中国地区多溴联苯醚在不同环境介质中的监测进展

多溴联苯醚(Polybrominated diphenyl ethers, PBDEs)为一类新型的溴代阻燃剂,广泛应用于塑料制品、纺织品、电路板和建筑材料等领域。随着生产量和使用量的增加,PBDEs已造成全球环境污染,其带来的环境问题已引起各国关注。同时PBDEs的长距离迁移性和难降解性,使其在环境介质中进行富集,从而加重污染。归纳了中国地区PBDEs的监测进展,分别从大气、水体、沉积物和土壤中PBDEs的污染水平以及原因进行了分析和探讨。在此基础上,对于我国PBDEs的研究方向提出了展望。     

Impacts of Off-Road Vehicles (ORVs) on Macrobenthic Assemblages on Sandy Beaches

Sandy beaches are the prime sites for human recreation and underpin many coastal economies and developments. In many coastal areas worldwide, beach recreation relies on the use of off-road vehicles (ORVs) driven on the shore. Yet, the use of ORVs is not universally embraced due to social conflicts with other beach user groups and putative environmental consequences of vehicle traffic on sandy shores. Such ecological impacts of ORVs are, however, poorly understood for endobenthic invertebrates of the intertidal zone seawards of the dunes. Consequently, this study quantified the degree to which assemblages of intertidal beach invertebrates are affected by traffic. The study design comprised a series of temporally replicated spatial contrasts between two reference sites (no ORVs) and two beaches with heavy ORV traffic (in excess of 250,000 vehicles per year) located in South-East Queensland, Australia. Macrobenthic assemblages on ORV-impacted beaches had significantly fewer species at substantially reduced densities, resulting in marked shifts in community composition and structure. These shifts were particularly strong on the middle and upper shore where vehicle traffic was concentrated. Strong effects of ORVs were detectable in all seasons, but increased towards the summer months as a result of heavier traffic volumes. This study provides clear evidence that ORVs can have substantial impacts on sandy beach invertebrates that are manifested throughout the whole community. Demonstrating such an ecological impact caused by a single type of human use poses a formidable challenge to management, which needs to develop multi-faceted approaches to balance environmental, social, cultural, and economic arguments in the use of sandy shores, including management of “beach traffic.”     

2003~2018年干旱对中国森林绿度异常的影响

基于卫星观测和气象再分析数据提取2003~2018年间中国森林绿度异常现象(月尺度LAI长期趋势的累积偏差), 并分析干旱对森林绿度异常影响的时空动态变化, 探究不同森林类型的干旱敏感性.结果表明: ①干旱导致的绿度异常现象频率分布呈现出南高北低的空间格局, 而高强度异常现象主要分布于中国的东北与西南地区.②2003~2018年间绿度异常严重程度呈现显著增加趋势(即绿度异常强度指数下降), 变化率为: -0.06/a(P<0.05), 而绿度异常面积比率下降, 变化率为-0.0049/a.③中国森林对干旱胁迫较为敏感的区域主要分布于云南北部与大兴安岭北部, 这是由区域的地质和气候特点以及植被类型共同作用导致的.④干旱主导区不同森林类型的干旱敏感性依次为: 阔叶林>针叶林>混交林, 绿度异常与SPEI回归斜率依次为1.8>1.3>1.2.⑤针叶林遭受的干旱强度最高, 2003~2018年间统计的SPEI中位数为-1.65, 绿度异常现象也最为严重, 多年绿度异常指数中位数为-1.81, 说明干旱强度而非敏感性主导了森林绿度异常的现象.     

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers.     

毒死蜱的微波辅助无极汞灯光降解机理研究

毒死蜱是目前全球应用最广泛的有机磷杀虫剂之一,光化学降解是其主要的环境降解途径.文章研究了毒死蜱在水相中微波辅助无极汞灯(MW-EDML)下光降解过程,并应用LC-MS法对其降解产物进行了鉴定.同时,采用量子化学方法中的密度泛函数方法B3LYP/6-31G(d)基组计算了毒死蜱的量子化学参数,探讨了其光降解特性与分子结...     

Compression of home ranges in ghost crabs on sandy beaches impacted by vehicle traffic

Animal movement is a pivotal element of many ecological processes, and on ocean-exposed sandy shores, ghost crabs (genus Ocypode) undertake extensive nocturnal forays on the beach surface. Because crab populations are also threatened by vehicle traffic, indicators that can detect sublethal effects before population declines are manifest are important. To this end, we tested on a barrier island in Eastern Australia whether movement patterns of crabs respond predictably to disturbance by vehicles; this was done by tracking (using the spool-and-line technique) crabs at night in beach sections open and closed to traffic. Beach traffic not only halved population densities of crabs on the unvegetated beach seawards of the dunes, but it also fundamentally changed crab behaviour and movement: individuals from beach areas rutted by tyre tracks travelled shorter distances in a more erratic zigzag pattern, and they had significantly compressed home ranges. Such behavioural changes linked to human pressures could be well suited as an early warning signal for wider negative ecological impacts (as demonstrated by reduced abundances). They also emphasize the need to incorporate sublethal effects into the assessment and management of ecological changes resulting from beach recreation.     

Accumulation, contamination, and seasonal variability of trace metals in the coastal zone – patterns in a seagrass meadow from the Mediterranean

Amongst a plethora of threats to seagrass ecosystems, contamination with heavy metals may well be one of the most significant. We therefore set out to track contamination levels with Cu, Zn, Pb and Cd in the principal autotrophic compartments and sediments of a meadow of Posidonia oceanica in the Gulf of Naples, Mediterranean Sea. With respect to metal levels, leaves and their associated epibiota are certainly not a homogenous compartment, as might perhaps be inferred from the common use of the term “leaf–epiphyte complex” in the literature. Save for Cu, all metal species analysed showed appreciable differences in concentration between seagrass leaves and epibiota. These results give strength to our argument that in ecotoxicological work leaves and epibiota should not be treated as a single unit. Although absolute differences in trace-metal levels among sampling periods varied somewhat with the specific component analysed (i.e. macrophyte organs, epibiota, sediment), an overall trend of markedly higher heavy-metal levels during the winter season is a striking one. Whilst annual cycles in growth dynamics of the seagrasses explain a significant fraction of the temporal variance, seasonality in productivity is a doubtful explanation for similar patterns in non-living sedimentary components; consideration of additional variables therefore seems sensible. As variables with consistent explanatory powers we suggest: (1) seasonal cycles in storm frequency and amplitude which remobilise metals bound in the sediments of the sea floor, and (2) increased precipitation during the cold season which may significantly increase marine metal levels through elevated weathering of rocks and elevated fluvial inputs of anthropogenic contaminant loads. Whereas Cd and Pb concentrations in seagrass leaves from the Gulf of Naples fall within the range for coastal areas subjected to low levels of heavy-metal pollution, Cu and Zn reach levels typical of highly contaminated regions, such as the waters bordering major coastal cities. Any direct comparisons of the pollution status of seagrass beds between different geographic areas are, however, likely to be confounded by the indiscriminate application of the “leaf–epiphyte complex”: the magnitude of the confounding effect depends on the ratio of epibiota/leave biomass, time of sampling, and metal species analysed. Received: 15 May 1997 / Accepted: 2 February 1998     

西藏亚东地区铁杉树轮样本稳定氧同位素的气候响应

为调查树轮稳定氧同位素在西藏南部的气候应用潜力,选择了西藏亚东县三个铁杉(Tsuga chinesis Pritz.)样本进行分析。其中两个样本表现出长期的稳定氧同位素下降趋势,而另一个表现出增高趋势,且三者相关性很低。当对三条稳定氧同位素序列进行一阶差处理之后,它们的相关关系有了非常显著的提高,表现出很好的一致性(p0.0001)。无论是原始还是一阶差树轮稳定氧同位素序列,它们都与夏季相对湿度和降水反相关,而与温度正相关,然而方差解释量未能达到古气候重建的最低要求。周期分析发现亚东树轮稳定氧同位素序列仅存在4.657年的显著周期,可能与ENSO活动有关,进一步研究显示1978年之前上年冬天到当年夏天的赤道中东太平洋海表温度对亚东树轮稳定氧同位素有显著影响(p0.01),而在1978年之后则无任何影响,20世纪70年代末期的全球气候突变改变了ENSO对该地树轮稳定氧同位素的影响。     

负载型纳米金催化剂对室内空气中甲醛的去除

采用沉积-沉淀法(deposition precipitation,简称DP法)和共沉淀法(coprecipitation,简称 CP法)制备了负载型纳米金催化荆Au/Fe2O3,催化剂中金含量(质量分数)小于1%.并以甲醛完全氧化反应作为研究的目标反应.这个反应可以有效地去除室内空气中的有害成分甲醛.通过催化活性的测试和XRD、TEM、TPR等技术对催化剂进行了表征.结果表明,两种方法制备的催化剂有各自的优势和特点,其中DP法制备的催化剂金含量(质量分数)只有0.67%的情况下,经过条件优化,甲醛完全转化温度为80℃,是一个较好的结果;而CP法制备的样品有较好的抗热性,可能有利于催化剂的使用寿命.因此,本工作为该类催化剂实用化提供了有价值的信息和依据.     

伊逊河流域总磷污染来源解析

2017—2018年TP成为滦河一级支流伊逊河流域的主要污染因子,部分国控断面水质主要以GB 3838—2002《地表水环境质量标准》Ⅳ类、Ⅴ类为主.为开展伊逊河TP污染定量识别研究,在2017年和2018年伊逊河流域水体TP污染时空特征分析的基础上,从流域磷铁矿工业污染、城镇生活污水、雨水径流、河道内源释放以及农业非点源等方面开展TP污染研究.结果表明:①伊逊河流域上游至下游TP污染程度呈加剧恶化趋势,上游唐三营控制单元污染较轻,下游李台控制单元TP污染最重;丰水期TP污染较重,枯/平水期污染较轻;从年度看,2017年TP污染严重,2018年年均ρ（TP）下降了50.00%.②2017年、2018年伊逊河流域TP污染来源差异显著,2017年磷输入主要来自于磷铁矿工业污染,占比为33.46%;选矿企业整改后,2018年磷输入主要来源变为畜禽养殖和城镇生活污染,二者占比合计为59.91%.针对伊逊河流域TP污染特征,提出伊逊河流域TP污染控制建议:加强选矿企业环境监管,进一步完善监管体系;加强流域水土流失治理,实施矿山披绿;大力实施绿色农业工程,加强畜禽养殖布局优化.