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1.
三角帆蚌对精养鱼塘水体主要水质因子的调控   总被引:8,自引:0,他引:8  
利用三角帆蚌作为调控水质的生物过滤材料,建立蚌单养与鱼蚌混养的两种生物调控系统并与当地传统的精养鱼塘养殖系统模式作同步比较,分析了三角帆蚌对水体的主要水质因子变化及鱼产量的影响.养殖6个月后,鱼蚌混养生物调控系统水质优良,其中,鱼蚌混养水体中单胞藻总数为340万个/ml,蓝藻与绿藻数量之比(蓝绿比)为1:1.8,DO值为7.5mg/L,氨氮为2.42mg/L,总氮为2.76mg/L,磷酸磷为0.06mg/L,总磷为0.11mg/L,COD为36.0mg/L,悬浮物为30.2mg/L,蚌成活率为75.0%,鱼类成活率为71.0%.蚌单养的水体中单胞藻总数为86万个/mL,蓝绿比为2.1:1,DO值为7.5 mg/L,氨氮为2.00mg/L,总氮为2.14 mg/L,磷酸磷为0.04mg/L,总磷为0.07 mg/L,COD为20.0 mg/L,悬浮物为8.0 mg/L,蚌成活率为85.0%.但其蓝绿比则表现为蓝藻爆发型.作为无蚌对照组的养鱼系统中,水质逐渐恶化,鱼类生长受到抑制,易发生病害,鱼类成活率仅为58.8%.研究结果表明:鱼蚌混养系统可有效地改良水质,提高鱼类的存活率.  相似文献   

2.
报道了自主开发的内循环式A/O/IAT-IAT同步脱氮除磷工艺的运行特性.试验以模拟废水为处理对象,对该工艺在三种不同工况下的运行效果进行比较.试验结果显示,在进水COD、BOD5、NH4^+-N、PO4^3--P浓度分别为629.7~821.6mg/L、360~580ms/L、36.9~59.8mg/L、6.0~7.6mg/L,总水力停留时间为20hr,污泥龄为3.5d,污泥回流比为200%的条件下,COD、BOD5、NH4^+-N和PO4^3--P去除率分别为97%~99%、99%、89%~99%和89%~98%,出水水质达到了国家城镇污水处理厂污染物排放一级A标准(GB18918—2002).在各项运行控制条件中,HRT和SRT是影响该工艺运行效果的主要因素.  相似文献   

3.
李岩 《科技信息》2009,(14):263-263
1.工程概述 朝阳市污水处理厂是服务于朝阳市城区工业、生活污水排放的唯一的污水处理设施。工程于2006年11月破土动工,至2008年6月建成并投入设备调试及试运行.其平面规划按规范进行,绿化率为47%,环形道路,污水与污泥处理兼顾,常规分析化验仪器完备,是一个完整的污水处理系统。工程设计进水水质为:COD 480mg/L,BOD 5210mg/L,SS 250mg/L,NH3-N 30mg/L。磷酸盐(以P计)4.0mg/L.设计出水水质执行《城镇污水处理厂污染物排放标准》(GB18918-2002)一级标准的B标准:COD60mg/L,BOD520mg/L,SS20mg/L,NH3-N15mg/L,磷酸盐(以P计)1.5mg/L.  相似文献   

4.
采用水解酸化——SBR工艺处理焦化废水,进水水质为COD1 100mg/L,NH3-N210mg/L时,水解酸化4h,SBR曝气8h,搅拌3h,再曝气4h,沉降1.5h,出水COD68.2mg/L,NH3-N 51.2mg/L,去除率分别达到93.8%,75.6%.  相似文献   

5.
为探讨有效微生物( EM)对蟹塘水质和螃蟹成活率的改善作用,在南京市高淳区螃蟹文化园开展了EM应用试验研究。试验结果表明:在中华绒螯蟹养殖过程中投加EM,能有效降低水体中污染物的质量浓度,提高螃蟹成活率,但EM投加质量浓度不宜过大。当籽( EM)=1.5 mg/L时,蟹塘水体中NH+4-N、NO-2-N、COD和TP的质量浓度比不投加EM的对照塘降低12.7%~29.2%,螃蟹成活率提高2.4%;籽( EM)=6.0 mg/L时,NH+4-N、COD和TP的质量浓度分别降低1.1%、14.4%、0.03%,而NO-2-N 升高15.6%,螃蟹成活率升高1.0%。由此可见,当 EM 投加质量浓度过高(6.0 mg/L)时,水质指标及成活率改善效果不如EM投加质量浓度较低时(1.5 mg/L),且会引起NO-2-N的累积。  相似文献   

6.
采用好氧颗粒污泥膜生物反应器处理畜禽废水,分别对COD、NH4^+-N、NO2^--N、NO3^--N的去除效果和对膜通量的影响进行了研究。结果表明:在水力停留时间(HRT)为8h,进水COD浓度为600mg/L,NH4^+-N浓度为40mg/L的条件下,出水COD、NH4^+-N的浓度分别为46.6和4.8mg/L。NO2^--N和NO3^--N的去除率也可达90%以上。并且好氧颗粒污泥的加入减缓了膜的污染。  相似文献   

7.
通过对黄河上游多卡寺段地表水质量的调查与监测,得出监测结果:pH8.22,溶解氧(DO)7.5mg/L,悬浮物199.2mg/L,化学需氧量(COD)12mg/L,氯化物114.1mg/L,硫酸盐247.8mg/L,总硬度126.6mg/L,矿化度427.9mg/L,钙镁总量67.4mg/L,锌0.03mg/L。结果表明:黄河上游多卡寺段水体水质均未超过于《地面水环境质量标准》(GB3838-2002)的一级水标准,水体未受到污染,水质良好。  相似文献   

8.
菹草-伊乐藻群落对富营养化水体水质的净化效果   总被引:2,自引:0,他引:2  
在富营养化湖泊内的围隔中,引种菹草、伊乐藻,分别构建菹草-伊乐藻群落(围区A)与单-菹草群落(围区B),跟踪观测水草恢复生长情况,调查两类群落对水体水质的净化作用,结果发现:菹草-伊乐藻群落不仅能在春季保持对水体营养盐较高的去除效果,并能在春末初夏时有效缓解菹草死亡给水质带来的不利影响;在菹草旺盛生长期(阶段I),与对照区(无水生高等植物)相比,菹草-伊乐藻群落对TN、NH4^+-N、TP、Chla的去除率达50.7%、83,2%、32.0%、38.3%,单一菹草群落对TN、NH4^+-N、TP、Chla的去除率也达到47.3%、72.5%、32.4%、45.2%;而在菹草开始衰亡后这一时期(阶段Ⅱ)菹草-伊乐藻群落对TN、NH4^+-N、TP的去除率分别为47.1%、69.4%、11.2%,而围区B内TN、NH4^+-N浓度则与对照区相比差异不显著(P〉0.05,N=9),TP浓度甚至上升了24.3%,  相似文献   

9.
SBR工艺用于生活污水除磷脱氮的试验研究   总被引:3,自引:0,他引:3  
采用SBR工艺处理有机物含量低、氨氮含量高的城市污水,经过反复试验研究发现,该工艺对生活污水中氮、磷等污染物具有良好的去除效果。试验结果表明,采用试验水样平均进水水质为CODCr=197mg/L;BOD5=95mg/L;SS=203mg/L;NH4^ -N=63mg/L;PO4^-3=1.3mg/L,各项污染物的平均去除率为:CODCr80%,BOD583%,NH4^ -N75%,TP61%,处理后出水水质均能达到国家规定的排放标准(GB8978-1996),并提出了该工艺处理低碳高氮城市污水的最佳工艺条件。  相似文献   

10.
污水高效处理和资源化的固定化微生物技术研究   总被引:18,自引:3,他引:18  
采用功能化大孔载体FPUFS并以载体结合法固定化高效微生物菌群B350,所得固定化B350置于曝气池中构成一个有效容积为1500L的固定化微生物-曝气生物滤池(I-BAF)污水处理系统。通过对进水与出水氨氮(NH4^ -N)、挥发酚及化学耗氧量(COD)的检测分析,以煤气厂焦化污水的现场连续运转处理为例对I-BAF系统的处理效果进行了系统研究。研究了I-BAF系统对实际工业污水的处理性能,得出了I-BAF系统的去除COD、挥发酚和氨氮的效果曲线。结果表明:I-BAF系统对煤气厂焦化污水具有较好的处理效果,在进水COD为3450mg/L,NH4^ -N为451mg/L,挥发酚177mg/L,色度120倍时,处理出水COD为57.5mg/L,NH4^ -N.285mg/L,挥发酚0.498mg/L,色度为12。这一处理效果是现行其他方法难以达到的,因此本研究对污水的高效处理和资源化具有重要的意义。  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  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.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

16.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

17.
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   

18.
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   

19.
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   

20.
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   

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