Bioaccumulation and effects of sediment-associated gold- and graphene oxide nanoparticles on Tubifex tubifex

With the development of nanotechnology,gold(Au) and graphene oxide(GO) nanoparticles have been widely used in various fields,resulting in an increased release of these particles into the environment.The released nanoparticles may eventually accumulate in sediment,causing possible ecotoxicological effects to benthic invertebrates.However,the impact of Au-NPs and GO-NPs on the cosmopolitan oligochaete,Tubifex tubifex,in sediment exposure is not known.Mortality,behavioral impact(GO-NP and Au-NP) and uptake(only Au-NP) of sediment-associated Au-NPs(4.9±0.14 nm) and GO-NPs(116±0.05 nm) to T.tubifex were assessed in a number of 5-day exposure experiments.The results showed that the applied Au-NP concentrations(10 and 60 μg Au/g dry weight sediment) had no adverse effect on T.tubifex survival,while Au bioaccumulation increased with exposure concentration.In the case of GO-NPs,no mortality of T.tubifex was observed at a concentration range of 20 and180 μg GO/g dry weight sediment,whereas burrowing activity was significantly reduced at 20 and 180 μg GO/g dry weight sediment.Our results suggest that Au-NPs at 60 μg Au/g or GO-NPs at 20 and 180 μg GO/g were detected by T.tubifex as toxicants during short-term exposures.     

试验方法和接种物来源对苯甲酸钠快速生物降解率的影响

化学品的快速生物降解性直接影响其在环境中的迁移、转化和归宿,是鉴别其环境危害性和持久性的基本指标,是政府管理部门对化学品进行风险管理的重要科学依据,在生态毒理测试中具有非常重要的地位。为探讨试验方法、接种物来源以及两者的交互效应对苯甲酸钠生物降解率的影响,2013—2015年间以广州地区2个主要处理生活污水的污水处理厂(DTS、LD)为接种物来源,采用OECD 301系列试验方法(301B、301D和301F)进行了苯甲酸钠的快速生物降解性试验,共获得89个标准化测试数据。统计分析结果显示,接种物来源、试验方法与接种物来源的交互效应对苯甲酸钠生物降解率影响不显著,但试验方法单一因素的影响显著。本研究表明,当受试物为易生物降解时,接种物来源、试验方法和接种物来源的交互效应对该受试物的生物降解率无显著的影响,但在同一条件下,选择不同的试验方法往往会导致最终生物降解率出现明显差异。     

广东清远电子垃圾处理地沉积物对伸展摇蚊的慢性毒性效应

电子垃圾拆解引起的环境污染和生态风险已成为全球关注的热点问题,不适当的电子垃圾拆解过程造成处理区水体沉积物受到多类有机化合物和重金属污染,直接威胁生活在沉积物中的底栖动物。在典型电子垃圾处理地广东清远采集沉积物,测定样品中以烃类为主的色谱难分离混合物(unresolved complex mixture,UCM)的含量,开展伸展摇蚊全生命周期慢性毒性测试。结果表明,清远沉积物中的UCM浓度(0.08±0.01)%接近于这类污染物对伸展摇蚊的慢性半致死性效应浓度(0.073±0.022)%。同时发现清远沉积物对以摇蚊为代表的底栖无脊椎动物具有显著慢性毒性效应,且可通过测定UCM含量初步估算。这为开展以电子垃圾处理地沉积物为代表的,受到以麻醉作用为主要致毒机制的混合物污染的沉积物的毒性评价提供了一种有效方法。     

The impact of different voltage application modes on biodegradation of chloramphenicol and shift of microbial community structure

● Presented coupled system enhanced biodegradation of antibiotic chloramphenicol. ● HRT and electrical stimulation modes were key influencing factors. ● Electrical stimulation had little effect on the chloramphenicol metabolic pathway. ● Microbial community structure varied with the voltage application mode. Exoelectrogenic biofilms have received considerable attention for their ability to enhance electron transfer between contaminants and electrodes in bioelectrochemical systems. In this study, we constructed anaerobic-aerobic-coupled upflow bioelectrochemical reactors (AO-UBERs) with different voltage application modes, voltages and hydraulic retention times (HRTs). In addition, we evaluated their capacity to remove chloramphenicol (CAP). AO-UBER can effectively mineralize CAP and its metabolites through electrical stimulation when an appropriate voltage is applied. The CAP removal efficiencies were ~81.1%±6.1% (intermittent voltage application mode) and 75.2%±4.6% (continuous voltage application mode) under 0.5 V supply voltage, which were ~21.5% and 15.6% greater than those in the control system without voltage applied, respectively. The removal efficiency is mainly attributed to the anaerobic chamber. High-throughput sequencing combined with catabolic pathway analysis indicated that electrical stimulation selectively enriched Megasphaera, Janthinobacterium, Pseudomonas, Emticicia, Zoogloea, Cloacibacterium and Cetobacterium, which are capable of denitrification, dechlorination and benzene ring cleavage, respectively. This study shows that under the intermittent voltage application mode, AO-UBERs are highly promising for treating antibiotic-contaminated wastewater.     

铜和镉对珠江天然仔鱼和幼鱼的毒性效应及其潜在生态风险

以静水实验法探讨珠江流域主要金属污染物铜和镉对当地天然仔鱼和幼鱼的急性毒性效应。结果显示,铜对西江赤眼鳟和鲴仔鱼(48 h)和广东鲂幼鱼(96 h)的LC50分别为0.066、0.055和0.10 mg·L-1,对应的安全浓度分别为0.006、0.010和0.010 mg·L-1;镉对赤眼鳟和鲴仔鱼(48 h)以及广东鲂幼鱼(96 h)的LC50分别为1.29、0.83和3.20 mg·L-1,对应的安全浓度分别为0.163、0.077和0.320 mg·L-1。其中,铜对上述受试鱼的安全浓度低于或接近我国《渔业水质标准》及《地表水环境质量标准》Ⅱ类水对铜的规定,而镉对这些受试鱼的安全浓度则高于相关标准对镉的规定。研究结果表明,珠江流域铜污染可能会对当地天然仔鱼、幼鱼群体的补充构成一定程度的威胁,但镉污染暂不会对该区域主要鱼类早期群体补充带来严重的生态风险。     

Cyanide generation during preservation of chlorinated wastewater effluent samples for total cyanide analysis.

Dechlorinating agents and pH adjustment are often used to preserve wastewater samples for cyanide analysis. The effects of four approved preservation protocols on the results of the total cyanide analysis of effluents from four water reclamation plants were examined. The results differed widely, and a clear pattern emerged. Immediate analysis without pH adjustment generally gave total cyanide concentrations below the reporting limit of 5 microg/L, irrespective of the dechlorinating agents used. When the pH was adjusted to > or =12, a slight increase in the measured total cyanide concentration was observed when thiosulfate was used to dechlorinate the samples, and a significant increase (>10 microg/L) was observed when arsenite was used as the dechlorinating agent. These results provide evidence that approved preservation protocols may give rise to cyanide formation in chlorinated wastewater effluent matrices.     

钻井噪声特性分析与噪声治理

通过对钻井井场噪声源的分布及特性进行现场勘察分析得知:井场区域内各种设备产生的高强度噪声在70～110dB(A)之间,以中低频噪声为主,主要以柴油发电机房为中心,以球面波形式向四周辐射,对井场作业人员及周围250m范围内的居民和环境产生不同程度的噪声危害。为了有效控制噪声对作业人员及井场周围环境的危害,提出了对重点噪声源、噪声传播途径采取隔声、吸声、消声等降噪措施来降低噪声污染。     

土壤中残留苯磺隆的高效液相色谱分析

本文报道了一种固相萃取净化，高效液相色谱测定土壤中苯磺隆的残留分析方法，不同土壤的添加回收率平均为８３．３％，８６．３％，７７．２％，线性范围２．５５－５１０ｎｇ，利用本法分析苯磺隆，精确、简便、快速。     

利用工业废铁泥制备α-FeOOH

以工业废铁泥为原料,经酸浸、还原、空气氧化、过滤等步骤制备α-FeOOH。采用X射线衍射仪、扫描电子显微镜、孔隙比表面分析仪对产品进行了分析表征。实验结果表明,在以十二烷基苯磺酸钠为表面活性剂、n(N aOH)∶n(FeSO4)为5.0的条件下,处理1kg废铁泥可得到α-FeOOH824.4g。     

西南酸雨地区土壤中铝溶出规律的探讨

本文介绍了实验室动态模拟结果,对西南地区酸性沉降引起的土壤铝淋溶过程予以探讨。通过计算机推算拟合,提出了预测土壤中铝淋溶容量计算法。运用正交实验法,研究了近似于天然的动态过程中影响铝淋溶的主要因素及各因素间的相关性。得到了当降雨pH<6.0时,酸性土或弱酸性土中铝溶量和时间呈指数关系,以及影响铝溶出因素主要是酸雨的pH值、土壤的缓冲能力和环境温度等结论。