去藻247处理滇池藻类水的应用研究

滇池现属重富营养化水体。本文采用国外一种新型除藻剂去藻247用于处理滇池水样。投加四个不同浓度的除藻剂,通过监测叶绿素a、总磷的变化,得出去藻247在处理滇池水样时对叶绿素和总磷有较好的去除效果,其中当投加量为4mg／L时效果最佳,对叶绿素和总磷的去除率分别达到：56．7％和38．9％。     

不同生长阶段的水华鱼腥藻模拟配水混凝处理效果

以添加了不同生长阶段水华鱼腥藻培养液的引黄水库水为研究对象,文中对比分析了聚合氯化铝(PAC)、氯化铁(FeCl3)、硫酸铝[Al2(SO4)3]对藻细胞和有机物的混凝去除效果,考察了原水pH对混凝效果的影响,并初步探讨了消毒副产物前体物的去除效果.结果表明:PAC对高藻水的混凝处理效果最好,对藻细胞、UV254和DO...     

天然黏土与PAC联用对含藻水体的处理效果研究

水环境的质量会直接影响社会经济的可持续发展，絮凝除藻是一种常见的化学除藻方法。天然絮凝剂因其来源广泛、危害较小等特点逐渐受到关注，本次研究选择天然黏土，并将它们与PAC联用以对含藻水体进行处理。结果表明：PAC对含藻水体具有显著的去除效果，但是PAC投加量过高时蓝藻去除率会呈下降趋势；高岭土和沸石与PAC的联用有利于蓝藻的去除，它们能够发挥助凝的作用，其中预先投加高岭土的效果更好，250目(粒径0.065 mm)沸石的去除效率更高。此外，水体pH值会显著影响黏土与PAC对含藻水体的去除效果。     

富营养化水体的PMSO强化聚合氯化铝絮凝处理工艺

针对常规混凝药剂对含藻水体处理效率低的问题,本试验利用单过硫酸氢钾复合盐为主要成分的"水王子"(PMSO)强化聚合氯化铝(PAC)絮凝处理含藻水体,考察其对含藻水体中藻类和高锰酸钾指数(COD_(Mn))的去除效果。结果表明,PMSO复配PAC能有效地提升絮凝过程对藻和COD_(Mn)的去除效能。当PAC的投加量为30 mg/L、PMSO投加量从2 mg/L增加到15 mg/L时,絮凝过程对COD_(Mn)的去除率从23.4%增加到40.2%,藻的去除率从37.0%增加到98.0%;PMSO投加量的增加能够有效地提高絮凝过程对藻类和COD_(Mn)的去除效率;当原水中藻浓度增高时,藻和COD_(Mn)的去除率随之下降。PMSO与PAC总投加量一定,其复配比为1:2时,对藻和COD_(Mn)的去除效率最高。     

超声波抑制滇池水华藻类生长的实验研究

通过叶绿素a浓度及藻体密度变化研究了超声波对滇池水华藻类生长的影响.当超声辐照5min时,藻体密度为时照组的35%,叶绿素a浓度下降了22.1%,表明超声波对滇池水华藻类生长有明显抑制作用.     

气浮除藻工艺的比较及影响因素

该文基于气浮理论,综述了近年来国内外气浮法去除富藻水中藻类工艺,并从混凝过程优化、表面活性剂选择、气泡特性影响和气浮参数优化等几个方面进行了论述,为实际运用提供借鉴。结果表明压力溶气气浮能够很好地完成除藻工作,产生的藻浆能够满足后续处置要求;混凝剂及表面活性剂需结合藻类表面特性来选择。试验中使用的PAC、AS及FC三种混凝剂都能够达到气浮除藻要求,含藻水中污染物去除率均达90%以上。气泡大小及稳定性与溶气方式及无机盐含量相关,气浮参数中pH应根据混凝剂的选择进行调节,处理富藻水时回流比控制在28%~30%为宜。     

新型聚合硅酸氯化铝锌铁絮凝剂的制备及其除藻效果

以水玻璃、工业盐酸、氯化锌、六水三氯化铁、聚合氯化铝为主要原料按照最优配比合成新型聚合硅酸氯化铝锌铁絮凝剂(PAZFSC),用X-射线衍射分析(XRD)和红外光谱分析等方法对该絮凝剂的结构及形貌进行了表征,并研究PAZFSC的工艺参数对傀儡湖冬季含藻水水样絮凝效果影响,且与传统絮凝剂聚合氯化铝(PAC)的絮凝效果进行比较。XRD和红外光谱分析的结果说明,向PAC中引入的铁、锌离子与PAC产生了一定的相互作用,合成了新的物质,提高了絮凝性能。PAZFSC投加量为14 mg/L、pH值在6～8、沉降时间为40 min时,絮凝除藻效果最佳。PAZFSC和PAC分别在投加量为14 mg/L和16 mg/L时,藻类去除率最佳,分别高达98.97%和92.34%,剩余浊度分别为0.8 NTU和1.4 NTU,PAZFSC除藻去浊都优于PAC。絮体的扫描电镜(SEM)表明,PAZFSC絮凝沉降后絮体密实性更好,絮体体积更大,沉降速度更快。     

国外简讯二则

Milwaukee有两家水净化工厂,他们用聚合氯化铝(PAC)代替硫酸铝进行水处理。用PAC处理过的水往往不带有会引起肠道疾病的寄生虫。但是,是用硫酸铝还是PAC进行水处理这一问题引起了争论。因为PAC对管道的腐蚀性较强,且处理速度较慢,PAC的显著特点是价格低廉、处理过程产生少量沉渣。商界有关人士认为:“硫酸铝和PAC的市场竞争力有待观察。     

聚合硅酸铝铁与聚合氯化铝混凝除藻比较研究

针对武汉市莲花湖湖水,采用聚合硅酸铝铁（PAFSC）和聚合氯化铝（PAC）进行混凝实验,比较了两种混凝剂的混凝效果及原水处理前后藻类群落变化。主要结论如下：（1）无论在低投加量还是在高投加量时,PAFSC的除藻、除浊效果均明显优于PAC。聚合硅酸铝铁与聚合氯化铝投加量增加时,两种混凝剂对原水Chl-a和浊度的去除率均呈现先迅速上升荐趋于平缓的过程;（2）PAFSC在去除藻类细胞、浊度方面均优于PAC;（3）PAFSC混凝处理微囊藻为主体的水华原水时,其效果比PAC更好。文章研究后表瞧：PAFSC是一种新型高效混凝剂,其混凝效果赙显优于PAC,当水体以微型藻为主时,可使用PAFSC替代PAC,能提高混凝效果。     

PAC与PAC/PAM对藻类的去除效果研究

采用静态试验研究了混凝工艺对水源水中的细胞内和溶解性(细胞外)微囊藻毒素的去除效果,并初步探讨了其去除机理。试验结果表明,当将原水的pH值调节到5.5~6.0混凝剂投加量定为30 mg/L时,对去除水中的细胞内微囊藻毒素效果明显,此方法的去除率可以达95.3%。PAC/PAM工艺对藻浓度、浊度的去除率都要高于PAC工艺,但对藻毒素的去除效果二者都不显著。但在混凝前投加活性炭,对源水进行预氧化处理,实验结果表明,PAC/PAM+C工艺可以显著地提高对溶解性微囊藻毒素的去除效果,去除率达到50%到60%,主要是因为混凝工艺的强化作用与活性炭结合能够明显地去除弱疏水性有机物。     

On-farm assessment of soil erosion and non-point source pollution in a rain-fed vegetable production system at Dianchi lake’s catchment, southwestern China

Vegetable is important cash crop in Dianchi lake’s catchment, but the non-point source (NPS) pollution from the intensive agricultural production systems is a critical hurdle on the alleviation of serious eutrophication in Dianchi lake. Our objectives were to quantify soil erosion and NPS pollution in rain-fed vegetable production systems at the area. The experiment was a randomized complete factorial design with two plastic mulch treatments (narrow vs. wide plastic mulch) and two rotation treatments (broccoli–zucchini–winter wheat vs. broccoli–zucchini–fallow). The narrow-plastic-mulch system has significantly (P < 0.05) increased runoff and soil loss than wide-plastic-mulch system. Results indicated that plastic mulch substantially accelerated runoff generation and soil erosion at vegetable seedling stages, whereas runoff and soil loss were apparently alleviated in furrow with residue mulch. The sediment transport played a predominant role in soil nitrogen (N) and phosphorus (P) movement by surface runoff. The annual losses of N and P via surface runoff in the vegetable field were ranged from 2.0 to 5.1 kg/ha and 0.3 to 1.1 kg/ha respectively in the three considerably drier rain season, but their losses never exceeded 1 % of the annual fertilizer application. Removal of crop residues was the major causes of N and P export from the soil in the vegetable fields, which exceeded 20 and 8 % of the annual nitrogen and phosphorus fertilizer application respectively. This implicated that inappropriately discarding of the residues would pose serious consequences for water contamination of Dianchi lake. As under appropriate discarding of residues, the wide-plastic-mulch system could improve NPS pollution control and crop production in vegetable field at Dianchi lake’s catchment.     

清洁底泥吹填技术及其在滇池福保湾的应用

浅水湖泊直立沿岸带一般具有水深岸陡、水体污染严重、底泥不利于水生植物生长等特点,生态恢复困难.为了修复受损的浅水湖泊直立沿岸带,结合在滇池福保湾的生态恢复实践和国内外的相关研究,提出采用清洁底泥吹填技术减少水深、改善底质性状、创造多样性地形,为水生植被恢复创造有利的生境条件.清洁底泥吹填技术的工艺流程为,首先对工程区周边进行勘察,确定泥源;接着选用合适的疏挖设备按工程区基底修复设计的要求进行吹填施工;最后在基底修复满足设计要求的前提下实施水生植被种植等工程.该技术在滇池福保湾的应用显示,吹填工程实施2年后,工程区内水生植物得到初步恢复,恢复效果明显好于未采用该技术的恢复区.     

利用滇池水华蓝藻提取生物燃料的方法比较

采用酸热法、有机溶剂法和热裂解法,利用滇池的水华蓝藻进行提取生物燃料的研究,并比较了这些方法的提取效率.滇池的水华蓝藻以微囊藻为主,酸热法和有机溶剂法提取的总酯含量为蓝藻干重的5%～10%,平均为7.21%;热裂解法提取生物燃料的效率最高,所提取的生物能(烃类)含量为蓝藻干重的16.5%～19.3%,平均为18.17%.表明利用水华蓝藻提取生物燃料符合现实水环境治理的需要,具有广阔的应用前景.     

Substituted Syndecan-2-Derived Mimetic Peptides Show Improved Antitumor Activity over the Parent Syndecan-2-Derived Peptide

We previously showed that a synthetic peptide (S2-P) corresponding to a portion of the human syndecan-2 (SDC2) sequence can bind to the pro-domain of matrix metalloproteinase-7 (MMP-7) to inhibit colon cancer activities. Since S2-P had a relatively weak binding affinity for the MMP-7 pro-domain, we herein modified the amino acid sequence of S2-P to improve the anticancer potential. On the basis of the interaction structure of S2-P and MMP-7, four peptides were generated by replacing amino acids near Tyr 51, which is critical for the interaction. The SDC2-mimetic peptides harboring an Ala-to-Asp substitution at the C-terminal side of Tyr 51 (S2-D) or with an Ala-to-Phe substitution at the N-terminal side of Tyr 51 and an Ala-to-Asp substitution at the C-terminal side of Tyr 51 (S2-FE) showed improved interaction affinities for the MMP-7 pro-domain. Compared to S2-P, S2-FE was better able to inhibit the SDC2–MMP-7 interaction, the cell surface localization of MMP-7, the gelatin degradation activity of MMP-7, and the cancer activities (cell migration, invasion, and colony-forming activity) of human HCT116 colon cancer cells in vitro. In vivo, S2-FE inhibited the primary tumor growth and lung metastasis of CT26 mouse colon cancer cells in a xenograft mouse model. Together, these data suggest that S2-FE could be useful therapeutic anticancer peptides for colon cancer.     

新筛选菌种Sphingopyxis sp.USTB-05对微囊藻毒素的生物降解

A promising bacterial strain for the biodegradation of Microcystins (MCs) was isolated from Dianchi lake in China and identified as Sphingopyxis sp. USTB-05 by the analysis of 16s rDNA. Initial MC-RR of 42.3 mg&;#8226;L－1 was completely degraded by USTB-05 within 36 h, which was a relatively high biodegradation rate of MC-RR. With the cell-free extract (CE) of Sphingopyxis sp. USTB-05, MC-RR was biodegraded at a more rapid biodegradation rate compared with its strain, so that initial MC-RR of 42.3 mg&;#8226;L－1 was completely biodegraded within 10 h. During the bio-reaction of MC-RR catalyzed by CE, two intermediate metabolites and a dead-end product of MC-RR were observed on HPLC profiles and all of them had similar scanning profiles in the wavelength from 200 to 300 nm, indicating that the group of Adda in all products of MC-RR remained intact.     

昆明滇池铬形态分布研究

对滇池水中铬形态化合物进行了分离和测定。依据实验数据和滇池环境对滇池中铬形态的迁移转化进行了讨论。为滇池铬污染的研究和治理提供了一定依据。     

Effect of high fat/high erucic acid diet on phosphatidate synthesis and phosphatidate phosphatase in the subcellular fractions of rat heart and liver

Rats of weaning age were fed for a period of 1,3 or 6 weeks either a control diet (laboratory stock diet) or a semisynthetic diet containing 20% by weight of either mustard seed oil (1/3 of the total fatty acids were comprised of erucic acid) or corn oil (2/3 of the total fatty acids consisted of linoleic acid). Mitochondrial and microsomal fractions were isolated from the hearts and livers of these rats, and the rate of acylation ofsn-[U-¹⁴C] glycerol 3-phosphate (P) was examined using palmitoyl-CoA or erucoyl-CoA as the acyl donor. In addition, activities of phosphatidate phosphatase of the mitochondrial, microsomal and soluble fractions were assayed. Studies on the acylation of glycerol 3-P with palmitoyl-CoA demonstrated that feeding of the high fat/high erucic acid diet for 1,3 or 6 weeks significantly increased the rate of formation of monoacylglycerol 3-P by the cardiac subcellular fractions as compared to the control. The rate of formation of diacylglycerol 3-P also increased but to a lesser degree. Feeding the high fat/high linoleic acid diet tended to increase acylation of glycerol 3-P by cardiac subcellular fractions. However, neither high fat diet influenced acyltransferase activities of the hepatic subcellular fractions or phosphatase activities of the cardiac and hepatic fractions. Studies on the acylation of glycerol 3-P with erucoyl-CoA demonstrated that the rate of acylation was ca. 1/10 that measured using palmitoyl-CoA in all experiments; in particular, the formation of diacylglycerol 3-P was extremely slow, suggesting that erucoyl-CoA is an unsuitable substrate for the position-2 of the monoacylglycerol 3-P. The rate of acylation by the cardiac and hepatic subcellular fractions was not influenced by the feeding of the high-fat diets. The rate of glycerol 3-P acylation by both cardiac and hepatic mitochondrial fraction was ca. 2/3 of the rate of acylation by the respective microsomal fraction. In addition, the ratio of monoacyl-to diacylglycerol 3-P synthesized by the mitochondrial fraction was smaller than that by the microsomal fraction. These results suggest that acylation of glycerol 3-P by the mitochondrial cannot be attributed to the action of the contaminating microsomal enzymes.     

昆明滇池旅游度假区水体景观污染特征分析

为了准确分析与评价滇池旅游度假区散落型水体景观的污染现状和空间特征,依照水体采样的基本原则和方法,确定了12个采样点对昆明滇池国家旅游度假区的水体环境进行分析,分析了水样中的pH、溶解氧(DO)、透明度(SD)、总磷(TP)、总氮(TN)、氨氮、化学需氧量、高锰酸钾指数、生化需氧量等评价指标,从而总结出度假区水体景观的污染特征。