scholarly journals Research on the Preparation of Microbial Capsules by Epoxy Resin-Coated Bacillus pasteurii

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yingying Hu ◽  
Weitao Liu ◽  
Xinlei Jia ◽  
Lanjuan Xu ◽  
Jianjun Shen ◽  
...  
Keyword(s):  
Reaction Time ◽  
Epoxy Resin ◽  
High Efficiency ◽  
Water Inrush ◽  
Experimental Results ◽  
Wall Material ◽  
Self Healing ◽  
Calcium Carbonate Precipitation ◽  
Underground Engineering ◽  
Bacillus Pasteurii

With the increasing number of underground engineering construction projects such as coal mining, tunnel, and subway, water inrush disasters occur more and more frequently. Inspired by the phenomenon of microbial mineralization and diagenesis, microbial-induced calcium carbonate precipitation (MICP) is used to repair cracks in cement-based materials, which provides a new idea to solve the problem of water inrush. To investigate the self-healing properties of microbial capsules, this paper selected epoxy resin E-51 cured by DMP-30 as the wall material and Bacillus pasteurii as the core materials for experiments. In this paper, a single-factor method was adopted to determine the optimal preparation process of microbial capsules and the oil-phase separation method to prepare the microbial capsules. The effects of various factors on the experimental results under different core-wall ratios, reaction time, reaction temperatures, and agitation rates were analyzed. Microbial capsules were analyzed by Fourier transform infrared spectroscopy and optical microscopy to explore the functional groups and features of microbial capsules. The experimental results showed that the microbial capsules achieved the best performance with a core-to-wall ratio of 1 : 3, a reaction temperature of 50°C, a reaction time of 40 min, and a stirring rate of 300 rpm. Meanwhile, we determined the spore survival rate of microbial capsules and finally studied the waterproofness, storage stability, and rupture under the pressure of microbial capsules. We concluded that microbial capsules have high-efficiency and self-healing properties.

scholarly journals Field Application of Microbial Self-Healing Cement Slurry in Chunguang 17-14 Well

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1544
Author(s):  
Lixia Li ◽  
Tianle Liu ◽  
Guosheng Jiang ◽  
Changliang Fang ◽  
Jiaxin Sun ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Field Application ◽  
Oil Wells ◽  
Dairy Wastewater ◽  
Self Healing ◽  
Cement Slurry ◽  
Calcium Carbonate Precipitation

Due to the inappropriate treatment of dairy wastewater, which can easily cause underground water pollution, there is an increasing need for a novel approach to reuse dairy wastewater. The technology of microbially induced calcium carbonate precipitation with environmentally friendly characteristics and high efficiency has been widely used for underground infrastructure remediation. However, there is a lack of in-depth research on the application of this technology under extreme underground environments, such as the borehole of oil wells with high temperature, high pressure, alkaline, and aerobic conditions. In addition, to reduce the cost of this technology when applied on a large scale, we adopted dairy wastewater to cultivate bacteria. Then, we put the bacterial solution into cement slurry in the borehole to improve the cementing quality. In this paper, the rheology properties, mechanical strength, permeability, porosity, and pore distribution of microbial cementing slurry were studied. Moreover, we applied this microbial cement slurry in the Chunguang 17-14 well of China, and the sealing channeling ability of cement sheath on site was evaluated. The results showed that dairy wastewater could serve as an alternative medium to provide nutrients and energy for the growth of bacteria with low cost. Additionally, the microbial cement slurry exhibited a good right-angle thickening performance and high mechanical strength. The field application displayed an anti-gas channeling ability after microbial remediation. The application of dairy wastewater incubated bacteria to cement slurry not only provides an alternative method for the reuse of dairy wastewater but is also conducive to prolonging the lifespan of oil wells.

scholarly journals Self-Healing Concrete by Biological Substrate

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4099 ◽  
Author(s):  
How-Ji Chen ◽  
Ching-Fang Peng ◽  
Chao-Wei Tang ◽  
Yi-Tien Chen
Keyword(s):  
Calcium Carbonate ◽  
Lightweight Aggregate Concrete ◽  
White Crystal ◽  
Repair Material ◽  
Self Healing ◽  
Bacterial Strains ◽  
Calcium Carbonate Precipitation ◽  
Bacillus Pasteurii ◽  
Concrete Crack ◽  
Crack Repair

At present, the commonly used repair materials for concrete cracks mainly include epoxy systems and acrylic resins, which are all environmentally unfriendly materials, and the difference in drying shrinkage and thermal expansion often causes delamination or cracking between the original concrete matrix and the repair material. This study aimed to explore the feasibility of using microbial techniques to repair concrete cracks. The bacteria used were environmentally friendly Bacillus pasteurii. In particular, the use of lightweight aggregates as bacterial carriers in concrete can increase the chance of bacterial survival. Once the external environment meets the growth conditions of the bacteria, the vitality of the strain can be restored. Such a system can greatly improve the feasibility and success rate of bacterial mineralization in concrete. The test project included the microscopic testing of concrete crack repair, mainly to understand the crack repair effect of lightweight aggregate concrete with implanted bacterial strains, and an XRD test to confirm that the repair material was produced by the bacteria. The results show that the implanted bacterial strains can undergo Microbiologically Induced Calcium Carbonate Precipitation (MICP) and can effectively fill the cracks caused by external concrete forces by calcium carbonate deposition. According to the results on the crack profile and crack thickness, the calcium carbonate precipitate produced by the action of Bacillus pasteurii is formed by the interface between the aggregate and the cement paste, and it spreads over the entire fracture surface and then accumulates to a certain thickness to form a crack repairing effect. The analysis results of the XRD test also clearly confirm that the white crystal formed in the concrete crack is calcium carbonate. From the above test results, it is indeed feasible to use Bacillus pasteurii in the self-healing of concrete cracks.

scholarly journals Early-Age Tensile Bond Characteristics of Epoxy Coatings for Underwater Applications

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 757 ◽  
Author(s):  
Kim ◽  
Hong ◽  
Han ◽  
Kim
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Epoxy Resin ◽  
Coating Thickness ◽  
Experimental Results ◽  
Early Age ◽  
Curing Time ◽  
Bond Performance ◽  
Coating Type ◽  
Bond Characteristics

In this study, coating equipment for the effective underwater repair of submerged structures was developed. The tensile bond characteristics of selected epoxy resin coatings were investigated by coating the surface of a specimen using each of the four types of equipment. Using the experimental results, the tensile bond strength and the coating thickness were analyzed according to the type of equipment, coating, and curing time. The results show that the type of coating equipment used had the greatest effect on the measured bond strength and coating thickness of the selected coatings. However, the effect of coating type and curing time on the bond strength and the thickness was observed to be insignificant. Compared with the developed equipment, the surface treatment of the coating was observed to be more effective when using the pre-existing equipment, and thus the bond performance of the coating was improved compared to using the pre-existing equipment. Based on the experimental results, improvements and needs involving the equipment for further research were discussed.

Effect of epoxy resin healing agent viscosity on the self-healing performance of capsules reinforced polymer composite

2021 ◽  
Vol 28 (4) ◽  
Author(s):  
Raj Kumar Pittala ◽  
Satish Ben B ◽  
Avinash Ben B
Keyword(s):  
Epoxy Resin ◽  
Polymer Composite ◽  
The Self ◽  
Self Healing ◽  
Reinforced Polymer ◽  
Healing Agent

Investigation of space charge behavior in self-healing epoxy resin composites

2021 ◽  
Author(s):  
Muhammad Zeeshan khan ◽  
Muhammad Hamza Younes ◽  
Aurang Zaib ◽  
Umar Farooq ◽  
Asim khan ◽  
...  
Keyword(s):  
Space Charge ◽  
Epoxy Resin ◽  
Resin Composites ◽  
Self Healing ◽  
Epoxy Resin Composites

Fabrication of urea formaldehyde–epoxy resin microcapsules for the preparation of high self‐healing ability containing SBS modified asphalt

2021 ◽  
Author(s):  
Song Yang ◽  
Jiaqi Ji ◽  
Hua Tao ◽  
Yaseen Muhammad ◽  
Junxian Huang ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Urea Formaldehyde ◽  
Self Healing ◽  
Modified Asphalt ◽  
Sbs Modified Asphalt

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.

A high-efficiency self-healing cementitious material based on supramolecular hydrogels impregnated with phosphate and ammonium

2021 ◽  
Vol 144 ◽  
pp. 106427
Author(s):  
Xiang Liu ◽  
Qiu Li ◽  
Bo Li ◽  
Wei Chen
Keyword(s):  
High Efficiency ◽  
Cementitious Material ◽  
Self Healing

INFLUENCE OF STICKY RICE AND ANIONIC POLYACRYLAMIDE ON THE CRYSTALLIZATION OF CALCIUM CARBONATE IN CHINESE ORGANIC SANHETU

2015 ◽  
Vol 22 (06) ◽  
pp. 1550073 ◽  
Author(s):  
HUI LIU ◽  
CHANGSHENG PENG ◽  
MIN DAI ◽  
QINGBAO GU ◽  
SHAOXIAN SONG
Keyword(s):  
Reaction Time ◽  
Calcium Carbonate ◽  
Organic Material ◽  
Organic Materials ◽  
Experimental Results ◽  
Additive Concentration ◽  
Reactant Concentration ◽  
Natural Organic Material ◽  
Anionic Polyacrylamide

The crystallization of calcium carbonate ( CaCO 3) in soil controlled by natural organic material was considered a very important reason to enhance the property of ancient Chinese organic Sanhetu (COS), but how the organic material affected the crystallization of CaCO 3 in COS is still unclear. In this paper, a natural organic material (sticky rice, SR) and a synthetic organic material (anionic polyacrylamide, APAM) were selected as additives to investigate their effect on the crystallization of CaCO 3. The experimental results showed that the morphology and size of CaCO 3 crystals could be affected by the concentration of additives and reaction time, while only the size of CaCO 3 crystals could be affected by the concentration of reactant. Although the morphology and size of CaCO 3 crystals varied greatly with the variation of additive concentration, reactant concentration and reaction time, the polymorph of CaCO 3 crystals were always calcite, according to SEM/EDX, XRD and FTIR analyses. This study may help us to better understand the mechanism of the influence of organic materials on CaCO 3 crystallization and properties of COS.

Removal of phenol from steel wastewater by combined electrocoagulation with photo-Fenton

2018 ◽  
Vol 78 (6) ◽  
pp. 1260-1267 ◽  
Author(s):  
Mohammad Malakootian ◽  
Mohammad Reza Heidari
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Current Density ◽  
Steel Industry ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Optimal Conditions ◽  
Suitable Alternative ◽  
Steel Mills ◽  
Real Wastewater

Abstract Phenol and its derivatives are available in various industries such as refineries, coking plants, steel mills, drugs, pesticides, paints, plastics, explosives and herbicides industries. This substance is carcinogenic and highly toxic to humans. The purpose of the study was to investigate the removal of phenol from wastewater of the steel industry using the electrocoagulation–photo-Fenton (EC-PF) process. Phenol and chemical oxygen demand (COD) removal efficiency were investigated using the parameters pH, Fe2+/H2O2, reaction time and current density. The highest removal efficiency rates of phenol and COD were 100 and 98%, respectively, for real wastewater under optimal conditions of pH = 4, current density = 1.5 mA/cm2, Fe2+/H2O2 = 1.5 and reaction time of 25 min. Combination of the two effective methods for the removal of phenol and COD, photocatalytic electrocoagulation photo-Fenton process is a suitable alternative for the removal of organic pollutants in industry wastewater because of the low consumption of chemicals, absence of sludge and other side products, and its high efficiency.

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