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861.
利用含砷氧化锌尘制备活性氧化锌 总被引:3,自引:0,他引:3
用NH3-(NH4)2SO4溶液浸取处理含砷氧化锌尘,可彻底清除砷,制备出合格的活性氧化锌。对于含砷质量分类为1%-2%的原料,产品中所含砷质量分数可降至0.0005%以下。该方法具有除砷彻底,不易产生二次污染的优点,为含砷氧化锌尘的综合利用提供了一种新方法。 相似文献
862.
J. Webb T. Misselbrook B. F. Pain J. Crabb S. Ellis 《Atmospheric environment (Oxford, England : 1994)》2001,35(36):6447-6451
Many farms have unroofed concrete yards used by livestock. These concrete yards have received little attention as sources of gaseous emissions. From 1997 to 1999 measurements were made of emissions of ammonia (NH3), nitrous oxide (N2O) and methane (CH4) from 11 concrete yards used by livestock. A postal survey was carried out to assess the areas of yards on farms in England and Wales to enable the measurements to be scaled up to estimate national emissions. Using the results of this study NH3-N emissions from farm concrete yards were calculated to be ca. 35×103 t annually. This is 13% of the current estimated total NH3-N emission from UK livestock. Concrete yards were an insignificant source of N2O and CH4 which were both <0.01% of current estimates of agricultural emissions. 相似文献
863.
Tomoyuki Imai Toshiki Matsui Yasuhiko Fujii Tasuku Nakai Suminori Tanaka 《Journal of Material Cycles and Waste Management》2001,3(2):103-109
A new iron oxide catalyst, which has a superior oxidation activity in carbon monoxide and polyethylene (PE) combustion, was
synthesized by an aqueous solution reaction. Catalytic oxidation of carbon monoxide over six kinds of hematite obtained from
the goethite was done using a microcatalytic pulse reactor, and the composition of the hematite with the highest oxidation
activity was determined. With the aim of suppressing dioxin formation on combustion, incineration tests of solid wastes in
PE refuse bags with and without the goethite were carried out using a commercial semibatch-type incinerator with a combustion
chamber of 6.2 m3. The result confirmed that the concentration of dioxins in the flue gas decreased considerably when the refuse was incinerated
in PE bags manufactured with goethite.
Received: July 24, 2000 / Accepted: October 18, 2000 相似文献
864.
865.
866.
沉积物和土壤中磷的生物有效性评估新方法 总被引:16,自引:4,他引:12
利用自制的氧化铁/醋酸纤维素复合膜(FeO/CAM)发展了一种沉积物和土壤磷的生物有效性评估的新方法. 结果表明:从沉积物和土壤中解吸的生物有效磷(FeO-P)含量随时间增加而增加,至16~20h左右,解吸过程接近平衡;随着土/水比增大而减小,至20~30g/L左右逐渐趋于平缓,且相对标准偏差较小;膜面积为20~30cm2时FeO-P含量差别较小,且相对标准偏差也较小;适当提高振荡频率(一般200r/min左右),有利于促进FeO-P的提取动力学过程.在用于评估水体沉积物和土壤解吸磷的生物有效性方面,FeO/CAM膜克服了氧化铁浸渍滤纸的缺点,易于商品化,具有更好的应用前景. 相似文献
867.
同步硝化反硝化处理氨氮废水过程中气态脱氮产物的研究 总被引:5,自引:2,他引:3
采用密闭的间歇式反应器对高质量浓度氨氮废水在同步硝化反硝化(SND)生物脱氮过程中产生的3种氮氧化物气体(NO,NO2和N2O)进行跟踪测试.结果表明,在由反应器排出的气体中,ρ(NO2)不高于实验室背景值,在脱氮产物中可忽略不计,而ρ(NO)和ρ(N2O)要高于背景值10倍以上.对于该脱氮系统,在低ρ(DO)和高pH的条件下产生的N2O相对较少.ρ(DO)为1.5~3.0 mg/L时,以NO和N2O形式脱除的氮分别占脱氮总量的0.58%和6.53%;ρ(DO) 为2.5~4.0 mg/L时,分别为0.48%和39.34%.此外,还分析了可实施的N2O控逸途径. 相似文献
868.
外源NO对Cu胁迫下番茄幼苗L-精氨酸代谢的影响 总被引:1,自引:0,他引:1
一氧化氮(nitric oxide,NO)作为生物活性分子,广泛参与各种生物和非生物胁迫。采用营养液培养,研究Cu胁迫下番茄体内L-精氨酸、NO、多胺代谢对外源NO的响应机制,以期为铜污染区域蔬菜种植提供科学依据和技术支持。结果表明,Cu胁迫下添加外源SNP(硝普钠,外源NO供体)能够调节番茄根系和叶片中精氨酸脱羧酶(Arginine Decarboxylase,ADC)、鸟氨酸脱羧酶(Ornithine Decarboxylase,ODC)及一氧化氮合酶(Nitric Oxide Synthase,NOS)活性。根系中,外源SNP能够上调NOS活性,L-精氨酸代谢向着NO合成方向进行;叶片中,外源SNP能够同时上调ADC、ODC、NOS活性,PA、NO的合成同时进行;此外,Cu胁迫下添加外源SNP能够增加根系和叶片L-精氨酸含量,而作为PA、NO的合成前体,精氨酸含量升高无疑会间接促进PA、NO的合成,从而提高番茄对Cu胁迫的抵抗能力。 相似文献
869.
As a large and diverse group of secondary metabolites, phenolic compounds are one of the most common chemical pollutants present in water resources. these compounds can have toxic effects on ecosystems and humans. Therefore, their removal from water sources appears to be of great importance. In this study, a magnetic graphene oxide (MGO) photocatalyst was synthesized and used to remove phenol from water. The fabricated GO magnetic nanocomposites were determined by SEM and FTIR techniques. Afterward, these nanoparticles were used to remove phenol from aquatic media considering different operational parameters, including pH of the solution, initial concentration of phenol, contact time, and adsorbent dosage. The results showed that the magnetized GO nanoparticles could remove 90.83% of phenol molecules under the optimal conditions of solution pH = 3.0, initial phenol concentration of 20 mg/L, adsorbent concentration of 300 mg/L, and contact time of 120 min. additionally have compared the results of UV, Fe3O4/GO, and Fe3O4/GO/UV on the removal of phenol under optimum conditions. Accordingly, the phenol removal efficiencies for UV alone, Fe3O4/GO, and Fe3O4/GO/UV were obtained at 4.5, 65.73, and 90.83%, respectively. Based on the findings, the prepared magnetic GO nanoparticles have extended capabilities such as easy and rapid separation from sample and high potential in removing phenolic compounds, so, it can be introduced as an appropriate adsorbent for removal of this pollutant from water and wastewater. 相似文献
870.
采用L-谷氨酸(L-Glu)改性氧化石墨烯(GO)制备吸附剂L-Glu/GO,并进行了XRD、FTIR和SEM表征。考察了不同因素对L-Glu/GO吸附Cu2+的影响,并对L-Glu/GO的吸附-解吸能力进行了研究。实验结果表明:L-Glu/GO对Cu2+的吸附在10 min内就可达到吸附平衡;在Cu2+初始质量浓度为70 mg/L、初始pH为5、L-Glu/GO投加量为0.200 g/L、吸附时间为120 min、吸附温度为30 ℃的条件下,L-Glu/GO的最大吸附量可达292.460 mg/g。准二级动力学和Langmuir模型能很好地拟合此吸附过程,且显示该吸附过程可促进L-Glu/GO对Cu2+的吸附。热力学研究结果表明该吸附过程是一个自发的放热过程。经过5次吸附-解吸循环后,L-Glu/GO对Cu2+的吸附率仍在92%以上,表明该吸附剂再生性好,可重复使用。 相似文献