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1.
水力吸泥-离心脱水疏浚过程的环境特征分析   总被引:2,自引:0,他引:2  
城市建成区的中、小河道底泥污染特征为重金属和有机污染富集于浮动性表层底泥中,以水力吸泥-离心脱水组合疏浚工艺用于清理此种底泥的环境特征分析,采用现场疏浚操作时,同步进行相关物流与水体采样监测的方法进行,结果显示:水力吸泥的疏浚泥浆其污染物组成与原状底泥一致;泥浆经离心脱水后,805以上的颗粒物可回收于含固率谪于70%的脱水泥饼中;脱水泥饼颗粒物的污染程度显著低于原状底泥;离心上清液浓缩了底泥中的各种污染物,其直接排入河道是造成水力疏浚过程水体水质损害的最主要因素;离心上清液可经混凝-澄清-过滤过程有效地净化,研究证明该组合疏浚工艺配套离心上清液澄清后,可符合相关类型受污梁底泥疏浚的环境保护要求,且大部分疏浚物流可就地利用于浸地或农田。  相似文献   

2.
ICEAS反应器处理城市污水的试验研究   总被引:2,自引:0,他引:2  
对ICEAS工艺的处理效果进行了研究,结果表明,ICEAS既能去除污水中的有机物,还能达到脱氮除磷的效果,出水COD浓度为15 2~42 2mg·L-1,COD总去除率可达80%~88%;出水BOD5浓度为5 12~16 90mg·L-1,总去除率可达85%~93%;出水氨氮浓度为4 5~7 5mg·L-1,总去除率为60%~70%,磷的去除率为60%~75%.  相似文献   

3.
综述了混凝—微滤在饮用水处理和工业废水处理中的应用情况,分析了膜污染的特征和膜清洗的方法,讨论了粒度分维在混凝—微滤工艺中的研究进展。  相似文献   

4.
设计厌氧消化-化学混凝-SNAD联合工艺对海产品加工中的高浓泡药间废水进行处理.厌氧消化对废水中COD去除率最高可达94.37%,平均可达89.77%,有机氮与聚合磷转化为NH+4-N、PO3-4-P,浓度分别达总氮、总磷浓度的85%~90%;20 g·L-1的聚合氯化铝可实现总磷浓度1 000 mg·L-1废水的总磷去除率99.83%,出水磷浓度为1.70 mg·L-1.SNAD系统中控制温度为32~35 ℃,以空气流量10~15 mL·min-1间歇曝气(ton/toff=10 min/5 min)控制DO为0.1 mg·L-1左右,pH为7.5~8.0,HRT为24 h,运行稳定时最高可处理总氮浓度为655 mg·L-1的废水,总氮、COD去除率分别为72.71%、56.70%.高通量测序结果表明反应器内形成了SNAD系统,AOB、AnAOB和DNB含量分别为2.72%、2.09%、1.46%.  相似文献   

5.
利用从芽途径快速繁殖蝴蝶兰的研究   总被引:11,自引:0,他引:11  
报道了利用从生芽途径快速繁殖蝴蝶兰的研究结果,试验表明:培养基MS+BA1.0mg·L-1+NAA0.05mg·L-1+GA30.5mg·L-1能够诱导花梗休眠芽转化为营养芽.花梗芽在培养基MS+BA5.0mg·L-1+NAA0.05mg·L-1上能够诱导产生丛生芽.在丛生芽增殖阶段,以BA12.5mg·L-1+NAA0.05mg·L-1的增殖效果最好.BA、KT、ZT均能诱导产生"丛生芽",其中以ZT和BA的诱导效果最好.另外,在增殖阶段,外植体采用双芽接较单芽接的增殖效果好.在生根阶段以1 2MS+NAA0.5mg·L-1+w=0.2%的活性炭+φ=10%的椰子水的生根效果较佳,生根率可达100%,且植株生长健壮.试管苗移栽在水苔上的成活率较高,成活率达96 7%.  相似文献   

6.
催化氧化 -混凝组合工艺处理造纸黄液研究(I)   总被引:1,自引:0,他引:1  
草浆造纸黑液经酸析分离木质素后 ,废水中的 COD仍高达 80 0 0~ 1 2 0 0 0 mg·L- 1 .以生化过程为末端处理工艺时 ,要达到一级、二级和三级排放标准 ,其中有机物的去除率应分别为 60 .0 %、3 0 .0 %及0 .0 % .最佳处理方案为 Fenton试剂 +Ca(OH) 2 混凝组合工艺 ,此时双氧水的加入量为 0 .75 g· L- 1 .由于该废水中甘露醇等对羟基自由基的猝灭作用 ,从而使得双氧水的氧化效率很低 .  相似文献   

7.
预处理工艺控制膜污染试验及其机理分析   总被引:1,自引:0,他引:1  
探讨了3种不同预处理技术对延缓超滤膜污染的作用.试验表明,前臭氧+在线混凝+超滤(工艺1)、前臭氧+超滤(工艺2)、前臭氧+预氯化+超滤(工艺3)3种工艺超滤膜过滤的临界通量分别为86.5,59.8,68.1L·(m2·h)-1.其中工艺1临界通量最大,且其稳定运行的时间最长(约190h),能够在一定程度上控制膜污染,这主要是因为水中的有机污染物质通过"矾花"被吸附到胶体类颗粒物上,通过膜筛分截留,减缓了有机污染物质与膜表面的接触与相互作用.控制、缓解膜污染方面,工艺3效果最好,其原因是在NaClO作用下有机物分子特征改变,一方面降低膜的通量负荷,改变其亲疏水性,另一方面NaClO使得滤饼层的电负性增大,过滤截留物和溶解性有机物较易在水力冲洗中被冲掉,跨膜压差得到很好恢复.通过扫描电镜发现,超滤膜表面附着一层滤饼层,滤饼层较疏松,而膜孔已被污染物堵塞;红外光谱研究发现,超滤膜经过氧化预处理和化学清洗,膜表面的某些基团被氧化,膜表面特性被改变.  相似文献   

8.
亚硝酸盐反硝化脱氮   总被引:3,自引:0,他引:3  
利用单纯形优化法获得了从亚硝酸盐反硝化脱氮的工艺条件为 :pH8.3,温度 2 8℃ ,C/N比1.6 ,泥 /水比为 0 .32 ,在此条件下能够稳定、高效地处理高浓度的含氮废水 (NO2 - -N〈35 0mg·L- 1) ,其脱氮速率高达 16 2mg·L- 1·h- 1,脱氮率 >99%。  相似文献   

9.
黄浦江原水的生产性试验研究   总被引:1,自引:0,他引:1  
采用杨树浦水厂新建的组合工艺(预臭氧氧化→高密度澄清池→砂滤→后臭氧氧化→生物活性炭)处理有机物和氨氮含量较高的黄浦江原水,研究水力负荷对该工艺处理黄浦江原水效果的影响,并分析该工艺在最佳水力负荷下长期运行时处理效果的变化情况.结果表明:该工艺能够长期稳定运行,出水水质达到国家饮用水标准,适宜作为微污染水源水的有效处理工艺;在设计水力负荷范围内,适当增加处理水量可更好地发挥该工艺的效用,且对有机污染物的去除率不会有明显降低;杨树浦水厂调试运转中该工艺流程的最佳水力负荷定为1 200m3/h.  相似文献   

10.
试验针对混凝-沉淀-再絮凝-超滤组合工艺对水中有机物的强化去除效果和膜污染的控制效能展开研究.结果表明:再絮凝-超滤组合工艺对有机物的单元去除率可达26%,远高于传统的超滤膜组合工艺;同时,该工艺对有机物的去除主要体现在对中性亲水性有机物和分子量分别大于10kDa和小于1kDa的有机物方面,与传统超滤膜工艺有较大区别.当采用硫酸铝作为再絮凝剂,其投加量达到6.0mg/L时,统一膜污染指数(UMFI)达到最小(0.061 3m2/L),表明再絮凝预处理工艺能够更为有效地控制超滤膜的污染.Zeta电位的测试结果表明:再絮凝过程可使沉后水中残余的胶体Zeta电位降至0,从而减轻了膜表面对污染物的吸附;而再絮凝过程中微小絮体的形成也使得沉后水中颗粒物粒径增大,防止了膜孔堵塞现象的发生并使得形成的滤饼层结构较为松散,从而取得良好的超滤膜污染控制效果.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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