多功能污水处理剂高铁酸钾的制备与应用

介绍了多功能污水处理剂高铁酸钾的特性及其制备工艺和应用范围,讨论了反应温度、反应时间、铁盐浓度等条件对高铁酸钾产率的影响.确定的优化条件为氧化反应温度30℃±5℃,时间50 min,铁盐浓度30%,混合次氯酸盐为饱和溶液.     

有机膨润土的制备及其在6-硝废水处理中的应用

以CTMAB为改性剂制备有机膨润土,并用改性后的膨润土吸附6-硝废水.膨润土改性条件为:液固体积(mL)质量(g)比6∶1,pH值为1,反应温度为60℃,反应时间为1 h进行酸活化;将上述酸活化的膨润土按膨润土阳离子交换容量的100%加人CTMAB,反应时间为80 min得到有机膨润土;6-硝废水吸附条件为:取上述有机...     

废液晶显示器偏光片水热产乳酸研究

以废液晶显示面板中的偏光片为原料,对其进行水热产乳酸研究,并考察了反应温度(250～375℃)、反应时间(1～11min)以及氧化剂(体积分数为30％的H2O2)投加量(0～1.0 mL)对乳酸产率的影响.结果表明,反应温度、反应时间均会对偏光片水热产乳酸产生一定影响,乳酸产率随反应温度和反应时间的增加呈现先增加后减少的趋势,最佳水热条件为反应温度350℃,反应时间5 min,此时乳酸产率达17％左右.投加氧化剂能显著提高乳酸的产率,在最佳水热条件下,氧化剂投加量为0.6 mL时乳酸的产率可提高到21％.     

新型材料处理化学镀镍废水

采用一种同时具备吸附和离子交换功能的新型材料CARBONITE对低浓度化学镀镍废水进行实验研究,分别探讨了CARBONITE用量、pH值、温度和反应时间对CARBONITE去除废水中Ni2+的影响,并考察了CARBONITE的再生性能。实验结果表明,当CARBONITE投加量为1.5 g/L,pH值为6.8,温度为40℃,反应时间为6 h时,CARBONITE对Ni2+去除率可达最大值91.39%。用pH值为4的硫酸溶液对吸附后的CARBONITE进行再生实验,效果良好,再生3次之后的CARBONITE对Ni2+的去除率仍能达到82%左右。     

Fenton氧化破解剩余污泥的实验研究

研究了利用Fenton氧化破解污泥,并以SCOD、TOC、TSS和VSS的变化来表征剩余污泥破解程度.结果表明:pH 2.0,H2O2和Fe2+投加量分别为9.0 g/L和0.8 g/L,反应时间1.5 h,反应温度60℃为Fenton氧化破解污泥的最佳反应条件.该条件下,TSS由8.14 g/L减少到5 g/L,TS...     

催化湿式氧化中负载型催化剂的稳定性与应用

催化剂在应用过程中必须具有良好的催化活性和稳定性.优化制备的CuO/γ-Al2O3催化剂用于处理高浓度难降解的乳化液废水时具有良好的催化活性,在200℃时反应2 h,TOC去除率为81.3%,比未加催化剂的湿式氧化提高了14.9%.该催化剂对分散兰废水具有更高的活性和稳定性:在220℃反应1.5 h后,COD和TOC去除率分别为68.8%和56.5%,比非催化氧化分别提高了18.7%和18.9%.     

涂料废渣水热减量及其产物特性

采用水热技术处理涂料废渣,考察了水热温度、反应时间、含水率和投碱量对涂料废渣减量及其产物特性的影响,并用SEM、元素分析对涂料废渣进行表征。实验结果表明:随着水热温度的升高及时间的延长,涂料废渣减量效果及水热液中COD、TN浓度不断增加,固体产物的热值也随之增加,而含水率对涂料废渣减量的影响不大;随着碱投加量的增加,涂料废渣减量效果和水热液中COD、TN浓度逐渐提高,固体产物的热值呈不规则变化。水热温度220℃、水热时间4 h、含水率77.5%、投碱量0.17 g(NaOH,投加量以每克干物质(DS)计)为涂料废渣减量的最佳反应条件。在最优条件下,总减量率和干重减量率分别为79.1%和52.1%,含水率为47.2%。水热固体产物热值较高,可以作燃料为其他工艺提供热能。     

稀土系列催化剂对焦化废水的催化湿式氧化

以稀土元素Ce制得催化剂系列 ,在高温、高压条件下对焦化废水进行催化湿式氧化研究 ,考察载体、焙烧温度、活性组分的配比对催化剂的催化活性的影响 ,以及反应温度、氧气分压、反应时间和催化剂用量对氧化过程的影响 ,设计正交实验确定最佳的工艺参数 :反应温度为 2 40℃、氧气分压 3 .0MPa ,催化剂用量 30g/L ,此时废水的COD去除率达到90 %以上     

负载氧化镧的活性炭还原NO的研究

稀土金属具有一些特殊的性能,这使得其对碳质材料还原NO的反应可能表现出特殊的催化效果,而此方面的研究没有报道.为了研究稀土金属对活性炭还原NO反应的催化效果,采用浸渍法制备了负载氧化镧的活性炭颗粒(La/C),并在无氧的固定床反应器中进行了程序升温反应和等温反应,考察了气体流量、NO的入口浓度、反应温度和氧化镧负载量对反应活性的影响,同时对反应机理和动力学进行了初步探讨.研究结果表明负载氧化镧的活性炭还原NO的反应是一级反应.由于炭表面3%(质量分数)的氧化镧的存在,C-NO反应的起始反应温度从500 ℃降低到300 ℃,反应活性大大提高,反应活化能从88.95 kJ/mol降低到51.05 kJ/mol.氧化镧的负载量对反应活性有重要影响,但负载量的大量增加对反应活性的提高效果甚微,最佳负载量为1.5%.La/C体系在反应中较稳定,而反应温度的升高对其稳定性不利.     

应用超临界水气化技术的垃圾渗滤液资源化制氢技术研究

利用超临界水气化技术从垃圾渗滤液中制取H_2,当垃圾渗滤液总有机碳(TOC)和TN初始质量浓度分别为3 207~14 810、530~1 480mg/L时,分析了温度、压力、反应时间和催化剂Na2CO3对气化产物中H_2摩尔分率和产率的影响,以及TOC、TN去除率的变化趋势。结果表明:(1)随着温度的升高,H_2摩尔分率、产率和TOC、TN去除率均提高,500℃时分别达到55.60%、94.73mol/kg、71.89%、36.65%。H_2主要来源于蒸汽重整及水气转换反应。(2)压力的升高不利于H_2的产生,而有利于CH4的获得。(3)适宜的反应时间为5min。(4)催化剂Na2CO3的投加增加了气相产物中H_2摩尔分率和产率,有利于H_2的获得;TN去除率增加,但TOC去除率却下降。     

Junge relationships in measurement data for cyclic siloxanes in air

In 1974, Junge postulated a relationship between variability of concentrations of gases in air at remote locations and their atmospheric residence time, and this Junge relationship has subsequently been observed empirically for a range of trace gases. Here, we analyze two previously-published datasets of concentrations of cyclic volatile methyl siloxanes (cVMS) in air and find Junge relationships in both. The first dataset is a time series of concentrations of decamethylcyclopentasiloxane (D₅) measured between January and June, 2009 at a rural site in southern Sweden that shows a Junge relationship in the temporal variability of the measurements. The second dataset consists of measurements of hexamethylcyclotrisiloxane (D₃), octamethylcyclotetrasiloxane (D₄) and D₅ made simultaneously at 12 sites in the Global Atmospheric Passive Sampling (GAPS) network that shows a Junge relationship in the spatial variability of the three cVMS congeners. We use the Junge relationship for the GAPS dataset to estimate atmospheric lifetimes of dodecamethylcyclohexasiloxane (D₆), 8:2–fluorotelomer alcohol and trichlorinated biphenyls that are within a factor of 3 of estimates based on degradation rate constants for reaction with hydroxyl radical determined in laboratory studies.     

The growth response of Alternanthera philoxeroides in a simulated post-combustion emission with ultrahigh [CO2] and acidic pollutants

Although post-combustion emissions from power plants are a major source of air pollution, they contain excess CO₂ that could be used to fertilize commercial greenhouses and stimulate plant growth. We addressed the combined effects of ultrahigh [CO₂] and acidic pollutants in flue gas on the growth of Alternanthera philoxeroides. When acidic pollutants were excluded, the biomass yield of A. philoxeroides saturated near 2000 μmol mol⁻¹ [CO₂] with doubled biomass accumulation relative to the ambient control. The growth enhancement was maintained at 5000 μmol mol⁻¹ [CO₂], but declined when [CO₂] rose above 1%, in association with a strong photosynthetic inhibition. Although acidic components (SO₂ and NO₂) significantly offset the CO₂ enhancement, the aboveground yield increased considerably when the concentration of pollutants was moderate (200 times dilution). Our results indicate that using excess CO₂ from the power plant emissions to optimize growth in commercial green house could be viable.     

Relationship between ammonia stomatal compensation point and nitrogen metabolism in arable crops: current status of knowledge and potential modelling approaches

The ammonia stomatal compensation point of plants is determined by leaf temperature, ammonium concentration ([NH4+]apo) and pH of the apoplastic solution. The later two depend on the adjacent cells metabolism and on leaf inputs and outputs through the xylem and phloem. Until now only empirical models have been designed to model the ammonia stomatal compensation point, except the model of Riedo et al. (2002. Coupling soil-plant-atmosphere exchange of ammonia with ecosystem functioning in grasslands. Ecological Modelling 158, 83-110), which represents the exchanges between the plant's nitrogen pools. The first step to model the ammonia stomatal compensation point is to adequately model [NH4+]apo. This [NH4+]apo has been studied experimentally, but there are currently no process-based quantitative models describing its relation to plant metabolism and environmental conditions. This study summarizes the processes involved in determining the ammonia stomatal compensation point at the leaf scale and qualitatively evaluates the ability of existing whole plant N and C models to include a model for [NH4+]apo.     

O3、H2O2/O3及UV/O3在焦化废水深度处理中的应用

采用O₃、H₂O₂/O₃和UV/O₃等高级氧化技术(AOPs)对某焦化公司的生化出水进行深度处理，考察了O₃与废水的接触时间、溶液pH、反应温度等因素对废水COD去除率的影响，确定出O₃氧化反应的最佳工艺参数为：接触时间40 min，溶液pH 8.5，反应温度25℃，此条件下废水COD及UV₂₅₄的去除率最高可达47.14%和73.47%；H₂O₂/O₃及UV/O₃两种组合工艺对焦化废水COD及UV₂₅₄的去除率均有一定程度的提高，但H₂O₂/O₃系统的运行效果取决于H₂O₂的投加量。研究结论表明，单纯采用COD作为评价指标，并不能准确反映出O₃系列AOPs对焦化废水中有机污染物的降解作用。     

Impact of biochar application to a Mediterranean wheat crop on soil microbial activity and greenhouse gas fluxes

Biochar has been recently proposed as a management strategy to improve crop productivity and global warming mitigation. However, the effect of such approach on soil greenhouse gas fluxes is highly uncertain and few data from field experiments are available. In a field trial, cultivated with wheat, biochar was added to the soil (3 or 6 kg m⁻²) in two growing seasons (2008/2009 and 2009/2010) so to monitor the effect of treatments on microbial parameters 3 months and 14 months after char addition. N₂O, CH₄ and CO₂ fluxes were measured in the field during the first year after char addition. Biochar incorporation into the soil increased soil pH (from 5.2 to 6.7) and the rates of net N mineralization, soil microbial respiration and denitrification activity in the first 3 months, but after 14 months treated and control plots did not differ significantly. No changes in total microbial biomass and net nitrification rate were observed. In char treated plots, soil N₂O fluxes were from 26% to 79% lower than N₂O fluxes in control plots, excluding four sampling dates after the last fertilization with urea, when N₂O emissions were higher in char treated plots. However, due to the high spatial variability, the observed differences were rarely significant. No significant differences of CH₄ fluxes and field soil respiration were observed among different treatments, with just few exceptions. Overall the char treatments showed a minimal impact on microbial parameters and GHG fluxes over the first 14 months after biochar incorporation.     

二氧化铅电极的制备、表征及其电催化性能研究

以电沉积法制备了Ti/PbO2和Ti/MnO2/PbO22种电极.采用SEM、XRD和XPS等分析方法表征了电极的形貌、元素组成及元素化学态,并以罗丹明B为目标有机物,考察了所制备电极的析氧极化曲线和电催化活性以及Ti/MnO2/PbO2电极的循环伏安曲线.研究结果表明,Ti/MnO2/PbO2电极的稳定性、使用寿命、析氧电位和电催化活性较Ti/PbO2电极都有所提高,并且罗丹明B在Ti/MnO2/PbO2电极上的反应主要发生在析氧反应区,且反应不可逆.     

钛基IrO2-SnO2电极在烟气海水脱硫恢复系统中的应用

采用浸渍-热分解法制备了含IrOx-TiO2中间层的IrO2-SnO2电极,得到的电极具有较高的析氯电催化活性和较强的稳定性,并通过电化学氧化法对Na2SO3海水脱硫模拟液进行处理,考察了电流密度、温度、pH值和电解时间等电解工艺参数对Na2SO3去除率和化学需氧量COD的影响.结果表明,在电流密度为200 mA/cm...     

Susceptibility of epigeic earthworm Eisenia fetida to agricultural application of six insecticides

Ecotoxicological risks of agricultural application of six insecticides to soil organisms were evaluated by acute toxicity tests under laboratory condition following OECD guidelines using the epigeic earthworm Eisenia fetida as the test organism. The organochlorine insecticide endosulfan (LC₅₀ - 0.002 mg kg⁻¹) and the carbamate insecticides aldicarb (LC₅₀ - 9.42 mg kg⁻¹) and carbaryl (LC₅₀ - 14.81 mg kg⁻¹) were found ecologically most dangerous because LC₅₀ values of these insecticides were lower than the respective recommended agricultural dose (RAD). Although E. fetida was found highly susceptible to the pyrethroid insecticide cypermethrin (LC₅₀ - 0.054 mg kg⁻¹), the value was higher than its RAD. The organophosphate insecticides chlorpyrifos (LC₅₀ - 28.58 mg kg⁻¹), and monocrotophos (LC₅₀ - 39.75 mg kg⁻¹) were found less toxic and ecologically safe because the LC₅₀ values were much higher than their respective RAD.     

Effects of nickel chloride and oxygen depletion on behaviour and vitality of zebrafish (Danio rerio, Hamilton, 1822) (Pisces, Cypriniformes) embryos and larvae

We examined acute (2 h exposure of 5-day-old larvae) and subchronic (exposure from fertilization up to an age of 11 days) effects of NiCl(2).6H2O on embryos and larvae of zebrafish (Danio rerio), both alone and in combination with oxygen depletion. The following endpoints were recorded: acute exposure: locomotory activity and survival; subchronic exposure: hatching rate, deformations, locomotory activity (at 5, 8 and 11 days) and mortality. In acute exposures nickel chloride (7.5-15 mg Ni/L) caused decreasing locomotory activity. Oxygen depletion (or=10 mg Ni/L resulted in delayed hatching at an age of 96 h, in decreased locomotory activity at an age of 5 days, and increased mortality at an age of 11 days (LC20=9.5 mg Ni/L). The observed LOEC for locomotory activity (7.5 mg Ni/L) is in the range of environmentally relevant concentrations. Since locomotory activity was already affected by acute exposure, this parameter is recommended to supplement commonly recorded endpoints of toxicity.     

Sources and processes affecting concentrations of PM10 and PM2.5 particulate matter in Birmingham (U.K.)

Hourly average concentrations of PM₁₀ and PM_2.5 have been measured simultaneously at a site within Birmingham U.K. between October 1994 and October 1995. Comparison of PM₁₀ and NO_x data with two other sites in the same city shows comparable summer and winter mean concentrations and highly significant inter-site correlations for both hourly and daily mean data. Over a four-month period samples were also collected for chemical analysis of sulphate, nitrate, chloride, ammonium and elemental and organic carbon. Analysis of the data indicates a marked difference between summer and winter periods. In the winter months PM_2.5 comprises about 80% of PM₁₀ and is strongly correlated with NO_x indicating the importance of road traffic as a source. In the summer months, coarse particles (PM₁₀−PM_2.5) account for almost 50% of PM₁₀ and the influence of resuspended surface dusts and soils and of secondary particulate matter is evident. The chemical analysis data are also consistent with three sources dominating the PM₁₀ composition: vehicle exhaust emissions, secondary ammonium salts and resuspended surface dusts. Coarse particles from resuspension showed a positive dependence on windspeed, whilst elemental carbon derived from road traffic exhibited a negative dependence.