scholarly journals Phosphorus Co-Existing in Water: A New Mechanism to Boost Boron Removal by Calcined Oyster Shell Powder

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 54
Author(s):  
Chi-Hao Yang-Zhou ◽  
Jia-Xin Cao ◽  
Shan-Shan Dong ◽  
Su-Hua Chen ◽  
Ruby N. Michael
Keyword(s):  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Oyster Shell ◽  
Ease Of Use ◽  
Synergistic Mechanism ◽  
Simulated Wastewater ◽  
Co Precipitation ◽  
The Relationship ◽  
Shell Powder

The removal of boron (B) from water by co-precipitation with hydroxyapatite (HAP) has been extensively studied due to its low cost, ease of use and high efficiency. However, there is no explicit mechanism to express how resolved B was trapped by HAP. Thus, in this work, the process of removing B from water was studied using a low-cost calcium (Ca) precipitation agent derived from used waste oyster shells. The results showed that the removal rate of B in the simulated wastewater by calcined oyster shell (COS) in the presence of phosphorus (P) is up to more than 90%, as opposed to virtually no removal without phosphate. For B removal, the treated water needs to be an alkaline solution with a high pH above 12, where B is removed as [CaB(OH)4]+ but is not molecular. Finally, the synergistic mechanism of co-precipitation between HAP and dissolved B, occlusion co-precipitation, was explained in detail. The proposed method discovered the relationship between Ca, P and B, and was aimed at removing B without secondary pollution through co-precipitation.

scholarly journals Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1732
Author(s):  
Yuanyuan Yu ◽  
Yongjun Sun ◽  
Jun Zhou ◽  
Aowen Chen ◽  
Kinjal J. Shah
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Monomer Concentration ◽  
Synthesis Process ◽  
Response Surface Optimization ◽  
Metal Capture ◽  
Total Monomer Concentration

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.

Wear Characteristics of the Sub-Aperture Tools and Material Removal Rate in Precision Grinding with Loose Abrasives

2007 ◽  
Vol 329 ◽  
pp. 69-74
Author(s):  
H. Cheng ◽  
H.Y. Tam ◽  
Y. Gao ◽  
Yong Bo Wu ◽  
Y. Wang
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
High Efficiency ◽  
Removal Rate ◽  
Process Analysis ◽  
Actual Process ◽  
Correlative Function ◽  
Glass Specimen ◽  
Grinding Tool ◽  
The Relationship

This paper proposes a sub-aperture grinding tool for loose abrasive computer controlled surfacing, which is designed to perform epicyclic motion and rotate around its centre at a rapid rate, whilst the entire mechanism revolves around a secondary centre at a slower rate. In actual process, the wear of the tool could affect the material removal function, and make the process unstable, thus in fact, it is difficult to make a deterministic manufacturing. The focus of the present paper is on wearing characteristics of sub-aperture tools and the wear evenness as the main objectives. To make a further study, material removal function of the tool is firstly established through theoretically modelling, next, a correlative function with weighted factors is built, which is suitable for specifying the wearing degree of the tool. Finally, to discover the relationship between the material removal rate and the tool wearing characteristics, and to optimize the grinding process, analysis and experiments are then carried out on a K9 glass specimen by means of three kinds of tool materials, i.e., polyurethane pad, aluminum plate and pitch based on the proposed technique and model. The results indicated that the required high efficiency and precision could be achieved by choosing proper processes.

Preparation of Hydrated Calcium Silicate Gel and its Adsorption Properties for Cu(II)

2020 ◽  
Vol 993 ◽  
pp. 1445-1449
Author(s):  
Shi Jie Liu ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Ya Li Wang ◽  
Nan Li ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Adsorption Method ◽  
Hydrated Calcium Silicate ◽  
Adsorption Performance ◽  
Optimum Reaction

Calcium silicate hydrate gel (CSH) was synthesized by calcium acetate and sodium silicate. The structure and morphology of CSH were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy and Scanning electron microscopy. The adsorption performance of CSH was measured by static adsorption method. The results show that CSH has porous structure and large specific surface area, and the optimum reaction conditions is the reaction temperature of 25°C and calcium-silicon ratio of 1.2. It has the maximum adsorption capacity of more than 150 mg/g and the removal rate of more than 86% with Cu2+. And it shows the excellent adsorption performance, even when the concentration of Cu2+ is less than 200mg/L, the removal rate is above 90%. The research may provide a low-cost and high-efficiency adsorbent.

scholarly journals Facile synthesis of a high purity α-MnO2 nanorod for rapid degradation of Rhodamine B

2021 ◽  
Author(s):  
shumin wang ◽  
Ao Guan ◽  
Jiahan Wang ◽  
Xiaofang Fu ◽  
Xiang Guo ◽  
...  
Keyword(s):  
Rhodamine B ◽  
High Efficiency ◽  
Catalytic Mechanism ◽  
Ph Value ◽  
Removal Rate ◽  
Precipitation Method ◽  
Characteristic Peak ◽  
Catalytic Stability ◽  
Rapid Removal ◽  
Co Precipitation

Abstract Manganese dioxide (α-MnO2) nanorods with diameters of about 5-15 nm and lengths of 100-150 nm were synthesized by a simple co-precipitation method. XRD, TEM, HRTEM, SAED and XPS were used to analyze the crystallographic information, microstructure and chemical bonding of the as-prepared sample. The α-MnO2 nanorod exhibited a high efficiency and rapid removal rate of rhodamine B (RhB), which reached about 97.5% within 10 min when pH=4 (and pH=6.6) and 97.7% within 50 min when pH = 9 in the presence of H2O2. The results also indicated that a lower pH value is conducive to the movement of the characteristic peak and the attenuation of the intensity of the characteristic peak of RhB dye. Then a possible catalytic mechanism was revealed. Moreover, the α-MnO2 nanorod exhibits an excellent recyclability and catalytic stability. This research indicates that α-MnO2 nanorods have a potential application in practical dye pollutant treatment.

scholarly journals New traps for the capture of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) (Diptera: Culicidae) eggs and adults

2020 ◽  
Author(s):  
Karina Rossi da Silva ◽  
William Ribeiro da Silva ◽  
Bianca Piraccini Silva ◽  
Adriano Nobre Arcos ◽  
Francisco A. da Silva Ferreira ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
High Efficiency ◽  
Low Cost ◽  
High Sensitivity ◽  
Ease Of Use ◽  
Monitoring And Control ◽  
Density Index ◽  
Egg Density ◽  
And Control

AbstractThe control of arboviruses carried by Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) can be performed with tools that monitor and reduce the circulation of these vectors. Therefore, the efficiency of four types of traps in capturing A. aegypti and A. albopictus eggs and adults, with the biological product Vectobac WG®, was evaluated in the field. For this, 20 traps were installed in two locations, which were in the South (Londrina, Paraná) and North (Manaus, Amazonas) Regions of Brazil, from March to April 2017 and January to February 2018, respectively. The UELtrap-E and UELtrap-EA traps captured A. aegypti and A. albopictus eggs: 1703/1866 eggs in Londrina, and 10268/2149 eggs in Manaus, respectively, and presented high ovitraps positivity index (OPI) values (averages: 100%/100% in Londrina, and 100%/96% in Manaus, respectively); and high egg density index (EDI) values (averages: 68/75 in Londrina, and 411/89 in Manaus, respectively), so they had statistically superior efficiency to that of the CRtrap-E and CRtrap-EA traps in both regions, that captured less eggs and adults: 96/69 eggs in Londrina, and 1091/510 eggs in Manaus, respectively. Also presented lower OPI values (averages: 28%/4% in Londrina, and 88%/60% in Manaus, respectively); and lower EDI values (averages: 10.5/9 in Londrina, and 47/30 in Manaus, respectively). The capture ratios of Aedes adults in the UELtrap-EA and CRtrap-EA traps in Londrina and Manaus were 53.3%/29.5% and 0%/9.8%, respectively. UELtrap-E and UELtrap-EA can be adopted as efficient tools for Aedes monitoring due to their high sensitivity, low cost and ease of use.Author summaryAedes aegypti and Aedes albopictus are species of mosquitoes responsible for the transmission of several arboviruses that cause infections worldwide. However, there are still no effective and safe vaccines or medications to prevent or treat arboviruses transmitted by these vectors, except for yellow fever. Moreover, current methodologies for monitoring and controlling A. aegypti and A. albopictus are not fully effective, as evidenced by the increasing cases of the arbovirus transmitted by these mosquitoes or have incompatible costs with the socioeconomic conditions of a large number of people. Thus, the traps tested in this study can be used as more effective and economical tools for monitoring and controlling A. aegypti and A. albopictus, since they are made with low cost material and they showed high efficiency in the capture of eggs, evidenced by the high values of ovitraps positive index and eggs density index, besides that one of the models captured Aedes spp. adults in both regions where they were tested. Therefore, the traps have potential for reducing Aedes spp. eggs and adults in the environment and sensibility for determining the local infestation index, which can be reconciled with official government strategies for more accurate vector monitoring and control actions.

scholarly journals The Moderating Effect of Technology Acceptance Perspectives on the Formation of e-SQ and Service Satisfaction in Low Cost Carrier Airline

2014 ◽  
Vol 2 (2) ◽  
pp. 41-47 ◽  
Author(s):  
Muhammad Khairi Majid ◽  
Norhani Bakri ◽  
Nur Shazwani Laila Junaidi ◽  
Rahmat Roslan Buang
Keyword(s):  
Service Quality ◽  
Technology Acceptance ◽  
Low Cost ◽  
Moderating Effect ◽  
Ease Of Use ◽  
Perceived Usefulness ◽  
Service Satisfaction ◽  
Perceived Ease Of Use ◽  
Low Cost Carrier ◽  
The Relationship

As there is an increasing demand in public transportation and electronic transaction, the service quality of website determines the success of the service provider. Therefore, electronic service quality (e-SQ) plays an important role for any business involved in online transaction to attract customers. Customer’s assessment of e-SQ is usually based on their actual experiences of interaction with the website. According to previous research, there exists relationship between e-SQ and service satisfaction. The moderating effect of technology acceptance model (TAM) shows positive result. As e-SQ and TAM improve, this will, in turn, improve service satisfaction. However, the relationship between “e-SQ-TAM service satisfactions” has been found to be not consistent in the case of low cost carrier airline in Malaysia. With concern to further understanding of this area, the present study explores dimensions of e-SQ in low cost carrier airline context and their relationship with service satisfaction. Furthermore, the moderating effect of perceived ease-of-use and perceived usefulness (TAM) was explored. This study employed convenience sampling and questionnaire method to gain data; 392 completed questionnaires were gathered from Malaysia Airline Industry (low cost carrier) website users. The result indicated that e-SQ dimensions: customization, site privacy and aesthetic, efficiency, system availability and fulfillment constitute e-SQ for low cost carrier airline. Moreover, the result also illustrates that perceived ease-of-use and perceived usefulness (TAM) positively moderate the relationship between e-SQ and service satisfaction.

Performance of Treating Domestic Sewage with Coagulation-Ultrafiltration System

2015 ◽  
Vol 737 ◽  
pp. 557-560
Author(s):  
Hui Yuan Zhong ◽  
Guan Yi Liu ◽  
Jun Xia Li ◽  
Hao Wang
Keyword(s):  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Sewage Treatment ◽  
Membrane System ◽  
Integrated Treatment ◽  
Domestic Sewage ◽  
Ultrafiltration Membrane ◽  
Cod Removal Rate ◽  
Organic Particles

This study used coagulation - ultrafiltration technology for domestic sewage treatment, which was used widely in water supply and secondary treatment with sewage, in order to achieve high efficiency, low-cost, integrated treatment of domestic sewage treatment. This article chooses fly ash coagulant is not only simple preparation process, low cost, and with the traditional aluminum chloride and ferric chloride coagulation effect. The research results show that the coagulation can make the organic particles size distribution to move to larger particles area and significantly reduce colloidal substance. Ultrafiltration membrane system can further remove the coagulation treatment failed to completely remove polymer and part in the process of low molecular substances, to achieve high organic matter removal efficiency. The backwash of ultrafiltration membrane can make membrane flux recovery by about 80%. This system of SS can remove more than 95%, COD removal rate can reach 60% ~ 70%.

Modeling Material Removal Rate of Heavy Belt-Grinding in Manufacturing of U71Mn Material

2016 ◽  
Vol 693 ◽  
pp. 1082-1089 ◽  
Author(s):  
Rong Quan Wang ◽  
Jian Yong Li ◽  
Yue Ming Liu ◽  
Wen Xi Wang
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Belt Grinding ◽  
Abrasive Particles ◽  
Grinding Conditions ◽  
Modeling Material ◽  
Abrasive Cutting

The heavy belt-grinding is a new machining method, which combined the characters of heavy-duty grinding and belt-grinding together, with high efficiency and low cost. In the present paper the removal rate model of heavy belt-grinding in manufacturing of U71Mn steel is established. It is assumed that the distribution of the abrasive particles protrusion height of the abrasive belt surface closes to Gaussian distribution. The model is presented by calculating the removal volumes of all abrasive grains contributing to cutting action based on the probability theory, elastic-plastic mechanics and abrasive cutting theory. It is analysis that the material removal rate depends essentially on the mechanical properties of the workpiece and the belt and the grinding conditions. It is proportional to the average pressure, belt velocity and the indentation depth and is inverse proportion to the grain size.

scholarly journals Fe3O4-NPs/Orange-Peel composite as magnetic heterogeneous Fenton-like catalyst towards high-efficiency degradation of methyl orange

2021 ◽  
Author(s):  
Qiang Zhao ◽  
Congcong Zhang ◽  
Xiaoqiang Tong ◽  
Yunling Zou ◽  
Yan Li ◽  
...  
Keyword(s):  
Methyl Orange ◽  
High Efficiency ◽  
Low Cost ◽  
Orange Peel ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Heterogeneous Fenton ◽  
Fe3o4 Nps ◽  
Degradation Ratio ◽  
Co Precipitation

Abstract Fe3O4-NPs/orange-peel (MOP) composite was prepared via one-step in-situ co-precipitation method as magnetic heterogeneous Fenton-like catalyst. The properties of MOP were characterized by SEM, TEM, BET, XRD, FT-IR, TGA and XPS technologies. Its Fenton-like catalytic responses towards removal of methyl orange (MO) were investigated, in which the effects of initial dye concentration, pH, temperature and H2O2 dosage were studied. The MO degradation ratio up to 98.0% was obtained within 20 min in optimized conditions. The catalyst also shows excellent catalytic stability exhibiting nearly 90% degradation ratio in 10th cycle within 20 min, whereas pure Fe3O4-NPs showing only 62.5% in this stage. Due to the stabilization of complexing orange peel hydroxyl to Fe oxide in the composite and its magnetic separation property, Fe3O4-NPs/orange-peel composite exhibits excellent Fenton-like catalytic performance which offers great prospects for low-cost and high-efficiency organic dye wastewater treatment.

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