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1.
以磷石膏为原料、十六烷基三甲基溴化铵为表面活性剂,采用沉淀法制备羟基磷灰石(HAP),结合FT-IR、XRD、SEM等手段对材料进行表征.以合成的羟基磷灰石作为吸附剂处理含铅废水,探讨p H、HAP的投加量、吸附时间及Pb2+初始浓度等对去除率的影响.优化实验确定最佳的实验条件为:HAP投加量为2 g/L,Pb2+初始浓度为500 mg/L,吸附时间为20 min,其中溶液p H值对Pb2+的吸附基本没有影响.结合SEM/EDX对吸附前后HAP进行分析,结果进一步证实Pb2+被吸附在HAP上.  相似文献   

2.
利用合成纳米锰钾矿去除模拟废水中Cd(Ⅱ),研究不同去除反应条件对废水中镉离子去除率的影响.结果表明:合成纳米锰钾矿对水溶液中Cd2+的去除平衡时间约为2h;在Cd2+质量浓度为50mg·L-1、溶液初始pH=6.50、反应温度25℃、处理剂粒径96~120μm、每升模拟废水中投加2g合成纳米锰钾矿时,平衡后Cd2+去除率为90.6%.当Cd2+质量浓度不高于300 mg·L-1时,吸附等温线近似符合Langmuir模型,合成纳米锰钾矿最大理论吸附量为120.5mg·g-1.纳米锰钾矿对于Cd2+的去除是表面配位吸附、静电吸附、离子交换三种模式共同作用的结果.  相似文献   

3.
利用合成纳米锰钾矿去除模拟废水中Cd (Ⅱ),研究不同去除反应条件对废水中镉离子去除率的影响.结果表明:合成纳米锰钾矿对水溶液中Cd2+的去除平衡时间约为2 h;在Cd2+质量浓度为50 mg · L-1、溶液初始pH=6.50、反应温度25℃、处理剂粒径96~120μm、每升模拟废水中投加2g合成纳米锰钾矿时,平衡后Cd2+去除率为90.6%.当Cd2+质量浓度不高于300 mg·L-1时,吸附等温线近似符合Langmuir模型,合成纳米锰钾矿最大理论吸附量为120.5mg·g-1.纳米锰钾矿对于Cd2+的去除是表面配位吸附、静电吸附、离子交换三种模式共同作用的结果.  相似文献   

4.
研究块状花生壳对Cd2+和Pb2+的吸附特性.考察吸附剂投加量、溶液初始pH、吸附时间和溶液初始浓度等对吸附的影响,在此基础上拟合分析吸附动力学和吸附等温线.结果表明:吸附36h达到平衡,块状花生壳对Cd2+和Pb2+的吸附均符合准二级动力学模型和Langmuir吸附等温线模型.在25℃,Cd2+和Pb2+的初始浓度为100mg/L时,块状花生壳对二者的吸附量分别可达到10.47mg/g和17.37mg/g.  相似文献   

5.
以脱乙酰度为90%壳聚糖为原料,制备膨润土负载壳聚糖复合吸附剂,用于吸附含镉废水溶液中的Cd2+.探讨壳聚糖负载量、pH值、吸附时间、吸附剂加入量、Cd2+初始质量浓度对去除率的影响.结果表明,对于初始质量浓度为10mg/L的含镉模拟废水溶液,在膨润土与壳聚糖质量比为1∶0.03,加入量为8g/L,pH=6,吸附时间为50min的条件下,Cd2+的去除率在94%以上.该吸附剂经再生处理后可循环使用4次.  相似文献   

6.
耐铅锌微生物对矿山酸性废水中Zn2+和pb2+吸附性能分析   总被引:1,自引:0,他引:1  
以分离于某铅锌矿选矿废水排水沟土壤中的菌株T1为对象,研究重金属离子Zn和Pb初始质量浓度、pH、吸附时间、吸附温度和菌体浓度等因素对菌株T1吸附矿山酸性废水中Zn2+和pb2+的影响.结果表明:考虑处理效果与经济成本的优化,在Zn2+和pb2+的初始质量浓度分别为100 mg/L和30 mg/L,溶液pH4.0,菌体质量浓度3g/L,吸附时间6h,温度30℃的条件下,菌体T1对Zn2+和pb2+的最大吸附率分别为79.86%和69.04%,此时吸附量分别为26.62 mg/g和6.9 mg/g.在一定的质量浓度范围内(Zn2+为25~125 mg/L,pb2+为10~50 mg/L),菌株T1吸附Zn2+和pb2+的过程符合Langmuir等温吸附方程,该过程以表面吸附为主.  相似文献   

7.
以4A和13X分子筛为吸附材料,考察废水pH值和Cd2+初始浓度等对Cd2+去除率的影响,并研究了分子筛对Cd2+的吸附性能。结果表明,4A和13X分子筛投加量为0.16g/L、废水pH值为5、Cd2+浓度为20mg/L时,Cd2+去除率达到95%以上;分子筛对Cd2+的去除机理以离子交换吸附为主,交换出来的Na+与分子筛吸附的Cd2+摩尔浓度比为2;在吸附热力学和动力学方面,4A和13X分子筛均符合Langmuir吸附等温模型和Lagergren二级速率方程,计算的饱和吸附容量Q0分别为150.15、163.67 mg/g,二级反应速率常数K2分别为2.45×10-3、3.96×10-4 g/(mg·s)。该吸附反应是一种单分子层反应速度较快的化学吸附过程。  相似文献   

8.
利用廉价生物吸附剂去除污水中Pb2+和Zn2+的技术,研究了食用菌菌糠的吸附特性,调查污水pH、重金属初始浓度、吸附剂用量、吸附时间和温度对其吸附性能的影响.结果表明,在食用菌菌糠吸附剂用量分别为16g/L和12g/L,pH值分别为5和6,初始重金属质量浓度为20mg/L,吸附时间为3h,25℃条件下,达到了最大吸附量,对Pb2+和Zn2+的去除率分别达到92.79%和88.96%,处理后的Pb2+和Zn2+质量浓度分别为1.442mg/L和2.208mg/L,接近污水综合排放标准(GB8978—1996)中的排放质量浓度1mg/L和2mg/L.食用菌菌糠对Pb2+和Zn2+的吸附等温线符合Fleundlich模式.  相似文献   

9.
采用盐溶液对沸石进行改性,考察了改性沸石吸附处理低浓度含镉废水的影响因素,研究结果表明,在废水质量浓度为10.93mg/L、pH为7.37、改性沸石用量为1.0g、吸附时间为50min、反应温度为25℃的条件下,水中Cd2+最高去除率达到98.99%.  相似文献   

10.
细菌纤维素的制备及其吸附Cd2+的研究   总被引:4,自引:1,他引:3  
以木葡糖酸醋杆菌为菌株,通过L18(37)正交试验优化发酵生产细菌纤维素的条件.将制得的细菌纤维素用于吸附重金属离子Cd2+,考察了溶液pH值、吸附时间等因素对吸附效果的影响,并进一步模拟吸附动力学和吸附等温线.结果表明,纤维素制备的最佳发酵条件为:玉米浆干粉5%,蔗糖6%,发酵液初始pH值6.0,菌种加入量12%,二级种子活化时间22 h及静态发酵时间7 d.在此条件下纤维素产量为12.36 g/L.pH值是影响细菌纤维素对Cd2+吸附效果的重要参数.对Cd2+的吸附符合二级反应动力学特征和Langmuir吸附等温方程,并具有良好的线性,说明细菌纤维素对Cd2+是典型的单分子层吸附.  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 Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

18.
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   

19.
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   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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