scholarly journals Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francesca Nyega Otim ◽  
I-Ru Chen ◽  
Ochan Otim
Keyword(s):  
Chlorella Vulgaris ◽  
Coastal Waters ◽  
Biomass Accumulation ◽  
Treated Wastewater ◽  
Algae Bloom ◽  
Ph Measurements ◽  
Ph Variation ◽  
Initial Ph ◽  
Turbidity Increase ◽  
Measuring Ph

AbstractAlgae bloom in coastal waters is partly supported by residual nutrients in treated wastewater (WW) released from coastally located treatment plants. In response, a Chlorella vulgaris-based photobioreactor was recently proposed for lowering nutrient levels in WW prior to release. However, the solution requires maintaining biomass accumulation to within a photobioreactor capacity for optimum operation. For high density Chlorella vulgaris suspensions, this is easily done by monitoring turbidity increase, a property directly related to biomass accumulation. For low density suspensions however, direct turbidity measurement would require a cumbersome process of concentrating large volumes of Chlorella vulgaris suspensions. Here, we demonstrate that by measuring pH of the suspensions, turbidity (T) can be estimated indirectly by the following wastewater-dependent expression: pH = aT + pH0, hence avoiding the need to concentrate large volumes. The term pH0 is the initial pH of the suspensions and a, a wastewater-dependent constant, can be computed independently from a = − 0.0061*pH0 + 0.052. In the event %WW is unknown, the following wastewater-independent Gaussian expression can be used to estimate T: pH = 8.71*exp(− [(T − 250)2]/[2*1.26E05]). These three equations should offer an avenue for monitoring the turbidity of dilute Chlorella vulgaris suspensions in large, stagnant municipal Chlorella vulgaris-based wastewater treatment system via pH measurements.

scholarly journals Phenotypic correlations among meat quality traits in broilers

2011 ◽  
Vol 41 (8) ◽  
pp. 1475-1481 ◽  
Author(s):  
Luana Bertollini de Jesus Silva ◽  
Leila de Genova Gaya ◽  
Ana Paula Madureira ◽  
Graziela Tarôco ◽  
José Bento Sterman Ferraz ◽  
...  
Keyword(s):  
Meat Quality ◽  
Protein Denaturation ◽  
The Other ◽  
Poultry Meat ◽  
Quality Traits ◽  
Ph Measurements ◽  
Water Losses ◽  
Phenotypic Correlations ◽  
Meat Quality Traits ◽  
Initial Ph

The goals of this research were to estimate the phenotypic correlations among various meat quality traits from a male broiler line and to describe the relation among these variables. Phenotypical correlations were determined among quality traits, isolating the effects of slaughter date, the age of the mother and sex. The evaluated traits were pH measurements taken at time 0 and at 6 and 24 hours after slaughtering, color parameters, water loss due to exudation, thawing and cooking of the meat, and shear force. Important associations (P<0.01) were found to be significant and, in most cases, weak or moderate, varying from -0.35 to 0.28. The initial pH of the meat was not associated (P>0.05) to the other traits of the meat, whereas the pH at 24 hours after slaughter was able of directly interfering with the attributes of the meat, since this trait was inversely related with lightness and water losses, which indicates an effect of pH fall along 24h after slaughtering on protein denaturation. This study demonstrates that the variables of poultry meat quality are related and that there is a phenotypical association between lightness and cooking losses and the other attributes of the meat. The pH at 24 hours after slaughtering, lightness and cooking losses could be efficient meat quality indicators in this broiler line.

Harmful cyanobacterial toxic blooms in waste stabilisation ponds

2000 ◽  
Vol 42 (10-11) ◽  
pp. 179-186 ◽  
Author(s):  
B. Oudra ◽  
M. El Andaloussi ◽  
S. Franca ◽  
P. Barros ◽  
R. Martins ◽  
...  
Keyword(s):  
Chlorella Vulgaris ◽  
Health Hazard ◽  
Normal Growth ◽  
Treated Wastewater ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Diameter ◽  
Histopathological Study ◽  
Ecological Implication ◽  
Shellfish Poisoning ◽  
Mammalian Toxicity

A coccoid picocyanobacterium Synechocystis sp. (0.6-2 μm of cell diameter) was found to be dominant during summer period in the experimental wastewater stabilisation pond of Marrakesh. The taxonomy of this isolated strain was confirmed by electron microscope study. The general patterns of ultrastructure and the mode of cell division resemble Chroococcales. The cyanobacterium strain was axenic and cultured on both inorganic Z8 and BG13 media. Mammalian toxicity was confirmed by mice bioassay. The major sympton of poisoning was severe diarrhoea. Histopathological study shows a slight hepatotoxicosis associated with a pronounced change in the intestinal mucosa which shows swelling and destruction of villi epithelium and shedding of enterocytes into the lumen. Although slow, these kinds of poisoning are comparable to those induced by okadiac acid intraperitoneal mice injection (diarrhetic shellfish poisoning “DSP” toxins). By using the enzyme-linked immunosorbent assay (ELISA), the amount ofhepatotoxins “microcystins” was determined. The result shows that Synechocystis can produce a small amount of total microcystine [an average of 15 μg−1 dry weight corresponding to 20 ng(109cell)−1]. These findings lead us to consider Synechocystis as both a potent neurotoxin and hepatotoxin producer. Because of the confirmed cyanobacterium toxicity, an eventual ecological implication should be considered. However, a toxic chronic test experiment on Daphnia was simultaneously carried out. Juvenile D. magna (less than 24 hours old), were fed three concentrations (104, 106, 108 cells / ml) of Synechocystis. A group of organisms fed with Chlorella vulgaris (3. 105 cells/ml) and another group without food, were studied as control treatments. Only animals cultured with 104 cells/ml of cyanobacterium survived at 80% until the end of the test (21 days). Reproduction and normal growth occurred in control treatments fed with Chlorella vulgaris and the group fed with the lowest concentration of Synechocystis. One-way ANOVA statistical analyses show significant differences in Daphnia survival and growth, between treatments with and without Synechocystis and between treatments with and without food. In terms of this study, there is evidence that toxic picocyanobacteria blooms occurring in wastewater stabilization ponds of Marrakesh, could have harmful repercussions on zooplanktonic, bacteria and other algae communities. Consequently, this will constitute a possible hindrance for sewage self-purification process and system treatment performance. In addition, the reuse of such treated wastewater effluent for irrigation will constitute an additional, potent, health hazard for animals and human's.

scholarly journals Technical note: Stability of tris pH buffer in artificial seawater stored in bags

Ocean Science ◽  
2021 ◽  
Vol 17 (3) ◽  
pp. 819-831
Author(s):  
Wiley H. Wolfe ◽  
Kenisha M. Shipley ◽  
Philip J. Bresnahan ◽  
Yuichiro Takeshita ◽  
Taylor Wirth ◽  
...  
Keyword(s):  
Dissolved Inorganic Carbon ◽  
Technical Note ◽  
Artificial Seawater ◽  
Upper And Lower Bounds ◽  
Sensor Calibration ◽  
Time Data ◽  
Ph Change ◽  
Ph Measurements ◽  
Experimental Conditions ◽  
Initial Ph

Abstract. Equimolal tris (2-amino-2-hydroxymethyl-propane-1,3-diol) buffer in artificial seawater is a well characterized and commonly used standard for oceanographic pH measurements. We evaluated the stability of tris pH when stored in purportedly gas-impermeable bags across a variety of experimental conditions, including bag type and storage in air vs. seawater over 300 d. Bench-top spectrophotometric pH analysis revealed that the pH of tris stored in bags decreased at a rate of 0.0058±0.0011 yr−1 (mean slope ±95 % confidence interval of slope). The upper and lower bounds of expected pH change at t=365 d, calculated using the averages and confidence intervals of slope and intercept of measured pH change vs. time data, were −0.0042 and −0.0076 from initial pH. Analyses of total dissolved inorganic carbon confirmed that a combination of CO2 infiltration and/or microbial respiration led to the observed decrease in pH. Eliminating the change in pH of bagged tris remains a goal, yet the rate of pH change is lower than many processes of interest and demonstrates the potential of bagged tris for sensor calibration and validation of autonomous in situ pH measurements.

scholarly journals The effect of low initial medium pH on in vitro white poplar growth

2013 ◽  
pp. 67-80
Author(s):  
Branislav Kovacevic ◽  
Dragana Miladinovic ◽  
Marina Katanic ◽  
Zoran Tomovic ◽  
Sasa Pekec
Keyword(s):  
Biomass Accumulation ◽  
Dry Mass ◽  
White Poplar ◽  
Medium Ph ◽  
Shoot Height ◽  
Initial Ph ◽  
The Media ◽  
Initial Medium ◽  
Shoot Mass

The effect of low initial medium pH on shoot and root development of five white poplar (Populus alba L.) genotypes was tested. The shoot height, fresh mass of shoots per jar, dry mass of shoots per jar, number of roots, as well as the length of the longest root were measured and final pH of the media determined, after 35 days of culture in vitro. Three initial pH values of the medium were tested: 3.0, 4.0 and 5.5 as control. Agar solidification at pH 3.0 was not achieved after sterilization in autoclave, but it was successful after sterilizing in a microwave oven. The obtained results indicate that the tested genotypes are able to significantly influence the changes of media pH during culture. The effect of differences among the examined media was significant for biomass accumulation and final media pH. Generally, significantly higher values of fresh and dry shoot mass, shoot height and the longest root length were recorded on a medium with initial pH 3.0 then on a standard medium with pH 5.5.The implications of the obtained results for the improvement of in vitro propagation of white poplars are discussed.

scholarly journals Studies on Groundwater Problems in an Area Subjected to Sea Water Ingression and Seepage Into Groundwater in Karaikal District Using GIS

2018 ◽  
Vol 7 (3.10) ◽  
pp. 150
Author(s):  
T Subramani ◽  
P Krishnan
Keyword(s):  
Water Quality ◽  
Coastal Waters ◽  
Submarine Groundwater Discharge ◽  
Sea Water ◽  
Groundwater Discharge ◽  
Treated Wastewater ◽  
Coastal Zones ◽  
Fresh Groundwater ◽  
Submarine Groundwater ◽  
Pumping Rates

Fresh groundwater quality and accessibility in coastal zones is influenced via seawater interruption into coastal aquifers, and coastal water quality and biological community status might be altogether influenced by groundwater pollutants that are transported into coastal waters by submarine groundwater discharge (SGD). SGD and its pertinent evaluation as one associating part  among the different principle local pathways of freshwater and tracer/poison contributions from land to sea and the coordinated framework working of both and as primary segments of the same coastal groundwater framework. An elective technique might be to control seawater interruption through fake groundwater revive, for example by adequately treated wastewater, which may impressively decrease long haul patterns of saltiness increment in pumped groundwater, notwithstanding for little simulated energize rates contrasted with pumping rates. Both the outside sources and the interior wellsprings of water seepage might be distinguished via doing infrared thermo-realistic assessments subsequent to directing water snugness tests, flooding tests or pressure driven tests as suitable. A contextual investigation was led to discover the examinations on groundwater issues in a region subjected to sea water ingression and seepage into groundwater in Karaikal   

scholarly journals Technical note: Interpreting pH changes

2021 ◽  
Vol 18 (4) ◽  
pp. 1407-1415
Author(s):  
Andrea J. Fassbender ◽  
James C. Orr ◽  
Andrew G. Dickson
Keyword(s):  
Technical Note ◽  
Ion Concentration ◽  
Ph Change ◽  
Ph Measurements ◽  
Hydrogen Ion Concentration ◽  
Ph Changes ◽  
The Past ◽  
Initial Ph ◽  
Relative Change

Abstract. The number and quality of ocean pH measurements have increased substantially over the past few decades such that trends, variability, and spatial patterns of change are now being evaluated. However, comparing pH changes across domains with different initial pH values can be misleading because a pH change reflects a relative change in the hydrogen ion concentration ([H+], expressed in mol kg−1) rather than an absolute change in [H+]. We recommend that [H+] be used in addition to pH when describing such changes and provide three examples illustrating why.

Bio-Treatment of APMP Effluent with Activated Sludge

2014 ◽  
Vol 675-677 ◽  
pp. 505-509
Author(s):  
Ting Zhi Liu ◽  
Hao Yu Wang ◽  
Shuai Li ◽  
Yuan Liu
Keyword(s):  
Activated Sludge ◽  
Ph Value ◽  
Effluent Treatment ◽  
Treated Wastewater ◽  
Process Conditions ◽  
Wood Extractives ◽  
Mechanical Pulp ◽  
Alkaline Peroxide ◽  
Initial Ph ◽  
Optimized Conditions

Aerobic activated sludge was more appropriate for APMP(Alkaline Peroxide Mechanical Pulp) effluent treatment than anaerobic processes because the high content of toxic wood extractives in the effluent. In this article, Eucalyptus APMP effluent was treated with activated sludge and the process conditions was optimized. The optimized conditions were: the initial pH value was 6.0, SV30of activated sludge was 35%, and loading volume of flask was 150ml (250ml flask), cultured shakily for 3 days at 35°Cand 150rpm. The removal of COD was 66.75%, from 4181mg/l to 1390mg/l, and the color of the effluent and treated water were 2541C.U. and 1557C.U. under the optimized conditions, respectively. In most cases, the color of treated wastewater was increased compared with the initial effluent, but the removal of COD was significant.

Lime requirement of acidic Queensland soils.II. Comparison of laboratory methods for predicting lime requirement

Soil Research ◽  
1990 ◽  
Vol 28 (5) ◽  
pp. 703 ◽  
Author(s):  
RL Aitken ◽  
PW Moody ◽  
PG Mckinley
Keyword(s):  
Soil Water ◽  
Ph Measurements ◽  
Laboratory Methods ◽  
Water Suspensions ◽  
Initial Ph ◽  
Predetermined Level ◽  
Laboratory Procedures ◽  
Soil Caco3 ◽  
Initial Buffer ◽  
Extractable Al

A number of laboratory procedures for predicting lime requirement were evaluated by using 40 acidic surface soils from eastern Queensland. The methods were compared on the basis of their ability to predict the lime requirement to pHw values of 5.5 and 6.5 obtained from soil-CaCO3-moist incubations. The laboratory methods evaluated included 1M KC1 extractable Al, equilibration of soil : water suspensions with varying amounts of added Ca(OH)2, the Shoemaker, McLean and Pratt (SMP) single-buffer method, the SMP double-buffer method, the Yuan double-buffer method and the Mehlich single-buffer method. Aluminium extracted ,with 1M KCl was a poor predictor of lime requirement to pH, 5.5. In most of the soils tested, the actual amounts of lime required to reduce Al to a predetermined level far exceeded those calculated on the basis of 1 M KCl extractable Al values of untreated soils. Batch equilibration of soil : water suspensions containing Ca(OH)2 proved a reliable but relatively time-consuming method of determining lime requirement. All of the buffer methods were reasonably well correlated with lime requirement (0.61 < r2 < 0.82). Buffer methods which had a high initial buffer pH and a relatively high buffer strength were less well correlated with lime requirement than weaker buffers of lower initial pH. The Mehlich single-buffer method (initial pH 6.6) fitted both these latter criteria and gave good correlations with lime requirements to pHw 5.5 (r2 =0.78) and pHw 6.5 (r2 = 0.80). Compared with the single-buffer methods, neither of the double-buffer methods (which require two pH measurements) was better correlated with lime requirements.

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