水成膜泡沫灭火剂简介

水成膜泡沫灭火剂(AFFF)是国外60年代发展起来的一种新型高效泡沫灭火剂。其主要特点是能在烃类燃料表面上形成一层能够抑制燃料蒸发的水膜,靠泡沫和水膜的双重作用迅速灭火。     

不含PFOS水成膜泡沫灭火剂的研究

PFOS类物质(全氟辛烷磺酰基化合物及衍生物)是制造水成膜泡沫灭火剂使用的关键原材料,属于持久性有机污染物,对人身、动植物及环境危害巨大,作为《斯德哥尔摩公约》缔约国,国内新建、改建和扩建的各类使用场所将停止使用含PFOS水成膜泡沫灭火剂.目前我国该领域的PFOS替代技术尚不成熟,核心技术主要为国外垄断.本研究基于国产...     

水成膜泡沫灭火剂生物降解研究

采用二氧化碳产生法测定了水成膜泡沫灭火剂的28 d生物降解性能,考察抑茵剂甲醛及灭火剂浓度对水成膜泡沫灭火剂生物降解率的影响.试验结果表明,添加甲醛及在一定范围内改变灭火剂浓度均不会影响水成膜泡沫灭火剂的生物降解率.从灭火剂组成成分角度分析了尽管含有难降解的氟碳表面活性剂,但水成膜泡沫灭火剂整体表现出易于生物降解的原因.     

非PFOA型水成膜泡沫灭火剂

介绍以RfCONHCH2CH2N(CH2CH2COONa)2氨基酸型氟碳表面活性剂与碳氢表面活性剂复配,并加入辅助添加剂,配成非PFOA新型高浓度水成膜泡沫灭火剂原液,并对该原液的3%型泡沫溶液的各种性能(表面张力,铺展性,灭火性能等)进行测定。试验结果表明:该水成膜泡沫溶液的表面张力和界面张力很低,并且可以在10 s以内很快灭火。抗烧时间也可以达到10 min以上。     

水成膜泡沫灭火剂的应用前景

本文通过讨论氟表面活性剂对环境的影响阐述水成膜泡沫液的应用前景。     

SD—AAFFF型水成膜泡沫灭火剂的研究

众所周知 ,泡沫灭火剂是扑灭 B类火灾 ,特别是烃类火灾的最常用和最有效的手段。半个多世纪以来 ,随着石油和石化工业的迅猛发展 ,泡沫灭火剂也发展成为品种繁多、性能各异的系列产品。然而 ,对于需求量最大的低倍数泡沫灭火剂而言 ,无论是蛋白型泡沫还是合成型泡沫 ,其发展趋势是一致的 ,那就是都向水成膜泡沫的方向发展。这是因为水成膜型泡沫具有极低的表面张力和与燃料间极低的界面张力 ,这就使得泡沫液析出的水可以在比重比其小的烃类燃料表面上形成水膜并迅速扩散 ,利用水膜和泡沫的双重覆盖作用实施灭火。大量的应用性灭火试验表明 …     

新型水成膜灭火剂储存寿命测定方法

探讨了一种从量化角度推算水成膜泡沫灭火剂在标准条件下储存寿命的方法,并运用此方法对新型高效水成膜泡沫灭火剂的储存寿命进行了估算,得出其标准储存寿命为7年以上.     

水成膜泡沫在航空煤油表面的封闭性效果

采用不同环境温度、不同混合比对水成膜泡沫在燃油液面的覆盖开展了封闭性验证实验,通过测定可燃蒸气的浓度及检测时间分析了水成膜泡沫的封闭性随环境温度、混合比的变化规律.实验结果表明:水成膜泡沫的封闭性随环境温度的升高而变差,对于3％的水成膜泡沫,环境温度为40℃时的初次检测可燃蒸气的时间比80℃时的检测时间延长149 s;...     

AFFF 对航空煤油油池火的抑灭有效性研究

按照国家标准灭火试验的要求,采用不同的泡沫喷射率对不同尺寸航空煤油油池火开展了灭火效果试验,分析油盘尺寸、泡沫喷射率对灭火效果的影响,验证固定喷射率条件下,能够扑救的最大尺寸的油盘。结果表明：当油盘面积为0.8 m2 时,泡沫喷射率为2.9 L/min 时的灭火时间比为1.3 L/min 时缩短近60 s;当泡沫喷射率为1.3 L/min 时,最大可控制1.0 m2 航空煤油油池火的90%燃烧,未能将其完全扑灭;当泡沫喷射率为2.9 L/min 时,可完全扑灭2.0 m2 及其以下的航空煤油油池火。     

泡沫：PFOS的升级换代（2）

(接上期 )本部分将论述调聚物产品、无氟产品、现代产品评价、碳氢化合物储罐保护等内容。1 2　什么是适宜的泡沫 ?　　你所需要的是可通过具体应用装置保护你方危险物的适宜泡沫 ,以确保你的金钱能得到很好的回报。如前所述 ,这并不意味着最便宜的泡沫。要确定这一点 ,我们需要首先决定是合成泡沫还是蛋白泡沫能为你方特定的用途和设施提供最大的好处。选择一个可用两种方法生产泡沫的厂商是获得无偏见建议的最可靠途径。一个可供选择的办法是找一个专门研究该领域 ,而且对消防业中你方特定领域有丰富工作经验的著名独立顾问 ,但这样的人非…     

Defluoridation from aqueous solutions by granular ferric hydroxide (GFH)

This research was undertaken to evaluate the feasibility of granular ferric hydroxide (GFH) for fluoride removal from aqueous solutions. Batch experiments were performed to study the influence of various experimental parameters such as contact time (1 min-24 h), initial fluoride concentration (1-100 mg L⁻¹), temperature (10 and 25 °C), pH (3-12) and the presence of competing anions on the adsorption of fluoride on GFH. Kinetic data revealed that the uptake rate of fluoride was rapid in the beginning and 95% adsorption was completed within 10 min and equilibrium was achieved within 60 min. The sorption process was well explained with pseudo-first-order and pore diffusion models. The maximum adsorption capacity of GFH for fluoride removal was 7.0 mg g⁻¹. The adsorption was found to be an endothermic process and data conform to Langmuir model. The optimum fluoride removal was observed between pH ranges of 4-8. The fluoride adsorption was decreased in the presence of phosphate followed by carbonate and sulphate. Results from this study demonstrated potential utility of GFH that could be developed into a viable technology for fluoride removal from drinking water.     

As(V) removal from aqueous solutions by fly ash

The present work examines the possible use of fly ash, a by-product of coal power stations, as a means of removing arsenic (V) from water, or equivalently, of restricting its movement in the solid wastes or the soil. Kinetic and equilibrium experiments were performed in order to evaluate the removal efficiency of lignite-based fly ash. Both adsorption and desorption experiments were done at three pH levels, namely 4, 7 and 10. The results indicated that arsenic can be removed from water by fly ash, yet the degree of removal depended markedly on the pH. Removal at pH 4, as demonstrated by the adsorption isotherms, was significantly higher than that at the other two pH values. For 80% removal of arsenic, the solid phase concentration at pH 4 was up to 4 times greater than that at the other two pH levels. During the desorption studies only a small amount of the pre-adsorbed arsenic was released into the water. This amount was practically independent of the initial fly ash loading. This indicates that adsorption of arsenic on fly ash is almost irreversible and, therefore, there are good prospects for arsenic fixation on fly ash in practical applications.     

Copper(II) removal from aqueous solutions by fly ash

The removal of Cu(II) by adsorption on fly ash has been found to be concentration, pH and temperature dependent. The kinetics of adsorption indicates the process to be diffusion controlled. The Langmuir constants have been calculated at different temperatures, and the adsorption has been found to be endothermic (ΔH = 15.652 kcal mol^?1). The maximum removal is observed at pH 8.0, and variation in adsorption with pH has been explained on the basis of surface ionisation and complexation.     

Rigid foam polyurethane (PU) derived from castor oil (Ricinus communis) for thermal insulation in roof systems

This paper discusses the response of the thermal insulation lining of rigid foam polyurethane (PU) derived from castor oil (Ricinus communis) in heat conditions, based on dynamic climate approach. Liners have been widely used, because the coverage of buildings is responsible for the greatest absorption of heat by radiation, but the use of PU foam derived from this vegetal oil is unprecedented and has the advantage of being biodegradable and renewable. The hot wire parallel method provided the thermal conductivity value of the foam. The thermogravimetric analysis enabled the study of the foam decomposition and its lifetime by kinetic evaluation that involves the decomposition process. The PU foam thermal behavior analysis was performed by collecting experimental data of internal surface temperature measured by thermocouples and assessed by representative episode of the climatic fact. The results lead to the conclusion that the PU foam derived from castor oil can be applied to thermal insulation of roof systems and is an environmentally friendly material.     

Removal of arsenic (III) and arsenic (V) from aqueous medium using chitosan-coated biosorbent

A biosorbent was prepared by coating ceramic alumina with the natural biopolymer, chitosan, using a dip-coating process. Removal of arsenic (III) (As(III)) and arsenic (V) (As(V)) was studied through adsorption on the biosorbent at pH 4.0 under equilibrium and dynamic conditions. The equilibrium adsorption data were fitted to Langmuir, Freundlich, and Redlich-Peterson adsorption models, and the model parameters were evaluated. All three models represented the experimental data well. The monolayer adsorption capacity of the sorbent, as obtained from the Langmuir isotherm, is 56.50 and 96.46 mg/g of chitosan for As(III) and As(V), respectively. The difference in adsorption capacity for As(III) and As(V) was explained on the basis of speciation of arsenic at pH 4.0. Column adsorption results indicated that no arsenic was found in the effluent solution up to about 40 and 120 bed volumes of As(III) and As(V), respectively. Sodium hydroxide solution (0.1M) was found to be capable of regenerating the column bed.     

Development of halogenated hydrocarbon foam (halofoam) extinguishants

The authors report on a study in which a number of halogenated hydrocarbon foams were developed, which are more effective than bromochloromethane in extinguishing Types A, B, and C fires. Note: This paper is a summary of a report by the same title, No. AFAPL-TR-71-21, prepared by Arthur D. Little, Inc. for Wright-Patterson Air Force Base, Ohio, April 1971. A patent application was field with the United States Patent Office on April 29, 1971. Mr. Atallah’s presentation at the 75th Annual Meeting of the National Fire Protection Association on May 19, 1971 in San Francisco, California was also based on this report.     

Removal of chromium(VI) from aqueous solutions by polymer inclusion membranes

The transport through polymer inclusion membranes (PIMs) was found as the effective and selective method of chromium(VI) anions removal from chloride acidic aqueous solutions. The optimal PIMs content was as follows: 41 wt% of cellulose triacetate as the support, 23 wt% of tri-n-octylamine as the ionic carrier, and 36 wt% of o-nitrophenyl pentyl ether as the plasticizer. The results obtained show a linear decrease of permeability coefficient and initial flux values with source phase pH increase. Also linear decrease of initial flux in log-log scale with chromium(VI) concentration increase was observed. Value of slope of this relationship was found to be 0.96 which indicates a first order of chromium(VI) reaction with tri-n-octylamine at membrane/aqueous source interface. Transport of chromium(VI) through PIMs reduces the concentration of chromium(VI) in source aqueous phase from 1.0 to 0.0028 ppm, which is below permissible limit in drinking water in Poland. Competitive transport of chromium(VI), cadmium(II), zinc(II), and iron(III) from acidic aqueous solution across PIMs was found to be efficient for chromium(VI) (99%), and cadmium(II) (99%).