Occurrence and fate of barbiturates in the aquatic environment

Barbiturates have been widely used as sedative hypnotics in the mid-1960s and since then mainly as veterinary drugs. To monitor their presence and fate in the aquatic environment, a method based on gas chromatography-mass spectrometry (GC-MS) has been developed to quantify butalbital, secobarbital, hexobarbital, aprobarbital, phenobarbital, and pentobarbital, all with a limit of detection (LOD) down to 1 ng/L. From the various investigated waste and surface water samples, barbiturates were only, but regularly detected in the Mulde, a tributary of the river Elbe in Germany at relevant concentrations up to several microg/L. Investigations of groundwater being affected with wastewater infiltration several decades ago also revealed a barbiturate pattern, indicating a strong recalcitrance of these drugs. To confirm this hypothesis, studies were carried out on biotic and abiotic degradation. Both, the biodegradability under aerobic conditions and hydrolysis did not show any degradation, implementing, that the investigated barbiturates, once released into the aquatic environment, show high stability over a long period of time.     

Research Watch: Particulate transport of PAHs into the aquatic environment

Air.     

水环境中纤维微塑料去除技术研究展望

微塑料作为一种水环境中大量存在的新兴污染物已引起学者和公众的重视,而且目前常用的污水处理工艺无法实现对微塑料的完全去除,导致大量的小尺寸微塑料和纤维微塑料在水环境中积累,对生物体造成持续危害.为减少环境中的微塑料污染,通过对现有的水环境微塑料去除技术相关工作的综述,探讨了各项技术的去除机制、效率和可行性.并针对目前传统...     

Occurrence and solid-liquid partition of sulfonated naphthalene-formaldehyde condensates in the aquatic environment

Sulfonated naphthalene-formaldehyde condensates (SNFC) are high production volume chemicals used in a variety of applications, for example, as concrete plasticizers, tanning agents, or dye dispersants. They enter the aquatic environment primarily by the wastewater path. The occurrence and fate of the monomers, which are different isomers of mono- and disulfonated naphthalene, was intensively investigated in previous studies. However, the environmental fate of the persistent higher molecular SNFC is so far widely unknown. This paper describes an ultrasonic extraction under alkaline conditions, followed by ion-pair HPLC with fluorescence detection for the analysis of SNFC oligomers from solid environmental matrixes such as sewage sludge, suspended solids, and river sediments. Limits of quantification of about 0.1 mg kg-1 d.m. were well below the measured concentrations in environmental samples. SNFC were adsorbed to suspended solids and river sediments in three major German rivers (Rhine, Neckar, and Danube) in concentrations typically up to several mg kg(-1) d.m. A total content of about 4 g kg(-1) d.m. was measured in a sewage sludge of a municipal wastewater treatment plant, which receives wastewater from a textile dyeing plant. Furthermore, the first quantitative field data on the partition of SNFC and their monomers between the aqueous phase and solid environmental compartments are presented. Solid-liquid partition coefficients (Kd) of oligomers with a chain-length ranging from three to six naphthalenesulfonate units were derived from the analysis of corresponding wastewater and sewage sludge samples and from suspended solids and river water samples, respectively. Determined Kd values were in the range from 10(2) to 10(4) L kg(-1).     

Emission, fate and effects of soluble silicates (waterglass) in the aquatic environment

Soluble silicates, commercially known as waterglass, are among the largest volume synthetic chemicals in the world. Silicon from waterglass is rapidly transformed to the biologically active orthosilicic acid (referred to as dissolved silicate). This paper aims to assess the impact of waterglass on the aquatic environment in Western Europe. The emission to surface waters from the four most relevant application areas, household detergents, pulp and paper production, water and wastewater treatment, and soil stabilization, is estimated to be ca. 88-121 kton of SiO2 per year. This is a small fraction (<2%) of the estimated total amount of dissolved silicate transported by rivers to the oceans. Locally, increases in dissolved silicate concentration will decrease the ratios of N:Si and P:Si, which could influence phytoplankton species composition and favor the growth of diatoms over other groups of algae. Significant adverse effects in aquatic ecosystems are not expected.     

动物性水产品及其养殖环境中抗生素抗性基因的研究进展

抗生素抗性基因的污染问题已经在国际社会引起了广泛关注。中国作为抗生素使用大国,食品中抗性基因的污染更是关系到国计民生的重大问题,然而相关研究尚处在起步阶段,亟需更加系统、深入的研究。本文综述了动物性水产品及其养殖环境中抗生素抗性基因的赋存情况以及研究现状,总结了现阶段在水产养殖业中经常检测到的各种抗性基因,概述了其常用检测方法,以及近年来发展迅速的宏基因组学和机器学习分析方法在抗性基因研究中发挥的作用。最后,本文对近年来抗性基因相关健康风险评价的研究进展进行了归纳。本文将对如何进一步深入研究我国水产养殖中抗生素抗性基因的传播机制、预警和防控机制提供较为全面、系统的引导和借鉴。     

Photochemical fate of sulfa drugs in the aquatic environment: sulfa drugs containing five-membered heterocyclic groups

The photochemical fate of five sulfa drugs with varying five-membered heterocyclic substituents (sulfamethoxazole, sulfisoxazole, sulfamethizole, sulfathiazole, and sulfamoxole) was investigated in aqueous solution. The rate of direct photolysis of these compounds is dependent upon the identity of the heterocyclic R group as well as the pH of the solution. Matrix deconvolution methods were employed to determine the absorption spectrum and photolysis rate of each protonation state (cationic, neutral, and anionic). From these data, quantum yields for direct photodegradation were calculated for each protonation state of the sulfa drugs. The quantum yields calculated range from <0.005 for the neutral state of sulfamethizole to 0.7 +/- 0.3 for the protonated state of sulfisoxazole. The protonation state that is most photoreactive varies among the sulfa drugs and cannot be attributed to the rate of photon absorption. Products arising from the direct photolysis of the sulfa drugs were also investigated. For all the compounds, sulfanilic acid was observed as a common product. The singlet oxygen quenching rates of the sulfa drugs were determined by laser flash photolysis and range from (2 +/- 1) x 10(4) M(-1) s(-1) for sulfamethoxazole to (3.0 +/- 0.7) x 10(8) M(-1) s(-1) for sulfamoxole. Reaction of the sulfa drugs with hydroxyl radical is not modulated by the R group, and the rate constants are all near the bimolecular diffusion-controlled limit of 10(10) M(-1) s(-1). The photodegradation of the sulfa drugs in natural water samples of Lake Josephine (St. Paul, MN) and Lake Superior was attributed solely to direct photolysis. This study indicates thatthese similarly structured antibiotics will be subject to a wide range of photodegradation rates with sulfathiazole degrading relatively quickly, sulfisoxazole and sulfamethizole degrading moderately, and sulfamethoxazole degrading much more slowly.     

Lessons from endocrine disruption and their application to other issues concerning trace organics in the aquatic environment

In the past 10 years, many thousands of research papers covering the many different aspects of endocrine disruption in the environment have been published. What has been learned from all this research? We have tried to reduce this very large volume of research into a relatively small number of "lessons". Hence, this paper is not a typical review, but instead it summarizes our personal opinions on what we consider are the major messages to have come from all this research. We realize that what has been a lesson to us may have been obvious from the outset to someone more knowledgeable on that particular aspect of the burgeoning field of endocrine disruption. In addition, it is inevitable that others will consider that we have "missed" some lessons that they would have expected to find included in our list. If so, we encourage them to submit them as responses to our paper. Our own lessons range widely, from the design and interpretation of data from fieldwork studies, through some key messages to come out of the very many laboratory studies that have been conducted, to issues around the sources and fates in the environment of endocrine-disrupting chemicals, and finally to the key role of sewage treatment in controlling the concentrations of these chemicals in the aquatic environment. Having (hopefully) learned our lessons, we have then applied them to the difficult issue of how best to approach future concerns about the potential impacts of other new and emerging contaminants (e.g., pharmaceuticals) on wildlife.     

Dairy wastewater, aquaculture, and spawning fish as sources of steroid hormones in the aquatic environment

A suite of androgens, estrogens, and progestins were measured in samples from dairy farms, aquaculture facilities, and surface waters with actively spawning fish using gas chromatography-tandem mass spectrometry (GC/MS/ MS) to assess the potential importance of these sources of steroid hormones to surface waters. In a dairywaste lagoon, the endogenous estrogens 17beta-estradiol and estrone and the androgens testosterone and androstenedione were detected at concentrations as high as 650 ng/L. Samples from nearby groundwater monitoring wells demonstrated removal of steroid hormones in the subsurface. Samples from nearby surface waters and tile drains likely impacted by animal wastes demonstrated the sporadic presence of the steroids 17beta-estradiol, estrone, testosterone, and medroxyprogesterone, usually at concentrations near or below 1 ng/L. The endogenous steroids estrone,testosterone, and androstenedione were detected in the raceways and effluents of three fish hatcheries at concentrations near 1 ng/L. Similar concentrations were detected in a river containing spawning adult Chinook salmon. These results indicate that dairy wastewater, aquaculture effluents, and even spawning fish can lead to detectable concentrations of steroid hormones in surface waters and that the concentrations of these compounds exhibit considerable temporal and spatial variation.     

Accelerated aromatic compounds degradation in aquatic environment by use of interaction between Spirodela polyrrhiza and bacteria in its rhizosphere

Accelerated degradation of organic chemicals by aquatic plant-bacterial associations was reported for the first time with elucidation of the role and contribution of aquatic plant and bacteria in its rhizosphere using a fast-growing giant duckweed, Spirodela polyrrhiza. The results clearly showed the accelerated degradation of all the three aromatic compounds (phenol, aniline and 2,4-dichlorophenol [2,4-DCP]) tested by aquatic plant-bacterial associations. In phenol degradation system, phenol-degrading bacteria indigenous to the rhizosphere fraction of S. polyrrhiza mainly contributed, while in aniline degradation system S. polyrrhiza mainly contributed by stimulating aniline-degrading bacteria both in the rhizosphere and balk water fraction. On the other hand in 2,4-DCP degradation system, S. polyrrhiza itself mainly contributed to its removal by uptake and degradation. Thus, the mechanisms for accelerated removal of aromatic compounds were quite different depending on the substrates. S. polyrrhiza showed selective accumulation of phenol-degrading bacteria in its rhizosphere fraction, while aniline- and 2,4-DCP-degrading bacteria were not much accumulated. S. polyrrhiza secreted peroxidase and laccase. However, both of the enzymatic activities increased with the addition of aromatic compounds, degrading ability of S. polyrrhiza itself should be owing to the production of peroxidase rather than laccase because the change of peroxidase activity and concentration of each aromatic compound well concurred. From the results obtained in the present study, it can be concluded that the feasibility of the use of aquatic plant-bacterial associations to accelerate the degradation of organic chemicals especially recalcitrant compounds in aquatic environment was shown.     

水产资源利用的新技术产品发展趋势

为促使我国水产品资源在开发利用上涌现出更多的新方法和新技术,以提高水产资源的综合利用率,最大限度地提高其附加值。根据水产资源的现有利用技术及产品状况,归纳总结出了一些具有发展潜力的水产资源综合利用的新技术产品,主要包括食用微藻产品技术、水产资源生物质能转化技术、水产加工中的酶应用技术和水产加工中的新型发酵技术等,并提出了一些新的产品开发思路。     

研究蒸煮反应动力学的实验和计算新方法

提出一种研究蒸煮反应动力学的实验和计算新方法。通过对不同恒温条件下的反应速率常数计算,采用与实际蒸煮反应相同的液比,用较短的时间周期的有效碱浓度变化值和木素含量变化值计算得出了硫酸盐法和烧碱蒽醌法棉秆蒸煮反应的活化能。棉秆硫酸盐法蒸煮反应的活化能和棉秆烧碱蒽醌法蒸煮反应的活化能在整个脱木素阶段基本是一致的。硫酸盐法蒸煮反应的活化能为95.0kJ/mol。烧碱蒽醌法蒸煮反应的活化能是138.1kJ/mol,高于硫酸盐法蒸煮反应活化能,说明硫酸盐法蒸煮脱木素反应比烧碱蒽醌更容易。     

Cold plasma for the preservation of aquatic food products: An overview

Cold plasma (CP) is an upcoming technology implemented for the preservation of highly perishable foods, especially aquatic food products (AFPs). The high moisture content, high-quality protein with all essential amino acids and unsaturated fatty acids makes AFP more susceptible to microbial spoilage and oxidation of lipids and proteins. Spoilage lowers the nutritive value and could generate toxic components, making it unsafe for consumption. In recent times, the rising demand for food products of aquatic origin with preserved quality and extended shelf-life has been recorded. In addition, minimally or nonthermally processed and preserved foods are gaining great attention. CP technology has demonstrated an excellent ability to inactivate microorganisms without promoting their resistance and triggering some deteriorative enzymes, which are typical factors responsible for the spoilage of AFP. Consequently, CP could be recommended as a minimal processing intervention for preserving the quality of AFP. This review focuses on different mechanisms of fish spoilage, that is, by microorganisms and oxidation, their inhibition via the application of CP, and the retention of quality and shelf-life extension of AFP.     

湖州市水产品和环境样品中副溶血性弧菌污染及其影响因素分析

目的了解湖州市水产品及其环境样品中副溶血性弧菌(VP)污染情况,并探讨淡水产品中VP污染的可能影响因素。方法 2014—2017年采集湖州市水产品及其环境样品1 388份,分别进行定性VP检测、O群血清学分型和tlh、tdh、trh三种毒力基因型检测,比较分析VP在淡水产品、海产品及其生长环境中的分布特征,进一步分析湖州市淡水产品中VP污染的可能影响因素。结果水产品中VP检出率为25.68%(265/1 032),淡水产品检出率(30.33%,175/577)明显高于海产品(19.78%,90/455),差异有统计学意义(χ~2=14.83,P0.001)。环境样品中,水底沉积物和存养水体的VP检出率分别为0.86%(1/116)和13.71%(17/124),养殖水体中未有VP检出。经多因素Logistic回归分析,水产品种类、保存方式、流通环节和时间在一定程度上影响VP污染淡水产品。在毒力基因型分布上,水产品与环境样品间差异无统计学意义(P0.05),均以tlh+tdh-trh-为主。在血清型分布上,淡水产品与海产品间差异无统计学意义(P0.05),均以O3血清型为主,其次为O4血清型。结论湖州市淡水产品中副溶血性弧菌污染严重,其污染主要来自流通环节中的交叉污染,应进一步加强监测与管理。