Phosphorus transport in saturated slag columns: experiments and mathematical models

1996 ◽  
Vol 34 (1-2) ◽  
pp. 153-160 ◽  
Author(s):  
S. H. Lee ◽  
S. Vigneswaran ◽  
K. Bajracharya
Keyword(s):  
Mathematical Models ◽  
Sorption Capacity ◽  
Algal Blooms ◽  
Sandy Loam ◽  
Dynamic Condition ◽  
Water Environment ◽  
Breakthrough Curves ◽  
Column Experiments ◽  
Phosphorus Transport ◽  
Waste Products

Excessive phosphorus (P as orthophosphate) is one of the major pollutants in natural water that are responsible for algal blooms and eutrophication. P removal by slag is an attractive solution if the P sorption capacity of slag is significant. To design an efficient land treatment facility, basic information on the behaviour of P in the media-water environment is required. In this study, detailed column experiments were conducted to study the P transport under dynamic condition, and mathematical models were developed to describe this process. The column experiments conducted with dust and cake waste products (slag) from a steel industry as adsorbing indicated that they had higher sorption capacity of P than that of a sandy loam soil from North Sydney, Australia. P transport in the dust and cake columns exhibited characteristic S-shaped or curvilinear breakthrough curves. The simulated results from a dynamic physical nonequilibrium sorption model (DPNSM) and Freundlich isotherm constants satisfactorily matched the corresponding experimental breakthrough data. The mobility of P is restricted by the adsorbents and it is proportional to the sorption capacity of them.

scholarly journals Column Experiments on Sorption Coefficients and Biodegradation Rates of Selected Pharmaceuticals in Three Aquifer Sediments

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 14 ◽  
Author(s):  
Aleksandra Kiecak ◽  
Friederike Breuer ◽  
Christine Stumpp
Keyword(s):  
Environmental Concern ◽  
Sandy Loam ◽  
Breakthrough Curves ◽  
Coarse Sand ◽  
Transport Processes ◽  
Column Experiments ◽  
Transport Parameters ◽  
Degradation Rates ◽  
The Impact ◽  
Flow Velocities

The presence of pharmaceuticals in the environment, and in groundwater, has been recognized as a great environmental concern. Biodegradation and sorption are the main processes leading to the removal of contamination from the water phase. The aim of this study was to determine the transport processes of selected pharmaceuticals (antipyrine, atenolol, carbamazepine, caffeine, diclofenac, ketoprofen, sulfamethoxazole) in selected sediments (coarse sand, medium sand, sandy loam) in laboratory experiments. Moreover, the impact of flow velocities on the sorption and degradation rates of the selected compounds was studied. Column experiments were performed at three flow velocities, under abiotic and biotic conditions, applying conservative (bromide) and reactive tracers (pharmaceuticals). From the breakthrough curves, retardation factors and degradation rates were determined and the influence of variable flow conditions on transport parameters was evaluated. Low observed concentrations and recoveries of atenolol indicated a strong influence of sorption on its transport. Diclofenac, caffeine, and carbamazepine were also affected by sorption but to a lesser extent. Sulfamethoxazole, ketoprofen, and antipyrine were recovered nearly completely, indicating an almost conservative transport behavior. Biodegradation was small for all the compounds, as the results from biotic and abiotic column experiments were similar. Transport of the tested pharmaceuticals was not influenced by different flow velocities, as similar modelled degradation rates and retardation factors were found for all tested flow velocities.

Evaluation of distribution coefficients for the prediction of strontium and cesium migration in a uniform sand

1982 ◽  
Vol 19 (1) ◽  
pp. 92-103 ◽  
Author(s):  
W. D. Reynolds ◽  
R. W. Gillham ◽  
J. A. Cherry
Keyword(s):  
Distribution Coefficient ◽  
Breakthrough Curves ◽  
Distribution Coefficients ◽  
Column Experiments ◽  
Advection Equation ◽  
Dispersion Models ◽  
Advection Dispersion ◽  
Liquid Phases ◽  
Long Tails ◽  
The Mathematical Model

The validity of using a distribution coefficient (Kd) in the mathematical prediction of strontium and cesium transport through uniform saturated sand was investigated by comparing measured breakthrough curves with curves of simulations using the advection-dispersion and the advection equations. Values for Kd were determined by batch equilibration tests and, indirectly, by fitting the mathematical model to breakthrough data from column experiments. Although the advection-dispersion equation accurately represented the breakthrough curves for two nonreactive solutes (chloride and tritium), neither it nor the advection equation provided close representations of the strontium and cesium curves. The simulated breakthrough curves for strontium and cesium were nearly symmetrical, whereas the data curves were very asymmetrical, with long tails. Column experiments with different pore-water velocities indicated that the shape of the normalized breakthrough curves was not sensitive to velocity. This suggests that the asymmetry of the measured curves was the result of nonlinear partitioning of the cations between the solid and liquid phases, rather than nonequilibrium effects. The results indicate that the distribution coefficient, when used in advection-dispersion models for prediction of the migration of strontium and cesium in field situations, can result in significant error.

scholarly journals Sport i rekreacja przy wybranych akwenach objętych zakwitami alg i sinic na przykładzie wybranych zbiorników Polski

2015 ◽  
Vol 13 (3) ◽  
pp. 105-117
Author(s):  
Justyna Pacelt ◽  
Wojciech Szeligiewicz
Keyword(s):  
Algal Blooms ◽  
Water Contamination ◽  
Human Life ◽  
Water Environment ◽  
Recreational Activity ◽  
Basic Resource ◽  
Holiday Season ◽  
Water Conditions ◽  
Toxic Blooms ◽  
Financial Losses

The water environment constitutes a basic resource for not only human life but also recreational activity during the holiday season. In reservoirs with high trophic level caused mainly by water contamination, algal blooms occur. This phenomenon is especially intensive in spring and than in summer and affects the use of water reservoirs and coastal areas by people. One type, toxic blooms, is very dangerous for human health. If people who use the reservoir for recreational and professional purposes are unaware of the occurrence of this type of bloom, it may cause serious health problems and financial losses. To avoid this situation, cooperation among institutions which monitor water conditions on each reservoir must be established.

scholarly journals Conjunctive Use of BTC and Batch Methods for Heavy Metal Transport

2020 ◽  
Author(s):  
Mohamed Fahmy Hussein ◽  
Hassan Khater
Keyword(s):  
Heavy Metal ◽  
Distribution Coefficient ◽  
Sandy Loam ◽  
Mathematical Formulation ◽  
Breakthrough Curves ◽  
Retardation Factor ◽  
Model Parameters ◽  
Dilute Solution ◽  
High Concentration ◽  
Theoretical Concepts

Abstract Marginal sediments can be used to combat punctual pollution by heavy metals in industrial zones. Such practice requires information on metal-concentration in the workshop discharge water. Knowledge about the reaction of the heavy metal with the sediment available in the landscape is of utmost importance. Modeling of batch experiments and breakthrough curves, BTC, supplies relevant information in this regard. We modeled the static batch-data by Freundlich isotherms for testing CdCl2 aqueous solutions equilibria with sandy loam sediment and the dynamic column-data by two codes, CfitM and CfitIM, under saturated water flow conditions. Three Cd-concentrations (5, 20, and 40 ppm) were employed to investigate the conjunction of using two procedures for obtaining the pertinent parameters for the transport of such a heavy metal and the design of the adequate Cd-trap. The results showed the deviations of the two techniques due to differences in their theoretical concepts, mathematical formulation, and performance. The batch method showed utility in supplying first guesses for the retardation factor, R, to insert into the 4-parameter analytical code, CfitIM, applied for column BTC modeling. The iteratively-obtained-parameters of the Freundlich equation were then employed to generate the distribution coefficient, k d. The generated value was, in turn, used to get more fair guess for the retardation factor, R, to use as a fixed-value in the CfitIM code to get an in-depth insight into the BTC dynamics and to obtain the other pertinent model parameters. The BTC runs indicated that the concentration controls the distinctive adsorption and transport rate and behavior of the heavy metal in the sediment column. The most dilute solution offered the highest Cd impediment, as shown by the most significant values for the distribution coefficient, k d, and retardation factor, R. The malfunction of the sediment as a trap appeared at Cd-concentrations four to eight folds higher than the most dilute solution. However, the loamy sand trap is successful when fed with a dilute aqueous solution. A set of successive traps is to arrange in tandem lines when moderate to high concentration is to discharge from an industrial workshop. The results emphasize the utility of the mutual use of these two lab procedures for the design of adequate traps and landfills and the simulation of more complex situations in the field. The point-pollution control needs to continue running batch and BTC experiments and to carry out their corresponding modeling.

scholarly journals SIZE EFFECT OF COPPER NANOPARTICALS ON MICROCYSTIS AERUGINOSA

2018 ◽  
Vol 16 (2) ◽  
pp. 361-367
Author(s):  
Nguyen Trung Kien ◽  
Tran Thi Thu Huong ◽  
Nguyen Hoai Chau ◽  
Dang Dinh Kim ◽  
Duong Thi Thuy
Keyword(s):  
Particle Size ◽  
Microcystis Aeruginosa ◽  
Copper Nanoparticles ◽  
Algal Blooms ◽  
Water Environment ◽  
Freshwater Ecosystems ◽  
Particle Sizes ◽  
Toxic Cyanobacteria ◽  
The Stability ◽  
Effect Of Copper

Cyanobacterial and toxins produced in cyanobacterial water blooms cause serious environmental problems which effects on freshwater ecosystems. The use of nanomaterials to control algal blooms is a new potential way for practical application due to its antibacterial as well as distinct physicochemical properties of nanomaterials. The particle size is one of the most determinant characteristics creating the different between nanomaterials and their larger bulk counterparts. However, size-dependent toxicity of nanoparticles has remained largely unknown. This study aimed to evaluate effect of three different nanoparticle sizes (d ≤ 10 nm; 30 nm ≤ d ≤ 40 nm and d ≥ 50 nm) on toxic cyanobacteria Microcystis aeruginosa. The copper nanoparticles were synthesized by electrochemical method and coated with chitosan to enhance the stability of materials in the water environment. The copper nanoparticle concentrations selected for toxic test were range from 0 (control); 0,01ppm; 0,05ppm; 0,1 ppm; 1ppm and 5 ppm. After ten days of experiment, the growth of M. aeruginosa was mainly affected at concentrations of 1 ppm and 5 ppm and there are no differences in inhibition between the particle sizes with efficiency of more than 80% in comparison to control. The highest toxicity of copper nanoparticles in M. aeruginosa was observed at particle size of 30 nm ≤ d ≤ 40 nm with EC50 = 0,73 ppm, which was respectively three to seven times less than the particle sizes of d ≥ 50 nm (EC50 = 2,62 ppm) and d ≤ 10nm (EC50 = 5,02 ppm) at the same time.

scholarly journals Simulations of breakthrough curves for fixed-bed column adsorption of Cobalt (II) ions on spent tea leaves

2020 ◽  
Author(s):  
Kibrewossen Tesfagiorgis ◽  
Abel E. Navarro ◽  
Bow Ming Chen ◽  
Nicholas Herrera ◽  
Joel Hernandez ◽  
...  
Keyword(s):  
Mathematical Models ◽  
High Surface ◽  
Fixed Bed ◽  
Surface Heterogeneity ◽  
Breakthrough Curves ◽  
Concentration Data ◽  
Residual Concentration ◽  
Fixed Bed Column ◽  
Natural Logarithm ◽  
Column Adsorption

Abstract The objective of this study is to model the breakthrough adsorption curves of Co (II) ions using spent tealeaves in fixed-bed column experiments. Spent leaves of green tea (GT), peppermint tea (PM) and chamomile (CM) were packed in glass columns with a diameter of 2 cm and height of 15 cm, and used as filters for the removal of the pollutant. Aqueous solutions of Cobalt (II) ions (100 mg/L) at pH 6 were prepared and pumped against gravity through the columns at a uniform flow rate of 5 mL/min. Breakthrough curves were fitted for the residual concentration data using the Thomas, Yoon-Nelson, and Clark models, with added empirical terms to delineate the lower tail of the breakthrough curve. These mathematical models were successfully linearized using the natural logarithm for parameter estimation. The results reveal that the Co (II) adsorption fits all three models for all the adsorbents. The Thomas model indicated that the calculated adsorption capacities followed the trend: PM > GT > CM with values of 59.7, 25.2, and 24.9 mg/g respectively. Moreover, CM showed the highest adsorption rates with all the mathematical models, whereas Yoon-Nelson theory provided evidence that PM has the longest 50% adsorption breakthrough among the adsorbents. Lastly, morphological and textural studies indicate that all spent leaves are good candidates as adsorbents due to their high surface heterogeneity. This study proposes the use of spent tealeaves as Co (II) adsorbents because they are inexpensive and environmentally beneficial.

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