循环冷却水系统海生物污损化学控制

分析了滨海电厂主要污损海生物的特性及危害,简述了循环冷却水系统海生物污损的控制方法,并重点介绍了杀生剂处理方法.对比了各类杀生剂的作用机理、使用策略、药剂用量、环境毒性和环保处理等,提出氧化性杀生剂和非氧化性杀生剂交替使用控制海生物污损,并对杀生剂的应用技术进行了探讨.     

冷镀锌涂料的生物污损研究

为讨论冷镀锌涂料的防污性能,用富锌涂料作对照在青岛中港进行了3 a多的海港实验,并与50多年前在此进行的污损生物调查结果进行比较,详细分析了两者差别原因。首次用PRIMER 6软件处理试板生物污损,分析污损生物多样性,并和传统统计方法相比较,得出相同的结果。可以一定程度上为进一步量化生物污损群落的组成、污损生物及生物污损的研究迈出可喜的一步。     

热带、亚热带近海设施生物污损特点与研究展望

生物污损现象会严重影响海洋设施的安全与使用寿命,对涉海经济活动产生极大危害。在热带和亚热带海区,引发生物污损的种类主要为牡蛎和藤壶,其次是珊瑚和水螅。今后的研究应着重于弄清大型污损生物对腐蚀的影响,建立污损生物数学生态模型,开展海洋恢复生态学研究工作。     

青岛港湾污损生物及其量化初探

叙述了3种防腐涂层在青岛海港近两年海港挂片的污损生物结构,分析了污损群落组成。用湿重法分析了大型污损生物各物种在污损群落中的质量分数,用网格法分析了各物种附着面积占总附着面积的占比。结果表明,Zn防护层带有一定毒性,但在该海域年检时均未发现对污损群落中优势种常见种的改变;用湿重法评估污损群落,往往会使复海鞘和被覆型苔藓虫(个体小、数量多)优势种被排除;而网格法得出的群落物种面积占比往往是复海鞘、被覆型苔藓虫覆盖下的污损生物种类被忽略。     

海洋污损和防污涂料

海洋中存在着无数生物,其中污损生物有4000～5000种之多,大部分为动物性或植物性生物。这些污损生物依靠其固着在浸水表面的本性进行生长、繁殖,因此会造成降低船速、腐蚀钢铁的危害作用,严重影响舰船的航期和在航率。国内外海军战史上不乏生物污损影响航速、贻误战机的实例。目前各国正在向海洋开发资源,污损生物往往固着于海上钻井平台水下较浅部位,造成很大的扭力矩,势必使设计和制造中加大保险系数,消耗更多的材料。这种厚实不易剥离的污损生物层,会使支脚转动不灵,给平台定     

近海污损生物生态研究及建议

海洋污损生物是关系到设施安全的重要因素之一,开展近海污损生物生态研究不仅可为海洋设施的设计、建造和保养提供科学依据,而且还有助于促进海洋生态系统作用机制研究的深入,揭示污损生物时空变化规律及其关键制约因素,并为海洋恢复生态学的发展提供借鉴。     

海洋附着生物对聚合物材料的污损

研究了常见海洋附着生物对９种聚合物材料的污损。不同的海生物对聚合物的附着亲和性有差异，按附着生物的总干重计，污损程度的顺序是：ＰＥ（Ｎ）〉ＰＭＭＡ〉ＰＥＴ〉ＰＥ（Ｏ）〉ＰＶＢ〉ＰＣＰ〉ＰＶＣ〉ＰＳ〉ＰＶＡｃ〉Ｔｅｆｌｏｎ。聚四氟乙烯（Ｔｅｆｌｏｎ）污损程度最小。这种污损次序与材料的表面自由能显示一定的相关性，通常表面自由能小的材料附着污损较少，因此低表面自由能材料有利于无毒防污。     

试析生物质炭在重金属污染土壤修复中的应用

土壤污染因具有隐蔽性、滞后性、治理难度大、进入人体后给人体健康造成不可逆的伤害,已经引起了人们的重视,我国政府也颁布了多项土壤污染修复技术导则.按照污损土地的污染源、污染类型、污染范围、污染程度,采取物理、化学、生物等技术对污损土壤进行修复,以达到美化环境、提升人居健康品质.其中生物炭因具有较大的大孔隙率、较大的比表面...     

无锡防污涂料的现状和发展（Ⅲ）

2.5无毒技术2.5.1不粘去污损涂料(N on-stick fouding-release coating)不粘去污损涂料是借低摩擦、超光滑表面来防止污损生物附着的一种尝试性技术,这样就使污损生物难以固定在此表面上,这种技术的设想几乎与自抛光共聚物同时出现,然而后者显得更为有效且价廉,因此不粘去污损涂料的开发只是到了20世纪90年代后开始禁用三丁基锡系产品时才起步,对这种涂料能具有防止附着性能的解释有多篇文献以供参考犤112～117犦,而关于这种类型的涂料防止海生物附着的物理要素可以归结如下犤118〗:●低表面能;●低弹性率;●亲水层与憎水层的微相分离构造;…     

我国仿生防污涂料研究取得重大进展

船舶在海洋中航行,底部非常容易附着各种各样的污损海生物,会带来极大的危害。为了防止海生物的附着污损,一般采用的方法是在船舶底部涂装海洋防污涂料,给轮船穿上一层“防护外衣”。但传统的防污涂料含有防污毒剂,又给海洋环境带来了一定的污染。“面对新的问题,海洋生物给了我们启示,在大海里众多大型生物都是通过非常“友好”的方法来防止污损。”     

群体感应抑制控制膜生物污染的研究进展

水中微生物及其代谢产物沉积吸附在膜表面,进而生长繁殖,形成了膜生物污染。膜生物污染的控制已经成为学者们研究的热点之一,而基于驱散群体感应体系对膜生物污染进行控制是国内外新兴的研究课题之一。本文综述了传统的膜生物污染控制方法,并阐述了基于驱散群体感应体系控制膜生物污染的研究新进展,并提出前景展望。     

On-line monitoring and quantitative analysis of biofouling in low-velocity cooling water system

To monitor and analyze the biofouling phenomenon caused primarily by microbial suspended solids (MSS), a ‘biofouling tube’ apparatus consisting of a carbon steel tube, a differential pressure transmitter, a corrator, and a cooling water circulation device was designed and fabricated. By measuring continuously the pressure drop across the biofouling tube and using the correlation between the fluid’s friction factor and surface roughness, we quantitatively analyzed the influence of MSS concentration, temperature, and fluid velocity on the rate of biofilm growth on the metal surface. The result indicated that the fluid velocity had the most profound impact, e.g., lowering the linear velocity from 0.3 to 0.15 m/sec resulted in about a four times higher biofouling rate. Up to 50 ppm MSS, the biofouling rate was proportional to the MSS concentration. The biofouling rate at 35°C was about 1.75 times higher than that of 45°C., probably due to the diminishing effect of thermolabile microorganisms exposed at 45°C. It was also demonstrated that the biofouling could be significantly reduced by incorporating cooling water treatment programs such as protective pre-filming and adding corrosion inhibitors. This apparatus, if installed on-site at a sidestream of a cooling water system, could be used to monitor the biofouling tendency on-line and to suggest timely preventive maintenance actions.     

Microbial community in seawater reverse osmosis and rapid diagnosis of membrane biofouling

Due to the acceleration of global warming and the stress that population growth has placed on the global water supply, seawater reverse osmosis (SWRO) desalination is arising as a promising technology to overcome the stress placed on current water resources. However, the biofouling of RO membranes is a common problem, as it causes flux decline, demands frequent cleanings, and consumes high energy, resulting in a shortened lifespan of the system. In an attempt to address these issues, detailed knowledge of the microbial bacteria present, which have a strong correlation between biofilm community structure and operational problems, is ultimately expected to lead to greater control of biofouling. Furthermore, a more rapid diagnosis of biofilm bacteria in SWRO processes is required for faster process feedback. In this study, previous approaches that have been proposed for understanding, diagnosing, and predicting biofouling are reviewed. Finally, the future outlook towards controlling biofouling in SWRO is discussed.     

热泵工况下竖直不锈钢表面微生物污垢动态生长行为

城镇二级出水所含致垢微生物将导致其热能回用过程中在换热面上形成以微生物污垢为主的混合污垢,影响换热、流动效率。以可控微生物种类及浓度的模拟二级出水为介质,对典型热泵供暖、制冷工况下微生物污垢在模拟板式换热器的竖直不锈钢壁面上的形成过程进行了研究,关注起始阶段垢层微观结构演变与宏观垢量生长特性,并考查了流速、菌浓度对成垢过程的影响。实验表明：垢层微观结构演变与宏观垢量增长存在同步关系,污垢生长速率对应于微观结构演变;流速对于成垢过程影响呈非单调性;菌浓度低至10³ CFU·ml^-1（CFU,菌落形成数）时成垢量可忽略。实验结果可指导除垢时间点的选择及改进抑垢、除垢方法。     

膜生物反应器污水处理过程中膜生物污染的研究进展

本文论述了用于污水处理的膜生物反应器的膜污染及其影响因素，同时，重点分析了膜生物污染的形成机理、微生物粘附和繁殖生长，并讨论了膜的生物污染现象、形成过程、危害以及防治措施。     

Anti‐biofouling anion exchange membrane using surface modified quaternized poly(ether imide) for microbial fuel cells

This article deals with a novel way of improving the anti‐biofouling potential of an anion exchange membrane (AEM) by surface modification with ethanol amine (AEOH), a low cost material without affecting the chemical structure and morphology of Quaternized Poly(ether imide) ( QPEI), the host membrane. The anti‐biofouling potential of the AEM was evaluated using bacteria anti‐adhesion test, hydrophilicity, surface roughness, water uptake, and the AEOH modification time. The data reveal that power density in all MFCs attain the highest in the sixth batch and thereafter declined albeit in a varying rate as expected measuring the least for QPEI‐30. Periodical measurement of internal resistance and protein content on the membrane surfaces were found to be the least for QPEI‐30 when compared with others. A reduced biofouling with improved anti‐biofouling property is attributed to the enhanced hydrophilicity due to surface modification. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44432.     

不同营养下混合菌种微生物污垢生长机理与交互作用

再生水源热泵能有效回用废热,但再生水换热器的微生物污垢问题一直没有完全解决,严重影响换热效率和系统安全。利用长期监测并且进行16S rRNA鉴定得到的再生水及其污垢中两种主要代表菌属芽孢杆菌属和气单胞菌属,在实验室内配制模拟流体进行混合菌种微生物污垢实验。通过在特制的机理流道上进行不同菌种比例和不同营养物质浓度的污垢生长实验,得出芽孢杆菌属和气单胞菌属的单独生长规律和混合生长规律,总结了混合生长时两种菌属的协同和抑制规律,同时考察了营养物质浓度对生长规律和交互作用的影响。结果表明:芽孢杆菌属成垢能力较强,细胞分裂速度高,耐贫营养能力强;气单胞菌属成垢能力弱于芽孢杆菌属,但分泌物生成速率高,可以与芽孢杆菌属协同生长;两种菌属交互作用在不同阶段和条件下,协同与抑制作用共存并轮流占据主导。     

Effect of dechlorination point location and residual chlorine on biofouling in a seawater reverse osmosis plant

Experiments were carried out to test the effect of dechlorination dosing point location and the concentration of residual chlorine on bacterial growth and biofouling in a seawater reverse osmosis (SWRO) plant. The plant is located in Al-Birk on the Red Sea coast, southern Saudi Arabia. The plant was routinely operated with injection of chlorine as a biocide in the intake chamber in the open sea and with the injection of sodium metabisulfite (SBS) to remove chlorine after the dual media filter (DMF). During the experiments, the SBS dosing point was shifted to two locations after the micron cartridge filter (MCF): first, to a point 13 m ahead of the high pressure pump (HPP) and second, to a point just ahead (<1 m) of the HPP. Due to fluctuations in residual chlorine resulting from certain operational and physical circumstances, it was possible to assess biofouling potential when free chlorine is regarded as high (≥0.5 mg/l) or low (<0.5 mg/l) within a maximum of 1 mg/l. Bacterial generation (doubling) time was used to evaluate biofouling. Generation time was higher (lower multiplication capacity) when the SBS dosing point was before the MCF (after DMF). It decreased significantly, reflecting higher multiplication capacity and higher biofouling potential, when the SBS dosing point was moved to after the MCF. Generation times in high-pressure RO feed water were similar when the SBS dosing point was moved to two locations after the MCF. This indicated minimal contribution of the low-pressure pipe between the MCF and the HPP to biofouling. In general, biofouling increased as the SBS dosing point was moved forward along the pretreatment line, closer to the RO membranes. Generation times were similar when residual chlorine was less or more than 0.5 mg/l. Bacteria were capable of biofilm formation in the chlorinated section of the plant.     

TiO2-treated different fired brick surfaces for biofouling prevention: Experimental and modelling results

Biofouling on building façades, caused by the growth of bacteria, algae, cyanobacteria, fungi, lichens and plants leads to aesthetical degradation and to an increase in the maintenance costs consequently. Recently, the use of nanotechnology to prevent this phenomenon has been increased due to their efficiency and affordable cost. Currently, the research focuses on the numerical modelling of biofouling in order to simulate the biofouling processes and to find the correlations between physical properties of substrata and growth of microorganisms. In this paper, biofouling tests were conducted on fired brick substrata with different intrinsic characteristics (porosity and roughness) by means of an accelerated growth test. Biofouling was evaluated through time by digital image analysis of specimens׳ surface and then the Avrami׳s law was applied to modelize the biofouling process. The model was adapted to include the inhibitory effect of TiO₂ and a modified equation of Avrami was proposed. Results show a good agreement between simulation and the experimental data. Furthermore, the assumptions taken into account to discretize the real phenomenon were acceptable. The experimental analysis and the numerical modelling showed how the roughness and the porosity influenced the algal attachment.