岛屿生境下苦槠丛枝菌根(AM)与根际土壤磷酸酶活性的相关性研究

以浙江千岛湖典型生境片断化区域苦槠(Castanopsis sclerophylla)为材料,研究了水库形成后岛屿化导致的群落生境差异对苦槠AM侵染率的影响以及AM侵染率与根际土壤磷酸酶活性的相关性.结果表明,以生境面积为因子进行单因素方差分析,则不同岛屿生境对苦槠AM侵染率影响差异不显著;但以Pearson相关性分析,AM侵染率与岛屿面积之间呈显著负相关.苦槠根际土壤酸性磷酸酶活性在中岛、大岛与陆地间差异显著,但与AM侵染率之间无显著相关性.     

低温生物膜和活性污泥的生物活性比较

通过 (5± 1)℃下生物膜系统 (BF)和活性污泥系统 (AS)处理生活污水长达 8个多月的运行 ,对比研究了两系统的生物活性 .结果表明 ,活性污泥不仅生物活性较高 ,而且具有更有利的传质条件 .在水力停留时间HRT =8h的条件下 ,生物膜和活性污泥胞外分泌物中的还原糖含量分别为 1.75 %及 1.9% ,挥发性污泥组分 (VSS)中的ATP含量分别为 1.0 8mg/ g及 1.4 3mg/g ;电镜检测结果表明 ,生物膜结构致密 ,而活性污泥疏松多孔有利于物质传递 .图 5表 2参 14     

Effects of Cd2+ and Pb2+ on the substrate biofilms in the integrated vertical-flow constructed wetland

The effects of single Cd~(2+)and Pb~(2+),and combined Cd~(2+)and Pb~(2+)on dehydrogenase activity and polysaccharide content of the substrate biofilms in the integrated vertical-flow constructed wetland(IVCW)were studied.Dehydrogenase activities decreased linearly with the increasing concentrations of Cd~(2+)and Pb~(2+)at different times(6,24,72,and 120 h).The activities at both 6 and 24 h were significantly higher than that at 72 and 120 h in the case of single and combined treatments.The single Cd~(2+)...     

Relation of hepatic EROD activity and CYP1A level in Sebastiscus marmoratus exposed to benzo[a]pyrene

This study was designed to investigate the in vivo effects of benzo[a]pyrene (BaP) on hepatic ethoxyresorufin-O-deethylase (EROD) activity and its correlation with cytochrome P450 1A (CYP1A) protein levels in Sebastiscus marmoratus, which were exposed through a water column to BaP (10, 100, 1000 ng/L, respectively) or were treated with intraperitoneal injections of BaP (0.5, 1, 5, 10 mg/kg, respectively) every 7 d. The results showed that after 25 d of waterborne exposure to 1000 ng/L BaP, fish hepatic CYP1A levels and EROD activity were significantly induced. In contrast, EROD activity was not altered 7 d after second ip injections, whereas, CYP1A protein levels were increased. Dose-dependent increase of biliary BaP metabolites demonstrated that the catalytic activity of CYP1A was induced by treatment with BaP. The lowest observable effect concentration with regard to biliary BaP metabolites (100 ng/L) was much lower than that with reference to EROD activity (1000 ng/L). The results suggest that biliary polycyclic aromatic hydrocarbon (PAH) metabolites were shown to better reflect the contamination gradients of PAHs than EROD activity. It appeared to be necessary to measure CYP1A protein levels to complement the EROD activity in relevant toxicological assessments.     

硫化镉光催化降解活性染料的研究

以硫化镉为光催化剂,钨灯模拟可见光,研究了硫化镉对活性染料亚甲基蓝的光催化降解过程。考察了光照时间、催化剂用量、污染物的初始浓度、反应体系的pH值等对光催化过程的影响。结果表明,以钨灯为光源下,硫化镉能较好对亚甲基蓝进行降解。     

石油降解菌的筛选及其降解效率的研究

从石油污染土壤中分离纯化得到1株特征明显的石油降解菌,研究了不同的油含量、温度及添加物等因素对石油降解菌的脂酶活性和除油率的影响。结果表明:实验菌株属于假单胞菌属;脂酶活性与除油率正相关;除油率随油浓度的升高而降低;石油降解率通常随温度的降低而降低;添加蔗糖不利于石油的降解;添加表面活性剂吐温80有利于脂酶的产生和代谢。     

微曝气条件下S-TE剩余污泥溶解性研究

研究了微曝气、不同温度条件下S-TE预处理对剩余污泥溶解和各种化学组分变化的影响.结果表明,S-TE污泥溶解存在2种反应(酶催化反应和热解反应)和2个过程:嗜热菌胞外酶(主要为蛋白酶和淀粉酶)首先解聚污泥胶团,进而溶解细菌的细胞壁,水解胞内有机物质.接种嗜热菌Bacillus stearothermophilus sp.AT06-1比不接种促进了污泥悬浮固体的溶解,接种条件下最适宜的溶解温度为65℃,此温度下,污泥VSS和TSS溶解率相对于不接种试验提高程度最大,2 d时VSS、TSS溶解率分别达到34.09%和24.16%,比不接种试验同期分别提高了7.57%和6.87%;微曝气条件下SCOD和VFA得到累积,最大累积量达到4 531 mg/L和2 319 mg/L,有利于厌氧消化;此时蛋白酶活性提高也最大.污泥溶解产生的蛋白质被蛋白酶水解,蛋白质浓度先升高后降低.     

丹江口库区新生消落带不同土地利用酶活性比较

随着南水北调中线工程的建成,丹江口水库水位上涨形成了大量新生消落带,消落带生态环境变化对水库水质具有较大影响,土壤酶活性和土壤养分的改变在一定程度上能反映土壤生态环境的变化.基于此,以丹江口水库新生消落带为研究区域,选取库周从未经历淹没的区域作为对照,采用裂区试验设计方法,以样地类型（新生消落带和对照区）为主处理,以3种不同土地利用类型（林地、农田和草地）为副处理,研究了土壤酶（脲酶、转化酶、过氧化氢酶和碱性磷酸酶）活性与土壤养分之间的关系.结果表明:①新生消落带土壤中w（TN）、w（NO₃--N）和w（OM）均显著低于对照区（P < 0.05）,而农田、草地的w（NH₄+-N）与林地的w（TP）显著高于对照区（P < 0.05）.②与对照区相比,新生消落带农田和草地的脲酶、转化酶、碱性磷酸酶和过氧化氢酶活性均降低,其中,农田和草地脲酶活性分别降低了79%和54%,而林地脲酶与过氧化氢酶显著增加,林地脲酶活性升高了133%,林地碱性磷酸酶与转化酶活性变化不显著.③不同土地利用类型的土壤理化性质对酶活性的影响不同,新生消落带农田土壤含水量、w（NH₄+-N）的升高及w（TN）、w（TP）、w（OM）的降低是导致酶活性降低的主要影响因素,新生消落带林地土壤pH、w（TP）、w（TN）对酶活性的增加有主要影响,新生消落带草地土壤含水量、w（NH₄+-N）、w（TN）、w（TP）、w（OM）对酶活性的降低有主要影响.研究显示,消落带林地在淹没期间能够吸附固定土壤及水体中的氮磷,水落后土壤酶活性的升高有利于土壤中养分的分解,减少氮磷对库区水体的污染.      

Characteristics and ozone formation potential of volatile organic compounds in emissions from a typical Chinese coking plant

Coking industry is an important volatile organic compounds (VOCs) emission source in China, however, detailed information on VOCs emissions is lacking. Therefore, we selected a typical mechanized coking plant and collected air samples according to the Emission Standard of Pollutants for Coking Chemical Industry (GB16171-2012). Using gas chromatography-mass spectrometry method, we analyzed the VOCs in the air samples, and applied maximum increment reactivity (MIR) rule to estimate ozone formation potential (OFP) of the VOCs emitted from the coke production. More than 90 VOCs species were detected from the coking plant, including alkanes, alkenes, alkynes, aromatic hydrocarbons, halogenated hydrocarbons and oxygenated VOCs. The concentrations of VOCs (ρ(VOCs)) generated at different stages of the coking process are significantly different. ρ(VOCs) from coke oven chimney had the highest concentration (87.1 mg/m³), followed by coke pushing (4.0 mg/m³), coal charging (3.3 mg/m³) and coke oven tops (1.1 mg/m³). VOCs species emitted from the coke production processes were dominated by alkanes and alkenes, but the composition proportions were different at the different stages. Alkenes were the most abundant emission species in flue gases of the coke oven chimney accounting for up to 66% of the total VOCs, while the VOCs emissions from coke pushing and coal charging were dominated by alkanes (36% and 42%, respectively), and the alkanes and alkenes emitted from coke oven top were similar (31% and 29%, respectively). Based on above results, reduction of VOCs emissions from coke oven chimney flue gases is suggested to be an effective measure, especially for alkenes.     

纳米富勒烯对土壤酶活性和微生物群落的影响

采用室内暗培养试验,研究了纳米富勒烯对土壤呼吸强度、酶活性及微生物结构群落多样性的影响.结果表明,添加纳米富勒烯抑制了土壤呼吸强度(p0.05),较对照处理CO_2累积量降低了1.2%～11.3%.纳米富勒烯显著抑制了土壤脲酶活性(p0.05),与对照相比,降低了19.1%～33.7%,土壤脱氢酶活性整体上表现为随纳米富勒烯添加量增加先增加后降低的趋势.与之相反,添加不同剂量纳米富勒烯整体上提高了土壤碱性磷酸酶活性,但差异不明显(p0.05).利用磷脂脂肪酸(Phospholipid Fatty Acids, PLFAs)分析发现,添加纳米富勒烯(10～500 mg·kg~(-1))后土壤总PLFAs含量较对照降低了3.6%～27.3%,在低剂量(≤50 mg·kg~(-1))纳米富勒烯处理下革兰氏阳性细菌、革兰氏阴性细菌、真菌、细菌含量均有所提升,而当纳米富勒烯剂量达到500 mg·kg~(-1)时,土壤微生物数量在不同程度上受到抑制.土壤微生物生态学指数(Shannon、Simpson和Pielou指数)、聚类分析(Cluster analysis)、主成分分析(Principal component analysis)均显示纳米富勒烯对土壤中微生物群落多样性产生了负面影响.