Comparison of heavy metal concentrations in fish samples from three fish farms (Eastern Mediterranean) utilizing antifouling paints

Although aquaculture is considered the fastest growing food production industry, nevertheless there is little information regarding pollutant levels in cultured fish. Samples of cultured sea bass – Dicentrarchus labrax (Linnaeus, 1758), sea bream – Sparus aurata (Linnaeus, 1758), and sharpsnout sea bream – Diplodus puntazzo (Walbaum, 1792) from three fish farms located in the Eastern Mediterranean which utilized antifouling paints on the nets were analyzed for quantitative determination of zinc (Zn), chrome (Cr), and copper (Cu) in the gills, the liver, and the muscle separately for each tissue and fish. The results show that the highest levels of zinc (up to 29.6 mg kg^?1 dry wt) were found in the gills of all samples of sea bream and sharpsnout sea bream while in the samples of sea bass, the highest levels of zinc and chrome were found in the liver (up to 39.3 and 13.8 mg kg^?1 dry wt, respectively). Insofar, as copper is concerned the highest exposure was found in the liver of sharpsnout sea bream (up to 5.49 mg kg^?1 dry wt). The results indicate that the use of antifouling paints in aquaculture practices are a significant source of chemical pollution in cultured fish and poses a risk to the exposed organisms.     

Graft Copolymers, for Erodible Resins, from α-Hydroxyacids Oligomers Macromonomers and Acrylic Monomers

Environmental concerns result in a progressive withdrawal of antifouling paints containing organotin derivatives. The nature of the binders is critical with regard to the erosion of the protecting film through factors such as bond cleavage, dissolution, and diffusion of the degradation products. The versatility of acrylic polymers, due to the possibility of varying their chemical structure had conducted, in the first stage, to combine different types of repeating units in the macromolecular backbone. Formulation and evaluation, in natural sites, of these binders, with a well-defined hydrophobic/hydrophilic balance and with hydrolyzable pendant groups, have shown the possibility to prepare new organotin free resins which can be formulated and which are erodible in seawater over a long period (more than 2 years). A further step has been engaged with the development of graft copolymers containing biocompatible and hydrolyzable oligomers of -hydroxyacids. Their preparation requires the synthesis of -methacryloyloxyoligo--hydroxyacid macromonomers. Copolymers prepared from a mixture of the macromonomer and of an alkyl ester of acrylic acid were formulated with a biocide and deposited on a plate. Their ability to release cuprous oxide, as a model molecule, has been checked and quantified by the inductively coupled plasma analytical method. The uptake of water in the paint, which is enhanced by the hydrolysis of -hydroxyacid oligomers, as determined by the enzymatic measurement of liberated L-lactic acid, conducts to the polymer erosion and to a protecting bioactive surface.     

纳米二氧化硅改性聚酰胺复合膜及其抗污染性能

采用经3-氨基丙基三甲氧基硅烷（APTMS）修饰的纳米二氧化硅（SiNPs）,对正渗透聚酰胺复合膜（TFC）进行抗污染改性.在静电吸附作用下,APTMS-SiNPs可通过表面涂覆的方式接枝在带负电的TFC表面,以提高膜的亲水性和抗污染效能.改性后,大量纳米材料成功接枝在膜表面,膜表面的接触角降低了54%,而膜电位和表面粗糙度无明显变化.采用海藻酸钠作为代表污染物,对原膜和改性膜的动态污染行为进行探究,通过监测污染阶段的通量变化和膜表面滤饼层含量,发现改性膜在膜污染后期表现出优良的抗污染性能,最终通量衰减降低了28%,膜表面滤饼层含量减少了35%.改性膜的抗污染性能主要归因于APTMS-SiNPs带来的膜表面亲水性的大幅提高.     

无杀生剂型防污涂料的研究进展

综述了几种无杀生剂的防污涂料包括低表面能防污涂料、仿生防污涂料、表面自愈型防污涂料等的研究现状。阐述了该类防污涂料商品化产品的应用现状,其中国外公司的低表面能防污涂料,如阿克苏诺贝尔旗下IP公司的Intersleek系列、JOTUN公司的Sealion Repulse等占据着中国防污涂料市场80%以上的份额,并对该类涂料的发展趋势进行了展望。     

Enhancement of the flux for polypropylene hollow fiber membrane in a submerged membrane-bioreactor by surface modification

IntroductionThe combination of membrane separation withthe process of biological reactor is called membranebioreactor (MBR). Studies on MBRs have receivedconsiderable attentions due to the deterioration of thewater environment and the advantages they poss…     

Effects of nano carbon black and single-layer graphene oxide on settlement,survival and swimming behaviour of Amphibalanus amphitrite larvae

The effects of two carbon-based nanomaterials, nano-sized carbon black (nCB), and single-layer graphene oxide (GO) on settlement of Amphibalanus amphitrite (Cirripedia, Crustacea) cypris larvae (cyprids) were assessed after 24, 48, and 72 h of exposure. Additionally, the effects of these nanomaterials on the mortality and swimming behaviour of the nauplius larvae (nauplii) of the same organism were determined after 24 and 48 h. The data indicate that nCB is more effective as a potential antisettlement agent than single-layer GO; moreover, nCB did not show any adverse effects on the larvae. The swimming behaviour of II stage nauplii of A. amphitrite exposed to a suspension of nCB was inhibited only at very high nCB concentrations (≥0.5 mg/mL). Single-layer GO, on the contrary, showed lower antisettlement effects and was more active in altering the survival and inhibiting the swimming behaviour of the nauplii. An indication of the toxic or non-toxic mechanisms of the antisettlement properties of both of these nanomaterials is provided by the reversibility of the antisettlement activity. In conclusion, we propose nCB as an innovative antifouling nanomaterial that shows low toxicity towards the model organism (crustaceans) used in this study.     

国产防污漆中铜的海洋环境风险评估

为有效控制防污漆中杀生物活性物质给海洋环境带来的不利影响,亟需开展活性物质的环境风险评估研究,为筛选环境友好型活性物质提供依据。以25种国产防污漆中的铜为评估对象,采用防污漆活性物质环境风险评估的针对性方法,分步进行暴露评估、危害性评估和风险表征。暴露评估采用海洋防污剂预测环境浓度模型(MAMPEC)中的港口、码头和开阔海域等典型暴露场景;危害性评估基于铜对淡水和海水水生生物的慢性毒性数据,采用物种敏感度分布法和评估因子法;风险表征采用熵值法。结果表明,铜对全部水生生物和海水生物的预测无效应浓度分别为2.8和2.3μg·L~(-1),藻类对铜最为敏感。除1种配方外,其余24种防污漆配方中铜的风险熵均小于1,可判定铜为"相对低风险"类活性物质,使用上述防污漆时铜对生态环境造成的风险较小。铜在不同暴露场景中的环境风险分析表明其对水流交换较弱海域的码头造成的风险最大,其次是默认港口和码头,对于公海造成的风险最小。根据现有的评估结果,设计含铜型防污漆配方时,应使铜的释放速率不大于33.5μg·cm~(-2)·d~(-1),以避免对较封闭海域的生态环境造成不可忽视的风险。     

BEHAVIORAL RESPONSES TO TWO ESTUARINE FISH SPECIES SUBJECTED TO BIS (tri-n-butyltin) OXIDE1

ABSTRACT: The objective of this investigation was to evaluate the avoidance responses of juvenile striped bass, Morone saxatilis and Atlantic menhaden, Brevoortia tyrannus to bis (tri-n-butyltin) oxide. An avoidance responses was exhibited by striped bass at a total organic tin concentration of 24.9 μg/L. Atlantic menhaden exhibited avoidance to total organic tin concentrations of 5.5 μg/L and greater. Atlantic menhaden are generally more sensitive to toxicants than striped bass; therefore, avoidance responses reported in this study are not surprising. It is highly likely that the concentrations of total organic tin that were avoided by the test species in this study were much higher than expected environmental concentrations. Ecologically significant hazards may occur due to potential effects that unperceived or non-avoided organotin concentrations may have on behavioral responses mediated by chemosensory systems.     

Effects of paint particles inhalation on superoxide dismutase and glutathione peroxidase activities in industrial painters

The aim of this study was to examine effects of lead (Pb)-based paints on malondialdehyde (MDA) levels as an indicator for lipid peroxidation; and on activities of serum antioxidant enzymes activities such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) in industrial painters. A total of 67 male painters and 50 age-matched and gender-matched controls were included in this cross-sectional study. There were 19 smokers and 48 non-smokers in the paint-exposed group and 20 smokers and 30 non-smokers in the control group. Hemoglobin concentrations were lower in painters’ blood compared to controls. The blood Pb concentrations were higher in painters compared to controls. SOD and GPx activities were significantly lower in painters compared to controls. MDA concentration was found to be significantly elevated. Smoking was found to be a major confounder. Data suggest that Pb-based paints affect oxidant parameters in occupationally exposed workers.