天津市滨海新区地震地质灾害评价与分区研究

收集了天津市滨海新区大量的工程地质勘察资料,针对滨海新区场地工程地质条件,从地震地质背景、历史震害的影响出发,依照相应规范和地质类比等方法,通过滨海新区活动断层影响、砂土液化、软土震陷的评判,探讨了滨海新区在未来强震作用下可能出现的地震地质灾害类型及空间分布特征。     

Persistence of repeated triadimefon application and its impact on soil microbial functional diversity

The effects of repeated applications of the fungicide triadimefon in agricultural soil on the microbial functional diversity of the soil and on the persistence of the fungicide in the soil were investigated under laboratory conditions. The degradation half-lives of triadimefon at the recommended dosage, simulated by a first-order kinetic model, were 23.90, 22.95, and 21.52 days for the first, second, and third applications, respectively. Throughout this study, no significant inhibition of the Shannon-Wiener index (H') was observed. However, the Simpson index (1/D) and the McIntosh index (U) were obviously reduced (p ≤ 0.05) during the initial 3 days after the first triadimefon application and thereafter, gradually recovered to or exceeded the level of the control soil. A similar trend in variation but with a faster recovery in the 1/D and U was observed after the second and third triadimefon applications, respectively. Taken together, the above results indicate that the repeated application of triadimefon enhanced the degradation rate of the fungicide and the recovery rate of the soil microbial functional diversity. It is concluded that repeated triadimefon applications in soil have a transient or temporary inhibitory effect on soil microbial communities.     

铁炭微电解工艺处理采油废水的研究

随着采油废水产生量的逐渐增大以及排放标准的日益严格,寻找一种经济、高效的处理方法显得十分必要。采用铁炭微电解技术对冀东油田采油废水进行了处理。考察了铁屑粒径、pH值、Fe/C质量比和反应时间对COD去除率的影响并设计了正交实验,结果表明,影响微电解工艺的因素主次关系为:pH>Fe/C质量比>反应时间,在最佳条件pH=5,Fe/C质量比为7∶1,反应时间50 min下,原水COD由170 mg/L降至95.6 mg/L,去除率达43.85%,出水满足国家二级排放标准。     

外源硅对不同pH水田土壤吸附铅的影响

通过等温吸附实验,研究了加硅对2种不同pH水田土壤吸附铅特性的影响。实验中用硝酸中和硅酸钠的碱性,各处理间钠离子和硝酸根离子的差异以硝酸钠补齐,消除了因硅酸盐的加入改变体系pH及伴随离子对土壤吸附铅可能产生的影响。结果表明,在本实验条件下,Langmuir方程、Freundlich方程和Temkin方程都能较好地描述不同硅浓度条件下两种土壤对铅的吸附特征,但以Freundlich模型为最优;加硅促进了酸性土壤对铅的吸附,抑制了碱性土壤对铅的吸附。     

旋转填料床/柠檬酸盐法吸收-解吸SO2

提出采用旋转填料床结合柠檬酸盐法脱除烟气中SO2的方法,考察了旋转填料床转子转速、液气比、初始柠檬酸根浓度和初始pH值等因素对脱硫效率的影响。结果表明,采用超重力法超重机转子转速为1 000 r/min、液气比为7L/m3、初始柠檬酸根浓度为1.5 mol/L、吸收液的初始pH值为5.0,脱硫效率稳定在99%左右。研究了水蒸气汽提法解吸SO2时初始柠檬酸根浓度、初始pH值、SO2浓度、富液流量和水蒸气流量对解吸效率的影响,得出了影响SO2解吸率的基本规律,并进行了分析。通过实验证明该方法在技术上是可行的,具有良好的应用前景。     

改性矿物吸附剂抗菌作用

通过对蒙脱石、沸石和蛭石进行改性处理，研究了三者对大肠杆菌（E．coB）和猪链球菌（S．suis）的抗菌作用。结果发现，经过改性处理后三者对细菌的抗菌能力上升，其中以双十八烷基二甲基溴化铵改性蒙脱石（DODMAB．MMT）的抗菌效果最好，对E．coli和S．suis的抗菌率达到95％以上。研究了DODMAB—MMT在体外对E．coli和S．suis的抗菌规律，以及对土壤中微生物的影响。结果表明，同等菌液浓度条件下，DODMAB—MMT对S．suis的抗菌效果好于E．coli。介质温度、pH值和有机物浓度都会对DODMAB—MMT的抗菌效果产生影响，在一定范围内，介质温度越高、pH值偏离中性、有机物含量越低时，抗菌效果越好。低浓度DODMAB—MMT（〈25rtlg／g土壤）对土壤中E．coli和S．suis基本无抗菌作用，高浓度DODMAB—MMT对土壤中的E．coli和S．suis具有抗菌作用。     

实时荧光定量PCR对A2/O短程硝化系统内氨氧化菌的定量分析

通过控制好氧区低DO浓度以及缩短好氧实际水力停留时间(actual hydraulic retention time,AHRT),在处理低C/N比实际生活污水的A2/O工艺中,成功启动并维持了短程硝化反硝化;系统亚硝酸盐积累率稳定维持在90%左右,氨氮去除率在95%以上。通过提取富集氨氧化菌(ammonia oxidizing bacteria,AOB)的基因组DNA,经两次常规PCR扩增和琼脂糖凝胶电泳,以纯化回收的DNA扩增片段作为实时荧光定量PCR检测AOB数量的DNA标准品,建立了检测AOB数量的实时荧光定量PCR标准曲线。利用实时荧光定量PCR技术比较了A2/O系统在不同运行条件及亚硝酸盐积累率情况下AOB菌群数量。结果表明,随着系统亚硝酸盐积累率的上升,系统内AOB菌群数量也大幅上升。全程硝化和短程硝化时,系统内的AOB菌群数量分别为5.28×109cells/g MLVSS和3.95×1010cells/g MLVSS。此外,亚硝酸盐积累率的下降相对于AOB菌群数量的下降有一定的滞后性。     

Investigation into organic phosphorus species in sediments of Baiyangdian Lake in China measured by fractionation and 31P NMR

Organic phosphorus (OP) species in sediments of the Baiyangdian Lake in China was investigated via fractionation and phosphorus-31 nuclear magnetic resonance ((31)P NMR) spectroscopy. Results of chemical fractionation showed that different OP fractions ranked in the order: humic acid-P?>?HCl-OP?>?fulvic acid-P?≈?NaHCO(3)-OP?>?residual OP. Labile OP and moderately labile OP, which can be degraded for phytoplankton uptake, contributed to 58.7-68.5% of total extracted OP, indicative of the potential P release from sediments in the lake. (31)P NMR spectroscopy results suggested the rank order of P species present in the NaOH-EDTA extractant of the sediments: orthophosphate?>?monoester-P?>?DNA-P?>?pyrophosphate-P. Phytate, polyphosphates, and phosphonates, which appeared in sediments of some deeper lakes, were not detected in the shallow lake. Significant correlations were identified between total P (TP) in water column and sediment TP, monoester-P and DNA-P, positively indicating that sediment P species, especially OP components, should probably contribute to the contents of P in water column and further to the lake eutrophication.     

微生物生理群在猪粪秸秆高温堆肥碳氮转化中的作用

在自制的强制通风静态堆肥反应箱中,猪粪与秸秆以鲜重7∶1的比例进行了堆肥化实验,在堆制的23 d里根据堆温变化分阶段采集堆肥样品,利用MPN法测定了堆料中纤维素分解菌和氮素微生物生理群的数量变化,同时测定了相应的碳、氮含量。结果表明,纤维素分解菌在稳定腐熟阶段较多,对于后期有机碳的降解和腐殖质含量的增大起了很大的作用,在堆制的23 d里,腐殖质增加了2.4%。整个堆制过程中,氨化细菌的数量最大且与氨气释放浓度和铵态氮含量呈显著正相关,都在高温期增加,降温期后减少,氨化细菌的数量在高温期的增加率远高于降温期后的减少率,而铵态氮在高温期的增加率远低于在降温后期的减少率,铵态氮总体上减少了74.1%;亚硝化细菌数量与硝态氮呈正相关;反硝化细菌数量在降温期上升幅度较大,堆制结束时为堆制初期的13倍,且与堆肥中硝态氮含量呈正相关;硝态氮含量增加了87.5%;堆肥后期硝态氮的增加可能与堆肥中存在能进行硝化作用的反硝化细菌有关。固氮菌数量在堆制结束时达堆制初期的2.61倍,主要在降温期增加较多,对堆肥中有机氮的形成起很大作用。     

Environmental lead pollution threatens the children living in the Pearl River Delta region, China

Introduction and purpose

The objective of this study is to determine children??s blood lead levels and identify sources of lead exposure. Childhood lead exposure constitutes a major pediatric health problem today in China. A blood lead screening survey program for children in the age group of 2?C12?years residing in Pearl River Delta region, south of China, was carried out from Dec 2007 to Jan 2008.

Methods

Blood lead levels and lead isotope ratios of a total of 761 participants were assessed by inductively coupled plasma mass spectroscopy. Measurements of urban environmental samples for source identification of children lead exposure were also performed.

Results and conclusions

The geometric mean value of the children??s blood lead levels was 57.05???g/L, and 9.6% of them were higher than 100???g/L. The blood lead levels were still much higher than those in developed countries. Based on the data of environmental lead source inventories, lead isotopic tracing revealed that there is about 6.7% past used gasoline Pb embedded in Shenzhen residential dust and about 15.6% in Guangzhou dust, respectively.