Effect of TiO2 nanoparticle aggregation on marine microalgae Isochrysis galbana

TiO_2 nanoparticles(NPs) could adversely impact aquatic ecosystems. However, the aggregation of these NPs could attenuate this effect. In this work, the biological effects of TiO_2 NPs on a marine microalgae Isochrysis galbana were investigated. The aggregation kinetics of TiO_2 NPs under different conditions was also investigated to determine and understand these effects. Results showed that, though TiO_2 NPs had no obvious impact on the size and reproducibility of algal cells under testing conditions, they caused a negative effect on algal chlorophyll, which led to a reduction in photosynthesis. Furthermore, fast aggregation of TiO_2 NPs occurred under all conditions, especially at the pH close to the p Hzpc. Increasing ionic strength and NP concentration also enhanced the aggregation rate.The aggregation and the following sedimentation of TiO_2 NPs reduced their adverse effects on I. galbana.     

Relationship between physicochemical properties and dewaterability of hydrothermal sludge derived from different source

Sewage sludge (SS) and deinking sludge (DS) were used to comparatively study the hydrothermal dewatering of sludge with different components. For a better overview, an insight into the relationship between physicochemical properties and dewaterability of hydrothermal sludge was provided. Results found that not all kinds of sludge were suitably conditioned by hydrothermal treatment (HT) in term of the elevation of dewaterability. Higher hydrothermal temperature tended to enhance the dewaterability of SS rather than DS, which was supported by the variation of their physicochemical properties (including water distribution, bonding energy, extracellular polymeric substance (EPS), particles size, acid functional groups and zeta potential in this study). In addition, the changes in surface morphology suggested that the reverse effect of HT on sludge dewaterability was mainly due to their dewatering behavior. For SS, the destruction of EPS structure leaded to the release of bound water, thereby strengthening sludge dewatering. Conversely, “Bridging effect” generated by lignocellulose in DS was beneficial for sludge dewatering; however, the increasing hydrothermal temperature degraded part of lignocellulose and weakened “bridging effect”, finally resulting in worse dewaterability of DS.     

广东省生活垃圾焚烧设施环境与健康风险评估构架研究

生活垃圾焚烧设施的建立是解决城市生活垃圾逐年增多的有效方式之一,但其所引发的环境与健康问题成为公众关注的热点。基于广东省对生活垃圾焚烧设施的研究,以环境管理为目标,结合国内外在该领域的研究现状,提出广东省生活垃圾焚烧设施环境与健康风险评估构架。通过该构架的多年实践,总结了广东省生活垃圾焚烧设施环境与健康风险评估研究所取得的成效,有望将该成果推而广之,从而使该行业实现绿色生态的蓬勃发展。     

重庆九龙坡城区和城郊大气污染物浓度特征研究

为了解重庆市九龙坡区城区和城郊大气污染物浓度特征,分析了城区和城郊国控空气站点2014年3月~2015年2月典型污染物的浓度变化。结果表明,除O_3表现出夏高冬低的季节变化趋势外,其它污染物均表现出冬高夏低的季节变化趋势。PM_(2.5)污染最严重,城区和郊区日均值超标率分别为31.4%和33.4%。城区和城郊的PM_(2.5)浓度之间没有显著性差异(p0.05),城郊O_3浓度显著高于城区(p0.01),NO_2、SO_2、CO和PM_(10)则是城区显著高于城郊(p0.01)。     

雾霾环境天气下对户外体育运动人群影响研究

构建雾霾环境天气下户外体育运动生理健康指标参数,以最大摄氧量(VO2)、最大通气量(VEmax)、氧脉搏O2P、心率(HR)等参量为约束指标,构建户外体育运动人群身体健康指标的约束体系,采用心电图的负荷试验和代谢分析实验方法测试雾霾环境天气下对户外体育运动人群健康影响,根据受测运动员的气体代谢和心肺功能指标进行雾霾环境天气下运动人群的心肺机能特征分析。雾霾环境天气下,应当减少户外运动,在空气质量好的环境下进行一定的有氧运动,避免吸入污染空气,导致肺部疾病。     

使用热处理污泥吸附剂去除废水中重金属铜的研究

基于重金属铜的高度危害性和污泥的高效重复利用的考虑,研究了在污泥吸附剂上去除合成废水中重金属铜的实例。将污泥干燥,研磨并在各种温度下进行热处理,使用SEM和FTIR技术分析了污泥的表面形貌和化学结构。实验所研究的参数是铜离子的初始浓度、反应时间、污泥用量以及污泥的热处理温度。实验数据显示随着污泥用量的增加,Cu+2的去除率增加,并根据使用的浓度范围,研究了Cu+2的初始浓度对重金属铜去除率的影响。对实验数据使用不同等温线进行模拟,获得线性拟合性能较好的等温模型。     

低碳经济发展中物流绿色发展趋势研究

文中主要对低碳经济发展中物流绿色发展趋势进行了研究,介绍了对低碳经济发展物流绿色发展评价,探讨了低碳经济发展中的不同问卷的调查结果,对物流绿色发展的认知、态度和行动进行了论述,在论述过程中,主要包括对低碳经济发展中的物流认知、对低碳经济发展中的物流态度、对低碳经济发展中的物流行动和对发展低碳经济物流的认知、态度与行动的比较,最后给出了低碳经济发展中物流绿色发展趋势,对低碳经济发展中物流绿色发展给出了研究基础。     

阳极溶出伏安法、石墨炉原子吸收法测定海水中总铬的方法比较研究

铬是海洋水体中的痕量重金属之一,海水的高盐基体对铬的测定有严重的干扰,而且海水中同时存在Cr(Ⅲ)和Cr(Ⅵ),两种不同价态给测定也带来了一定难度。文章从Cr(Ⅲ)的氧化率、方法检出限、精密度、实际样品加标等方面对过氧化氢氧化-阳极溶出伏安法与传统的MIBK萃取-无火焰原子吸收分光光度法进行了比较研究,发现两种方法在测试结果上无显著差异,但是过氧化氢氧化-阳极溶出伏安法具有更高的精密度,更低的检出限,且对Cr(Ⅲ)的回收率略有提升。     

Disease progression and mortality in neoplasticMya arenaria in the field

Four 6-mo mark-and-recapture experiments conducted in Long Island Sound, USA, from 1988 to 1990, involving approximately 2250 individual observations, demonstrated that under natural conditions significantly higher mortality (p0.001, chi-square test) occurred amongMya arenaria (L.) with hematopoietic neoplasia than those diagnosed as non-neoplastic. Using a blood-screening technique, the clams were diagnosed and placed in one of three diagnostic groups based on the severity of the disease (the percentage neoplastic cells per total number of blood cells): non-neoplastic (NN), 0%; low-severity neoplastic (LSN), < 50%; high-severity neoplastic (HSN), > 50%. Mortality of those clams initially diagnosed as HSN ranged from 48% to 78%, depending on the test period, as compared to 3% to 21% for the non-neoplastic. Mortality in the LSN treatment varied from 8% to 34%. Both progression and remission were evident in clams at all stages of the disease. Mortality and rates of progression and remission in individuals appeared to be linked to water temperatures. Differential mortality may be responsible for the apparent seasonal cycle of prevalence in populations.