA in the film matrix increased. The current film can be applied as a transparent photochromic security barcode for anticounterfeiting applications and smart packaging.

Impacts of nutrient reduction on temporal β-diversity of rotifers: A 19-year limnology case study on Lake Wuli, China

There have been many studies on the effects of eutrophication on beta diversity (β-diversity) of species assemblages. However, few studies have focused on the effects of nutrient reduction on β-diversity and community structure, and long-time series analyses are particularly scarce. We conducted a 19-year case study on the impacts of management intervention on the temporal β-diversity of aquatic grazers in a lake at the Yangtze River Basin. In our study, we compared the changes in temporal β-diversity as well as its two components, nestedness and turnover, and the synchrony of the rotifer community after management intervention. Our results showed that while the abundance of some sensitive species increased, there was no trend in species richness. Moreover, both the seasonality and interannual stabilities of rotifer assemblages increased. The species synchrony decreased in both spring and summer after management intervention. We also found that management intervention significantly reduced nutrient concentrations but not water clarity and phytoplankton abundance. The total nitrogen (TN): total phosphorous (TP) ratio was reduced after management intervention, causing an increase in the abundance of cyanobacteria that may contribute to the increase of rotifer synchrony in autumn. Our results imply that stable environmental fluctuations after management intervention may increase temporal β-diversity and stability of herbivorous assemblages. However, imbalanced changes in TN and TP after management intervention may weaken the top-down control of zooplankton on phytoplankton and slow down water clarity improvement.

Effects of precipitation changes on the stoichiometry and photosynthetic characteristics of Stipa bungeana Trin. at different growth stages in the Loess Plateau, China

AbstractThe aim of this study was to explore the response of the stoichiometric and photosynthetic characteristics of a dominant plant species in a typical grassland to changes in precipitation. Rain shelter technology was used to simulate 50%, 100%, and 150% of natural rainfall. The photosynthetic rate (Pn), intercellular CO2 concentration (Ci), transpiration rate (Tr), stomatal conductance (Gs), and ecological stoichiometry of the rhizosphere soil and Stipa bungeana at different growth stages were measured in May, July), and September, 2019 after 2 years of rainfall control. The results showed that the aboveground carbon (C) content of plants grown under 150% precipitation was significantly higher than that of plants grown under 100% precipitation in September. The aboveground nitrogen (N) content of plants under 50% precipitation was significantly higher than the plants grown under 100% precipitation. Under all different precipitation treatments, the aboveground C:N ratio was the lowest (16.4–19.6) in May. The range of average aboveground C: phosphorous (P) ratio was 373.7–617.8, and the N:P ratio in the descending order was July > May > September. The 50% precipitation treatment promoted the highest accumulation of underground C at all the growth stages. The productivity of the grassland under the 100% and 150% precipitation treatments was limited by the rhizosphere soil N and P. The underground C, P, C:P, and aboveground C:N ratios were sensitive indicators. Aboveground and underground N:P ratio showed the strongest significant correlation (P < 0.001), and the correlation between underground stoichiometry and rhizosphere soil P (P < 0.001) was stronger than that with rhizosphere soil N (P < 0.05). The correlation between Ci and stoichiometry was opposite in direction to the correlation between Pn, Tr, Gs, and stoichiometry. The research results will provide a scientific reference for understanding of the material cycle and judgment of vegetation nutrient limitations in the Loess Plateau.

An effective heat dissipation strategy improving efficiency and thermal stability of phosphor-in-glass for high-power WLEDs

Phosphor-in-glass (PiG) is one of the most important spectral converters to overcome thermal effect in high-power white light-emitting diodes (LEDs). The Al2O3–SiO2–B2O3–ZnO–Na2O–Li2O glass was designed and sintered with Y3Al5O12:Ce3+ (YAG: Ce) phosphors at the low temperature of 650 °C to obtain YAG: Ce-PiG. The optimized YAG: Ce-PiG shows the white light of the luminous efficiency (LE), correlated color temperature (CCT) and chromaticity coordinate (CIE) of 177.5 lm/W, 6410 K and (0.31,0.34), respectively. The white LEDs (WLED) were fabricated by coupling the YAG: Ce-PiG with a blue light emitting chip, and the correlation between the luminescence properties, the thickness of PiG and the ratio of phosphors was investigated. More importantly, the WLEDs of a maximum luminous efficiency can reach up to 199.5 lm/W with the thickness of 0.35 mm. In addition, a structure with vacuum packaging technique based on the WLEDs lighting combined with sapphire as substrate was fabricated, which can effectively reduce the heat accumulation during the working process of WLEDs. Compared with normal non-vacuum packaging, the working temperature of WLEDs was reduced by about 35%, from 359.2 to 232.2 °C, with the novel vacuum packaging technique under 30W high-power chip and the luminous performance can still be maintained at 94.7%. In a word, the prepared YAG: Ce-PiG exhibits a great potential for application in high-power solid-state WLEDs.

Optimization of Calcium and Phosphorous Ratio in the Practical Diet of Hypophthalmichthys molitrix

Optimization of Calcium and Phosphorous Ratio in the Practical Diet of Hypophthalmichthys molitrix

Unmasking and Managing Hypercalcaemia-In Clinical Settings!

Objective: In this article I present 2 cases of hypercalcaemia identified and managed in 2021 in smaller settings and review of literature of such cases in bigger facilities India with an objective of alerting private practitioners’ role in managing such cases efficiently. Hypercalcaemia is not a disease but just a biomarker of a total serum calcium concentration > 10.4 mg/dL (> 2.60 mmol/L) or ionized serum calcium > 5.2 mg/dL (> 1.30 mmol/L). Principal causes include Primary hyperparathyroidism, vitamin D toxicity, and cancer. The serum Calcium and Phosphorous (Ca/P) ratio is a most valuable tool for the diagnosis of Primary hyperparathyroidism, better than serum Calcium alone. Locations of cases reported: Kalimpong in West Bengal and Chikkaballapur near Bengaluru Participants: i) A - 66-year-old Kamala Pradhan, a known diabetic, my patient in Delhi for last 5 years presenting with pruritus, muscle weakness, lack of appetite and weight lost for 3 months and accidentally diagnosed after a Blood test as moderate hypercalcaemic due to over consumption of Vit. D (weekly 60 K units for 3 years) and ii) the second case of a rural 45 year’s old women from Bengaluru in May 2021 diagnosed as Cancer Cervix stage 3 at a private cancer hospital in Bangalore who succumbed in about 3 week’s time Measurements: i) In the first a serum test indicated serum Calcium level 20 mg/dl and Vitamin D 150ng/ml in first test and after management for a months’ time Calcium levels came down to 10mg/dl and Vitamin D levels to 50ng/ml. ii) Second case had calcium level of 120 mg/dl indicating Calcium crisis. Results: The first case of moderate hypercalcemia due to Vit D intoxication improved, the Calcium level came down to 10mg/dl and D Vitamin came down to 50ng/ml with clinical improvements in 12 weeks’ time. The Calcaemic crisis was not monitored as the patient died within 3 weeks of starting treatment. Conclusion: A case of successful management of moderate due to Vitamin D intoxication and another case of calcinemia crisis due to advanced cervical cancer, with serious complications, and death are reported for education of general practitioners. Material & Methods: The author a family physician for 54 years and a Public Health practitioner for 45 years, have used 2 cases of hypercalcaemia followed in 2021 and review some other published cases, along with a few retrospective studies in India and abroad, that lead to hypercalcaemia and current recommendations for the management of elevated serum calcium levels.

Novel Protein to Phosphorous Ratio Score Predicts Mortality in Hemodialysis Patients

Lowering serum phosphorus in people on hemodialysis may improve their survival. However, prior studies have shown that restricting dietary protein intake, a major source of phosphorus, is associated with higher mortality. We hypothesized that a novel metric that incorporates both these values commensurately can improve survival prediction. We used serum phosphorous and normalized protein catabolic rate (nPCR), a surrogate of dietary protein intake, to form a new metric R that was used to examine the associations with mortality in 63,016 people on hemodialysis (HD) of oneyear after treatment initiation. Survival models were adjusted for case-mix, malnutrition-inflammation cachexia syndrome (MICS), and residual kidney function (RKF). Individuals treated with hemodialysis were divided into five groups in accordance with R value. Group 1 included sick individuals with high phosphorous and low nPCR. Group 5 included individuals with low phosphorous and high nPCR. After 1-year follow-up, survival difference between the groups reflected R value, where an increase in R was associated with improved survival. The association of R with mortality was strengthened by adjustment in demographic variables and attenuated after adjustment to MICS. Mortality associations in accordance with R were not influenced by residual kidney function (RKF). The novel protein to phosphorus ratio score R predicts mortality in people on dialysis, probably reflecting both nutrition and inflammation state independent of RKF. The metric enables better phosphorus monitoring, although adequate dietary protein intake is ensured and may improve the prediction of outcomes in the clinical setting.

Phosphor in glass composited with CsPb(BrI)3 perovskite nanocrystals embedded glass for high CRI WLED application

Here, YAG phosphor in tellurite glass composited with CsPb(BrI)3 nanocrystals embedded borosilicate glass have been successfully synthesized by Two-step melting method. The phase and morphology characterization proved that YAG and CsPb(BrI)3 nanocrystals existed in the prepared composite glass. The photoluminescence properties and color characteristics could be easily controlled by adjusting the mixing ratio of phosphor and quantum dot powder. In addition, by combining the phosphor and perovskite quantum dot glass composite material with a blue light-emitting diode, a white light-emitting diode (wLED) was successfully prepared. After a series of adjustments, the chromaticity coordinates (CIE) of the optimized high-performance wLED is (0.3376, 0.3531), the correlated color temperature (CCT) is 5299 K, and the color rendering index (Ra) is up to 86, which higher than that of the wLED packaged by single phosphor glass.

High probability of nitrogen and phosphorus co-limitation occurring in eutrophic lakes

Limnologists and governments have long had an interest in whether nitrogen (N) and/or phosphorous (P) limit algal productivity in lakes. However, the types and importance of anthropogenic and biogeochemical processes of N and P differ with lake trophic status. Here, a global lake dataset (annual average data from 831 lakes) demonstrates that total nitrogen (TN): total phosphorous (TP) ratios declined significantly as lakes become more eutrophic. From oligotrophic to hypereutrophic lakes, the probability of N and P co-limitation significantly increases from 15.0 to 67.0%, while P-only limitation decreases from 77.0 to 22.3%. Furthermore, TN:TP ratios are mainly affected by concentrations of TP (r = −0.699) rather than TN (r = −0.147). These results reveal that lake eutrophication mainly occurs with increasing P rather than N, which shifts lake ecosystems from stoichiometric P limitation toward a higher probability of N and P co-limitation. This study suggests that low N:P stoichiometry and a high probability of N and P co-limitation tend to occur in eutrophic systems.

Edaphic components of Mangrove Dominated Lothian And Prentice Island In Sundarbans North -East Coast of India.

Physico-chcmical analysis of mangrove soils in two islands (Prentice and Lothian) in sundarban areas were carried out and compared to highlight the quality of the soils that facilitate the existence as well as survival various flora and fauna to play immense role in the stability of the environment. Study revealed that there were slight differences in the grain size, pH, organic carbon and exchangeable calcium (Ca12) and magnesium (Mg12) content in soils of these two islands. The litter of the mangrove forest might. play vital role not only on the variation of carbon to nitrogen ratio (C/N) and carbon to phosphorous ratio (C/P) but also retention ability of these essential nutritional elements in soils. Ca+2 and Mg+2 were the principal cations as observed in exchange reactions. Potassiun ion (K+) recorded comparatively higher values than the sodium ion (Na+) in these soils probably due to more amnily for K+ uptake in the existing biotic community as well as trapping capacity by edaphic components in these areas.

Lanthanide ions doped nonhygroscopic La2Mo3O12 microcrystals based on multimode luminescence for optical thermometry

The non-contact thermometry based on fluorescence intensity ratio of phosphors has been extensively investigated owing to its high sensitivity and fast response. However, most of them only use a single mode of upconversion or downconversion emission for temperature sensing and ignore the affection of the humidity. In this work, the Yb/Er ions doped La2Mo3O12 microcrystals with nonhygroscopic property and multimode luminescence have been developed for temperature sensing. The optical thermometer could be based on not only luminescent intensity ratio of upconversion and downconversion, but also average fluorescence decay lifetime. The maximal absolute sensitivity can reach up to 6.2% K−1 and the maximal relative sensitivity is 1.63% K−1. Moreover, the fluorescence emission intensity of the doped La2Mo3O12 microcrystals will not be affected by the humidity compared to some doped molybdate and tungstate. These excellent performances suggest that the La2Mo3O12:Yb/Er microcrystals possess great potential for practical applications in temperature sensing.

Abstract P332: Microfluidic Model Of Late-stage Calcific Aortic Valve Disease Develops Calcium Phosphate Mineralizations

Introduction: Calcific aortic valve disease (CAVD) is an active pathological process leading to severe valve calcification. Late-stage CAVD is characterized by increased leaflet stiffness, disorganized collagen bundles and the deposition of glycosaminoglycans, such as chondroitin sulfate (CS), in the fibrosa layer. However, many details of the cellular pathological cascade remain unknown. Animal models such as mice, rabbits, and pigs are used in understanding human CAVD, but mice do not have similar anatomy, rabbits cannot spontaneously develop atherosclerotic lesions, and pigs require long, expensive and complex studies. Here we utilize microfluidic devices of the aortic valve fibrosa to model late-stage CAVD. Hypothesis: We assessed the hypothesis that microfluidic calcification will increase with increased shear rates and CS content. Methods: Valve-on-a-chip devices contained a hydrogel of 1.5 mg/mL collagen I-only healthy controls or 1.5 mg/mL collagen I with 1 mg/mL or 20 mg/mL CS. Porcine aortic valve interstitial cells (PAVIC) were embedded within and endothelial cells (PAVEC) were seeded onto the matrix. Steady shear stress at 1 dyne/cm 2 and 20 dyne/cm 2 were applied using a peristaltic pump for 14 days. Alizarin Red S (ARS), an assay to assess calcium deposition, was used to quantify calcific nodule formation. Scanning electron microscopy with energy dispersive x-ray (SEM/EDX) was used to further analyze sample mineralization. Results: Co-cultures in the presence of increasing shear stress and CS exhibit increased calcific nodule formation compared to static controls, both qualitatively and quantitatively (n≥3). SEM revealed the microstructure of calcified nodules and EDX confirmed calcium phosphate mineralization with physiologically-relevant calcium to phosphorous ratios (Ca/P= 0.88 - 1.4). Conclusions: These results show that in vitro calcification is driven by shear stress in the presence of PAVEC and CS. As seen in ex vivo studies of human calcification, these microfluidic-derived nodules are similarly composed of a range of naturally-occurring calcium phosphates. Given that CAVD has no targeted therapy, the creation of a physiologically relevant model of the aortic valve can provide a test bed for novel therapeutic interventions.

Extraction of REEs (Ce, Tb, Y, Eu) from Phosphors Waste by a Combined Alkali Roasting–Acid Leaching Process

Rare Earth (RE) phosphors waste contains valuable rare Earth elements (REEs), such as cerium, terbium, yttrium, and europium. In industry, the process of NaOH roasting followed by acid leaching is usually used to extract the REEs from the waste in China. Using this process, the leaching efficiencies of cerium and terbium are clearly lower than those of other REEs, which results in uneven extraction of REEs in the waste and low total REE leaching efficiency. The key reason is that the trivalent cerium and terbium in the waste are oxidized into RE oxides during NaOH roasting, which are difficult to dissolve in acid solution. To solve this problem, an optimized process of controlling the oxygen concentration during NaOH roasting is proposed in this paper. The influences of the oxygen concentration, roasting temperature, roasting time, mass ratio of waste phosphor to NaOH, HCl solution concentration, acid leaching temperature, acid leaching time, and liquid–solid ratio on the REE leaching efficiency were investigated. Under the optimum conditions, the leaching efficiencies of cerium and terbium increased dramatically and the total REE leaching efficiency is 99.11%.

Effects of Nutrient Content and Nitrogen to Phosphorous Ratio on the Growth, Nutrient Removal and Desalination Properties of the Green Alga Coelastrum morus on a Laboratory Scale

In wastewater, nutrient concentrations and salinity vary substantially, however, the optimal N:P ratio for the treatment using microalgae is not well described. In this study, the effects of higher and lower nitrate and phosphate contents and N:P ratios on growth, nutrient removal ability and halotolerance of the common green alga Coelastrum morus were investigated in model solutions. The results suggest that high nitrate content (above 100 mg L−1) with a similarly high phosphate concentration (resulting low N:P ratio) is not favorable for growth. The studied isolate can be considered as a halotolerant species, showing remarkable growth up to 1000 mg L−1 NaCl and it seems that despite the negative effects on growth, higher nutrient content contributes to higher halotolerance. A significant amount of nitrate removal was observed in media with different nutrient contents and N:P ratios with different salt concentrations. High N:P ratios favor phosphate removal, which is more inhibited by increasing NaCl concentration than nitrate uptake. Overall, with a relatively higher nutrient content and a favorable (5 or higher) N:P ratio, a common green algal species such as C. morus could be a promising candidate next to species from the Chlorellaceae and Scenedesmaceae families.