Using seafood waste as sludge conditioners

2001 ◽  
Vol 44 (10) ◽  
pp. 301-307 ◽  
Author(s):  
D.Y. Lee ◽  
S.R. Jing ◽  
Y.F. Lin
Keyword(s):  
Ferric Chloride ◽  
Specific Resistance ◽  
Oyster Shell ◽  
Particle Sizes ◽  
Sludge Dewatering ◽  
Insignificant Effect ◽  
Shrimp Shell ◽  
Ph Decrease ◽  
Shell Particles ◽  
Bone Particles

In this study, three kinds of seafood wastes (shrimp shell particles, oyster shell particles, and internal bone particles of squid) were added to dewatered sludge preconditioned with chemical conditioner (alum or ferric chloride). The specific resistance of sludge dewatering was calculated to evaluate the effectiveness of sludge dewatering. The result showed that adding chemical conditioners alone caused noticeable pH decrease and resulted in a conditioned sludge with poor filterability. The addition of oyster shell or internal bone of squid to chemically preconditioned sludge efficiently improved sludge dewatering. This result was possibly due to both the availability of alkaline and the function as skeleton builder provided by these two waste solids. Particle sizes (0.59-2.0 mm) of oyster shell and internal bone of squid were found to have insignificant effect on sludge dewatering.

Comparison of lime and alum as oily sludge conditioners

1997 ◽  
Vol 36 (12) ◽  
pp. 117-124 ◽  
Author(s):  
Tay Joo Hwa ◽  
S. Jeyaseelan
Keyword(s):  
Specific Resistance ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oily Sludge ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Sludge Cake ◽  
Solids Content ◽  
Optimum Chemical

Chemical conditioning improves sludge dewatering. Choice of chemical conditioners is very much dependent on the characteristics of the sludges and the type of dewatering devices. Lime, alum, ferric chloride and polyelectrolytes are commonly used chemical conditioners. Anaerobic digested sludge samples collected from a sewage treatment plant with different oil contents varying from 1.8% to 8.0% by weight have been examined in the laboratory to find out their specific resistance, capillary suction time and filter yield. Lime and alum were used separately as conditioners. Different dosages of conditioner varying from 2% to 12% by weight were used to determine the optimum chemical dosage for varying oil contents. Lime dosages of about 6% were found to yield favourable characteristics. Addition of alum decreases the specific resistances and capillary suction times of oily sludges rapidly up to 4% dosages. Alum dosages beyond 4% only increase the solids content in the sludge cake and increase the sludge volume to be handled. A correlation between CST and specific resistance to filtration was established. CST can be measured easily and quickly in the laboratories. Using the CST and the correlation a quick prediction on dewaterability can be established.

scholarly journals The Effect of Various Particle Sizes of Oyster Shell and Limestone on Performance of Laying Leghorn Pullets

1975 ◽  
Vol 54 (5) ◽  
pp. 1422-1433 ◽  
Author(s):  
P.C. Miller ◽  
M.L. Sunde
Keyword(s):  
Oyster Shell ◽  
Particle Sizes

scholarly journals Comparison of ferric chloride and aluminum sulfate on phosphorus removal and membrane fouling in MBR treating BAF effluent of municipal wastewater

2016 ◽  
Vol 7 (4) ◽  
pp. 442-448 ◽  
Author(s):  
Xin Li ◽  
Yali Liu ◽  
Fangfang Liu ◽  
Aimin Liu ◽  
Qilan Feng
Keyword(s):  
Ferric Chloride ◽  
Membrane Fouling ◽  
Phosphorus Removal ◽  
Aluminum Sulfate ◽  
Municipal Wastewater ◽  
Transmembrane Pressure ◽  
Particle Sizes ◽  
Fouling Control ◽  
Aerated Filter ◽  
Sludge Particle

A membrane bioreactor (MBR) was used for treating biological aerated filter effluent in a municipal wastewater plant, and chemical phosphorus removal was accomplished in the MBR. The results showed that ferric chloride of 20 mg/L and aluminum sulfate of 30 mg/L were the optimal dosages for total phosphorus (TP) removal, and the TP removal efficiency was over 80%. In long-term continuous operations, both ferric chloride and aluminum sulfate effectively mitigated membrane fouling, with the corresponding growth rate of transmembrane pressure decreased to 0.08 and 0.067 kPa/d, respectively. Sludge particle sizes analysis demonstrated that the decrease of particle sizes lower than 50 μm was the main reason for membrane fouling control. Simultaneously, the proteins and polysaccharide (PS) concentrations in the MBR supernatant were analyzed, and the PS concentration significantly decreased to 2.02 mg/L at aluminum sulfate of 30 mg/L, indicating the flocculation of aluminum sulfate on PS was the main reason for mitigation of membrane fouling.

Mechanical Properties and Morphology of Poly(Lactic Acid) Composites with Oyster Shell Particles

2011 ◽  
Vol 391-392 ◽  
pp. 590-594
Author(s):  
Rie Nobe ◽  
Jian Hui Qiu ◽  
Eiichi Sakai ◽  
Makoto Kudo ◽  
Min Zhang
Keyword(s):  
Lactic Acid ◽  
Fracture Strain ◽  
Oyster Shell ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Biodegradable Composites ◽  
Young’S Moduli ◽  
Degradation Temperature ◽  
Shell Particles ◽  
Poor Adhesion

The biodegradable composites were prepared with the oyster shell particles (OSP) and poly(lactic acid)(PLA) by injection molding. The mechanical and thermal properties were investigated. The degradation temperature of the composites decreased by increasing the content of OSP compared with PLA. From the results of tensile test, the tensile strength and the fracture strain of the composites decreased because of exist of OSP. However, the Young’s moduli of the composites increased compared with PLA. The SEM observation of morphology confirmed that the interface between PLA and OSP had poor adhesion.

Improved Centrifuge Sludge Dewatering by Automatic Backdrive Torque Control

1990 ◽  
Vol 22 (12) ◽  
pp. 303-308
Author(s):  
B. A. Garelli ◽  
E. L. Kokat ◽  
B. J. Schwartz
Keyword(s):  
Control Systems ◽  
Ferric Chloride ◽  
Direct Current ◽  
Performance Optimization ◽  
Torque Control ◽  
Water Reclamation ◽  
Sludge Dewatering ◽  
Digested Sludge ◽  
Regular Production ◽  
Solids Content

An investigation of different automatic torque control systems for performance optimization of solid bowl centrifuges was conducted at the Stickney Water Reclamation Plant of the Metropolitan Water Reclamation District of Greater Chicago (District). Two automatic hydraulic backdrives and a direct current automatic torque controlled backdrive were tested on centrifuges used for dewatering digested sludge conditioned with a polymer and a combination of polymer and ferric chloride. The centrifuge unit of an advanced design coupled with the direct current automatic torque controlled backdrive produced a cake having a solids content of 30% and a solids capture of 97%. The regular production unit produced a cake having a solids content of 15% and a solids capture of 85%.

Sludge dewatering using centrifuge with thermal/polymer conditioning

2001 ◽  
Vol 44 (10) ◽  
pp. 321-325 ◽  
Author(s):  
C.F. Lin ◽  
Y. Shien
Keyword(s):  
Water Treatment ◽  
Thermal Treatment ◽  
Specific Resistance ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Temperature Changes ◽  
Biological Sludge ◽  
Sludge Particle

Sludge dewatering is preceded by a conditioning operation to enhance water removal efficiency. In the conditioning operation, chemical coagulants or polymers are added to promote sludge particle aggregation for easier dewatering. In this study, an alternative conditioning method for sludge thermal treatment at temperatures up to 80°C was extensively investigated. Dewatering characteristics such as sludge capillary suction time and specific resistance to filtration, sludge viscosity and concentration of solid cakes were examined thoroughly. A good correlation between capillary suction time and specific resistance to filtration was established for sludges from water treatment, but not for biological sludge. Cationic polymer exhibits the best enhancement on sludge moisture removal. The sludge rheogram varies from 60 to 5 cP as temperature changes from 20 to 80°C for sludges from water treatment plant. The dewatering ability of sludge can be greatly enhanced by thermal treatment in conjunction with the use of polymers.

scholarly journals Influence of Mie scattering on nanoparticles with different particle sizes and shapes: Photometry and analytical ultracentrifugation with absorption optics

2005 ◽  
Vol 70 (3) ◽  
pp. 361-369 ◽  
Author(s):  
M.D. Lechner
Keyword(s):  
Analytical Ultracentrifugation ◽  
Mie Scattering ◽  
Precise Determination ◽  
Core Shell ◽  
Particle Sizes ◽  
Wide Range ◽  
Photometric Measurements ◽  
Shell Particles ◽  
Reliable Methods

Nanoparticles are used in large quantities for very different applications. A precise determination of the diameter and the particle size distribution which is responsible for the application properties is therefore essential. Reliable methods for measuring the above mentioned quantities are photometric measurements and analytical ultracentrifugation with an UV optics detector. Both methods are ruled by the Mie effect, that is scattering and absorption of the particles as function of the diameter, the wavelength, and the shape of the particles. The extinction coefficients ?=?/c for spheres, rods, and core shell particles have been calculated and plotted over a wide range of the size parameter ?d/?. Two examples for multimodal latex particles and core shell particles have been given and demonstrate the applicability of the method.

Investigation of the Processing of Biological Sediments by the Cryogenic Method

2020 ◽  
Vol 24 (10) ◽  
pp. 20-25
Author(s):  
L.I. Sokolov ◽  
A.N. Tyanin
Keyword(s):  
Activated Sludge ◽  
Specific Resistance ◽  
Sewage Treatment ◽  
Freezing Temperature ◽  
Sludge Dewatering ◽  
Sewage Treatment Plants ◽  
Yielding Capacity ◽  
Cryogenic Method

The study of the processes of intensification of sludge dewatering at sludge sites of sewage treatment plants (WWTP) is presented. The parameters that determine the water yielding capacity of the compacted and excess activated sludge have been clarified. The process of cascadecyclic freezing – thawing of biological sediments has been investigated. The degree of influence of cryogenesis on the specific resistance of the sediment filtration and its water yielding has been determined. Dependences of the resistivity of precipitation on the content of ashless substance and freezing temperature have been established.

scholarly journals Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

2011 ◽  
Vol 2 ◽  
pp. 638-644 ◽  
Author(s):  
Lars Borchardt ◽  
Martin Oschatz ◽  
Robert Frind ◽  
Emanuel Kockrick ◽  
Martin R Lohe ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Methane Combustion ◽  
Correlation Spectroscopy ◽  
Core Shell ◽  
Particle Sizes ◽  
Temperature Programmed Oxidation ◽  
Preparation Conditions ◽  
Temperature Programmed ◽  
Shell Particles ◽  
First Time

For the first time we present the synthesis of CeO2/Si(O)C core–shell particles prepared by the miniemulsion technique. The Si(O)C core was obtained by means of a polycarbosilane precursor (SMP10), which was subsequently functionalized with ceria and pyrolyzed to the ceramic. The size of these particles could easily be adjusted by varying the surfactants and the surfactant concentration, or by the addition of comonomers. Hence particle sizes ranged from 100 to 1000 nm, tunable by the preparation conditions. All materials were characterized by photon cross correlation spectroscopy, scanning electron microscopy and elemental mapping investigations. Furthermore, first catalytic tests were carried out by temperature programmed oxidation (TPO) of methane, and the activity of this material in lowering the onset temperature of methane combustion by 262 K was documented.

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