Temporal and Spatial Variations of Phytoplankton Community Structure in Lake Erhai,a Chinese Plateau Lake,with Reference to Environmental Factors

Russian Journal of Ecology - Temporal and spatial variations of phytoplankton community in Lake Erhai were investigated from May 2010 to April 2011. A total of 124 species belonging to 8 phyla and...     

TiO2气溶胶快速去除空气中的芥子气模拟剂

在自制反应器内,通过喷射法将纳米TiO_2分散成气溶胶形式,用以降解空气中的芥子气模拟剂二乙基硫醚(DES)。利用自行设计的一套气溶胶沉降行为评价装置,对TiO_2气溶胶的释放条件进行了优化。系统研究了相对湿度、反应温度、光强、催化剂加入量、反应物浓度等因素对DES降解速率和彻底矿化速率的影响。结果表明:TiO_2气溶胶对2.80 mg/L(近似芥子气快速致死浓度)DES降解的半衰期由涂覆型TiO_2的34.5 min缩短至8.5 min;TiO_2气溶胶光催化降解DES的最佳相对湿度为35%,此时CO_2最快生成速率可达34.64μg/(L·min),150 min内彻底矿化比例达66.1%;对于1.5 L反应器,催化剂加入量为30 mg时降解DES的量效比达到最佳状态;TiO_2气溶胶光催化适用于含低浓度DES空气的快速净化。     

助剂作用下超声浸取电解锰渣

用8-羟基喹啉、黄原酸钾、十六烷基三甲基溴化铵、磷酸三丁酯、柠檬酸5种物质作浸取助剂,考察了助剂作用下超声辅助浸取法从电解锰渣中提取锰的工艺条件。实验结果表明：用1%（质量分数）柠檬酸作浸取助剂,在固液比（g/mL）为1∶4、酸矿比（mL/g）为0.3∶1、浸取温度为70℃的条件下,超声浸取15min,锰浸出率平均可达57.28%,是加热酸浸法锰浸出率的2.72倍,是无助剂超声辅助浸取法锰浸出率的1.52倍。     

选择性吸附-高效生物降解法处理含硝基苯与苯酚混合废水

结合NDA-150型树脂（简称树脂）选择性吸附和生物降解的优点,对含硝基苯和苯酚的模拟混合废水（简称混合废水）进行处理。通过树脂的选择性吸附,使混合废水中的硝基苯和苯酚分离,随后用高效菌对树脂所吸附的硝基苯进行生物降解,同时实现树脂的再生。实验结果表明：通过调节混合废水的pH,树脂可有效地将混合废水中的硝基苯和苯酚进行选择性吸附分离;树脂对硝基苯的吸附是可逆的;树脂的再生程度受微生物对可利用硝基苯质量浓度的下限（1．2mg／L）限制;吸附-生物再生循环实验结果表明,该树脂可有效抵抗微生物的生物降解与破坏。     

污染物负荷对曝气生物滤池处理效果的影响研究

考察了进水有机负荷和氨氮负荷对曝气生物滤池出水水质的影响.结果表明,系统COD、氨氮和TN的去除率随进水有机负荷的增加而下降,在氨氮为28.3～33.6 mg/L、TN为39.0～45.8 mg/L条件下,有机负荷小于3.53 kg/(ms3·d)时,出水COD、氨氮和TN分别小于50、5、15 mg/L,去除率分别在85%、85%和65%以上;氨氮和TN的去除率随氨氮负荷的增加而下降,在COD为287.6～313.4 mg/L、氨氮负荷小于0.56 kg/(m3·d)时,出水氨氮小于8 mg/L,去除率在85%以上,出水TN小于15mg/L,去除率在65%以上.     

Study on a new correlation between diffusion coefficient and temperature in porous building materials

The diffusion coefficient (D) and partition coefficient (K_ma) are the two important parameters used to predict the volatile organic compound (VOC) emission or sorption characteristics in porous building materials. D and K_ma may be strongly affected by temperature (T). In this study, we derived a new correlation between D and T based on the assumption that molecular diffusion is dominant, and evaluated this correlation using a series of existing experimental data. The modeling results using the new correlation agree well with the experimental data. The correlation would be useful for assessment of indoor air quality under different environmental (temperature) conditions.     

一株高效脱硫脱氨氮菌的分离、鉴定及系统发育分析

从运行稳定的能同步脱臭的曝气生物滤池中采集样品,富集分离获得一株能高效脱硫脱氨氮的菌株TS-1。对分离菌株进行形态观察、生理生化试验及16S rRNA基因序列分析,结果表明,该菌株TS-1为革兰氏阳性菌,杆状;菌落在营养琼脂培养基上呈圆形,表面光滑,乳白色半透明;V-P试验阴性,能水解淀粉和明胶,利用柠檬酸盐生长;对菌株进行16S rRNA的PCR扩增,扩增产物测序结果表明分离菌株TS-1与巨大芽孢杆菌（Bacillus megaterium）同源性达到99%;以16S rRNA同源性为基础构建了包括24株相关种属细菌在内的系统发育树,在系统发育树中,分离菌株TS1与Bacillus megaterium在同一分支。结合形态观察、生理生化试验及16S rRNA基因序列分析结果,将其初步鉴定为巨大芽孢杆菌（Bacillus megaterium）。在常温（30±2）℃、转速为150 r/min的条件下,处理pH 7、S^2-和NH⁺₄-N分别为80 mg/L和88 mg/L的水样40 h,硫化物和氨氮的脱除率分别为91.8%和96.6%。     

红萍净化水产养殖水体的研究

利用红萍(Azolla)对富营养化水产养殖水体进行净化研究。结果表明,红萍能显著增加水体中的DO,增氧幅度随流量在16.88%～70.46%之间变化,随着养殖水体流经的层数增多或者处理的时间延长,红萍对水体的增氧量加大,水中DO最终趋向一个常数值K;同时,红萍对水体中的NH₃-N和TP都有明显的去除效果,NH₃-N去除率随流量在9.86%～38.90%间波动,TP的去除率则随流量的变化在5.80%～38.43%之间波动。可见,红萍是净化水质的良好材料,能有效改善水产养殖水环境。利用红萍净化水体将为解决高密度集约化水产养殖的瓶颈提供新途径,实现水产养殖用水的封闭循环利用。     

原子吸收光谱分析技术在环境,医学卫生和食品分析方面的应用

回顾了原子吸收光谱分析在我国环境、医学卫生和食品分析方面的应用概况。     

Zinc and cadmium accumulation and tolerance in populations of Sedum alfredii

To investigate the variation of Zn and Cd accumulation and tolerance of Sedum alfredii (a newly reported Zn/Cd hyperaccumulator), field surveys and hydroponic experiments were conducted among three populations of this species: two originating from old Pb/Zn mines in Zhejiang (ZJ) and Hunan (HN) Provinces and one from a "clean" site in Guangdong (GD) Province, China. Under field conditions, up to 12,524 and 12,253 mg kg(-1) Zn, and 1400 and 97 mg kg(-1) Cd in shoots of ZJ and HN plants were recorded respectively. Under hydroponic conditions, ZJ and HN plants accumulated significantly higher Zn and Cd in their leaves and stems, and possessed significantly higher Zn and Cd tolerance than GD plants. Among the two contaminated populations, ZJ plants showed higher Cd tolerance and accumulation (in leaves) than HN plants. The present results indicate that significant differences in Zn and Cd accumulation and tolerance exist in populations of S. alfredii.