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1.
利用稀土基无机合成材料去除饮用水中砷的研究   总被引:22,自引:0,他引:22  
张昱  杨敏  王桂燕  黄霞 《环境化学》2001,20(1):70-75
本文研制了一种新型除砷吸附剂,即基于稀土金属铈的无机铈铁吸附剂,并对该吸附剂的除砷效果进行了评价.活性氧化铝和新型研制的铈铁吸附剂对As(Ⅴ)吸附平衡比较实验结果表明:活性氧化铝除砷的最佳 pH为 3.5-5.5,最大吸附量为86mg As(Ⅴ)·g-1;而铈铁吸附剂的pH适用范围广,在pH3-7的范围内具有较高的除砷性能,最大吸附量可达16.0mgAs(Ⅴ)·g-1,该吸附材料对As(Ⅴ)的吸附基本符合Freundlich型等温方程式,硬度、盐度和氟离子不干扰吸附过程,但磷酸根离子干扰材料对As(Ⅴ)的吸附、铈铁无机吸附材料在饮水除砷中具有比较大的应用前景.  相似文献   

2.
用于降氟的亚粘土改性方法与吸附作用机理研究   总被引:5,自引:0,他引:5  
研究了改性方法和改性条件对用于降氟的亚粘土除氟性能的影响,得出了每 种改性方法的最佳改性条件,探讨了改性亚粘土的吸附机理,研究表明,改性亚粘土除氟率高、工业产换容量大,除氟率最高达100%,最大工作交换容量达243.30mg.kg^-1,改性亚粘土降氟功能归因子于所含针铁矿和伊利石对于F^-的专性吸附。  相似文献   

3.
稀土铈基无机吸附剂对氟的吸附性能   总被引:15,自引:0,他引:15  
焦中志  张昱  杨敏  黄霞  马可民 《环境化学》2002,21(4):365-370
利用稀土铈基无机吸附剂(CFA)对水溶液中的氟进行了静态吸附试验和脱附再生试验,并对其部分物理化学特性表征和除氟机理进行了研究。结果表明:CFA吸附剂对氟的吸附具有较高的动力学特性和罗高的吸附量,较低的pH值有利于对氟的吸附,在平衡pH3-6的范围内对氟的吸附量较高;可以用Freundlich方程表示该静态吸附的吸附等温线;吸附后的吸附剂可以用稀氢氧化钠溶液再生,脱附率达到100%,再生后的活性比达到95%以上。  相似文献   

4.
单甲脒农药对大豆—土壤系统的生态影响   总被引:4,自引:0,他引:4  
研究了单甲脒农药(DMAH)对大豆-土壤系统的生态影响.结果表明:除CK外,5个设置浓度[(DMAH)/mL·L-1]0.25、0.5、2.5、5.0、25均对大豆虫害有不同的防治效果.其中>2.5时可防治大豆多种虫害;大豆对DMAH稀释液的pH值反应敏感,高浓度处理的叶片因酸度大而出现药害;推荐浓度[(DMAH)=0.25mL·L-1],对植株的生长和生理功能有促进作用.可使总生物量及产量分别增加20%左右,且籽粒中农药无残留,土壤农药残留量也小;当处理pH值<5时会对叶片有伤害.生理功能被抑制,总生物量及产量都不如CK;DMAH在植物器官及土壤都有不同程度的残留量.其中叶残留量大于籽粒及土壤.可以认为,低浓度DMAH处理不会对植物-土壤系统造成污染.  相似文献   

5.
地热温泉常含有高浓度的氟,给温泉利用带来不可忽视的环境问题,因此温泉水中氟离子吸附净化处理是重要的研究热点.本文采用废弃茶叶作为吸附剂,氟离子为目标离子,优化了茶叶吸附剂种类、溶液pH对吸附效果的影响.在pH 3、初始浓度为5 mg·L-1时,大红袍茶叶对氟离子的吸附容量达到0.126 mg·g-1.进一步考察了吸附剂对氟离子的吸附机制,结果表明,氟离子吸附符合Pseudo-secondorder动力学模型,等温线符合Freundlich模型,氟离子吸附过程主要通过与茶叶中的羟基和羧基活性基团发生交换作用.茶叶氟吸附量虽较其它天然吸附剂略低但无需复杂改性和前处理,具有环境友好,成本低廉,来源丰富,易与获得等优点,在含氟水净化处理具有潜在应用和发展前景.  相似文献   

6.
对经特殊的稳定化预处理所得的海洋巨藻(Durvilaea potatorum)生物吸附剂对Hg^2 的吸附动力学进行了研究,报导了不同Hg^2 初始浓度,、温度以及生物吸附剂平均粒径下动态吸附量与时间的关系。结果显示,各吸附动力学曲线呈优惠型;当生物吸附剂平均粒径为0.45mm时,Hg^2 的半饱和时间ts均不超过60min;Hg^2 初始浓度和生物吸附剂粒径越小,吸附温度越大,达到吸附平衡所需的时间越短,在测试范围内,生物吸附剂的平衡吸附容量与粒径和温度无关,同时考察了吸附过程中的传质效应并对液膜传质系数kL进行了关联,结果表明:当吸附时间t≤ts时,Hg^2 的吸附速率为液膜传质控制;在测试范围内,kL为0.0407-0.112cm/s,本研究结果为利用海洋巨藻(Durvilaea potatorum)生物吸附剂处理含汞的规模化应用提供了一定的依据。图5表2参11  相似文献   

7.
通过温室盆栽试验研究不同比例粉煤灰钝化污泥人工土壤上高麦草的生长发育及营养状况,试验结果表明:土壤中加入粉煤灰钝化污泥显著增加了高麦草的干物重.脱水污泥加入其鲜重的10%粉煤灰钝化后再按1∶1和1∶5体积比与土壤混合配成的人工土处理和加入其鲜重的35%粉煤灰钝化后再按1∶1体积比与土壤混合配成的人工土处理高麦草的产量都显著高于自然土壤施用化肥的处理,高麦草的发芽率也不受影响.随着粉煤灰加入量的增加,高麦草地上部Ca,Mg和B的浓度(w/%或w/mg.kg-1)增加而K,Fe,Mn和Zn的浓度下降,高麦草根中Fe,Mn,Cu和Zn的浓度显著高于其地上部中的浓度.所有粉煤灰钝化后污泥人工土壤高麦草都没有出现N和P的缺乏和重金属毒害,说明合适比例的粉煤灰钝化污泥人工土壤是高麦草的良好生长介质.  相似文献   

8.
红土复合聚合氯化铝以及三氯化铁去除水华藻类的研究   总被引:3,自引:0,他引:3  
采用红土复合聚合氯化铝(PAC)以及三氯化铁(FeCl3)制得的复合絮凝剂对水样中的藻类絮凝沉降效果进行了研究。结果表明,与PAC复合FeCl3混凝剂不同,红土的加入可增加絮体的密实度,加快絮体沉降速度,沉淀后的絮体在微扰动下不再漂浮上升从而有效提高除藻效果。采用正交试验探讨了复合絮凝剂除藻的最优配比,用混凝剂(红土:PAC:FeCl3=50mg:8.75mg:17.5mg)处理水样,1h后水样浊度由22.35NTU降至1.85NTU,浊度去除率为91.72%。讨论了温度、pH值等因素对除藻效果的影响,并对除藻机理进行了初步的探讨。  相似文献   

9.
采用静态吸附法研究了不同比例钙铝、铁铝、锰铝的磷酸盐共沉物的除氟性能,比较发现,铝与铁的磷酸盐共沉物除氟效果最好,锰离子对磷酸铝的除氟效果则有明显的抑制作用。以吸附性能较好的1∶100铁铝比例的磷酸盐共沉物为吸附剂,研究了接触时间、pH值、吸附剂量等对其除氟效果的影响,结果表明,在25℃、氟离子初始质量浓度为10 mg.L-1、pH值为6~8、振荡时间为90 m in、投加量为2.5 g.L-1条件下,1∶100铁铝比例的磷酸盐共沉物对氟的吸附量可达2.7 mg.g-1。  相似文献   

10.
李辉  李柏全  邵红 《生态环境》2010,19(11):2698-2701
以硼泥、膨润土、粉煤灰、锯末为原材料制备硼泥陶粒吸附剂,应用于高浊度废水的处理,以浊度的去除率为指标,通过对pH值、流速、填料高度、锯末量、粒径、处理时间等因素的考察,确定合适的工艺条件。结果表明:对于浊度为795~820 NTU的废水,在pH为12、流速在1 200 s.L-1、填料高度50 cm、粒径4 mm、锯末量为40 g、处理时间60 min,废水的除浊率达到94%。实现了对硼泥的资源化利用,为制备吸附剂的来源及吸附剂处理废水的应用开辟了新途径。  相似文献   

11.
大宝山矿水外排的环境影响:Ⅰ.下游水生生态系统   总被引:15,自引:2,他引:15  
通过水质生物检测、理化分析及野外水生大型无脊椎动物多样性实地调查等综合方法,就广东大宝山矿区南侧拦泥库溢出的酸性矿水对下游横石水河生态系统的影响进行了系统研究。结果表明,大宝山矿区拦泥库溢出的酸性矿水对隆线溞具有较强的急性生物毒性,酸性矿水24h,48h及96h对水溞的半致死体积分数LC50分别为13.55%、10.30%、6.20%;安全体积分数为0.06%。通过在暴雨期间对拦泥库上游洪水的各项指标的分析结果表明,拦泥库溢出的酸性矿水pH值可低至2.15,其中铁及重金属的质量浓度分别为:铁216.79mg/L、锌73.23mg/L、铜32.63mg/L、铅1.82mg/L、镉0.87mg/L。在尾矿坝下游3.5km处,重金属质量浓度分别为:铁51.63mg/L、锌2.83mg/L;铜1.64mg/L、铅2.67mg/L、镉0.1mg/L,和锰20.50mg/L。从矿水排放口到受矿水影响的下游50km范围内,河水pH的变化幅度为3.36-7.42。大型无脊椎动物多样性的调查显示,从尾矿坝到受矿水影响的下游25km范围内,未发现任何底栖动物,而在横石水河上游未受矿水影响的对照点中至少有36利底栖动物存在。可见由大宝山矿区排出的酸性矿水对下游溪流的水生生物多样性和河流生态系统造成了严重的破坏。  相似文献   

12.
鞑靼荞麦离体再生体系的建立   总被引:1,自引:0,他引:1  
研究了苗龄、外植体、激素配比对鞑靼荞麦(Fagopyrum tataricum Gaertn.)离体培养的影响,初步建立了鞑靼荞麦离体再生体系.结果表明,鞑靼荞麦离体再生的最佳取材时间为苗龄6~8 d;诱导愈伤组织的最适培养基为Ms+2.0 mg/L 2,4.D+1.5 mg/L 6-BA,子叶诱愈率达75%左右,下胚轴诱愈率可高达86.62%;愈伤组织分化的最适培养基为MS+0.1 mg/L IAA+2.0 mg/L 6-BA+1.0 mg/L K1.+0.5 mg/L TDZ,来自下胚轴愈伤组织的分化率可达9.52%.下胚轴的诱愈率与分化率均高于子叶,更适于离体再生培养.培养基巾加入AgNO_3后,能有效降低褐化率.生根最适培养基为含有0.5 mg/L NAA的1/2MS培养基,生根率在50%左右.TDZ在诱导鞑靼荞麦的愈伤组织分化出芽的过程中起到明显的促进作用,可提高分化率约20%.表3图2参23  相似文献   

13.
长期继代培养马铃薯愈伤组织的植株再生   总被引:12,自引:0,他引:12  
对影响马铃薯愈伤组织发生、生长和长期继代培养的愈伤组织再生植株的几种因素进行了研究。马铃薯茎段的愈伤组织发生频率高于叶片的愈伤组织发生频率。Dicamba诱导茎段和叶片的愈伤组织发生频率在90%以上;而2,4-D的诱导效果不佳并诱发外植体生根。再生培养其中加入0.5g/L的酶解酷蛋白是必需的;蔗糖的浓度以2%-4%为宜;附加ZT2.0mg/L、GA0.1mg/L可使长期继代的愈伤组织的植株再生频率  相似文献   

14.
氢氧化铝废渣处理含氟废水的研究   总被引:12,自引:1,他引:11  
在一定条件下氢氧化铝废渣活化处理,用于处理50mg/L的含氟废水,投加量为2‰,pH值为6 ̄11,去氟率达96%。吸附平衡浓度与吸附量关系符合Langmuir等温式,求出20.0℃、25.0℃、30.0℃时的饱和吸附量和吸附系数。其吸附速度符合鲛岛吸附动力学方程式。  相似文献   

15.
A pilot-scale airlift oxidation ditch using bubble diffuser and baffle as aerator was operated in a wastewater treatment plant (WWTP) to investigate its flow characteristic and wastewater treatment performance. Compared with the conventional oxidation ditch process, effective depth and oxygen utilization efficiency of this new process was improved by underwater aeration. Furthermore, it had a reversed velocity distribution, which decreased from the bottom to the top on vertical section. Velocity measurement showed that a velocity over 0.2m/s at the bottom was sufficient to prevent sludge settlement during long term operation. Application of these concepts would save land area and energy consumption by about 25%―50% and 55%, respectively. In this new system, organic biodegradation and nitrification could be well achieved. Denitrification could occur steadily in the straight part by adjusting the airflow rate. An average TN removal rate of 63% was achieved with dissolved oxygen (DO) concentrations between 0.6mg/L and 1.5mg/L. The main pollutants in the effluent could meet the strictest discharge standard (COD<50mg/L, NH4+―N<5mg/L, and TN<15mg/L) in China now.  相似文献   

16.
有机凹凸棒粘土吸附水中苯酚的试验   总被引:16,自引:0,他引:16  
凹凸棒粘土经溴化十六烷基三甲胺(CTMAB)改性后,对水中酚具有较强的吸附能力,苯酚浓度为100mg/L时,加入量为4%,pH为8.0时,去除率达到88.5%,且有机凹土经再生后可反复使用。吸附平衡浓度与吸附量关系符合Freundlich吸附等温式。  相似文献   

17.
加压生物接触氧化法处理染料废水   总被引:3,自引:0,他引:3  
本试验用一种新方法——加压生物接触氧化法处理染料生产废水.试验规模为1m~3/h.废水先经调节预处理,进水水质平均COD为619mg/L,BOD_5为336mg/L时,经6.5h处理后,出水COD去除率可达70%,BOD_5去除率在98%以上.与常规法相比,它具有处理时间短,主要设备占地面积小,设备投资省及操作总能耗低的特点.  相似文献   

18.
The effect of dissolved oxygen (DO) concentration on nitrite accumulation was investigated in a pilot-scale pre-denitrification process at room temperature for 100 days. In the first 10 days, due to the instability of the system, the DO concentration fluctuated between 1.0 and 2.0 mg/L. In the next 14 days, the DO concentration was kept at 0.5 mg/L and nitrite accumulation occurred, with the average nitrite accumulation rate at 91%. From the 25th day, the DO concentration was increased to 2.0 mg/L to destroy the nitrite accumulation, but nitrite accumulation rate was still as high as 90%. From the 38th day the nitrite accumulation rate decreased to 15%–30% linearly. From the 50th day, DO concentration was decreased to 0.5 mg/L to resume nitrite accumulation. Until the 83rd day the nitrite accumulation rate began to increase to 80%. Dissolved oxygen was the main cause of nitrite accumulation, taking into account other factors such as pH, free ammonia concentration, temperature, and sludge retention time. Because of the different affinity for oxygen between nitrite oxidizing bacteria and ammonia oxidizing bacteria when DO concentration was kept at 0.5 mg/L, nitrite accumulation occurred.  相似文献   

19.
To understand acute toxicity and oxidative stress of perfluorinated compounds in the freshwater ecosystems, we exposed freshwater mussels (Unio ravoisieri) to perfluorooctane sulfonate (PFOS), over a range of concentrations from 10 to 100?mg/L, in a laboratory experiment. Lethal concentration (LC50) was of about 65.9?mg/L after 96?h of exposure. The oxidative stress was assessed in gill and digestive gland of the freshwater mussels after 7 days of exposure to different nominal PFOS concentrations (C1=?2?mg/L, C2?=?6?mg/L and C3=?10?mg/L). C1 and C2 increased significantly (p?<?.05) the superoxide dismutase activity in both tissues compared, while the highest C3 decreased the enzyme activity. This implements an unfavourable response that highlights the excess of reactive oxygen species produced after contamination. The Catalase activity was also increased by about 40.05% and 66.63%, respectively, in gill and digestive gland after exposure to C3. The Malondialdehyde (MDA) level was increased in both gill and digestive gland in a concentration-dependent pattern. In contrast, the contamination of U. ravoisieri by PFOS did not affect the acetylcholinesterase activity in both organs (p?>?.005). These results provided information on potential biomarkers that could be effectively applied for the monitoring of freshwater ecosystem using indicator species such as U. ravoisieri.  相似文献   

20.
A novel SBM-C-PBR was constructed for microalgae cultivation. Membrane fouling was greatly mitigated by membrane carbonation. NH4+ and P removal rates were around 80% in SBM-C-PBR. Biomass was completely retained by membrane. In this study, a novel sequence batch membrane carbonation photobioreactor was developed for microalgae cultivation. Herein, membrane module was endowed functions as microalgae retention and CO2 carbonation. The results in the batch experiments expressed that the relatively optimal pore size of membranes was 30 nm, photosynthetically active radiation was 36 W/m2 and the CO2 concentration was 10% (v/v). In long-term cultivation, the microalgal concentration separately accumulated up to 1179.0 mg/L and 1296.4 mg/L in two periods. The concentrations of chlorophyll a, chlorophyll b and carotenoids were increased about 23.2, 14.9 and 6.3 mg/L respectively in period I; meanwhile, the accumulation was about 25.0, 14.5, 6.6 mg/L respectively in the period II. Furthermore, the pH was kept about 5.5–7.5 due to intermittent carbonation mode, which was suitable for the growth of microalgae. Transmembrane pressure (TMP) was only increased by 0.19 and 0.16 bar in the end of periods I and II, respectively. The pure flux recovered to 75%–80% of the original value by only hydraulic cleaning. Scanning electron microscope images also illustrated that carbonation through membrane module could mitigate fouling levels greatly.  相似文献   

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