PSD and Fractal Dimension for flocculation with different parameters and ferric chloride, aluminium polychloride and aluminium sulfate as coagulants

2021 ◽  
Vol 43 ◽  
pp. 102180
Author(s):  
Sabrina de Oliveira Anício ◽  
Verônica dos Santos Lopes ◽  
André Luiz de Oliveira
Keyword(s):  
Fractal Dimension ◽  
Ferric Chloride ◽  
Aluminium Sulfate

Phosphorus removal in ponds

1995 ◽  
Vol 31 (12) ◽  
pp. 331-339 ◽  
Author(s):  
Ernesto R. Lopez ◽  
Rao Y. Surampalli ◽  
Shankha K. Banerji ◽  
Charles J. Pycha
Keyword(s):  
Ferric Chloride ◽  
Phosphorus Removal ◽  
Metal Salts ◽  
Basic Data ◽  
Special Study ◽  
High Quality ◽  
Aluminium Sulfate ◽  
Treatment Facilities ◽  
The Subject ◽  
Lagoon Systems

The municipal lagoon treatment systems which remove phosphorus by chemical addition are the subject of this special study. The objectives of this study were to determine the degree of success of lagoon treatment systems in removing phosphorus and to identify any operational problems. In order to obtain basic data for this study, thirty-two lagoon treatment systems in Michigan and Minnesota were investigated. Chemicals typically used for phosphorus removal include metal salts such as aluminium sulfate (alum), ferrous and ferric chloride, lime, and various polymers. The overall experience with these lagoon systems is that the technology, in its various configurations, has been working very well. Of the thirty-two lagoon treatment facilities reviewed, only two facilities were having problems meeting consistently the effluent phosphorus limits. Generally, the permitted effluent phosphorus limit is 1 mg/l. The influent phosphorus concentrations varied between 0.5 and 15 mg/l. Alum and ferric chloride applications produced consistently high quality effluents while lime applications were not as effective in removing phosphorus. None of these lagoon treatment systems experienced problems with build-up of sludges to levels which affected the effluent concentrations. Accumulated amounts were an inch or less per year, consistent with solids build-up in the primary lagoon cells.

Effluent pretreatment by iron coagulation applying various dose-pH combinations for optimum particle separation

1998 ◽  
Vol 38 (6) ◽  
pp. 27-34 ◽  
Author(s):  
A. Adin ◽  
Y. Soffer ◽  
R. Ben Aim
Keyword(s):  
Particle Size ◽  
Ferric Chloride ◽  
Wastewater Reuse ◽  
Transport Systems ◽  
Particle Removal ◽  
Turbidity Removal ◽  
Particle Count ◽  
Aluminium Sulfate ◽  
Total Particle ◽  
Size Groups

Wastewater reuse often requires particle destabilization and removal to protect water transport systems and membranes from clogging. Flocculation process of activated sludge effluent applying ferric chloride is examined and comparison with alum (aluminium sulfate) application is made in this work. Optimum flocculation conditions are determined based on the removal efficiency of different particle size groups and on turbidity as a function of coagulant dosage and pH. Results show that the best removal for ferric chloride coagulant occurs at pH 4-5 and dosage of 20-30 mgl−1. Settled water total particle count (TPC) of particle size ≥2μm was reduced by more than 99%, while turbidity removal reached 86%. Zeta potential measurements and visual observations indicate domination of adsorption and charge neutralization mechanisms. Best removal with alum occurred at pH 6-7 while dosing 30 mgl−1 and higher. Destabilization mechanism of adsorption and sweep coagulation is proposed. Generally alum performed somewhat better than iron for turbidity removal and worse for TPC removal. CMD (count mean diameter) is proposed for particle removal index: the higher the TPC removal, the lower the CMD.

Characterisation of medical-waste sterilisation-plant wastewater and a preliminary study of coagulation–flocculation treatment options

2010 ◽  
Vol 62 (2) ◽  
pp. 266-272 ◽  
Author(s):  
O. Özkan ◽  
H. Mıhçıokur ◽  
Ş. T. Azgın ◽  
Ö. Özdemir
Keyword(s):  
Ferric Chloride ◽  
Ph Value ◽  
Treatment Options ◽  
Oxygen Demand ◽  
Medical Waste ◽  
Municipal Sewage ◽  
Nitrogen And Phosphorus ◽  
Aluminium Sulfate ◽  
Coagulant Dosage ◽  
Pre Treatment

Wastewater from a medical-waste sterilisation plant (MWSP) contains unique pollutants and requires on-site treatment to prevent contamination of the municipal sewage system and receiving water bodies. Therefore, to meet the prescribed discharge standards and comply with the legal regulations, pre-treatment must be applied to MWSP wastewater. In this study, the capabilities of coagulation–flocculation processes were investigated for MWSP wastewater treatment. Processes using ferric chloride, ferrous sulfate and aluminium sulfate as coagulants were characterised. During the coagulation experiments, seven different coagulant dosages and four different pH values were evaluated to determine the optimum coagulant dosage and pH value. The highest removal efficiency of chemical oxygen demand (COD) was obtained using 300 mg/L of ferric chloride at pH 10. A COD removal of about 60% as well as considerable reductions in the amounts of suspended solids, nitrogen and phosphorus were realised.

scholarly journals Characterisation of titanium tetrachloride and titanium sulfate flocculation in wastewater treatment

2009 ◽  
Vol 59 (12) ◽  
pp. 2463-2473 ◽  
Author(s):  
Y. Okour ◽  
H. K. Shon ◽  
I. El Saliby
Keyword(s):  
Wastewater Treatment ◽  
Ferric Chloride ◽  
Titanium Tetrachloride ◽  
Sludge Reduction ◽  
Turbidity Removal ◽  
Titanium Sulfate ◽  
Ph Values ◽  
Aluminium Sulfate ◽  
Organic Removal ◽  
Very High

Flocculation with titanium tetrachloride (TiCl4) and titanium sulfate (Ti(SO4)2) was investigated in terms of different coagulant doses, pH, turbidity, dissolved organic carbon (DOC), UV-254, colour, zeta potential, particle size and molecular weight distribution. The two coagulants were compared with the commonly used coagulants such as ferric chloride (FeCl3) and aluminium sulfate (Al2(SO4)3). Titanium tetrachloride showed the highest turbidity removal, while titanium sulfate showed the highest reduction of UV-254 and colour at all pH values. The four coagulants were found to have similar organic removal up to 60–67% and resulted in similar organic removal in terms of various MW ranges. The decantability of the settled flocs was very high for titanium tetrachloride, titanium sulfate and ferric chloride compared with aluminium sulfate. The dominating coagulation mechanisms for titanium tetrachloride and titanium sulfate are still to be studied, since different precipitation reactions might take place at different pH even without flocculant addition. Titanium tetrachloride and titanium sulfate were found as effective new coagulants in wastewater treatment not only in terms of organic matter removal, but also in sludge reduction through the production of titanium dioxide.

Use of fractals to describe microstructures of porous thick-film platinum electrodes

1992 ◽  
Vol 50 (1) ◽  
pp. 314-315
Author(s):  
Steven D. Toteda
Keyword(s):  
Fractal Dimension ◽  
Power Plants ◽  
Electrical Response ◽  
Cubic Phase ◽  
Platinum Electrodes ◽  
Fine Grained ◽  
Impedance Response ◽  
Platinum Particles ◽  
Energy Surfaces ◽  
Highly Porous

Zirconia oxygen sensors, in such applications as power plants and automobiles, generally utilize platinum electrodes for the catalytic reaction of dissociating O2 at the surface. The microstructure of the platinum electrode defines the resulting electrical response. The electrode must be porous enough to allow the oxygen to reach the zirconia surface while still remaining electrically continuous. At low sintering temperatures, the platinum is highly porous and fine grained. The platinum particles sinter together as the firing temperatures are increased. As the sintering temperatures are raised even further, the surface of the platinum begins to facet with lower energy surfaces. These microstructural changes can be seen in Figures 1 and 2, but the goal of the work is to characterize the microstructure by its fractal dimension and then relate the fractal dimension to the electrical response. The sensors were fabricated from zirconia powder stabilized in the cubic phase with 8 mol% percent yttria. Each substrate was sintered for 14 hours at 1200°C. The resulting zirconia pellets, 13mm in diameter and 2mm in thickness, were roughly 97 to 98 percent of theoretical density. The Engelhard #6082 platinum paste was applied to the zirconia disks after they were mechanically polished ( diamond). The electrodes were then sintered at temperatures ranging from 600°C to 1000°C. Each sensor was tested to determine the impedance response from 1Hz to 5,000Hz. These frequencies correspond to the electrode at the test temperature of 600°C.

Comment on "On the fractal dimension of stream networks"

1990 ◽  
Vol 26 (9) ◽  
pp. 2243-2244 ◽  
Author(s):  
David G. Tarboton
Keyword(s):  
Fractal Dimension ◽  
Stream Networks

Heterogeneity of Cerebral Blood Flow: a Fractal Approach

2000 ◽  
Vol 39 (02) ◽  
pp. 37-42 ◽  
Author(s):  
P. Hartikainen ◽  
J. T. Kuikka
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Fractal Dimension ◽  
Frontal Lobe ◽  
Fractal Analysis ◽  
Relative Dispersion ◽  
Emission Computed Tomography ◽  
Brain Blood Flow ◽  
Healthy Controls ◽  
Fractal Approach

Summary Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and singlephoton emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (= coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17 ± 0.05 (mean ± SD) for the left hemisphere and 1.15 ± 0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04 ± 0.03 than in healthy controls. Conclusion: Within the limits of spatial resolution of SPECT, the heterogeneity of brain blood flow is well characterized by a fractal dimension. Fractal analysis may help brain scientists to assess age-, sex- and laterality-related anatomic and physiological changes of brain blood flow and possibly to improve precision of diagnostic information available for patient care.

Sign in / Sign up

Export Citation Format

Share Document