人工水草技术在波罗江农田排水硬化沟渠中的应用

针对农田排水沟渠硬化,缺乏天然净化能力的问题,根据生态截污沟渠原理,采用人工水草技术进行大理市波罗江农田排水水质的原位净化研究。结果表明：人工水草对农田排水具有良好和稳定的净化效果,当沟渠进水COD_Mn为3.8~7.3 mg/L,TN、TP和NH₃-N浓度分别为1.18~2.65、0.05~0.19和0.45~0.83 mg/L,水力停留时间（HRT）为2.1~2.5 h时,经人工水草处理后,农田排水COD_Mn、TN、TP和NH₃-N的去除率分别达到10.86%~40.35%、13.04%~60.52%、15.65%~48.68%和13.59%~55.13%。     

金属基工程纳米颗粒与水生高等植物的相互作用：研究现状综述

如今释放到水体环境中的工程纳米颗粒(ENP)数量与日俱增。为确保生态健康,需要进行相关的风险评估。本文综述了金属基ENP与水生高等植物之间的相互作用,找到了信息缺口并提出对未来研究的构想,为在该领域内的进一步探索提供了基础。本文讨论集中在以下3点：1. ENP的生物利用性;2. 生物对ENP的摄取、消化、转移以及生物累积;3. ENP对水生高等植物的毒性效果。由于ENP自身特性所带来的影响不明确以及水质状况记载情况不佳,ENP的摄取及相关动力学方面存在着很大的信息差距。分解似乎是驱动ENP生物累积的一种关键机制,然而纳米颗粒却常常被一些有着极少内化作用的植物的表面所吸收。然而,关于ENP在植物内的内化作用鲜有记载,因此纳米颗粒的内化作用对于生物累积及毒性的影响尚不明确。即使金属基ENP的纳米毒性已被报道,分解依然被认为是其毒性的主要机制。为推动该领域内的研究发展,未来的研究需结合ENP自身特性的影响、水体的理化参数以及它们之间的相互作用。相互作用对于ENP的生物利用性和对水生高等植物健康的风险都有重要影响。为了快速追踪类似数据的产生,我们建议测试方案趋向一致化。
精选自Melusi Thwala, Stephen J. Klaine, Ndeke Musee. Interactions of metal-based engineered nanoparticles with aquatic higher plants: a review of the state of current knowledge. Environmental Toxicology and Chemistry: Volume 35, Issue 7, pages 1677–1694, July 2016. DOI: 10.1002/etc.3364
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3364/full
     

微塑料对土壤动植物的毒性效应研究进展

陆地生态系统是地球上最直接和主要的塑料汇.从微塑料暴露对陆生植物的直接毒性、间接毒性以及与其他污染物的联合毒性角度分析了其对植物的毒性效应;通过对土壤动物的生长、行为和氧化应激等方面的效应研究,阐述了微塑料对动物的毒性作用规律.基于当前研究讨论了微塑料对动植物毒性的主要影响因素.结果表明,对于大部分陆生植物来说,微塑料能影响种子萌发,吸附在根系表面进入植物体引发氧化胁迫和抑制光合作用,造成细胞和遗传毒性等;土壤动物能不同程度地摄食和积累微塑料,并分别在基因、细胞、组织和个体水平上造成基因表达异常、氧化应激、肠道毒性及改变生长与行为等毒性效应,该效应还与微塑料添加剂和吸附的其他污染物相关;环境相关含量下的微塑料对土壤动植物的影响不容忽视,其粒径是影响毒性效应的关键因素之一.研究结果可为评估土壤环境中微塑料的生态风险提供依据,并对未来的重点研究方向进行了展望.     

陕西省城镇污水处理厂进出水中主要离子与重点元素分布特征

污水处理厂出水中主要离子和重点元素的浓度特征及去除效果会影响受纳水体的盐度、碱度等指标,从而影响河湖的生态服务功能,但是这方面的研究长期以来未得到充分关注。在陕西省全境选择51家城镇污水处理厂,测定进水和出水中的钾、钙、钠、镁、氟、氯和硫酸根离子,以及铁、锰、硼、钼、锶等重点元素的浓度。测定结果显示:陕西省城镇污水处理厂进水和出水中的阳离子以钠离子为主,其次是钙、镁离子,钾离子浓度最低;阴离子中,氯离子浓度最大,其次为硫酸根离子。就总离子浓度而言,陕北和关中地区污水处理厂进水的离子浓度普遍高于陕南地区。相关性分析结果显示:在污水处理厂进水中,钠、氟、氯、镁及硫酸根离子相互之间均呈现显著正相关关系;铁、锰在进水中没有表现出明显的相关关系,而在出水中呈现显著的正相关关系。污水处理厂仅能够处理污水中少量的氟、钾和镁离子。铁元素和锰元素在经过污水处理厂的处理后,浓度有所升高。此研究的研究结果可为河湖水化学组成管理决策提供参考。     

再生水河道菹草管控的生态响应研究

在北京地区典型再生水补水型河道开展试验,通过在菹草(Potamogeton crispus)生长期对其进行基于生物量控制条件下的不同收割强度处理,研究光照强度等环境影响因子、菹草生长特征、浮游动物及底栖动物分布的响应机制,以期为北京再生水补水型河道提供生态修复技术支撑与沉水植物管控方案.结果表明:①菹草收割强度对水体浊...     

铜陵狮子山矿区尾矿库及周边17种乡土植物重金属含量及富集特征

矿区废弃地定居植物调查与筛选是植物修复研究的重点.通过研究安徽铜陵狮子山尾矿库及周边土壤重金属含量,以及库区乡土植物对Cu、Cd、Zn、Mn、Pb、Ni等重金属的转移特征与富集能力,筛选出适应该地区生态修复的先锋植物.研究结果表明,选择的17种优势植物根系土壤中重金属含量Cu、Pb、Zn、Cd、Ni、Mn的平均浓度均超过铜陵市土壤背景值.刺槐、苦卖菜、蒲公英、白茅、野茼蒿、野豌豆、刺儿草、葛根、酸模、商陆、苜蓿草、油菜、节节草、黄花菜、鼠鞠草都表现出对2种以上的重金属转移系数大于1,可作为潜在的富集植物予以考虑.刺槐、苦卖菜、野茼蒿、葛根、苜蓿草等5种植物对重金属Cd的富集系数和转运系数都大于1;白茅、刺儿草对重金属Cu、Pb、Zn和Mn的转运系数大于1,但富集系数却小于1,说明这两种植物能够将根部吸收的Cu、Pb、Zn和Mn元素转移至植物地上部,从而达到降低土壤重金属污染.     

乡镇生活污水处理厂抗生素污染水平及生态风险评价

抗生素的滥用使得大量抗生素进入污水处理厂中,但乡镇污水处理厂中抗生素的污染尚未引起重视.为了解乡镇污水处理厂中抗生素的污染水平及去除特性,考察了15座乡镇污水处理厂进出水中15种抗生素的污染水平和去除效率,并评估了其对水生生物和人体健康构成的风险.结果表明,进出水中四环素类抗生素（TCs）检出浓度最高,四环素（TC）和土霉素（OTC）最高检出浓度可达（4 943.69±4.31）ng·L^-1和（3 907.81±52.04）ng·L^-1.在乡镇污水处理厂中,A/O和A²/O工艺对抗生素的去除能力强于MBR工艺.生态风险评估表明,TCs和喹诺酮类抗生素（FQs）具有较大的风险商值,会对水生生物造成中高风险;而磺胺类抗生素（SAs）对水生生物造成低风险.虽然抗生素会对水生生物造成风险,但对人体健康的风险可忽略不计.研究结果可为今后乡镇污水处理厂工艺的升级改造和地区抗生素排放标准的制定提供支撑.     

不同植物人工湿地净化效果及基质微生物状况差异分析

为研究不同植物对人工湿地污染物净化效果和基质微生物状况的影响,采用序批式运行的沙培模拟人工湿地,探讨了菖蒲、香蒲、千屈菜、芦苇和白鹤芋5种湿地植物在不同HRT(水力停留时间,分别为1,3和5 d)下对模拟废水中TP,NH₄+-N和COD_Cr去除效果的影响,比较了不同植物类型模拟人工湿地中基质微生物的数量差异. 结果表明,不同植物系统对污染物的去除随HRT延长逐渐提高,HRT为5 d时各植物系统对污染物的去除效果最佳.TP,NH₄+-N和COD_Cr的最高去除率分别达90.4%,61.7%和96.4%.相对于其他试验系统,菖蒲系统对各污染指标均具有最优的去除效果. 植物种类对基质微生物数量的影响无显著差异.研究还发现,各系统中亚硝酸细菌数量与NH₄+-N去除率之间呈显著相关.      

Phytoremediation potentials of selected tropical plants for Ethidium bromide

Background, Aims and Scope Research and development has its own benefits and inconveniences. One of the inconveniences is the generation of enormous quantity of diverse toxic and hazardous wastes and its eventual contamination to soil and groundwater resources. Ethidium bromide (EtBr) is one of the commonly used substances in molecular biology experiments. It is highly mutagenic and moderately toxic substance used in DNA-staining during electrophoresis. Interest in phytoremediation as a method to solve chemical contamination has been growing rapidly in recent years. The technology has been utilized to clean up soil and groundwater from heavy metals and other toxic organic compounds in many countries like the United States, Russia, and most of European countries. Phytoremediation requires somewhat limited resources and very useful in treating wide variety of environmental contaminants. This study aimed to assess the potential of selected tropical plants as phytoremediators of EtBr. Materials and Methods This study used tomato (Solanum lycopersicum), mustard (Brassica alba), vetivergrass (Vetiveria zizanioedes), cogongrass (Imperata cylindrica), carabaograss (Paspalum conjugatum), and talahib (Saccharum spontaneum) to remove EtBr from laboratory wastes. The six tropical plants were planted in individual plastic bags containing soil and 10% EtBr-stained agarose gel. The plants were allowed to establish and grow in soil for 30 days. Ethidium bromide content of the test plants and the soil were analyzed before and after soil treatment. Ethidium bromide contents of the plants and soils were analyzed using an UV VIS spectrophotometer. Results Results showed a highly significant (p≤0.001) difference in the ability of the tropical plants to absorb EtBr from soils. Mustard registered the highest absorption of EtBr (1.4±0.12 μg kg⁻¹) followed by tomato and vetivergrass with average uptake of 1.0±0.23 and 0.7±0.17 μg kg⁻¹ EtBr, respectively. Cogongrass, talahib, and carabaograss had the least amount of EtBr absorbed (0.2±0.6 μg kg⁻¹). Ethidium bromide content of soil planted to mustard was reduced by 10.7%. This was followed by tomato with an average reduction of 8.1%. Only 5.6% reduction was obtained from soils planted to vetivergrass. Soils planted to cogongrass, talahib, and carabaograss had the least reduction of 1.52% from its initial EtBr content. Discussion In this study, mustard, tomato, and vetivergrass have shown their ability to absorb EtBr from contaminated soil keeping them from expanding their reach into the environment and preventing further contamination. Its downside, however, is that living creatures including humans, fish, and birds, must be prevented from eating the plants that utilized these substances. Nonetheless, it is still easier to isolate, cut down, and remove plants growing on the surface of the contaminated matrices, than to use strong acids and permanganates to chemically neutralize a dangerous process that can further contaminate the environment and pose additional risks to humans. Though this alternative method does not totally eliminate eventual environmental contamination, it is by far produces extremely insignificant amount of by-products compared with the existing processes and technologies. Conclusions Mustard had the highest potential as phytoremediator of EtBr in soil. However, the absorption capabilities of the other test plants may also be considered in terms of period of maturity and productivity. Recommendations and Perspectives It is recommended that a more detailed and complete investigation of the phytoremediation properties of the different plants tested should be conducted in actual field experiments. Plants should be exposed until they reach maturity to establish their maximum response to the toxicity and mutagenecity of EtBr and their maximum absorbing capabilities. Different plant parts should be analyzed individually to determine the movement and translocation of EtBr from soil to the tissues of plants. Since this study has established that some plants can thrive and dwell in EtBr-treated soil, an increased amount of EtBr application should be explored in future studies. It is suggested therefore that a larger, more comprehensive exploration of phytoremediation application in the management of toxic and hazardous wastes emanating from biotechnology research activities should be considered especially on the use of vetivergrass, a very promising tropical perennial grass. ESS-Submission Editor: Professor Zhihong Xu (zhihong.xu@griffith.edu.au: www.griffith.edu.au/centre/cfhr)