Study on Effectes of Different Inorganic Electrolytes on Flocculation Falling of Slurry

2011 ◽  
Vol 233-235 ◽  
pp. 877-881
Author(s):  
Deng Gao Ji ◽  
Xu Long Guo ◽  
Yang Hui Cai ◽  
Su Qin Peng ◽  
Jian Hua Lian
Keyword(s):  
Zeta Potential ◽  
Functional Groups ◽  
Image Analyzer ◽  
Surface Functional Groups ◽  
Floc Size ◽  
Coal Particles ◽  
Coal Slime ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Better Than

In order to strengthen the thin coal slime settlement, and improve the efficiency of solid-liquid separation, in this paper, as the research object of Wuyang coal slime, carried out the studies on the effect of flocculation and settling with different inorganic electrolytes, and using electrophoresis analyzer, image analyzer and FTIR, characterized inorganic electrolytes effect on zeta potential of coal particles, floc size and surface functional groups. The results showed that: the effect of flocculation and falling, with CaCl2 and non-ionic PAM, is better than several other inorganic electrolytes. When the amount of non-ionic PAM is 3ml, CaCl2 best dosage is 4ml, corresponding to the initial falling speed is 24.49cm/min, supernatant turbidity is 22NTU. It has certain effect to the zeta potential of coal particles, floc size and the functional groups of coal surface after adding inorganic electrolytes.

scholarly journals The Study of Optimization of Flocculation and Destabilization Technology of Waste PEM Drilling Fluid in Bohai Oilfield

2021 ◽  
Vol 9 ◽  
Author(s):  
Yang Liu ◽  
Yuchen Zhang ◽  
Tao Xie ◽  
Ming Yue ◽  
Dongsen Wang ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Influence Factor ◽  
Ph Value ◽  
Drilling Fluid ◽  
Mean Value ◽  
Factors Affecting ◽  
Clay Particles ◽  
Liquid Yield ◽  
Solid Liquid ◽  
Solid Liquid Separation

In light of the difficulty of solid-liquid separation of waste PEM drilling fluid in the Bohai oilfield, constructing an inorganic-organic flocculation system is proposed and the processing method of destabilization technology is optimized. The biggest influence factor on the flocculation process of PEM drilling fluid was determined by designing an orthogonal test. The flocculation mechanism was researched through single factor optimization, combined with zeta potential and particle size distribution test. The results showed that the most significant factors affecting the flocculation of waste PEM drilling fluid were the dosage of inorganic flocculant CaCl2 and flocculation pH value. When the dosage of inorganic flocculant CaCl2 was 1.2% (w/v), the dosage of organic flocculant SDYJ-2 was 0.05%, the flocculation pH value was 3, and the flocculation time was 5 min, the flocculation technology reached the optimization and then the liquid yield can reach 70.96%. The mechanism of flocculation and destabilization was as follows: the inorganic flocculant of CaCl2 mainly reduced the zeta potential of clay particles through electric neutralization. 1% CaCl2 could reduce the potential mean value of drilling fluid system from -38.1 mV to -32.5 mV, and then decrease the repulsion among suspensions. Through bridging curling and electric neutralization, the organic flocculant of SDYJ-2 can absorb and wrap the clay particles after flocculation destabilization to form a network spatial structure, which made clay particles aggregate into large flocs and particles. D50 can increase by 21.5 times, when the concentration of SDYJ-2 was 0.15%.

scholarly journals Flocculating and dewatering performance of hydrophobic and hydrophilic solids using a thermal-sensitive copolymer

2017 ◽  
Vol 76 (3) ◽  
pp. 694-704 ◽  
Author(s):  
Shulei Li ◽  
Yinfei Liao ◽  
Guosheng Li ◽  
Zhen Li ◽  
Yijun Cao
Keyword(s):  
Solid Surfaces ◽  
Effect Of Temperature ◽  
Solution Temperature ◽  
Adhesion Forces ◽  
Oil Sand ◽  
Floc Size ◽  
Hydrophobic Particles ◽  
Floc Strength ◽  
Solid Liquid ◽  
Solid Liquid Separation

Thermal-sensitive polymers have been tested on settling, compacting or dewatering of clays or oil sand tailings. However, not much attention has been paid to explore the effect of temperature on flocculating performance using thermal-sensitive polymers. In this study, poly(NIPAM-co-DMAPMA) was synthesized and employed to investigate the flocculating and re-flocculating performance of hydrophilic and hydrophobic particles at two specific temperatures; meanwhile settling and dewatering behaviors were also investigated. The results demonstrated that good flocculating performances were achieved at both room temperature (∼23 °C) and lower critical solution temperature (45 °C). Furthermore, larger flocs were formed at 45 °C as the copolymer was added. Floc strength and re-flocculating ability of the flocs were also intensified prominently at 45 °C. Additionally, settling and dewatering rates of suspensions were improved, and the moisture of filtered cakes was reduced when suspensions were at 45 °C. The phenomena could be justified by the phase transition of the copolymer from hydrophilicity to hydrophobicity as the temperature increased. There were much stronger adhesion forces between particles and higher adsorption amount of the copolymer onto solid surfaces at 45 °C. Therefore, the copolymer may be promising in solid–liquid separation to improve the floc size, floc strength, and settling and dewatering rate to achieve much lower moisture filtered cake.

Dewatering of Sewage Sludge with Coal as a Conditioner Using Thermal Compression

2013 ◽  
Vol 295-298 ◽  
pp. 1452-1455 ◽  
Author(s):  
Li Fan ◽  
Ming Yuan Zhou ◽  
Xiu Li Li
Keyword(s):  
Weight Loss ◽  
Sewage Sludge ◽  
Solid Content ◽  
Thermal Compression ◽  
Coal Particles ◽  
Sludge Cake ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Filter Aid ◽  
Volatile Materials

Thermal compression is effective for solid-liquid separation of various materials. In this paper, thermal compression was applied on the dewatering of sewage sludge with coal as a filter aid. Experiments with 0.25-1 mm coal particles (0.2 kg coal/kg dry sludge solid) obtained cakes of solid content over 49%. Higher dosage of coal generated cakes with lower moisture content. The combustion behavior of the sludge cake was studied using TG/DTG analysis. The results showed that a total weight loss of 65.1% occurred from 25 °C to 800 °C, including two major weight loss stages corresponding to loss of moisture and volatile materials respectively.

Research on a Vertical Settlement Type Dehydrator with Spiral Sieves

2012 ◽  
Vol 562-564 ◽  
pp. 838-841
Author(s):  
Gang Feng Zheng ◽  
Jia Wei Zha ◽  
Hai Zeng Liu ◽  
Ling Li
Keyword(s):  
Liquid Separation ◽  
Maintenance Costs ◽  
Settlement Type ◽  
Work Cycle ◽  
Continuous Feeding ◽  
Coal Slime ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Continuous Material

This article designed a kind of dehydration device using spiral sieve for solid-liquid separation of coal slime water. The device based on the spiral feeding extrusion, using the materials own gravity to achieve solid-liquid separation, so as to realize the continuous material feeding. Due to the mutual extruding of the material, spiral sieve and spiral rotor, the device has the following advantages: less work cycle, continuous feeding, easy for application and maintenance, reliable work, less repair point and low maintenance costs.

Nutrient conditions and reactor configuration influence floc size distribution and settling properties

2012 ◽  
Vol 65 (1) ◽  
pp. 156-163 ◽  
Author(s):  
G. A. C. Ehlers ◽  
D. Wagachchi ◽  
S. J. Turner
Keyword(s):  
Size Distribution ◽  
Nutrient Concentrations ◽  
Size Analysis ◽  
Liquid Separation ◽  
Floc Size ◽  
Treatment Processes ◽  
Floc Size Distributions ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Nutrient Conditions

Floc formation and settleability is critical for effective solid–liquid separation in many wastewater treatment processes. This study aimed to investigate the relationship between particle size distribution and nutrient conditions in different bioreactor configurations. Size distribution profiles of flocs that formed in continuous (B1), continuous with clarifier and return sludge (B2) and SBR (B3) reactors were investigated in parallel under identical nutrient conditions. An eight-fold dilution of the influent COD of a synthetic dairy processing wastewater resulted in a ‘feast and famine’ regime that triggered significant effects on the biomass and flocculation characteristics. Floc size analysis of reactor MLSS revealed a shift in floc sizes when reactors were fed with the minimum (famine) COD wastewater feed (0.61 g L−1). Increasing floc size distributions were detected for all reactors during the minimum COD feed although different size patterns were observed for different reactor configurations. These increases corresponded with variations in aggregation and EPS quantities. The SBR yielded comparatively larger flocs when operated under both COD feeds as indicated by d(0.9) values (90% of particles ≤ d in size). Overall the results indicated that floc formation and floc size are mediated by nutrient concentrations and represents an important step towards improved solid–liquid separation.

Nitrogen Removal in a Real-Time Controlled Sequencing Batch Membrane Bioreactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Cake Layer ◽  
On Line ◽  
Solid Liquid ◽  
Solid Liquid Separation

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.

Investigations on the filtration of natural aquatic suspensions supported by dosing small amounts of Fe(III)-salts (βFe ≤ 0.1 mg.L-1): mode of action and basic design criteria

2002 ◽  
Vol 2 (2) ◽  
pp. 91-98
Author(s):  
R. Winzenbacher ◽  
R. Schick ◽  
H.-H. Stabel ◽  
M. Jekel
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Iron Hydroxides ◽  
Essential Step ◽  
Iron Salts ◽  
Alkaline Earths ◽  
Co Precipitation ◽  
Solid Liquid ◽  
Solid Liquid Separation

Improved removal of particles during the treatment of natural aquatic suspensions has been achieved by pre-ozonation and the addition of small quantities of iron salts (βFe ≤ 0.1 mg.L-1; “Fe(III)-assisted filtration”) followed by rapid filtration. As shown by investigations on a large-scale installation at Lake Constance Water Supply, this procedure reliably reduces suspended solids by at least 2-3 powers of ten in long-term use. However, the high efficacy of Fe(III)-assisted filtration cannot be explained on the basis of known coagulation mechanisms (like adsorption-charge neutralization, co-precipitation). Instead, the essential step was found to be the conditioning of the filter medium by coating it with colloids containing Fe(OH)3, and this “Fe coating” process occurs only in the presence of alkaline earths (especially Ca2+). According to further experiments, the enhanced solid-liquid separation was ultimately traced to chemical interactions such as the formation of calcium-organic association structures between the iron hydroxides and other solids. For design of Fe(III)-assisted filtration steps, finally, a βCa/DOC ratio above 40 mg.mg-1 and pre-oxidation with ozone dosages not exceeding 2 mg O3/mg DOC was recommended.

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