镇江滨江带湿地修复对浮游生物群落结构的影响

在镇江滨江带50 m×50 m的开放性湿地内进行实验,通过构建高位湿地、架设植物浮巢来改善滨江带湿地生境梯度和生境异质性,营造适宜各类士著动植物生长发育的湿地环境,从而达到增强生态系统延展性及增加生物多样性的目的.结果表明,高位湿地的构建、植物浮巢的架设等生态修复措施对提高研究区浮游植物、浮游动物群落的生物多样性有着显...     

1，2-二氯苯在3种基质中的吸附研究

采用平衡振荡法研究了1，2-二氯苯在3种人工湿地基质中的吸附情况。结果表明，1，2-二氯苯在12 h达到吸附平衡，可由Lagergren一级吸附动力学模型得出3种土壤的吸附速率常数分别为0.3338 h-1、0.2679 h-1和0.2537 h-1，壤土的吸附效果明显好于细砂、粗砂。30℃的吸附等温线既符合Freud...     

四环素高效降解酵母菌Trichosporon mycotoxinivoransXPY-10降解特性

Trichosporon mycotoxinivorans XPY-10是一株分离自抗生素制药厂的高效四环素降解酵母菌。为了建立该菌株降解四环素的适宜条件，分别研究了碳源、有机氮源、金属离子等营养物质及初始底物浓度、接种量、pH、温度、装液量、摇床转速等理化因素对菌体生长及四环素降解效率的影响。结果表明，菌株XPY-10生长的最适碳源和氮源分别为蔗糖和蛋白胨。在含有0.05% FeSO₄的培养基中，菌株XPY-10降解四环素的适宜条件为：接种量2%，pH 8，温度34℃，装液量100 mL（250 mL 三角瓶），摇床转速180 r/min。在此条件下，菌株XPY-10在7 d内对初始浓度为600 mg/L的四环素降解率为83.63%。本菌株对养殖废水及制药废水中四环素的污染治理有一定的应用前景。     

石灰预处理和干发酵对稻草热解特性影响

深入研究生物质热解有助于热解机理的理解,利用热重分析来探讨石灰预处理和干发酵对稻草热解特性的影响。结果表明:预处理使木质素和半纤维素含量增加,而干发酵使VS、半纤维素和纤维素含量降低;预处理和干发酵改变稻草热解特性,但未改变稻草的热反应机理;热解一级动力学方程很好模拟稻草热解的主失重阶段,稻草热解活化能数值为42.3～47.8 kJ/mol,属于正常范围;预处理降低反应活化能,而干发酵增加反应活化能。这为秸秆及其干发酵残渣的气化提供了重要的设计依据。     

Effects of 4-methylbenzylidene camphor (4-MBC) on neuronal and muscular development in zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) embryos

The negative effects of overexposure to ultraviolet (UV) radiation in humans, including sunburn and light-induced cellular injury, are of increasing public concern. 4-Methylbenzylidene camphor (4-MBC), an organic chemical UV filter, is an active ingredient in sunscreen products. To date, little information is available about its neurotoxicity during early vertebrate development. Zebrafish embryos were exposed to various concentrations of 4-MBC in embryo medium for 3 days. In this study, a high concentration of 4-MBC, which is not being expected at the current environmental concentrations in the environment, was used for the purpose of phenotypic screening. Embryos exposed to 15 μM of 4-MBC displayed abnormal axial curvature and exhibited impaired motility. Exposure effects were found to be greatest during the segmentation period, when somite formation and innervation occur. Immunostaining of the muscle and axon markers F59, znp1, and zn5 revealed that 4-MBC exposure leads to a disorganized pattern of slow muscle fibers and axon pathfinding errors during the innervation of both primary and secondary motor neurons. Our results also showed reduction in AChE activity upon 4-MBC exposure both in vivo in the embryos (15 μM) and in vitro in mammalian Neuro-2A cells (0.1 μM), providing a possible mechanism for 4-MBC-induced muscular and neuronal defects. Taken together, our results have shown that 4-MBC is a teratogen and influences muscular and neuronal development, which may result in developmental defects.     

Oceanic diffusion and the pelagic insects Halobates spp. (Gerridae: Hemiptera)

Five pelagic Halobates species occupy a vast area from 40^∘ north to 40^∘ south in the three major oceans. Oceanic diffusion, constantly acting to disperse these insects, must be an important factor in determining their life history and distribution. We investigated the effects of oceanic diffusion on the following aspects of these insects. (1) The estimated radius of a patch of Halobates could be expanded by oceanic diffusion alone from an initial point of origin to 1250 km in 60 d. This distance is about 1/12 of the maximum distributional range of H. micans in the Pacific Ocean. Mutual encounter rates due to oceanic turbulence could be as high as 11 d⁻¹ even at low population densities (100 ind km⁻²). This suggests that individuals from their original habitat could find mates even when they had been carried a long distance. Thus, extensive gene mixing may occur over the whole range of a species' distribution. (2)␣Estimated growth rates are rather low (0.0026 to 0.0079 d⁻¹) compared with those of other insects. However, they are offset by a long life span (over 90 d) and an extended oviposition period (perhaps over 2␣months). Thus, pelagic Halobates spp. appear to have adopted a strategy of slow growth and prolonged longevity to cope with living in an unstable physical environment that is constantly disturbed by storms and winds. Received: 5 February 1995 / Accepted: 30 October 1997     

糖蜜酒精废水两相UASB处理工艺的酸化段特征

文章考察了糖蜜酒精废水二相UASB处理工艺的酸化段特征 ,试验结果表明酸化段的容积负荷达到3 0kgCOD/m3 时 ,系统仍能正常运行 ,TOC去除率在 3 5%以上 ,酸化段的SO4 2 -去除率在 70 %。糖蜜酒精废水酸化率在 50 % ,二相厌氧生物处理系统并未将产酸微生物与产甲烷微生物截然分开 ,在产酸相中仍含有一定数量的产甲烷菌。     

南京市臭氧、VOCs和PANs污染特征及变化趋势

对2013—2016年基于国家环境空气质量监测站以及省建大气多参数站所获取的南京市O_3、NO_2、CO、VOCs、PANs观测结果进行综合评价,结果表明:2016年南京市O_3第90百分位日最大8 h平均质量浓度比2013年上升33.3%,超标天数中O_3引起的超标占比增至32.0%。南京市区大气中非甲烷总烃冬季浓度高于夏季,含氧挥发性有机物则与之相反;在5—9月,含氧挥发性有机物组分在日变化过程中出现峰值的时间先后顺序依次为醚、醛、酮类,且O_3和过氧乙酰硝酸酯(PANs)生成存在有一定的线性关系。VOCs/NOx比值表明南京市处于VOCs控制区,因此对NO_2浓度下降不敏感,植物源挥发性有机物连续3年上升,夏季大气光化学反应活性未显著下降,这些现象是城市O_3浓度维持在较高水平的重要因素。     

The effect of Mg<Superscript>2+</Superscript> on digestion performance and microbial community structures in sludge digestion systems

The important criteria in anaerobic digestion is the rate-limiting step which decides the fate of value-added products especially from waste-activated sludge (WAS). Hence, the present study investigated the effect of magnesium (Mg²⁺) addition on anaerobic digestion of WAS. The lab-scale experiments were conducted at 25 °C with Mg²⁺ doses ranging from 0.01 to 0.2 mol/L. Maximum total volatile fatty acids (VFAs) production (372.78 mg COD/L) occurred at a Mg²⁺ dose of 0.2 mol/L, which was about eight times higher than the control tests. Further, Mg²⁺ addition facilitated sludge dewaterability and phosphorus removal. The mechanism of improved VFAs generation was analyzed from the view of both chemical and biological effects. Chemical effect significantly enhanced the release of calcium and iron in WAS, resulting in the disintegration of WAS, which benefited hydrolysis and acidification processes. Illumina MiSeq sequencing analysis revealed that enrichment of functional bacteria and the increase of bacterial diversity were obtained in the 0.2 mol Mg²⁺/L experiment, while the influence was negative on the reactor with 0.025 mol/L Mg²⁺. Meanwhile, methanogens were accordantly inhibited in the experiments with Mg²⁺ addition.     

典型建筑固体废弃物再生骨料对环保砖性能的影响

随着我国城市化和工业化进程的快速推进,城市建设产生大量的建筑废弃物,燃煤电厂产生大量炉底渣,建筑固废的处置在城市可持续发展过程中备受关注。以建筑垃圾再生骨料、炉底渣和石粉等区域特色的骨料制备环保砖,系统考察了骨料对环保砖力学性能的影响。实验结果表明,再生骨料的种类对环保砖抗压强度的影响显著。再生骨料中混凝土的增加,环保砖抗压强度逐渐增加;而再生骨料中粘土砖含量的增加,环保砖抗压强度明显降低。环保砖抗压强度随炉底渣的含量增加而降低,石粉对环保砖抗压强度有提升作用。