Research on Dewatering Ability of Municipal Sludge under the Treatment of Coupled Acid and Microwave

Geofluids ◽

10.1155/2021/7161815 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Xudong Zhang ◽

Peng Ye ◽

Yajun Wu ◽

Zhen Guo ◽

Yuan Huang ◽

...

Keyword(s):

Particle Size ◽

Extracellular Polymeric Substances ◽

Treatment Time ◽

Microwave Treatment ◽

Particle Size Analysis ◽

Size Analysis ◽

High Water Content ◽

Municipal Sludge ◽

Sludge Dewatering ◽

Sem Test

Municipal sludge is a by-product of urban sewage treatment; it has high water content and contains many hydrophilic extracellular polymeric substances (EPS). It is difficult to achieve deep dewatering of sludge. Therefore, it is necessary to find an efficient method to treat sludge. In this study, an acid-microwave treatment method was proposed to improve the dewatering ability of sludge. A vacuum filtration test and particle size analysis test were used to explore the improvement effect of dehydration performance. After centrifugation, the concentrations of soluble proteins and polysaccharides in the supernatant were measured to explore the disintegration of acid-microwave treatment on EPS. Finally, the microstructure of sludge treated by acid-microwave was studied via the SEM test. The results showed that short-term microwave radiation was conducive to sludge dewatering. However, the sludge dewatering performance deteriorated significantly when the treatment time was too long. The optimal microwave treatment condition was 700 W for 180 s, and the SRF of sludge was the lowest, which was 10.11 × 10 12 m / kg . After acid-microwave treatment, sludge particle size increased significantly. The concentration of protein and polysaccharide in supernatant increased with the increase of microwave treatment time. Acid-microwave treatment could significantly improve the release efficiency of the polysaccharide. Through the SEM test, it can be verified that the bulk floc structure of sludge is broken after microwave treatment, and acid-microwave treatment is beneficial to the aggregation of floc fragments to form large particles, which can provide larger pores for drainage.

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Effects of Particle Size Distribution on the Properties of Natural-Based Composite

International Journal of Engineering Materials and Manufacture ◽

10.26776/ijemm.04.04.2019.05 ◽

2019 ◽

Vol 4 (4) ◽

pp. 170-177

Author(s):

J. Abutu ◽

S.A. Lawal ◽

M.B. Ndaliman ◽

R.A. Lafia-Araga ◽

A.S. Abdulrahman

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Treatment Time ◽

Particle Size Analysis ◽

Coconut Shell ◽

Size Analysis ◽

Distribution Width ◽

Testing Procedures ◽

Coconut Shells

In this study, locally sourced natural materials (coconut shells and seashells) were used separately to produce composites. The powders were sieved with sieve size of 10 µm and characterized using a particle size analyser (DLS) in order to ascertain their particle size distribution. Also, the effects of particle size distribution on the performance of sourced coconut shells and seashells-based composite was investigated. About 52% of the characterized powder was afterward used along with other ingredients (35% binder, 8% alumina and 5% graphite) to produced composites using moulding pressure (14 MPa), moulding temperature (160 ºC), curing time (12 min) and heat treatment time (1 hr). The performance of the composites was thereafter evaluated using standard testing procedures. The results of particle size analysis indicated that the seashell powder (0.27) possesses lower distribution width (PDI) compared to the coconut shell powder (0.342) while the coconut shell (542.3 nm) showed lower Z-average diameter compared to the seashell powder (1096 nm) with some little traces of nanoparticles (<10 µm). Also, the experimental results obtained from composite characterization indicated that the coconut shell-based samples exhibited better performance in terms of its mechanical and tribological properties compared to the seashell-based samples.

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Suppression of Annual Bluegrass Weevil on a Golf Course Fairway with Split Applications of Chlor-Pyrifos and Experimental Formulations, 1996

Arthropod Management Tests ◽

10.1093/amt/22.1.362 ◽

1997 ◽

Vol 22 (1) ◽

pp. 362-362

Author(s):

P.R. Heller ◽

R. Walker

Keyword(s):

Particle Size ◽

Soil Temperature ◽

Treatment Time ◽

Particle Size Analysis ◽

Size Analysis ◽

Application Time ◽

Annual Bluegrass ◽

Water Ph ◽

Loam Soil ◽

Annual Bluegrass Weevil

Abstract The fairway consisted primarily of annual bluegrass (70%) and Kentucky bluegrass (30%) in Bedford County, PA. Applications were made when flowering dogwood was in full bloom. Treatment plots were 6 X 6 ft, arranged in a RCB design and replicated 4 times. Liquid formulations were applied with a CO2 compressed air sprayer with four 8004VS TeeJet nozzles mounted on a 6 fi boom, operating at 28 psi, and applied in 272 ml of water/36 ft2 or delivering 2 gal water/1,000 ft2. At the 1st treatment time (14 May), the following soil and environmental conditions existed: air temperature, 57°F; soil temperature at 1 inch depth, 64°F; soil temperature at 2 inch depth, 60°F; RH, 35% amount of thatch, 0.25-0.50 inches; soil textural class, loam; soil particle size analysis: 27.4% sand, 46.9% silt, 25.8% clay; soil moisture (oven dry weight) 46.6%; organic matter, 6.8%; water pH, 7; soil pH, 5.9; application time, mid-morning; and clear skies. The experimental area was irrigated with 0.1 inch 24 hr after treatment. At the 2nd treatment time (31 May), the following soil and environmental conditions existed: application time, late-morning; air tem perature, 61°F; soil temperature at 1 inch depth, 64°F; soil temperature at 2-inch depth, 58°F; RH, 48%; amount of thatch, 0.25-0.50 inch; soil texturai class, loam; soil particle size analysis: 27.4% sand, 46.9% silt, 25.8% clay; organic matter, 6.8%; soil condition, moist; water pH, 7; soil pH, 5.9; and cleai skies. The experimental area was irrigated with 0.1 inch 1 hr after treatment. Post-treatment counts were made on 19 Jun. Annual bluegrass weevil con trol was evaluated by removing three 4-inch cup cutter sod samples from each replicate and recording the total number of annual bluegrass weevil life stages (larva, pupa, adult) per sample. Totals were then converted to a ft2 count.

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