共查询到20条相似文献，搜索用时 93 毫秒
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以双氰胺、甲醛为主要原料合成了阳离子高效有机絮凝剂双氰胺一甲醛脱色剂,并与聚合氯化铝（PAC）以及聚丙烯酰胺（PAM）配合使用,处理模拟染料废水．通过考察脱色剂用量、絮凝剂的投加顺序、PAC用量以及pH值这几个方面对脱色率的影响,并通过正交试验寻求最佳试验条件．研究结果表明,影响脱色效果的主次因素依次为：脱色剂用量、pH值、聚合氯化铝用量．脱色剂用量为1．5—2．0mL／L,染料废水的pH值为7．5—9．5,PAC用量为50—90mg／L时,模拟染料废水的脱色率均可达92％以上,COD的去除率因染料种类的不同而存在一定的差异。不过也都在84％以上． 相似文献
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钱玲 《常熟理工学院学报》2013,(2):57-60
垃圾渗滤液是一种成分复杂、有机物浓度高、污染严重的废水.本文针对江苏镇江某垃圾填埋场的渗滤液,探索PAC和PFS两种混凝药剂进行混凝对该废液的处理效果,实验研究发现:在渗滤液酸碱平衡体系被打破的点(pH为4.5左右和11.5左右时),混凝效果最好;PFS的混凝效果要优于PAC的混凝效果;在PFS投加量为2200mg/L,PAM投加量为40mg/L时,可获得50%左右的COD浓度去除率. 相似文献
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为了快速培养出能同时去除生活污水中化学需氧量(COD)和氮的微氧颗粒污泥,采用膨胀颗粒污泥床(EGSB)反应器接种污水处理厂剩余污泥,研究了微氧颗粒污泥的培养过程以及稳定运行条件下供氧量对处理效果和污泥性能的影响。结果表明,水力停留时间(HRT)为6h,微氧颗粒污泥的成功培养仅需1个月;供氧速率在2.83.2gO2/d,COD,NH3-N和总氮(TN)的去除率最高分别可达91%,85%和81%,脱氮速率达1.7gN/d,出水水质最佳;成熟的微氧颗粒污泥粒径集中在0.453.2gO2/d,COD,NH3-N和总氮(TN)的去除率最高分别可达91%,85%和81%,脱氮速率达1.7gN/d,出水水质最佳;成熟的微氧颗粒污泥粒径集中在0.452mm,当供氧速率低于2.3gO2/d时,颗粒污泥结构致密,供氧速率在2.32mm,当供氧速率低于2.3gO2/d时,颗粒污泥结构致密,供氧速率在2.33.2gO2/d时,污泥性能稳定,供氧速率增加到3.2gO2/d时,污泥沉降性能下降,并出现颗粒解体和丝状菌生长优势。 相似文献
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综述了好氧颗粒污泥颗粒化研究进展及好氧颗粒污泥处理技术在废水生物处理中的应用．着重讨论了好氧颗粒污泥的形成机理,分析了好氧颗粒污泥培养过程中的影响因素,以及好氧颗粒污泥技术在废水生物处理和工程应用中的研究进展．好氧颗粒污泥的形成、发展和成熟过程可分为5个不同阶段,污泥颗粒化过程取决于基质组成与负荷、适当的水力选择压和工艺操作参数等因素． 相似文献
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壳聚糖改性硅藻土处理实验室有机废液 总被引：6，自引：0，他引：6
高校化学实验室产生的有机废液成分复杂,毒性大,直接排入下水道对环境造成污染.将非金属矿物--硅藻土经300℃活化处理后,与90%脱乙酰度壳聚糖的0.5%醋酸溶液按1:1.2质量比混合,制成壳聚糖改性硅藻土吸附剂,用于处理实验室有机废液.通过正交试验确定吸附有机废液的静态最佳操作条件是:壳聚糖与硅藻土质量比为1:20,吸附剂用量为30 g/L,废液中COD浓度为1000 mg/L,pH值为6,吸附平衡时间为30 min,有机废液经处理后COD去除率为72%.动态吸附实验结果表明:COD浓度不大于1000 mg/L的实验室有机废液,经两级处理,流经硅藻土-壳聚糖颗粒吸附柱后,流出液COD的残留量小于100 mg/L,符合国家排放标准. 相似文献
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王怀宇 《邢台职业技术学院学报》2008,25(3):64-66
本文以PAC／PAM复合絮凝剂处理洗毛废水进行小试。研究表明PAC与废水形成（20-30）μm的小絮体,PAM主要起到连接小絮体形成矾花。自由絮凝时,当COD：PAC：PAM为8．43：1：0．013、PH为5、水温为45℃时,COD、SS去除率分别达到97％、92％。 相似文献
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朱文菲 《泰州职业技术学院学报》2009,9(1)
实验采用激光微米粒度测试仪在线测定混凝处理时絮粒的成长过程,并初步探讨了搅拌槽内三种絮凝剂Pac、PFC、PAM以及复配的絮凝剂PAC与PAM、PFC与PAM处理长江水时的絮凝动力学.研究结果表明,在絮凝初期絮团的生长过程可以用絮凝动力学方程lnN/N0=-kt描述.其中,k值为初始速率常数.k值越大,絮凝速度越快,最终的混凝效果越好;反之,k值越小,则絮凝速度越慢,最终的混凝效果越差.在实际应用中可以通过k值的大小来确定混凝时所需要的最佳条件. 相似文献
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采用MTT法等方法研究壳聚糖碘液对白色念珠菌的抑制作用,结果得到壳聚糖碘液的50 %抑菌浓度(MIC50)和最小菌浓度(MBC)分别为250 mg/L和600 mg/L.实验结果表明壳聚糖碘液具有良好的杀白色念珠菌效果. 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献