Antifoam Research Articles

Soil microbial community response to surfactants and herbicides in two soils

The environmental impacts of herbicides on desirable plants and the soil biota are of public concern. The surfactants that are often used with herbicides are also under scrutiny as potentially harmful to soil biological systems. To address these concerns, we used two soils, a silt loam and a silty, clay loam from south central Missouri, to investigate the impacts of herbicides and surfactants on soil microbial communities using phospholipid fatty acid (PLFA) analysis. The surfactants used in this study were alkylphenol ethoxylate plus alcohol ethoxylate (Activator 90), polyethoxylate (Agri-Dex), and a blend of ammonium sulfate, drift reduction/deposition polymers and anti-foam agent (Thrust). The herbicides were glyphosate, atrazine and bentazon. Surfactants and herbicides were applied to soils at label rate, either alone or combined, to 4000g soil per pot. The two soils differed in history, texture, some chemical characteristics and several microbial community characteristics. A few of the chemicals altered some of the components of the microbial community after only one application of the chemical at field-rate. The Cole County, MO silt loam showed larger changes in the microbial community with application of treatments. For the Boone County, MO silty clay loam, Activator 90, Agri-Dex and bentazon treatments increased microbial biomass determined by PLFA; Thrust decreased PLFA markers, bacteria to fungi ratio; and Agri-Dex at both rates decreased monounsaturated fatty acids. Changes in the microbial community due to herbicides or surfactants were minimal in this study of a single application of these chemicals, but could be indicators of potential long-term effects. Long-term studies are needed to determine the changes in the microbial community after several years of annual applications of herbicides and surfactants on a wide array of soil types and management practices.

Повышение информативности эндоскопической диагностики предраковых изменений и рака желудка у больных с атрофическим гастритом

В статье представлены данные об изучении характера эндоскопических изменений слизистой оболочки желудка у больных с атрофическим гастритом с различной выраженностью структурных нарушений. Показано, что эндоскопические проявления атрофического гастрита являются неоднородными и характеризуются, помимо атрофических изменений, наличием изменений рельефа слизистой оболочки (узловатость, бугристость), очаговых гиперплазий, полипов, ксантом. Указанные изменения коррелируют с наличием кишечной метаплазии и дисплазии слизистой желудка. Частота атрофически-гиперпластических гастритов достоверно выше у пациентов с наличием предраковых изменений слизистой желудка.Показано, что применение пеногасителя симетикона повышает диагностическую эффективность эзофагогастродуоденоскопии, способствуя выявлению предраковой патологии и рака желудка.

Optimization of a fermented soy product formulation with a kefir culture and fiber using a simplex-centroid mixture design

The objective of this work was to optimize a fermented soy product formulation with kefir and soy, oat and wheat fibers and to evaluate the fiber and product characteristics. A simplex-centroid mixture design was used for the optimization. Soymilk, soy, oat and wheat fiber mixtures, sucrose and anti-foaming agent were used for the formulation, followed by thermal treatment, cooling and the addition of flavoring. Fermentation was performed at 25 °C with a kefir culture until a pH of 4.5 was obtained. The products were cooled, homogenized and stored for analysis. From the mathematical models and variables response surface and desirability an optimal fermented product was formulated containing 3% (w/w) soy fiber. Compared with the other formulations, soy fermented product with 3% soy fiber had the best acidity, viscosity, syneresis, firmness and Lactococcus lactis count.

The Development of Environment-Friendly and Energy-Saving Engineering Machinery General Oil

This article combines with the engineering machinery of diesel engine, the hydraulic system, the gear system, the hydraulic transmission system using oil of performance requirements; in order to meet the need of engineering machinery actual using condition. Through the study of base oil, antioxidant and corrosion inhibitor, detergent and dispersant additive, extreme pressure and anti-wear agent, rust inhibitor, anti-emulsifier, anti-foam agent, etc composite additives. using Poly-α-olefin (PAO) and dioctyl sebacate composite act as the engineering machinery general oil of base oil, and by using the artificial neural network algorithm targeted to a variety of the functional additive of screening and prediction, and using the genetic algorithm optimists the selection of formula, develop the environment-friendly and energy-saving engineering machinery general oil.

Foaming in wet flue gas desulfurization plants: Laboratory‐scale investigation of long‐term performance of antifoaming agents

Spontaneous foaming can cause a range of operational problems in industrial processes such as wet flue gas desulfurization (FGD). This work investigates the performance of selected antifoaming agents (Nalco FM‐37, Foamtrol 2290, and rapeseed oil) on foams generated by egg white albumin (protein), sodium dodecyl sulfate, and adipic acid at conditions of relevance for wet FGD plants. The addition of antifoaming agents breaks any existing foam and causes an induction period without foaming, after which the foam gradually will begin to reappear. Foaming by egg white albumin (2 g/L) at 0.014 m/s could be controlled by both commercial antifoaming agents (6.4 g/L), but not by rapeseed oil addition. Foaming by pure commercial antifoaming agents has also been demonstrated: up to 7 × 10−2 m foam was observed with 6.4 g/L Nalco FM‐37. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3741–3747, 2013

Development of electric rust preventive machining method system — safe water using for machining fluid: complete removal of bacteria (Enterobacter aerogenes)-

It is great concern that is environmental load in manufacturing. In machining site, metal working fluid (coolant) such as cutting oil, grinding fluid is used. It contains several chemicals that are oil, surface active agent, extreme pressure additive, antirust agent, antifoaming agent, preservative, biocide etc.. It is thought that it is not good for environment and human body. Machining fluid mist and splash contained several chemicals that are cause of danger for worker’s health while machining. Furthermore, time elapses, fluid is rotten by bacteria. Bad smell and degradation of machining performance occurs. Therefore, after using machining fluid, waste fluid is disposed. Incineration or coagulative precipitation and landfill etc. are necessary. It arise great disposal cost and environmental load as discharging of huge amount green house gas (CO2 etc.). Then, machining fluid decreasing or non-using is demanded in industry. So, in this investigation, new environmental machining method: the electric rust preventive machining method system that uses only water as machining fluid has been developed. In this paper, water purification recycle system in water machining system development is mentioned. Therefore, complete removal of bacteria (Enterobacter aerogenes) without using chemicals such as biocide is examined for corruption, malodor prevention and safe machining water.

Safety Assessment of Silylates and Surface-Modified Siloxysilicates

The Cosmetic Ingredient Review (CIR) Expert Panel assessed the safety of silica silylate, silica dimethyl silylate, trimethylsiloxysilicate, and trifluoropropyldimethyl/trimethylsiloxysilicate as used in cosmetics. These silylates and surface-modified siloxysilicates function in cosmetics as antifoaming agents, anticaking agents, bulking agents, binders, skin-conditioning agents--emollient, skin-conditioning agents-occlusive, slip modifiers, suspension agents--nonsurfactant, and viscosity increasing agents--nonaqueous. The Expert Panel reviewed the available animal and clinical data as well as information from a previous CIR safety assessment of amorphous silica. The CIR Expert Panel concluded that silica silylate, silica dimethyl silylate, trimethylsiloxysilicate, and trifluoropropyldimethyl/trimethylsiloxysilicate are safe as used when formulated and delivered in the final product not to be irritating or sensitizing to the respiratory tract.

Positive and negative impacts of specialty malts on beer foam: a comparison of various cereal products for their foaming properties

The foam stability of beer is dependent on the presence of foam-stabilizing polypeptides derived from the cereals from which it is made. It has long been argued that there is a tendency to boost the foam-stabilizing capabilities of these polypeptides at the heating stages involved in the production of the grist materials. The present study started with the intent to confirm whether these changes occurred and to assess the extent to which different cereal products differed in their foam-stabilizing tendencies. Cereal products differ enormously in their foam-stabilizing capabilities. Heavily roasted grains, notably black malt and roast barley, do have superior foaming properties. However, certain specialty malts, notably crystal malts, display inferior foam performance. The observed foaming pattern is a balance between their content of foam-positive and foam-negative components. Products such as pale malt do contain foam-negative materials but have a net balance in favour of foam-stabilizing entities. By contrast, wheat malt and especially black malt have a heavy preponderance of foam-positive components. Crystal malt displays the converse behaviour: it contains low-molecular-weight foam-negative species. Several of the cereal products appear to contain higher-molecular-weight foam inhibitors, but it appears that they are merely species that are of inherently inferior foam-stabilizing capability to the foaming polypeptides from egg white that were employed to probe the system. The foam-damaging species derived from crystal malt carried through to beers brewed from them. Intense heating in the production of cereal products does lead to enhanced foam performance in extracts of those products. However, not all speciality malts display superior foam performance, through their development of foam-negative species of lower molecular weight.

Rheological properties of self-compacting concrete paste containing chemical admixtures

Self-compacting concrete (SCC) was used for the filling layer of CRTSIII plate ballastless track, which needs excellent workability. The rheological properties of SCC cement paste containing chemical admixtures (CA) such as polycarboxylate-based superplasticizer (PCE), air-entraining agent (AE) and defoamer (DF) were investigated using a Brookfield R/S SST2000 soft solid tester with a vane geometry spindle. The cementitious materials were designed as one, two and, three components systems by addition of ordinary portland cement (OPC) with these chemical admixtures. The rheological properties of one-component system (PCE paste) were improved with increasing the content of PCE. For two components systems of PCE-AE and PCE-DF, yield stress and plastic viscosity reduced firstly and increased afterward with the increasing of AE content. And the plastic viscosity reached the optimum when the content of AE is 0.004wt%. In general, the trend of yield stress and plastic viscosity decreased with the increasing of the DF content. For three components systems, PCE-AE-DF systems, the rheological properties were improved compared with the sample with AE or DF, which attributed to mixes of the active components mentioned above (CA) which could have a synergetic effect.

Experimental Investigation on Mix Design and Mechanical Properties of Polymer (Latex) Modified Concrete

This paper presents the experimental investigation to enhance the mechanical properties of Polymer Modified Concrete (PMC) incorporating Styrene Butadiene Rubber (SBR) and describes the potential of using PMC as a structural material. PMC has been used for many years as an over layer in the bridges deck or for the repairing the defected concrete structures subjected to marine environment. But, because of low compressive strength due to foaming phenomenon, PMC has not been considered as a structural concrete. In this study, a range of investigations including sensitivity of PMC to water cement ratio, the effect of SBR proportion on compressive strength and modulus of rupture, selection of the proper antifoaming agent, the effect of various curing methods on compressive strength, proper mix design of PMC to achieve medium to high compressive strength are carried out. Also, the instructions for casting PMC are composed which can be stated as a standard for mixing and curing procedure of PMC. Results show that increasing the proportion of latex in PMC causes the strength reduction. But, using appropriate antifoaming agent (defoamer) and proper curing method, the mechanical properties can be recovered remarkably.

The efficiency of the use of chemical addivites for manifacture of concrete products

Purpose. To study various additives of a domestic production and to estimate expediency of their use for products of transport construction. Methodology. The study was conducted by introducing a superplasticizer and active mineral additives Findings. The complex additive should include effective superplasticizing admix, as well as additives which operate stiffening and hardening kinetics, air retaining substances and defoaming agents, dispersion and fine-dispersion mineral fillers. In recent years organo-mineral modifiers such as superplasticizer - an active mineral additive (microsilica, metakaolin, ash) obtained a wide circulation. Originality. The impact of various additives on the concrete quality is studied. It is found out that the complex additive PLKP deserves the special attention because it allows producing a concrete of very high durabilityand is recommended for use in railroad ties. Thus, the introduction of additives in the concrete can significantly increase the durability and reliability of concrete products. Practical value. Results of the research can be used to improve the reliability and durability of concrete structures. This calls for further researches on the selection of the concrete mixture with complex additive PLKP, as well as adding the active mineral components.

THE FLATULENCE SYMPTOM IN SMALL CHILDREN: CAUSES AND WAYS OF CORRECTION

Gastrointestinal tract malfunctions, food allergy, intestinal microbiocenosis disorder, disaccharide insufficiency, celiac disease and several other causes lead to an increased gas-formation, overdistension of intestinal loops and abdominal pains in 0-1-year-old children. The crucial task of flatulence elimination is the correction of causes of its occurrence. Frequent intestinal spasm episodes in infants reduce the quality of life of them and their families in general and are also associated with the subsequent child’s physical and mental maldevelopments. Simethicone-based suspension (in the form of antifoaming agent) helps to cope with the issue; it has carminative properties; this allows to reduce the amount of gases in the intestinal lumen, thus terminating pain symptoms.

IINTESTINAL COLIC IN INFANTS: APPROACHES TO THE COMPLEX TREATMENT

The authors describe the causes and mechanisms of development of intestinal colic syndrome in infants and give the approaches to treatment of this condition with modern anti-foaming agents on the base of simethicone.

S131023 電気防錆加工法の実用化開発研究 : 実用機の試作検討([S131-02]先進工作機械技術(2))

Conventionally, the machining fluid (metal working fluid, coolant) such as cutting oil or grinding fluid is used in machining in manufacturing. It contains several chemicals (oil, extreme pressure agent, surface active agent, rust preventive agent, anti foaming agent, biocide etc.) that influences environment and human body. While machining, it is afraid that worker's health hazard (skin diseases etc.) for mist or scattering of fluid. In addition, after use, it is necessary that waste fluid treatment (incineration, coagulative precipitation etc.) is performed to machining fluid. This disposal process brings about high cost and environmental load (CO_2 emission etc.). Therefore, the electric rust preventive machining method (water machining) that is new environmental friendly machining using only water as machining fluid is proposed and developed. The each element systems (water machining machine, water recycle system etc.) achieved required performance for water machining basically in previous investigation. Then, as new phase starting, this paper mentions about development of practical use machine in production field.

Interaction Forces between Bubbles in the Presence of Novel Responsive Peptide Surfactants

Reversibly switchable surfactants are increasingly important for controlling foam stability in many industrial applications because they can be recycled as foaming and antifoaming agents. Novel stimuli responsive peptide surfactants have been previously studied to classify the molecular conformation at the air-water interface before and after switching. In this study, Atomic Force Microscopy (AFM) was used to correlate the peptide conformation to directly measured changes in colloidal interaction forces between immobilized air bubbles before and after switching. The surface tension values extracted from the AFM force measurements were compared to macroscopic pendant drop measurements to help elucidate the importance of desorption in the switching mechanisms for some of the peptides. Results were compared to previous studies of macroscopic foam-column stability using these peptides. Differences in foam stability and the AFM force measurements were apparent, highlighting variations in directly measured equilibrium colloidal interactions to macroscopic bulk behavior. These results help elucidate the connection between the switching mechanism of novel stimuli responsive peptide surfactants and their effect on colloidal scale interactions between bubbles.

The influence of defoamer on removal of PAHs in soil washing

The use of surfactants during soil washing process can create massive foam, which has a negative impact on the effective use of equipment. A series of tests was conducted to evaluate the defoaming performance of three defoamers and to investigate the influence on removal of polycyclic aromatic hydrocarbons (PAHs) during enhanced soil washing by the addition of the defoamer. Results showed that polydimethylsiloxane oil, which is the most common biomaterial used in commercial antifoaming and defoaming agents, has the best defoaming performance. With the addition of 0.1% polydimethylsiloxane oil, the removal ratios of total 16 PAHs (ΣPAHs) increased up to 53.48% and 75.92% when washing time was 5 min and 30 min, respectively, compared with the removal ratios of 44.12% and 67.28% with Triton X-100 solution only. This indicated that the proper selection of defoamer not only solves massive foaming problem but also brings out a positive influence on PAH removal during the soil washing process. Implications: Three kinds of defoamers (kieselguhr, dodecanol, and polydimethylsiloxane oil) were collected to destroy the foam produced by Triton X-100. Among those defoamers, the polydimethylsiloxane (PDMS) oil has the best defoaming performances. The surface tension of the Triton X-100 solution with the addition of PDMS was lower. The addition of PDMS could improve the removal ratio of ΣPAHs during soil washing. That may be attributed to the addition of the nonionic surfactant Tergitol NP-10 as the emulsifier in the defoamer. After all, the results do not provide any indication of the influence on the solubilization micelles. It is thus questionable whether other components of PDMS oil could improve the PAH solubilization.

High Yield of Wax Ester Synthesized from Cetyl Alcohol and Octanoic Acid by Lipozyme RMIM and Novozym 435

Wax esters are long-chain esters that have been widely applied in premium lubricants, parting agents, antifoaming agents and cosmetics. In this study, the biocatalytic preparation of a specific wax ester, cetyl octanoate, is performed in n-hexane using two commercial immobilized lipases, i.e., Lipozyme® RMIM (Rhizomucor miehei) and Novozym® 435 (Candida antarctica). Response surface methodology (RSM) and 5-level-4-factor central composite rotatable design (CCRD) are employed to evaluate the effects of reaction time (1–5 h), reaction temperature (45–65 °C), substrate molar ratio (1–3:1), and enzyme amount (10%–50%) on the yield of cetyl octanoate. Using RSM to optimize the reaction, the maximum yields reached 94% and 98% using Lipozyme® RMIM and Novozym® 435, respectively. The optimum conditions for synthesis of cetyl octanoate by both lipases are established and compared. Novozym® 435 proves to be a more efficient biocatalyst than Lipozyme® RMIM.

친환경 콘크리트 개발을 위한 고분자 화합물의 적용에 관한 연구

본 연구는 수용성 폴리머의 일종인 폴리비닐아세테이트(Polyvinyl Acetate, 이하 PVAc)를 사용한 폴리머 시멘트 모르타르와 콘크리트의 특성에 관한 평가를 통하여 친환경 콘크리트 개발을 위한 기초자료를 획득하는 것이다. 이를 위해 PVAc를 혼입하지 않은 시멘트 모르타르 및 콘크리트와 결합재 대비 3%, 6%, 9%, 12%의 PVAc를 각각 혼입한 폴리머 시멘트 모르타르 및 콘크리트와의 비교분석을 통한 물리적 특성을 평가하였으며, 폴리머 혼입에 따라 늘어나는 공기량을 제어하기 위해 소포제를 첨가하여 PVAc 콘크리트의 특성을 평가하였다. 그 결과 PVAc가 혼입된 폴리머 시멘트 모르타르의 경우 압축강도는 낮아지나 휨강도와 건조수축의 성능이 향상되는 것으로 나타났으며, 콘크리트의 경우 혼입율이 6%일 때가 압축강도, 인장강도, 휨강도 및 탄성계수가 높아지는 것을 확인할 수 있었다. The objective of this paper is to obtain the basic data in order to develop an eco-friendly concrete through evaluation on the properties of polymer cement mortar and concrete using PVAc (Polyvinyl Acetate), as a kind of water-soluble polymer. For this purpose, the physical properties of cement mortar and concrete which does not contain the PVAc as the control batch were compared and analyzed with those using the PVAc. And then, the replacement amount of the PVAc was 3%, 6%, 9% and 12% by binder, respectively. And also, the properties of concrete using the PVAc were evaluated, by adding an antifoaming agent in order to control the air contents increasing with an increase of amount of polymer usage. As a result, in the case of polymer cement mortar using the PVAc, it presented that the compressive strength reduced, while the performance of flexural strength and drying shrinkage increased. When the replacement of the PVAc was 6% within concrete, the compressive, tensile, flexural strength and elastic modulus were increased.

Comparison of Photocatalytic Hydrogen Production from Glycerol and Crude Glycerol Obtained from Biodiesel Processing

Photocatalytic hydrogen generation from aqueous solutions of glycerol and crude glycerol (byproduct of biodiesel manufacturing) were compared using Pt/TiO2 and CuOx/TiO2 catalysts. Glycerol solutions generated more H2 than crude glycerol solutions, with the H2 generation rate approximately 2.5 times higher for Pt/TiO2 and approximately 4 times higher for CuOx/TiO2. Pt/TiO2 produced more H2 than CuOx/TiO2, with a ratio nearly 2.5 times higher for glycerol and nearly 3.5 times higher for crude glycerol. Ion exchange of crude glycerol solutions to replace Na+ with Li+ or K+ had little impact on reactions with CuOx/TiO2 whereas ion exchange with Li+ moderately reduced reaction rates with Pt/TiO2. An anti-foam agent reduced foaming problems associated with higher concentrations of crude glycerol but itself degraded. The addition of 0.4 mM NaH2PO4 reduced the H2 generation rate by nearly 60 % whereas the presence of 0.4 mM NaCl, 0.4 mM NaNO3 or 0.2 mM Na2SO4 reduced the H2 generation rate by only 10–20 % over the course of the reaction.

Comparative review of foam formation in biogas plants and ruminant bloat

This review gives an overview of the current knowledge concerning the problem of foam formation in the process of anaerobic digestion in biogas plants that utilize renewable resources or biogenic waste material for biogas production. Process upsets in biogas production induced by foam formation can have a negative impact on the efficiency of biogas plants. The foam can block gas pipes and cause severe damage to the bioreactor equipment, ranging from a failure of the feeders to a damage of the roof of the biogas plant. The most common foam removal methods - stirring in the foam, adding anti-foaming agents, diminishing substrate feeding, and altering the biogas reactor management - are not always successful. However, the reasons for the excessive foam formation during the biogas production process have not yet been elucidated in detail. In contrast, foam building in the rumen of ruminants as a cause for bloat has been studied thoroughly. In general, the interaction between proteins, polysaccharides (mucilage), and small plant particles is assumed to be the crucial factor. As the fermentation process in the rumen has many similarities with the biogas production process, the current research results on bloat in ruminants are summarized and compared with the process of foaming in biogas plants.