The Optimal Experimental Research on the Fluoride Removal from Efficient-Whirling Clarifier

2011 ◽  
Vol 374-377 ◽  
pp. 887-890
Author(s):  
Feng Ping Hu ◽  
Lin Yuan Wang ◽  
Jian Wen Luo
Keyword(s):  
Rotational Speed ◽  
Fluoride Concentration ◽  
Engineering Application ◽  
Fluoride Removal ◽  
Potassium Alum ◽  
Second Stage ◽  
Drinking Water Standard ◽  
Optimum Parameters ◽  
Polyaluminium Chloride ◽  
Better Than

In this paper the experiment research of fluoride removal was based on coagulating sedimentation method, and the defluorination effect of coagulant’s kinds and dosage、parameters of rotational speed and coagulant aid’s dosage was studied and optimized, which could provide crafts parameters of efficient-whirling clarifier for engineering application . In this experiment, five coagulants was compared, which including aluminum sulfate (Al2(SO4)3)、potassium alum(KAl(SO4)2)、ferric sulphate（Fe2(SO4)3）、ferric chloride（FeCl3）and polyaluminium chloride（PAC）. Parameters of rotational speed applied in this experiment were simulated from the G state of efficient-whirling clarifier, while polyacrylamide was employed as the coagulant aid. The experiment results showed that: First, the defluorination effect of polyaluminium chloride was better than that of other coagulants. Second, the optimum parameters of rotational speed was that mixing at the speed of 400 r/min for 60 seconds，the first stage of coagulation at the speed of 160r/min for 7minutes、the second stage of coagulation at the speed of 90r/min for 8 minutes and sedimentation for 15minutes. Third, PAM was helpful for the defluorination effect of PAC. The fourth, when fluoride concentration in raw water respectively were 2.0mg/L、5.0mg/L、10mg/L, the dosages of PAC respectively were 400 mg/L、500mg/L、1300mg/L and the dosage of PAM respectively were that of PAM was 0.09mg/L、0.12mg/L、0.09mg/L, which could make the outlet of fluoride concentration achieved the national drinking water standard (GB5749-2006).

Production and engineering application of C60 high-performance pump pebble concrete containing ultra-fine fly ash

2008 ◽  
Vol 35 (8) ◽  
pp. 757-763 ◽  
Author(s):  
Ying Li Gao ◽  
Bao Guo Ma ◽  
Shi Qiong Zhou
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Engineering Application ◽  
Chloride Ion ◽  
Test Method ◽  
Ordinary Concrete ◽  
Second Stage ◽  
Chloride Ion Penetration ◽  
Engineering Requirement ◽  
Better Than

C60 grade high-performance pump concrete incorporating river pebbles and ultra-fine fly ash (UFA) was successfully prepared, with UFA replacing 30% of the cement, for the second-stage of construction of the Hunan Xiangtan Power Plant. Some of the properties of this pump concrete were studied using both laboratory and on-site testing. The results indicated that workability of UFA concrete was excellent. The initial slump surpassed 180 mm, and the slump loss was small. The 28 d strength of the concrete met the engineering requirement of conforming to C60 strength grade. It is shown that the resistance–chloride ion penetration of UFA pump concrete is better than that of ordinary concrete in terms of Association for Testing and Materials test method C1202-94. Dry shrinkage of concrete slightly reduced with the addition of UFA, and UFA concrete shows better crack resistance compared with ordinary concrete. The production technology of UFA pump pebble concrete is summarized based on test and engineering applications.

scholarly journals Development of a novel Artemia eggshell-zirconium nanocomposite for efficient fluoride removal

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244711
Author(s):  
Wen Zhang ◽  
Yuqin Mao ◽  
Yin Lu
Keyword(s):  
Composite Material ◽  
Removal Efficiency ◽  
Treatment Time ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Pore Blockage ◽  
Pseudo Second Order ◽  
The Common ◽  
Kinetics Of ◽  
Better Than

Fluoride pollution in water has attracted widespread concern worldwide. In this study, an Artemia eggshell-zirconium (Aes-Z) nanocomposite has been used for fluoride removal. Material characterization results showed that nano-ZrO2 was immobilized on the inner surface of the Artemia eggshell, and there was no pore blockage on the composite material. Various parameters influencing on the fluoride removal, including treatment time, composite dosage, pH, initial fluoride concentration, and other anions, were analyzed. The removal efficiency of the composite material was better than that of the single zirconia material. The removal percentage of fluoride reached 93% in 30 min with an initial fluoride concentration of 10 mg/L and a nanocomposite dosage of 8.0 g/L. The composite material had a high removal efficiency for fluoride in the pH region 4.0–10.0. The adsorption of fluoride was not influenced by the common anions (e.g., Cl-, SO42-, and NO3-) in water. The regeneration revealed that the Aes-Z composite material could be reused and remove fluoride effectively in four cycles. The pseudo-second-order rate model adequately represented the adsorption kinetics of the Aes-Z composite material. A possible, defluoridation mechanism of the Aes-Z composite material was also proposed. This study demonstrates that Aes-Z is a promising adsorbent material for fluoride removal.

Design of automatic recharging system of robot based on RFID radio frequency technology

2020 ◽  
Vol 13 ◽  
Author(s):  
Zheng Xiao
Keyword(s):  
Mobile Robot ◽  
Radio Frequency ◽  
Engineering Application ◽  
Data Communication ◽  
Computer Application ◽  
Wireless Data ◽  
Robot System ◽  
Communication Module ◽  
Upper Computer ◽  
Better Than

Background: In order to study the interference of wired transmission mode on robot motion, a mobile robot attitude calculation and debugging system based on radio frequency (RF) technology is proposed. Methods: Microcontroller STM32 has been used as the control core for the attitude information of the robot by using MEMS gyroscope and accelerometer. The optimal attitude Angle of the robot is calculated through nRF24L01 which is the core of the wireless communication module, attitude acquisition module and wireless data communication upper computer application platform. Results: The results shows that the positioning accuracy is better than±5mm. Conclusion: The experimental results show that the proposed attitude solving and debugging system of mobile robot based on RF technology has better reliability and real-time performance. The propped model is convenient for debugging of mobile robot system and has certain engineering application value.

Effects of operational parameters on defluoridation efficiency using electrocoagulation process

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
M. Behbahani ◽  
M.R. Alavi Moghaddam ◽  
M. Arami
Keyword(s):  
Reaction Time ◽  
Anode Material ◽  
Removal Efficiency ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Operational Parameters ◽  
Applied Current ◽  
Initial Ph ◽  
Electrocoagulation Process ◽  
Electrode Connection

The aim of this study is to examine the effect of operational parameters on fluoride removal using electrocoagulation method. For this purpose, various operational parameters including initial pH, initial fluoride concentration, applied current, reaction time, electrode connection mode, anode material, electrolyte salt, electrolyte concentration, number of electrodes and interelectrode distance were investigated. The highest defluoridation efficiency achieved at initial pH 6. In the case of initial fluoride concentration, maximum removal efficiency (98.5%) obtained at concentration of 25mg/l. The increase of applied current and reaction time improved defluoridation efficiency up to 99%. The difference of fluoride removal efficiencies between monopolar and bipolar series and monopolar parallel were significant, especially at reaction time of 5 min. When aluminum used as anode material, higher removal efficiency (98.5%) achieved compared to that of iron anode (67.7%). The best electrolyte salt was NaCl with the maximum defluoridation efficiency of 98.5% compared to KNO3 and Na2SO4. The increase of NaCl had no effect on defluoridation efficiency. Number of electrodes had little effect on the amounts of Al3+ ions released in the solution and as a result defluoridation efficiency. Almost the same fluoride removal efficiency obtained for different interelectrode distances.

scholarly journals Characterisation of smectite-rich clay soil: Implication for groundwater defluoridation

2016 ◽  
Vol Volume 112 (Number 11/12) ◽  
Author(s):  
Rabelani Mudzielwana ◽  
Mugera W. Gitari ◽  
Titus A.M. Msagati ◽  
◽  
◽  
...  
Keyword(s):  
South Africa ◽  
Rural Areas ◽  
Contact Time ◽  
Clay Soil ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Limpopo Province ◽  
World Health ◽  
Fluoride Removal ◽  
X Ray

Abstract Groundwater is a widely used and affordable source of drinking water in most of the rural areas of South Africa. Several studies have indicated that groundwater in some boreholes in South Africa has a fluoride concentration above the level recommended by the World Health Organization (1.5 mg/L). Fluoride concentrations above the permissible limit (>1.5 mg/L) lead to dental fluorosis, with even higher concentrations leading to skeletal fluorosis. In the present work, we evaluate the application of smectite-rich clay soil from Mukondeni (Limpopo Province, South Africa) in defluoridation of groundwater. The clay soil was characterised by mineralogy using X-ray diffraction, by elemental composition using X-ray fluorescence and by morphology using scanning electron microscopy. Surface area and pore volume was determined by the Brunauer–Emmett–Teller surface analysis method. Cation exchange capacity and pHpzc of the soil were also evaluated using standard laboratory methods. Batch experiments were conducted to evaluate and optimise various operational parameters such as contact time, adsorbent dose, pH and initial adsorbate concentration. It was observed that 0.8 g/100 mL of smectite-rich clay soil removed up to 92% of fluoride from the initial concentration of 3 mg/L at a pH of 2 with a contact time of 30 min. The experimental data fitted well to a Langmuir adsorption isotherm and followed pseudo second order reaction kinetics. Smectite-rich clay soil showed 52% fluoride removal from field groundwater with an initial fluoride concentration of 5.4 mg/L at an initial pH of 2 and 44% removal at a natural pH of 7.8. Therefore smectite-rich clay soil from Mukondeni has potential for application in defluoridation of groundwater. Chemical modification is recommended to improve the defluoridation capacity.

scholarly journals Biosorption of Fluoride from Synthetic and Ground Water Using Chlorella vulgaris Immobilized in Calcium Alginate Beads in an Upflow Packed Bed Column

2017 ◽  
Vol 61 (3) ◽  
pp. 188 ◽  
Author(s):  
Poornima G. Hiremath ◽  
Thomas Theodore
Keyword(s):  
Experimental Data ◽  
Ground Water ◽  
Chlorella Vulgaris ◽  
Water Samples ◽  
Packed Column ◽  
Fluoride Concentration ◽  
Fixed Bed ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Fluoride Adsorption

The potential of immobilized Chlorella vulgaris to remove fluoride from synthetic and real ground water samples in a fixed bed was investigated. The effect of important kinetic parameters including column bed height, feed flow rate and influent fluoride concentration of solution on fluoride removal was studied. Thomas, Yoon-Nelson, and BDST models were used to analyze the experimental data and understand the influence on biosorption performance. The models’ predictions were in good agreement with the experimental data for all the process parameters studied, indicating that the models were suitable for fixed-bed column design. Fluoride adsorption was reversible. Desorption of fluoride ions was accomplished by pumping 0.1 N HCl solution. The reusability of adsorbent was studied by subjecting column to repeated cycles of fluoride adsorption and desorption. The suitability of immobilized C. vulgaris adsorbent for fluoride removal from ground water samples of Pavagada taluk, Tumakuru district was studied in the packed column.

scholarly journals Parameter Optimization of Polishing M300 Mold Steel with an Elastic Abrasive

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Xiao-Jun Wu ◽  
Xin Tong ◽  
Hao Sun ◽  
Huibo Jia ◽  
Lu Zhang
Keyword(s):  
Particle Size ◽  
Rotational Speed ◽  
Abrasive Particle ◽  
Polished Surface ◽  
Feed Speed ◽  
Range Analysis ◽  
Cutting Depth ◽  
Surface Polishing ◽  
Optimum Parameters ◽  
Influence Degree

In order to achieve high-quality polishing of M300 mold steel curved surface, an elastic abrasive is introduced in this paper, and its polishing parameters are optimized so that the mirror roughness can be achieved. Based on the Preston equation and Hertz contact theory, the theoretical material removal equation for surface polishing of elastic abrasives is obtained, and the polishing parameters to be optimized are as follows: particle size S, rotational speed Wt, cutting depth Ap, and feed speed Vf. The Taguchi method is applied to design the orthogonal experiment with four factors and three levels. The influence degree of various factors on the roughness of the polished surface and the combination of parameters to be optimized were obtained by the range analysis method. The particle swarm optimization algorithm optimizes the BP neural network algorithm (PSO-BP), which is used to optimize the polishing parameters. The results show that the rotational speed has the greatest influence on the roughness, the influence degree of abrasive particle size is greater than that of feed speed, and the influence of cutting depth is the least. The optimum parameters are as follows: particle size S 1200#, rotational speed Wt 4500rpm, cutting depth Ap 0.25mm, and feed speed Vf 0.8mm/min. The roughness of the surface polishing with optimum parameters is reduced to 0.021 μm.

scholarly journals Column Efficiency of Fluoride Removal Using Quaternized Palm Kernel Shell (QPKS)

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ayu Haslija Abu Bakar ◽  
Luqman Chuah Abdullah ◽  
Nur Amirah Mohd Zahri ◽  
Ma’an Alkhatib
Keyword(s):  
Fluoride Concentration ◽  
Fixed Bed ◽  
Palm Kernel ◽  
Fluoride Removal ◽  
Trimethylammonium Chloride ◽  
Transfer Resistance ◽  
Adsorption Models ◽  
Palm Kernel Shell ◽  
Bed Height ◽  
Fixed Bed Adsorption

In this research, the adsorption potential of quaternized palm kernel shell (QPKS) to remove F− from aqueous solution was investigated using fixed-bed adsorption column. Raw palm kernel shell waste was reacted with 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHMAC) in order to modify the surface charge. The effects of inlet F− concentrations (2–12 mg/l) and QPKS bed height (2–10 cm) with optimum pH (pH = 3) on the breakthrough characteristics of the adsorption system were determined. In the fixed-bed column, breakthrough time increases with increasing bed height due to increasing amount of active site on adsorbents to adsorb the fluoride ion. Decreasing trend of breakthrough values was obtained with increasing initial fluoride concentration due to greater driving force for the transfer process to overcome the mass transfer resistance in the column. The adsorptions were fitted to three well-established fixed-bed adsorption models, namely, Thomas, Yoon–Nelson, and Adams–Bohart models. The results fitted well to the Thomas and Yoon–Nelson models with correlation coefficient, R2 ≥ 0.96.

scholarly journals Novel Lanthanum Doped Magnetic Teff Straw Biochar Nanocomposite and Optimization Its Efficacy of Defluoridation of Groundwater Using RSM: A Case Study of Hawassa City, Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Temesgen Abeto Amibo ◽  
Surafel Mustafa Beyan ◽  
Tsegaye Markos Damite
Keyword(s):  
Rotational Speed ◽  
Ligand Exchange ◽  
Contact Time ◽  
Adsorption Process ◽  
Quadratic Model ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Removal Capacity ◽  
Mathematical Process

The problem extent of the large concentration of fluoride ions in drinking water is still a central health issue. In the present study, lanthanum doped magnetic Teff straw biochar (LDMTSB) was developed as a novel adsorbent for removing fluoride ions in the groundwater in Rift-Valley regions, especially Hawassa city, Ethiopia. The synthesized LDMTBC was characterized via FTIR, XRD, SEM, and BET. And, this analysis proposed that multiadsorption techniques such as ligand exchange, precipitations, and electrostatic interaction could be evinced throughout the fluoride ions adsorption process by LDMTSB. The constraints that influence the adsorption efficacy, namely, a dosage of LDMTSB, contact time, pH of the solution, and rotational speed, were analyzed and optimized using the response surface methodology approach. Under the optimum situations, LDMTSB dosage: 3.97 g, contact time: 56.36 min, rotational speed: 591.19 rpm, and pH: 3.968 demonstrate high efficacy of LDMTSB with 98.89% fluoride removal capacity. Further, the quadratic model (R2 = 0.9841) was designated for governing the mathematical process. The LDMTSB was successful in the removal of fluoride ions in the groundwater. This study provides a valuable economical solution for the application of Teff straw.

Regeneration Effect of Fluoride-Rich Granular Activated Alumina on Desorption Regent NaOH Solution

2013 ◽  
Vol 316-317 ◽  
pp. 653-656
Author(s):  
Bai Jie Niu ◽  
Wen Ming Ding ◽  
Dan Dang
Keyword(s):  
Adsorption Capacity ◽  
Sodium Hydroxide Solution ◽  
Fluoride Concentration ◽  
Column Experiment ◽  
Fluoride Removal ◽  
Activated Alumina ◽  
Optimal Method ◽  
Column Adsorption ◽  
Naoh Solution ◽  
Regeneration Effect

As an effective adsorbent, granular activated alumina (GAA) has been widely used in defluoridation. In order to reduce cost and operate environment-friendly, the adsorbent should be regenerated. In this paper, column experiment was done to characterize the fluoride removal properties and to develop an optimal method to regenerate fluoride-rich modified activated alumina (MGAA). The MGAA can be regenerated by utilizing sodium hydroxide solution desorption, deionized water washing and ferric sulfate reactivation and then used for futher defluoride operation. The influence of the concentration of desorption agent (NaOH solution) and desorbing time on desorption rate and the adsorption capacity of regenerated MGAA were studied. The optimal desorption condition was: 1% NaOH solution for desorption agent, desorbing time in 1.5h.In addition, when the regenerated MGAA was used again for column adsorption test, its adsorption capacity reached 94% of that of original sorbent in 1mg/L outlet fluoride concentration.

Sign in / Sign up

Export Citation Format

Share Document