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1.
复合纳米光催化环保涂料制备及其超临界CO2喷涂研究   总被引:1,自引:1,他引:0  
对纳米SO42-/TiO2-(Ag、Fe)有机包覆研究表明,用钛酸酯偶联剂对纳米SO42-/TiO2-(Ag、Fe)粒子进行有机包覆处理,能有效地增强无机TiO2基粒子在有机涂料体系中的分散性和稳定性,为光催化环保涂料的制备奠定基础。对复合纳米SO42-/TiO2-(Ag、Fe)光催化环保涂料的组成配比实验结果表明,光催化剂添加量为6%时适宜;在14MPa、60℃下用孔径为0.4 mm的喷嘴对CO2含量为30%的复合SO42-/TiO2-(Ag、Fe)氟碳树脂涂料进行喷涂,喷涂过程有机物排放量降低了43.5%,所得涂膜对罗丹明-B降解速率常数为3.84×10-2S-1,比用普通刷涂提高了17.8%。该涂膜还能将甲基橙、品红、苯酚等多种难降解的有机物彻底矿化,且经5次重复使用,光催化活性无明显下降,在可见光下反应140min就能将罗丹明-B完全矿化。  相似文献   

2.
TiO_ 2 photocatalyst can degrade organic pollutant in waste water efficiently. Metal ion-doped TiO_ 2 nanoparticles are prepared with different doping amount by sol-gel method. The prepared sample are evaluated by the photo-catalytic oxidation degradation experiment of methyl orange. The experiment results indicate that the photo-catalytic activities of Cr~(3+)-doped TiO_ 2 are photoactive than bare TiO_ 2, and that in the Cr~(3+)-doped TiO_ 2 system, 1.0% is optimal amount of doping. Furthermore, it is studied that the degradation rate of methyl orange can reach 92% in UV light of 4 hours and 85% in visible light of 6 hours.It can be expected that M~(n+)- TiO_ 2 photocatalyst is widely applied to the degradation of organic pollutant in waste water treatment.  相似文献   

3.
腐殖质是土壤有机质的主体部分,并且在碳截获、土壤结构、养分保持、生物地球化学循环等方面都占有重要的作用。本文以5种不同有机质含量农田黑土为主要研究对象,对比分析了长期施肥对不同有机质含量农田黑土富里酸(FA)、胡敏酸(HA)、胡敏素(HM)的含量的影响。结果表明:5种农田黑土FA、HA、HM的含量随土壤有机质含量的增加而增加,长期施肥可以增加农田黑土FA、HA、HM的含量,5种农田黑土FA含量差异达到了显著水平(P0.05)。相关分析表明:FA、HA含量与土壤有机碳、全氮、全磷呈显著正相关,与土壤pH值呈显著负相关(P0.05),HM含量与土壤有机碳、全氮、全磷含量、土壤p H值之间差异没有达到显著水平(P0.05)。  相似文献   

4.
对纳米SO42-/TiO2-(Ag、Fe)有机包覆研究表明,用钛酸酯偶联剂对纳米SO42-/TiO2-(Ag、Fe)粒子进行有机包覆处理,能有效地增强无机TiO2基粒子在有机涂料体系中的分散性和稳定性,为光催化环保涂料的制备奠定基础。对复合纳米SO42-/TiO2-(Ag、Fe)光催化环保涂料的组成配比试验结果表明:光催化剂添加量为6%时适宜;在14 MPa、60℃下用孔径为0.4 mm的喷嘴对CO2含量为30%的复合SO42-/TiO2-(Ag、Fe)氟碳树脂涂料进行喷涂,喷涂过程有机物排放量降低了43.5%,所得涂膜对罗丹明-B降解速率常数为3.84× 10^-2S^-1,比用普通刷涂提高了17.8%。该涂膜还能将甲基橙、品红、苯酚等多种难降解的有机物彻底矿化,且经5次重复使用,光催化活性无明显下降,在可见光下反应140 min就能将罗丹明-B完全矿化。  相似文献   

5.
长期定位施肥对水稻土有机质含量及组成的影响   总被引:4,自引:0,他引:4  
为揭示水稻土有机质的变化规律,通过长期定位施肥试验研究了27 年的不同施肥处理水稻土中有机质含量及其组成。结果表明,长期施肥不同处理的土壤有机质消长呈现明显差异,在等量氮、磷、钾养分的前提下,长期有机-无机肥配施比无肥或单施化肥更有利于稻田土壤有机质的积累;单施化肥、有机-无机肥配施各处理土壤腐殖酸、HA、FA变化趋势基本相同,但有机-无机肥配施土壤腐殖酸、HA、FA一直高于无肥及化肥处理,而且有机-无机肥配施有利于土壤中HA和FA的增加,HA/FA比值随着时间的延伸逐渐减小;有机-无机肥配施可以提高土壤易氧化有机质含量;而且长期施肥土壤有机质与易氧化有机质呈极显著正相关,与全氮、水解氮含量及产量显著正相关。易氧化有机质与土壤全氮、有效磷含量及产量呈显著正相关。其中水稻产量与易氧化有机质的相关性(r=0.8181*)比与有机质(r=0.8020)的相关性较高,说明易氧化有机质对水稻增产有较大的贡献。  相似文献   

6.
黄河源区河漫滩湿地退化过程土壤的变化特征   总被引:1,自引:0,他引:1  
笔者从黄河源区河漫滩湿地地理地形指标和土壤指标出发,分析和研究黄河源区河漫滩湿地退化过程中土壤变化特征。结果表明:黄河源区河漫滩湿地不同退化阶段土壤的酸碱值大于pH 7 时,pH随退化程度加剧有明显减少;随着退化梯度的加剧,土壤含水量减少,草土比也逐渐减小;黄河源区河漫滩湿地退化土壤为松砂土,黄河源区河漫滩湿地随着退化程度的加剧小于0.01 mm物理黏粒含量基本上呈现减少的趋势;黄河源区河漫滩湿地主要养分在垂直方向上都表现出上层高于下层的规律,土壤有机质和全氮随着湿地退化都呈现了逐渐减少的规律。多重比较的结果,全N、全K和有机质,在退化阶段5 与阶段1、阶段2、阶段3 和阶段4 之间差异显著(P<0.05),阶段1、阶段2、阶段3 和阶段4 之间差异不显著;碱解N在退化阶段2 与阶段5 之间差异显著(P<0.05),阶段1、阶段3 和阶段4 之间差异不显著;全P、速效P和速效K在河漫滩湿地退化过程中差异虽未达到显著水平,但随着退化进展,速效P是呈现出减少趋势,全P和速效K呈现出增加趋势。  相似文献   

7.
Taking a coconut shell powder activated carbon (PAC) as the carrier and butyl acetate titanate with ethanol as raw materials, TiO2/AC(activated carbon) photocatalyst was prepared through sol-gel and impregnation method, and batch experiments were carried out to investigate its performances of removing Carbamazepine from artificial water. The results indicate that TiO2/AC has a better removal of carbamazepine than powder TiO2 and PAC. In the same condition, the removal of carbamazepine in TiO2/AC system is 1.7 times than that in TiO2. When the initial concentration of Carbamazepine is 10 mg/L, and the dosage of TiO2/AC is 500 mg/L, in which the load capacity of TiO2 is 11.2%, the removal rate reaches at 91.5% while the PH is 1.0. The reaction of photocatalytic degradation process can be accorded with two-step dynamics kinetics with different concentrations. The constant of secondary reaction is inversely proportional to concentration. Using Langmuir-Hinshelwood (L-H) model, it concludes that the apparent adsorption equilibrium constant Ka is 9.215×10 3 L/mol, and the surface reaction rate constant Kr is 3.678×10 -6 mol/(L·min). Thus, microwave irradiation is the best way for catalyst regeneration.  相似文献   

8.
Data on suspended matter concentrations and the organic content of the suspended matter for January 1980 showed a division in the North Sea between the southern North Sea (high suspended matter concentrations, but relatively low organic content) and the central and northern North Sea (low suspended matter concentrations, but relatively high organic content). The Skagerrak, which receives suspended matter from the southern as well as from the central and northern North Sea, took up an intermediate position.In summer suspended matter concentrations were lower than in winter but more variable, in concentration as well as in organic content, because of admixtures of particulate matter from primary production. On deposition of the suspended matter, a considerable part of the organic matter was apparently lost (in the order of 75% or more), resulting in low organic-matter concentrations of fine-grained bottom deposits.Particle-size distributions followed two main types: one (A) with a sharp peak at 30 to 100 μm, and one (B) bell-shaped with a peak at 5 to 15 μm. Type A occurred in deeper water and consisted of particles with a high organic-matter content, type B occurred in shallow areas and consisted of particles with a low organic-matter content. The suspended particles were mainly microflocs of mineral particles and organic matter. The mineral particles of both types were predominantly of 2 to 5 μm size, which was determined after oxidation of the organic matter. It is concluded that particles of type-B distributions are regularly exchanged with the bottom through deposition and resuspension, which results in low organic-matter contents and prevents the microflocs reaching large sizes. Paricles of type-A distributions, on the contrary, can reach much larger sizes, because mostly they remain in suspension and do not lose organic matter, so that they do not easily fall apart.  相似文献   

9.
为了解土壤性状对兽用抗生素在土壤中的衰减及其生物有效性的影响,选择10 种理化性状相差较大的典型蔬菜地土壤,通过添加不同浓度(1、5、20 mg/kg)的4 种抗生素(土霉素、恩诺沙星、磺胺二甲嘧啶和泰乐菌素),在保持65%的土壤田间持水量和恒温(25℃)条件下培养,观察分析各类抗生素的残留量和生物有效性的动态变化。结果表明,试验初期(20 天内)土壤中抗生素的降解速率明显高于后期(50~100 天),进入土壤中的抗生素降解量随抗生素浓度的增加而增加,但降解比例却随抗生素添加量的增加而减小。4 种抗生素在土壤中的降解速率:磺胺二甲嘧啶>恩诺沙星>土霉素>泰乐菌素。培养前期土壤中有效态抗生素含量随培养时间的下降比抗生素的残留量下降更明显。各类抗生素的降解率主要与土壤粘粒含量和氧化铁含量呈负相关,与土壤有机质含量存在轻微正相关,但与土壤pH 和CEC无明显相关。培养初期(5 天),土壤中有效态抗生素含量与粘粒含量、氧化铁含量呈负相关,与有机质含量呈现正相关;但随培养时间的增加,其与土壤粘粒含量、氧化铁含量的相关性有所降低。  相似文献   

10.
笔者以太阳光为光源,研究了纳米TiO2降解毒死蜱的反应动力学,考察了纳米TiO2用量、毒死蜱起始浓度及溶液pH值对毒死蜱光催化降解速率的影响,旨在为将来实际生产中降解蔬菜、粮食、水果及农药废水中毒死蜱残留的污染提供依据。结果表明,TiO2最佳用量为50 mg/L;毒死蜱初始浓度越大,降解速率常数越小;在碱性条件下,有利于降解反应的进行。试验条件下毒死蜱的光催化降解符合一级反应动力学规律。  相似文献   

11.
纳米TiO2光催化降解苹果和洋李中毒死蜱残留的效果研究   总被引:1,自引:1,他引:0  
为了利用光催化降解剂降低甚至消除农产品的农药残留,解决食品安全问题。本研究以水果中的有机磷农药残留为研究对象,探索了纳米TiO2粉体和水凝胶对苹果和洋李中毒死蜱残留的光催化降解效果。结果表明:二者均能很好的降解苹果和洋李中的毒死蜱残留,TiO2水凝胶的光催化效果稍优于纳米TiO2粉体。纳米TiO2本身无毒,光催化活性高,作为光催化降解剂在降低或消除农产品中的有机磷农药残留这一领域具有广阔的发展前景。  相似文献   

12.
有机质水平常用作评价土壤肥力的首要指标,如何分析土壤有机质含量对正确评估土壤肥力有重要意义。在探讨现行标准在新垦耕地土壤有机质含量分析中存在问题的同时,提出了相应的改进方法。结果表明,用现行NY/T1121.6-2006标准测定的是以<2mm土粒为基数的有机质含量;若以包括>2mm砾石为基数计算时,新垦耕地土壤有机质水平下降了22%(平均值从23.1g/kg降至18.0g/kg);按照耕地质量评定与分等定级技术规范(DB33/T895—2013),土壤有机质生产能力赋值由0.84分降低到0.4分,属于低水平。研究结果为准确评估新垦耕地土壤有机质含量提供参考。  相似文献   

13.
四川省平昌县是长江流域生态修复的试点县之一,生态修复区布设在“长治”工程竣工后治理程度较好的小流域内,主要采取封禁治理的措施,加强植被的自我恢复能力。文章选取不同海拔,坡度,坡向,不同林种配置和林分结构的四个径流区进行研究,通过对植被重要值、物种多样性、优势度、均匀度等的计算分析以及对土壤肥力的测定分析,得出以下结论:(1)物种多样性较高的径流区其土壤肥力也较高,表现为:群落总体物种多度顺序为:深溪沟>许家沟>涵水沟>国林沟,土壤有机质含量大小顺序为:深溪沟>许家沟>涵水沟>国林沟,特别是灌草类越多,土壤肥  相似文献   

14.
江苏省扬州有机农业现状及发展对策研究   总被引:3,自引:2,他引:1  
为掌握江苏省扬州有机农业现状及问题,在扬州市范围内调查了土壤有机质、pH、基础地力产量状况以及有机农业的分布、规模、产品类型,并选择性调查了具有代表性有机农业区的面积、效益状况。结果显示:目前全市土壤有机质、pH、水稻基础地力产量平均值分别为28.3 g/kg、7.0、5760 kg/hm2。目前全市有机农业区面积2610 hm2,其产品类型主要为水稻、蔬菜、猕猴桃、茶叶、葡萄等,有机农业较传统农业增效36.5%~113.5%,初步掌握当前有机农业的主要技术措施、施肥结构,进一步阐述了有机农业生产中存在的问题并提出相应的对策,为有机农业的发展提供借鉴。  相似文献   

15.
光催化降解表土层中DDT的影响因素研究   总被引:3,自引:0,他引:3  
通过选用添加适量滴滴涕(DDT)的棕壤土,以紫外灯为光源进行光催化降解实验,研究土壤的水分含量、溶解性有机质(DOM)含量、pH值、不同的外源投加物质以及翻动土壤等各因素对于土壤中DDT光催化降解的影响,探讨光催化降解DDT的最优化条件。实验结果表明:随着水分含量的增加,DDT的降解率呈逐渐增大的趋势;当水分含量达50%时,DDT降解率达到最高,达67.5%;当水分含量超过50%后,DDT降解率呈缓慢下降趋势。在一定范围内,DDT的光催化降解率随溶解性有机质含量的增加而增加,但当溶解性有机质的含量超过1.0%时,降解率反而降低;和中性条件相比,DDT在酸性和碱性条件下都具有更高的光催化降解率;投加铁粉、Ti02对土壤中DDT的降解速率有明显的提高;溶解性有机质、Fe2O3、全元素肥料混合溶解性有机质对DDT的光催化降解效果略有提高,而单独加入全量元素肥料几乎对降解率没有影响;DDT的光催化降解率随着土层深度的增加而降低;定期翻动土壤可以有效提高DDT的光催化降解率。  相似文献   

16.
The new process for semiting Ti-Si ferroalloy using Panzhihua Iron & Steel Company (PISC) blast furnace titaniferous slag is introduced. The reduction and impoverishment law of TiO2 in slag and the effects of DC on smelting Ti-Si ferroalloy are studied when smelting Ti-Si ferroalloy by electrosilicothermal method,Ti-Si ferroalloy containing about 20% Ti can be produced by electrosilicothermal method. and Ti recovery rate is less than 60 %. And then, electrosilicoaluminothermal method is developed, by which Ti-Si ferroalloy containing Ti more than 30% and Si less than 35 % can be produced, and Ti recovery rate is higher than 80%. Ti-Si ferroalloy can replace TiFe martially in steelmaking,and residue slag can be used to make cement.  相似文献   

17.
为了规范枝条堆肥、施肥操作,提高有机肥肥效,以枝条腐解率、木质素降解率、种子发芽指数为评价指标,采用正交实验法研究了枝条粉碎度、氮源、微生物菌剂、水分含量等对枝条堆肥效果的影响,优化了枝条堆肥参数,揭示了堆肥过程中N、P、K、Ca、Mg、Zn、Mn的变化规律,比较了枝条有机肥与市售有机肥的施用效果.结果 表明:(1)影...  相似文献   

18.
棕壤有机质测定方法研究   总被引:2,自引:1,他引:1  
本研究采用烘箱加热的方法测定土壤有机质含量,试图探究一种快速、准确测定土壤有机质的方法。为此,以棕壤为例,使用烘箱加热法测定了24个棕壤样品的有机质含量,通过对土壤样品消解温度(100~125℃)和消解时间(30~90 min)的18种梯度组合,分析了改进的烘箱加热法、油浴法与元素分析仪测定结果的差异及适用性。研究表明,18种消解温度和消解时间梯度组合的烘箱加热法测定有机质含量与元素分析仪测定结果相关性均达到极显著水平(r>0.995);当消解温度为115℃、消解时间为30 min时,烘箱加热法测定的有机质含量与元素分析仪测定结果的标准偏差和偏差率为最小;与油浴法相比,烘箱加热法测定的土壤有机质含量的准确性提高了12.4%;因此,本改进方法中,对于供试棕壤的最佳消解温度115℃,消解时间为30 min。与传统的油浴加热法相比,烘箱加热法具有操作简单、测定速度快、温度易于控制、减少了环境污染等优点。  相似文献   

19.
山东省青州市西南部碳酸盐岩区的山楂、柿子种植历史悠久且果实品质上乘,通过系统配套采集山楂和柿子果实及其根系土,探究其含硒水平、富集规律及其影响因素,以期为后续富硒产业开发提供科学依据。研究结果表明:(1)研究区内山楂和柿子根系土中Se元素相对富集,其与有机质密切相关,由于有机质的吸附固化,易利用态硒含量低。(2)山楂和柿子果实中硒含量较低,富集系数也较低,山楂富硒率为17.65%,柿子均未达到富硒。(3)柿子和山楂中硒富集系数与根系土中有机质、硒含量均呈强负相关。(4)有机质吸附固化硒,虽提高了土壤硒含量,但降低了硒的生物可利用性,有机质是影响硒有效性的关键因素。  相似文献   

20.
《Agricultural Wastes》1984,9(2):87-99
Laboratory experiments showed that calcium hydroxide (as a laboratory reagent or as a commercial preparation), or calcium oxide, applied to rice straw by soaking for 24 h was as effective in increasing in vitro organic matter digestibility as sodium hydroxide applied by the spray method.Subsequently, twelve mature sheep, weighing 47–54 kg, were allocated to two groups and fed with diets containing rice straw treated with either the commercial preparation of calcium hydroxide or with sodium hydroxide. To provide equivalent amounts of base, the calcium hydroxide was applied at 9 g per 100 g straw dry matter and sodium hydroxide was applied at 5 g per 100 g straw dry matter. The calcium hydroxide was mixed with 1·2 litres of water per 100 g straw and allowed to react for 24 h, after which the straw was removed, pressed at 1 kg-cm2 to remove some of the excess water, and then dried. The sodium hydroxide was mixed with 100 ml of water per 100 g straw, sprayed on to the straw in a horizontal mixer and allowed to react for 24 h; the treated straw was then dried. Prior to feeding, each treated straw was supplemented with 2·5% urea, 0·6% potassium sulphate, 3% molasses and 3% minerals. Digestibility and ad libitum intake measurements were made during the last 10 days of a 28- to 33-day experimental period.The diet containing rice straw treated with calcium hydroxide had a similar organic matter digestibility to the diet containing rice straw treated with sodium hydroxide (61 and 63%, respectively), the ad libitum organic matter intakes were similar (66 and 62 g kg W−.75 day−1, respectively), and the calculated intakes of digestible organic matter were similar (40 and 39 g kgW−0·75) day−1, respectively).  相似文献   

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