scholarly journals Influence of Particle Size of River Sand on the Decontamination Process in the Slow Sand Filter Treatment of Micro-Polluted Water

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 100
Author(s):  
Xuemei Ji ◽  
Cui Zhao ◽  
Yufeng Lv ◽  
Jifu Yang ◽  
Bin Li
Keyword(s):  
Particle Size ◽  
Rural Areas ◽  
Size Range ◽  
Removal Rate ◽  
Polluted Water ◽  
Adsorption Model ◽  
Particle Size Range ◽  
River Sand ◽  
Term Operation ◽  
N Removal

Slow sand filters (SSFs) have been widely used in the construction of water plants in rural areas. It is necessary to find river sand of suitable particle size to improve SSF treatment of micro-polluted water so as to ensure the effective and long-term operation of these plants. In this study, SSF1# (particle size of 0.1–0.5 mm), SSF2# (particle size of 0.5–1 mm), and SSF3# (particle size of 1–1.5 mm) were selected. The physical absorption, CODMn and NH4+-N removal effect, and microbial community were analyzed. According to Langmuir and Freundlich adsorption model fitting, the smaller the particle size of the river sand, the more pollutants are adsorbed under the same conditions. SSF1# has the shortest membrane-forming time, highest CODMn and NH4+-N removal rate, and highest Shannon estimator, indicating that there are more abundant microbial species in the biofilm. Mesorhizobium, Pannonibacter, Pseudoxanthomonas, Aquabacterium, Devosia, and other bacteria have different proportions in each system, each forming its own stable biological chain system. The effluent quality of the three SSFs can meet drinking water standards. However, river sand with a particle size range of 0.1–0.5 mm is easily blocked, and thus the recommended size range for SSF is 0.5–1 mm.

Research on the Preparation of Economical Powder Concrete-UHPC

2014 ◽  
Vol 513-517 ◽  
pp. 108-112
Author(s):  
Ke Wu ◽  
Shang Chuan Zhao
Keyword(s):  
Particle Size ◽  
High Performance ◽  
High Performance Concrete ◽  
Size Range ◽  
Close Packing ◽  
Particle Size Range ◽  
River Sand ◽  
Reactive Powder ◽  
Cement Grinding ◽  
The Cost

In this paper I will introduce a new kind of powder concrete which I call it UHPC.UHPC is a kind of high performance concrete. Now the cost and the condition of ordinary powder concrete is too high. It is unfavorable to the popularization and application of powder concrete. This article mainly is to use gravel that have particle size range between 3 ~ 5 mm and particle size range between 1 ~ 3 mm and particle size range between 0.21 ~ 0.42 mm river sand .the aggregate will through the close packing to match. Gelling materials mainly use three kinds of cement. They are ordinary Portland cement 52.5, sulfur-aluminum cement, and superfine cement grinding. The appropriate ratio of gelled material will determine by the experiment. Poly carboxylic acid additive and defoaming agent will be used to configure the reactive powder concrete. Main purpose is to configure economy powder concrete in Regular maintenance condition.

381. Sampling Efficiencies of Three Personal Aerosol Samplers within and Beyond the Inhalable Particle Size Range

2001 ◽  
Author(s):  
V. Aizenberg ◽  
P. Baron ◽  
K. Choe ◽  
S. Grinshpun ◽  
K. Willeke
Keyword(s):  
Particle Size ◽  
Size Range ◽  
Particle Size Range

Performance of intermittent aeration reactor on NH4-N removal from groundwater resources

2010 ◽  
Vol 61 (12) ◽  
pp. 3061-3069 ◽  
Author(s):  
W. Khanitchaidecha ◽  
T. Nakamura ◽  
T. Sumino ◽  
F. Kazama
Keyword(s):  
Removal Rate ◽  
Groundwater Resources ◽  
Ammonium Nitrogen ◽  
Total Carbon ◽  
Intermittent Aeration ◽  
Reactor Performance ◽  
Total Carbon Content ◽  
Term Operation ◽  
N Removal ◽  
Synthetic Groundwater

To study the effect of intermittent aeration period on ammonium–nitrogen (NH4-N) removal from groundwater resources, synthetic groundwater was prepared and three reactors were operated under different conditions – “reactor A” under continuous aeration, “reactor B” under 6 h intermittent aeration, and “reactor C” under 2 h intermittent aeration. To facilitate denitrification simultaneously with nitrification, “acetate” was added as an external carbon source with step-wise increase from 0.5 to 1.5 C/N ratio, where C stands for total carbon content in the system, and N for NH4-N concentration in the synthetic groundwater. Results show that complete NH4-N removal was obtained in “reactor B” and “reactor C” at 1.3 and 1.5 C/N ratio respectively; and partial NH4-N removal in “reactor A”. These results suggest that intermittent aeration at longer interval could enhance the reactor performance on NH4-N removal in terms of efficiency and low external carbon requirement. Because of consumption of internal carbon by the process, less amount of external carbon is required. Further increase in carbon in a form of acetate (1.5 to 2.5 C/N ratios) increases removal rate (represented by reaction rate coefficient (k) of kinetic equation) as well as occurrence of free cells. It suggests that the operating condition at reactor B with 1.3 C/N ratio is more appropriate for long-term operation at a pilot-scale.

scholarly journals Switching cyclones to increase product particle size range for ore milling circuits

2015 ◽  
Vol 48 (17) ◽  
pp. 92-97 ◽  
Author(s):  
Stefan Botha ◽  
Ian K. Craig ◽  
Johan D. le Roux
Keyword(s):  
Particle Size ◽  
Size Range ◽  
Particle Size Range ◽  
Product Particle

scholarly journals Particulate Size of Microalgal Biomass Affects Hydrolysate Properties and Bioethanol Concentration

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Razif Harun ◽  
Michael K. Danquah ◽  
Selvakumar Thiruvenkadam
Keyword(s):  
Particle Size ◽  
Enzymatic Hydrolysis ◽  
Size Range ◽  
Enzyme Hydrolysis ◽  
Particle Size Range ◽  
Microalgal Biomass ◽  
Process Systems ◽  
Particulate Size ◽  
Biomass Particle Size ◽  
Bioethanol Yield

Effective optimization of microalgae-to-bioethanol process systems hinges on an in-depth characterization of key process parameters relevant to the overall bioprocess engineering. One of the such important variables is the biomass particle size distribution and the effects on saccharification levels and bioethanol titres. This study examined the effects of three different microalgal biomass particle size ranges, 35 μm ≤x≤ 90 μm, 125 μm ≤x≤ 180 μm, and 295 μm ≤x≤ 425 μm, on the degree of enzymatic hydrolysis and bioethanol production. Two scenarios were investigated: single enzyme hydrolysis (cellulase) and double enzyme hydrolysis (cellulase and cellobiase). The glucose yield from biomass in the smallest particle size range (35 μm ≤x≤ 90 μm) was the highest, 134.73 mg glucose/g algae, while the yield from biomass in the larger particle size range (295 μm ≤x≤ 425 μm) was 75.45 mg glucose/g algae. A similar trend was observed for bioethanol yield, with the highest yield of 0.47 g EtOH/g glucose obtained from biomass in the smallest particle size range. The results have shown that the microalgal biomass particle size has a significant effect on enzymatic hydrolysis and bioethanol yield.

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