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611.
以不同碱化度(B)的聚合氯化铝(PAC)和不同粘度的壳聚糖为原料制备出一系列PAC-chitosan复合絮凝剂。采用Al-Ferron逐时络合比色法研究了PAC-chitosan复合絮凝剂中铝的形态分布,探讨了PAC的B值、壳聚糖的含量(C)和粘度(η)对复合絮凝剂中铝的形态分布的影响。结果表明:壳聚糖与PAC之间发生了一定的相互作用,通过试验结果推断出当B=1.5,壳聚糖粘度η=800 Pa·s,C=0.6 mg/mL絮凝效果最佳。并用某造纸废水进行了烧杯絮凝试验。絮凝试验结果与推断结果相一致。 相似文献
612.
613.
耐热乳杆菌的分离及在食物垃圾乳酸发酵中的应用 总被引:1,自引:0,他引:1
食物垃圾在我国城市生活垃圾中占有较大比重.发酵食物垃圾生产乳酸是实现其资源化的有效方法.从厌氧发酵的食物垃圾中分离到一株耐热乳酸菌TY50,根据形态、生理生化特征和16S rDNA序列,确定该菌株属于乳杆菌属的干酪乳杆菌组群(Lactobacillus casei group),其最高生长温度为52℃.TY50发酵食物垃圾生产乳酸的最佳同液比为1:12,最适温度为45 ℃.在pH 5.5~6.0条件下,发酵食物垃圾产生36.29 g/L的乳酸,乳酸体积产牢和转化率(乳峻/垃圾干重)分别达到1.01 g/(L·h)和0.44. 相似文献
614.
以粉煤厌为原料采用两步法合成了2种单一沸石矿物种的NaA和NaX型沸石,并对产物的结构和性能进行了详细表征.2种沸石产物的吸附性能比较结果表明,NaA型沸石优于NaX型沸石.在静态吸附条件下,研究了NaA型沸石吸附水溶液中Cr(Ⅵ)的相关参数(溶液pH值、吸附温度和吸附时间),并用Langmuir和Freundlich等温吸附线对吸附结果进行拟和.结果表明:Cr(Ⅵ)的吸附行为符合Langmuir方程;饱和吸附量为47.78 mg/g.NaA型沸石对Cr(Ⅵ)的吸附是物理和化学吸附两种行为共同作用的结果. 相似文献
615.
Assessment of population exposure to particulate matter pollution in Chongqing, China 总被引:1,自引:0,他引:1
Wang S Zhao Y Chen G Wang F Aunan K Hao J 《Environmental pollution (Barking, Essex : 1987)》2008,153(1):247-256
To determine the population exposure to PM(10) in Chongqing, China, we developed an indirect model by combining information on the time activity patterns of various demographic subgroups with estimates of the PM(10) concentrations in different microenvironments (MEs). The spatial and temporal variations of the exposure to PM(10) were illustrated in a geographical information system (GIS). The population weighted exposure (PWE) for the entire population was 229, 155 and 211 microg/m(3), respectively, in winter, summer and as the annual average. Indoor PM(10) level at home was the largest contributor to the PWE, especially for the rural areas where high pollution levels were found due to solid fuels burning. Elder people had higher PM(10) exposure than adults and youth, due to more time spent in indoor MEs. The highest health risk due to particulate was found in the city zone and northeast regions, suggesting that pollution abatement should be prioritized in these areas. 相似文献
616.
A green-house study was conducted in late 2005 to investigate the aging behavior of p,p'-DDE in two types of soil, Hydragric Anthrosols (An) and Hydragric Acrisols (Ac), according to the World Reference Base (WRB) [FAO/ISRIC/ISSS. 1998. World reference base for soil resources. World soil resources reports, Rome. p. 87]. Paddy rice and dry rice were grown in submerged paddy soils and non-submerged upland soils, respectively. The concentration of extractable p,p'-DDE in fresh DDE-spiked soils was 746.2ngg(-1). During the first few weeks of the experiment, the extractability of p,p'-DDE became increasingly low as the aging period prolonged. However, certain amount of p,p'-DDE that had been captured by soil minerals and organic matter (OM) could be released and became extractable in the later period. The extractability of p,p'-DDE in submerged soils was significantly lower than that in non-submerged soil, because flooding could increase the binding of pollutants to soil particles. The plantation of both dry rice and paddy rice slowed down the aging process of p,p'-DDE. After one month's growth of rice, p,p'-DDE bound to soil particles was released and became extractable. The OM and silt content of An are higher than that of Ac, resulting in more bound residues and relative lower extractability of p,p'-DDE in An. In addition, the extractability of p,p'-DDE could be reduced by the addition of rice straw to soils. 相似文献
617.
Xu Y Wu Z Yu B Peng X Yu G Wei Z Wang G Li R 《Environmental pollution (Barking, Essex : 1987)》2008,156(1):162-167
It is well known that several morphospecies of Microcystis, such as Microcystis aeruginosa (Kützing) Lemmermann and Microcystis viridis (A. Brown) Lemmermann can produce hepatotoxic microcystins. However, previous studies gave contradictory conclusions about microcystin production of Microcystis wesenbergii (Komárek) Komárek. In the present study, ten Microcystis morphospecies were identified in waterblooms of seven Chinese waterbodies, and Microcystis wesenbergii was shown as the dominant species in these waters. More than 250 single colonies of M. wesenbergii were chosen, under morphological identification, to examine whether M. wesenbergii produce hepatotoxic microcystin by using multiplex PCR for molecular detection of a region (mcyA) of microcystin synthesis genes, and chemical analyses of microcystin content by ELISA and HPLC for 21 isolated strains of M. wesenbergii from these waters were also performed. Both molecular and chemical methods demonstrated that M. wesenbergii from Chinese waters did not produce microcystin. 相似文献
618.
619.
620.
反硝化除磷菌驯化富集方式的探讨 总被引:3,自引:0,他引:3
以SBR反应器分别采用一段式和二段式培养方法对反硝化除磷菌进行了驯化富集.结果表明,一段式和二段式培养方法驯化完成后的活性污泥沉降性能均较好,污泥体积指数(SVI)分别约为60、50 mL/g,反硝化除磷菌占聚磷菌的比例达到了77%和71%.两种培养方法下反硝化除磷菌PO3-4-P去除率和脱氮率分别达到了97%和95%以上,缺氧结束时水中PO3-4-P质量浓度小于1 mg/L.驯化完成后污泥的含磷率最高达到了3.7%(质量分数).因此,采用一段式或二段式驯化方法均能实现反硝化除磷菌的有效富集. 相似文献