十二烷基硫酸钠降解菌的分离、鉴定及其降解能力

从含十二烷基硫酸钠的废水中通过富集培养的方法得到一株可以十二烷基硫酸钠为惟一碳源生长的降解菌PB - 21.通过形态学特征观察、生理生化实验以及16S rRNA序列分析,对菌PB -21进行初步鉴定.鉴定结果表明,该菌为放线细菌属(Actinobacterium sp.),与Actinobacterium C46 - ...     

Sources and environmental behavior of dechlorane plus--a review

Intensive research has been carried out in the past few years on the occurrence and behavior of dechlorane plus (DP) in the environment, biota and humans. This review summarizes the information and research results generated since DP was first identified in the environment in 2006. We describe the reported measurement methods for DP and provide an integrated picture of its occurrence and behavior as an environmental contaminant. DP in ambient air and sediments is characterized by strong source related concentration elevations and temporal trends reflecting commercial use. Long-range atmospheric transportation of DP has been observed in remote regions, indicating a global presence of DP. Levels of DP in biota and in humans further reinforce its source related distribution. The change in DP isomer ratio in various environmental matrices from commercial products indicates that the behavior of the two isomers is not the same in the environment or in biota. With only limited data available so far, the biomagnification of DP in aquatic biota has not been conclusively demonstrated. This review also looks at reported dechlorination products of DP that might be of interest in future research.     

长江重庆段溶解性有机物的荧光特性分析

利用三维荧光光谱(EEMs),并结合平行因子分析(PARAFAC)及主成分分析(PCA),研究了长江重庆段溶解有机物(DOM)的荧光组分特征及其污染来源,并探讨了荧光强度同溶解性有机碳(DOC)及溶解氧(DO)的相关性.结果表明,PARAFAC模型识别出长江重庆段DOM由2类6个荧光组分组成,即类腐殖质荧光组分C1(350/422 nm)、C4(245,305/395 nm)、C5(260,340/420 nm)、C6(260/480 nm)及类蛋白荧光组分C2(275/300 nm)、C3(227,278/329 nm).在DOM来源组成中,陆源的类腐殖质含量占62.56%,类蛋白物质含量占31.31%.类腐殖质组分的荧光强度同DOC的含量存在明显的线性正相关(r=0.73),类蛋白组分的荧光强度同DO的含量呈明显的线性负相关(r=0.80).EEMs-PARAFAC不仅可以表征长江重庆段DOM的光谱特征,示踪长江重庆段的有机污染程度,还可以为三峡库区水体保护提供依据.     

化学洗脱法去除生物过滤塔中菌体的研究

研究生物量控制技术对于提高生物过滤法处理VOCs气体的长期运行性能具有重要意义.用4套平行的生物过滤塔处理甲苯气体,考察了NaOH溶液对生物过滤塔中菌体的去除效果及其对过滤塔去除甲苯性能的影响.NaOH循环洗脱的试验结果表明,在0.2%～0.8%的NaOH浓度范围内,适宜的循环洗脱持续时间为2～3 h.在4个试验浓度下,浓度为0.4%的NaOH溶液对菌体的去除效果最佳,此时菌体洗脱以脱附作用为主.对不同化学洗脱方式进行综合比较发现,循环洗脱是较为适宜的化学洗脱方式.对过滤塔甲苯去除性能的监测表明,洗脱后过滤塔的去除性能可在3～4 d内恢复,不同浓度NaOH对去除性能的影响差别不大.     

峨边县土壤环境质量现状与优质安全农产品基地建设浅析

通过对峨边县几种主要农业土壤中重金属含量的监测和结果评价,分析出了峨边县土壤环境质量的现状,为峨边县发展无公害农产品和绿色食品生产基地提出建议。     

云南省水资源承载力评价与时空分布特征研究

水资源承载力是衡量一个地区社会经济发展潜力的重要方面。选取水资源、社会、经济和生态环境评价指标,构建了区域水资源承载力综合评价模型;通过分析经济压力指数、人口压力指数、承载压力指数及协调指数,对云南省水资源的承载能力和利用状况进行评价,并探讨了其时空分布特征。结果表明：（1）云南省水资源与生产力布局、人口分布不协调,滇中地区经济相对发达,人口数量大,而水资源量较少,多属于轻度超载或濒临超载地区;（2）随着人口增加和经济发展,区域内水资源承载压力逐渐增大,如滇东北地区的昭通市由水资源承载适宜地区转变为水资源濒临超载地区,而滇西部地区的德宏市水资源承载力由承载盈余变为承载适宜;（3）从整体上看,目前云南省水资源利用率较低,工程性缺水问题较为突出。未来水利工程尤其是滇中引水等的建设及运行,将有效缓解水资源超载问题     

Enhanced coagulation of ferric chloride aided by tannic acid for phosphorus removal from wastewater

Phosphorus removal from wastewater is of great importance. In the present study, ferric chloride was selected as the coagulant, and tannic acid (TA), a natural polymer, as the coagulant aid to develop an effective coagulation process with the emphasis of phosphorus recovery from different types of wastewater. The results showed that TA can accelerate the settling speed by forming flocs with large size, reduce the residual Fe(III) to eliminate the yellow color caused by Fe(III), and slightly increase the phosphorus removal efficiency. The precipitate formed by TA-aided coagulation showed the advantage of releasing phosphorus faster than ferric phosphate, indicating the possibility of phosphorus recovery from wastewater as slow release fertilizer. To further understand the structural characteristics of the precipitate, analytical techniques such as Raman spectroscopy, X-ray photoelectron spectroscopy and matrix-assisted laser desorption ionization-time of flight mass spectrometry were employed. The analytical results indicated that TA–Fe–P complex was formed during the coagulation/flocculation processes. Solid phase in the precipitate consisted of TA–Fe–P complex, Fe–TA complex and/or ferric hydroxyphosphate.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in soils and sediments from Daliao River Basin, China

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) were analyzed in surface sediments and top soils collected from 30 sites in Daliao River Basin. The concentrations of PCDD/F ranged from 0.28 to 29.01 ng TEQ kg(-1) dw (mean value, 7.45 ng TEQ kg(-1)dw) in sediments, and from 0.31 to 53.05 ng TEQ kg(-1)dw (mean value, 7.00 ng TEQ kg(-1)dw) in soils. PCDD/F pollution in sediments from the mid- and downstream sections of Hun River was found to be relatively heavy, and the levels of PCDD/F contamination in paddy soils were generally higher than those of upland soils. Using multivariate statistical analysis, the PCDD/F homologue and congener profiles of all soil and sediment samples were compared with those of suspected PCDD/F sources. The results showed that, PCDD/F contamination in most sediments of Hun River should mainly originated from the production of organochlorine chemicals, while metal smelting was the important potential source of PCDD/F in the drainage area of Taizi River. PCDD/F contamination in paddy soils should be simultaneously attributed to the polluted water irrigation and the organochlorine pesticide application.     

铁对四尾栅藻生长的影响

采用实验室模拟培养的方法,分别测定了初始Fe3 摩尔浓度为0、10、100、1 000、10 000、30 000 nmol/L时的四尾栅藻生物量、叶绿素a浓度,同时利用扫描电镜观察了初始Fe3 摩尔浓度为0、10 000、30 000 nmol/L时的四尾栅藻细胞的表面结构.结果表明,初始Fe3 摩尔浓度在0、10 nmol/L时,四尾栅藻的生长受到抑制;初始Fe3 摩尔浓度超过10 000 nmol/L时,四尾栅藻生长受到的促进作用仍存在,但不显著;初始Fe3 摩尔浓度增加至30 000 nmol/L时,四尾栅藻生长未受到抑制;四尾栅藻叶绿素a浓度随时间的变化与四尾栅藻生长曲线相似,随初始Fe3 浓度的增加而增加;不同初始Fe3 浓度对四尾栅藻细胞表面结构影响不明显.