Antifoam Research Articles

An experimental investigation into the behaviour of antifoaming agents

As part of an on-going research program into the development of accurate computational fluid dynamics models of industrial bubble column bio-reactors, the behaviour of a range of commercially available antifoaming compounds was investigated. Experimental data from a laboratory scale system showed that increasing the antifoam concentration led to a decrease in the Oxygen Transfer Rate (OTR) up to a critical value, hypothesised to be related to the monolayer coverage of the gas-liquid interface; further increases in antifoam concentration had no additional impact. Beyond this critical antifoam concentration, a 3–5 fold reduction in the OTR was found, this reduction being independent of the type of antifoam used or the superficial air velocity. The issue of antifoam ‘deactivation’ was also examined with the results obtained being consistent with the deactivation of polyethylene oxide type antifoams being caused by their displacement from the gas-liquid interface by more hydrophobic material.

Study of the thermal stability of jojoba oil used as antifoaming agent in petroleum industry

Jojoba oil is a naturally occurring vegetal oil, used widely in cosmetic, pharmaceutical, dietetic foods, animal feeding and as a constituent of bio-diesel. In addition, its use in petroleum conditioning has been reported. In this research, four samples of jojoba oil were carefully characterized and their performance as antifoaming agents in light crude oil was studied. A derivative of Simmondsia chinensis was characterized by different techniques such as Fourier transform infrared spectroscopy, nuclear magnetic resonance and size exclusion chromatography. Thermal degradation of jojoba oil was followed by thermogravimetry analysis (TG), differential scanning calorimetry and, primarily, TG coupled to Fourier Transform infrared spectroscopy. Furthermore, a molecular dynamic simulation was carried out in order to investigate the behavior of this compound when subject to thermal degradation. Assessments in light crude oil determined said vegetal oil to have a good performance level as a foam inhibitor at a low temperature (20 °C). Its high degree of thermal stability was also established through calorimetric techniques.

Antifoaming agent market to reach $6.59 bn by 2021: M&M

Antifoaming agent market to reach $6.59 bn by 2021: M&M

Improving of bowel cleansing effect for polyethylene glycol with ascorbic acid using simethicone: A randomized controlled trial.

Background and Aim:Low-volume polyethylene glycol with ascorbic acid (PEG-Asc) use is reported to be as safe and effective as traditional 4-L polyethylene glycol use. However, PEG-Asc produces bubbles, which cause problems during colonoscopy. Data on the effects of using antifoaming agents such as simethicone with PEG-Asc are lacking. The aim of this CONSORT-prospective, randomized, observer-blinded, controlled trial is to compare the quality of bowel preparation and compliance between PEG-Asc users and PEG-Asc plus simethicone users.Methods:Adult outpatients aged 18 to 80 years undergoing colonoscopy were recruited to the study. Two hundred sixty patients were randomly assigned to 1 of 2 treatment arms, PEG-Asc or PEG-Asc plus simethicone. The primary outcome measure was the bowel cleansing quality using Boston bowel preparation scale and bubble scores. The secondary outcome measures were patient tolerability and doctor tolerability.Results:The simethicone group showed superior cleansing results (6–9 Boston scale scores: 99% vs. 84%, <5% bubble scores: 96% vs. 49%, P < 0.001) and fewer gastrointestinal symptoms (abdominal fullness: 24% vs. 55%, colicky pain: 5% vs. 24%, P < 0.001) than the non-simethicone group. Moreover, endoscopist fatigue during colonoscopy was lower in the simethicone group than in the non-simethicone group (1.31 ± 0.75 vs. 2.97 ± 2.14, P < 0.001).Conclusion:PEG-Asc plus simethicone use was more effective and associated with better patient and endoscopist tolerance than PEG-Asc use. Therefore, this combination is recommended as one of the promising methods for bowel preparation before colonoscopy.

Prevention of irreversible aggregation of whey soy proteins in their foam fractionation from soy whey wastewater

AbstractPrevention of irreversible aggregation of whey soy proteins (WSP) in their foam fractionation from soy whey wastewater is important for achieving their large‐scale recovery. For effectively preventing the irreversible aggregation of WSP, this work studied its dependencies on the WSP enrichment ratio and the height of the collected foam which freely collapsed. The results show that most insoluble aggregates formed in the desorption of WSP from the gas–liquid interface, and their formation was closely related to their high local enrichment in the foam. Based on the above results, a chemical defoaming agent with 25% Tween 20 was developed to reduce the relative content of insoluble aggregates in the foamate and the decrease reached about 80%, compared to the case without Tween 20. The prevented irreversible aggregation effectively improved food‐related properties of the WSP product. Copyright © 2016 Curtin University of Technology and John Wiley &amp; Sons, Ltd.

Differences in routine esophagogastroduodenoscopy between Japanese and international facilities: A questionnaire survey.

The mortality rate of gastric cancer (GC) is close to the incidence rate worldwide. However, in Korea and Japan, the mortality rate of GC is less than half of the incidence rate. We hypothesized that good-quality routine esophagogastroduodenoscopy (EGD) contributes to a high detection rate for early GC (EGC) and improves mortality in these countries. To clarify the differences in routine EGD, a questionnaire survey was conducted in 98 Japanese and 53 international institutions. Prevalence of screening examination among routine EGD was higher in Japanese than in international institutions. Japanese endoscopists noted that endoscopic mucosal atrophy was the most significant risk factor for GC, whereas international endoscopists paid more attention to clinical information such as age, symptoms and family history. Antispasmodics, mucolytics and defoaming agents were used more frequently in Japanese institutions. The examination time was similar (mostly 5-10min) between Japanese and international institutions. Japanese endoscopists took more pictures (>20 in almost all institutions) than international endoscopists (≤20 in two-thirds of institutions). In Japanese institutions, biopsy specimens were more frequently taken from areas of mucosal discoloration, unevenness or spontaneous bleeding rather than from obvious endoscopic lesions such as ulceration or polyps. In most Japanese institutions, one or two biopsy specimens were taken per lesion, compared with ≥three in international institutions. There were some discrepancies between Japanese and international institutions for routine EGD. Thus, standardization is required for adequate risk assessment, proper techniques, and knowledge of endoscopic diagnosis of EGC.

Effects of anti-foaming agents on biohydrogen production

The effects of antifoaming agents on fermentative hydrogen production using galactose in batch and continuous operations were investigated. Batch hydrogen production assays with LS-303 (dimethylpolysiloxane), LG-109 (polyalkylene), LG-126 (polyoxyethylenealkylene), and LG-299 (polyether) showed that the doses and types of antifoaming agents played a significant role in hydrogen production. During batch tests, LS-303 at 100μL/L resulted in the maximum hydrogen production rate (HPR) and hydrogen yield (HY) of 2.5L/L-d and 1.08mol H2/mol galactoseadded, respectively. The following continuously stirred tank reactor operated at 12h HRT with LS-303 at 100μL/L showed a stable HPR and HY of 4.9L/L-d and 1.17mol H2/mol galactoseadded, respectively, which were higher than those found for the control reactor. Microbial community analysis supported the alterations in H2 generation under different operating conditions and the stimulatory impact of certain antifoaming chemicals on H2 production was demonstrated.

Organophosphorus Flame Retardants (OPFR): Neurotoxicity

Organophosphorus flame retardants (OPFRs) are used as additives in plasticizers, foams, hydraulic fluids, anti-foam agents, and coatings for electronic components/devices to inhibit flames. These chemicals were developed and used as flame retardants because of environmental and health concerns of previously used brominated and chlorinated flame retardants (FRs). OPCFRs are divided into five main groups: organophosphates, organophosphonates, organophosphinates, organoposphine oxide, and organophosphites. Most of OPFRs are organophosphate esters that are further classified into the following five groups: 1. Aliphatic, 2. Brominated aliphatic, 3. Chlorinated aliphatic, 4. Aromatic-aliphatic, and 5. Aromatic phosphates. These OPFRs have the following neurotoxic actions: 1. Cholinergic Neurotoxicity, 2. Organophosphate-Induced Delayed Neurotoxicity (OPIDN), and 3. Organophosphate-Induced Chronic Neurotoxicity (OPICN) in addition to being endocrine disruptors. OPFRs have very low cholinergic neurotoxicity and this effect does not pose significant health hazards to adults or children. On the other hand, some OPFRs have shown to cause OPIDN that is a delayed central-peripheral axonopathy, characterized by neuronal cell death of the lower brain regions, spinal cord and peripheral nervous systems, leading to long-term neuronal injury. OPICN is characterized by neuronal cell death in the cortex, hippocampus campus and cerebellum and spinal cord. Finally, OPCFRs act as endocrine disrupters, that affect many functions of the body such thyroid glands and reproductive functions, and may be involved in the development of diabetes and cancer. Residues of these OPCFRs are widespread in the environment, home and workplaces. These chemicals adversely affect human health, especially for vulnerable population such as the elderly, pregnant women, fetuses, and children. Because some OPFRs cause neuronal cell death in the brain and spinal cord that do not repair as well as act as endocrine disrupters they may lead to permanent functional deficits such obesity, memory impairment, decreased motor skill and even more serious diseases such as diabetes and cancer. Because recent reports have accredited FRs for significant decrease in building fires, it is important to balance the risk and benefits of FRs and to use only the safest available FRs including OPFRs. *Corresponding author: Mohamed B. Abou-Donia, Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 277, USA, Tel: +919-68422/ Fax: 919-681-822, E-mail: donia@duke.edu Citation: Abou-Donia, M.B., et al. Organophosphorus Flame Retardants (OPFR): Neurotoxicity. (2016) J Environ Health Sci 2(1): 129. Organophosphorus Flame Retardants (OPFR): Neurotoxicity Mohamed B. Abou-Donia1* Mohamed Salama2, Mohamed Elgamal2, Islam Elkholi2,3, Qiangwei Wang1,4 Received date: July 07, 2015 Accepted date: May 05, 2016 Published date: May 11, 2016 DOI: 10.15436/2378-6841.16.022

The Performance of Low Air-Entraining Polycarboxylate Superplasticizer

A new low air-entraining polycarboxylate superplasticizer (denoted as L-PCE) was synthesized by using oxirane/epoxypropane (denoted as EO/PO) block-polyether as one of monomers. The molecular structure of EO/PO block-polyether monomer was characterized by proton nuclear magnetic resonance spectroscopy (denoted as 1H NMR). The pore parameters, workability, and compressive strength of the concrete added with L-PCE were compared to that added with conventional polycarboxylate superplasticizer (denoted as G-PCE) or the G-PCE compounding with defoaming agent. The results demonstrate that the air entraining performance of the L-PCE has been greatly improved than the G-PCE and the G-PCE compounding with defoaming agent. Then the problems, which the workability and slumps of fresh concrete decrease when G-PCE compounding with defoaming agent are added, can be solved. What is more, the interior pore structure of concrete has been optimized. The spacing factor of hardened concrete added with the L-PCE is 27% lower than that added with the G-PCE compounding with defoaming agent. And the 28d strength of the concrete added with the L-PCE is 10% higher than that added with the G-PCE compounding with defoaming agent.

Study on Properties of Environment-friendly Concrete Containing Large Amount of Industrial by-products

This study aims to reduce CO2 discharged from the cement and concrete industries by effective use of industrial by-products, such as fly ash, blast furnace slag, and so on. In this paper, the properties of concrete containing large amount of industrial by-products and very small amount of alkaline activator including cement or sludge from ready mixed concrete plant are analyzed. As the result, it was confirmed that concretes containing large amount of industrial by-products can achieve sufficient compressive strength. However, these concretes showed poor frost resistance. It was thought that the reason was coarsening of air void system and this caused their poor frost resistance. Therefore, in order to micronize the air void system and improve frost resistance, the combination of air entraining agent and antifoaming agent was applied. By this method, it was confirmed that the frost resistance of some these concrete improved.In this study, other properties of these concretes, such as fresh properties and other durability were evaluated and it was confirmed that these concretes show sufficient properties.

Destruction analysis of the antifoam additive

Досліджено структурні перетворення в молекулах антипінної присадки, які відбуваються при тривалому використанні гідравлічної оливи «Гідронікойл FH– -51». Знайдено, що молекули присадки зазнають деструкції з розривом зв’язків Si– O , в наслідок чого утворюються низькомолекулярні структури, здатні до ущільнення та термодеструктивних перетворень. Встановлено, що утворюються кисневмісні сполуки в результаті окиснення вуглеводнів всіх типів та деструкції антипінної присадки.

Gas-assisted magnetic separation for the purification of proteins in batch systems

In this paper, gas-assisted magnetic separation (GAMS), a technique that combines magnetic separation with flotation, was investigated for the potential large-scale separation of proteins. The GAMS process includes adsorption of target proteins and magnetic separation to recover protein-loaded magnetic particles from the dilute biosuspension with the assistance of bubbles. Microsized ethylenediamine-functionalized poly(glycidyl methacrylate) superparamagnetic microspheres (MPMs) and bovine serum albumin (BSA) were used as a model system. The feasibility of GAMS for capturing BSA-loaded MPMs from an appropriate medium was shown. High recovery of BSA-loaded MPMs was obtained by simple adjustment of the initial solution pH without extra detergents and antifoaming agents. The GAMS conditions were consistent with the adsorption conditions, and no proteins were desorbed from the MPMs during this process. Under the optimal conditions, the separation rate and recovery percentage reached 410mL/min and 98% in 0.61min, respectively. Conformational changes of BSA during the GAMS process were investigated by fluorescence spectroscopy and circular dichroism spectrometry.

Evaluation of thiolated silicone oil as advanced mucoadhesive antifoaming agent

Context: Silicone oils, such as dimethicone, are commonly administered against gastrointestinal gas accumulation and are attributed with mucoprotective features.Objective: Evaluation of thiolated silicone oil as advanced antiflatulence with a prolonged retention on small intestinal mucosa as an intended site of action.Materials and methods: 3-Mercaptopropionic acid (MPA) as a thiol ligand was covalently attached to silicone oil. This thiomer was assessed with regard to foam inhibiting action, droplet size of a suitable self-emulsifying system, mucoadhesion and cytotoxicity.Results: Antifoaming activity of silicone–MPA was complying with United States Pharmacopeia (USP) requirements for simethicone as standard antiflatulence. Another antifoaming test performed on porcine mucosa supported silicone–MPA's outstanding foam destruction, as this thiomer was superior in comparison to non-thiolated silicone oil and dimethicone with 14.7 ± 2.1 versus 73.3 ± 9.1 and 66.3 ± 7.5 s, respectively. A significantly enhanced mucoadhesiveness (p < 0.02) with 26.2 ± 7.1% silicone formulation remaining on small intestinal mucosa after 8 h was evident for the thiomer without any toxic effect.Conclusion: Thiolated silicone oil was found to exhibit excellent antifoaming and superior mucoadhesive features. The prolonged residence time of thiolated silicone oil promises to be beneficial in the treatment of flatulence, aerophagy and inflammation throughout the whole gastrointestinal tract.

Preparation of bio-composite from wood sawdust and gypsum

Bio-composite which is made of wood sawdust (SW) with novel modification and gypsum is presented in this paper. Attenuated total reflectance-fourier transform infrared (ATR-FTIR) characterizations reveal that the main compositions of sawdust water extractives are tannins, acetic acid, hemicellulose, and lignin. Positive effect of sawdust water extractives on gypsum was achieved by the addition of antifoam agent. Mechanical testing shows that the mechanism of sawdust induced reduction of gypsum performance may be attributed to the water absorption of sawdust. Subtraction and matching analysis with OMNIC software indicates that water-based epoxy (WEP) could be coated on the surface of sawdust by using spray coating, which resulted in a reduction of the water absorption of sawdust up to 25.6% and water content inside gypsum/sawdust composite up to 35.8%. Mechanical testing of gypsum/sawdust composite shows that the light weight composite with promising mechanical performance could be obtained by the WEP treatment: for 20% sawdust addition, the flexural strength and compressive strength of composite are 4.59MPa and 13.25MPa, respectively; for 30% sawdust addition, the flexural strength and compressive strength of composite are 3.36MPa and 8.73MPa, respectively.

Counteracting foaming caused by lipids or proteins in biogas reactors using rapeseed oil or oleic acid as antifoaming agents

Foaming is one of the major operational problems in biogas plants, and dealing with foaming incidents is still based on empirical practices. Various types of antifoams are used arbitrarily to combat foaming in biogas plants, but without any scientific support this action can lead to serious deterioration of the methanogenic process. Many commercial antifoams are derivatives of fatty acids or oils. However, it is well known that lipids can induce foaming in manure based biogas plants. This study aimed to elucidate the effect of rapeseed oil and oleic acid on foam reduction and process performance in biogas reactors fed with protein or lipid rich substrates. The results showed that both antifoams efficiently suppressed foaming. Moreover rapeseed oil resulted in stimulation of the biogas production. Finally, it was reckoned that the chemical structure of lipids, and more specifically their carboxylic ends, is responsible for their foam promoting or foam counteracting behaviour. Thus, it was concluded that the fatty acids and oils could suppress foaming, while salt of fatty acids could generate foam.

Scalable manufacturing of anchorage-dependent cells for allogeneic cell therpies: current limitations and an innovative solution

Current cell culture processes for allogeneic cell therapies widely utilize a 2D approach, where anchorage-dependent cells are grown on flat, plastic plates. While stacking plates can achieve a certain level of scale-up adequate for clinical production, scale-up to commercial manufacturing using this 2D approach is not operationally and economically feasible. Therefore an alternative 3D process, where cells are grown on microcarriers in suspension, is considered to be a viable option. However, this 3D approach has challenges to scale up in conventional stirred bioreactors, presumably due to the shear stress associated with high speed mixing. Novel single-use bioreactors with Vertical-Wheel technology have recently been introduced. These bioreactors promote efficient, homogenous liquid mixing and microcarrier suspension at lower agitation speeds. Computational fluid dynamics analysis indicates that the low shear environment inside these vessels is maintained across the full range of working volumes, from 0.1 to 500 liters. Human bone marrow-derived mesenchymal stem cells (hBM-MSC) were grown in Vertical-Wheel bioreactors without the use of anti-foaming agents or shear protectants. By optimizing culture conditions, including microcarriers, culture media, agitation speeds, and other operating parameters, a final hBM-MSC density exceeding 2x10cells/mL was achieved. Correlations between cell growth, microcarrier concentration, and Kolmogorov scales were also found, which can be applied to predict appropriate process conditions during scale-up. Other process conditions such as dynamic seeding conditions, media exchange, and in-reactor cell harvest for recovery from microcarriers were also evaluated. Relevant cell quality assays were used to address maintenance of cell quality during process scale-up. This study show the potential of Vertical-Wheel bioreactors as a viable manufacturing platform for the commercial production of allogeneic cell therapies.

Extraction of aroma compounds of fruit juices by air stripping using a bubble column operating with antifoam and its effect on juice properties

The objective of this work was to evaluate the effect of air bubbling on the physicochemical properties and ascorbic acid concentration of fruit juices during the extraction of their volatile aroma compounds using a bubble column operated with antifoam. The ideal concentration of a commercial antifoam agent was also evaluated to ensure a non-foaming operation during air bubbling in the fruit juice for the range of gas superficial velocity between 1 and 2cm/s. Besides, aroma extraction from a surrogate solution was evaluated, being the best extraction efficiency obtained for ethyl butyrate (97%), followed by hexanal (93%), ethyl acetate (81%) and linalool (32%). However, there was no significant variation of these efficiencies for the gas superficial velocities employed. Finally, after 4h of air bubbling in fresh fruit juice, there were no changes of pH, total soluble solids, titratable total acidity and color of the juice and just a 15% reduction in the concentration of the ascorbic acid. Thus, the use of air stripping in a bubble column was proved to be an interesting alternative to extract aroma compounds from fruit juice without causing any appreciable change in its properties.

新消泡剤クリレス®800シリーズの特徴と薬注の最適化

新消泡剤クリレス®800シリーズの特徴と薬注の最適化

几种消泡剂在乙烯废碱液脱硫过程中的消泡性能的研究

乙烯废碱液作为脱硫剂的湿法烟气脱硫工艺，脱硫效率高，具有良好的经济效益和环境效益。吸收浆液发泡溢流是湿法烟气脱硫过程中较为常见的现象，它对脱硫系统的稳定运行非常不利。乙烯废碱液有一定的发泡趋势，其发泡高度受溶液温度和气流速度的影响。乙烯废碱液中加入消泡剂TEGO-106，消泡效果最好，泡沫高度从27 cm降到2.2 cm，消泡效率为92%。添加TEGO-106消泡剂的最佳浓度为25 ppm。 The process of wet flue gas desulfurization in which ethylene waste alkali liquor was applied as the desulfurization absorbent was beneficial not only to environment but also to the economy for its high desulfurization efficiency. The absorber slurry foaming and overflowing was relatively common in wet flue gas desulfurization processes, which was adverse to the stable operation of the flue gas desulfurization systems. With the certain foaming tendency, the foam height of ethylene waste alkali liquor was affected by both the solution temperature and the gas velocity. Adding the defoaming agent TEGO-106, the defoaming effect was maximized; the foam height reduced from 27 cm to 2.2 cm and the defoaming efficiency reached 92 percent. The optimal concentration of TEGO-106 was 25 ppm.

Influence of Protein Extraction Techniques of Different De-oiled Residues from Jatropha curcas L. on Protein Recovery and Techno-functional Properties

As Jatropha curcas L. is a non-edible energy plant biodiesel production from J. curcas L. crude oil is an important field of interest in order to avoid the ‘tank or table’ discussion. As a by-product from oil extraction, high amounts of Jatropha meals are obtained requiring a concept for its sustainable utilization. Due to the high protein content (up to 40 %) in Jatropha seed cakes, added value can be generated by extraction of these proteins for further applications. The present study compared an aqueous and an enzyme-assisted process for protein extraction from screw-pressed and aqueous de-oiled Jatropha residue. Additionally, different methods for protein recovery were evaluated. Aqueous-extracted proteins were recovered by ultrafiltration, isoelectric precipitation and/or lyophilisation while the proteins from enzyme-assisted extraction were only lyophilized. Functionality of the obtained protein products was determined indicating good emulsifying properties as well as a good gelation behaviour for the aqueous-extracted proteins. In general, proteins from enzyme-assisted extraction had slightly lower functionality. The study indicates potential for the application of Jatropha proteins as emulsifiers in biodegradable bags or as antifoam agents.