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1.
采用产碱杆菌(Alcaligenes sp.)DN25去除金矿选矿废水和矿渣浸出液中的氰。考察了菌株DN25的除氰效果,研究了DN25生长和降解活性的影响因素。实验结果表明:利用DN25处理选矿废水,当反应时间为23 h时,总氰质量浓度分别从162.6,32.4,21.0,22.3 mg/L降至0,0.07,0,1.24 mg/L;利用DN25处理矿渣浸出液,当反应时间为25 h时,总氰质量浓度分别从 4.4,8.8 mg/L降至0.37,0.38 mg/L;处理后两种废水的总氰质量浓度均满足GB 8978—1996《污水综合排放标准》的要求;DN25可在初始总氰质量浓度为10~30 mg/L且仅含碳源的条件下生长但存在24 h停滞期,而在初始总氰质量浓度为5~20 mg/L且含碳、氮源的条件下没有生长停滞期。  相似文献   

2.
铝碳微电解法降解水中邻苯二甲酸酯   总被引:1,自引:0,他引:1       下载免费PDF全文
徐焕成  王平  赵雨  严洁 《化工环保》2014,34(6):511-514
采用铝碳微电解法降解水中邻苯二甲酸酯(PAEs)。首先考察了初始废水pH、铝碳质量比和反应时间对邻苯二甲酸二甲酯(DMP)降解率的影响,然后分别考察了超声波频率、其他金属的添加和H2O2加入量对铝碳微电解法降解模拟混合PAEs废水中DMP、邻苯二甲酸二乙酯(DEP)和邻苯二甲酸二丁酯(DBP)的影响。实验结果表明:在初始DMP质量浓度为20 mg/L、初始废水pH为12.0、铝碳质量比为1∶1、反应时间为30 min的条件下,DMP降解率达49.94%;在上述最佳反应条件下处理DMP,DEP,DBP的质量浓度分别为20,10,8 mg/L的模拟混合PAEs废水,当超声波频率为80 kHz时,模拟混合PAEs废水中DMP,DEP,DBP的降解率分别为63.38%,32.75%,32.23%,当铝铁质量比为100∶1时,DMP,DEP,DBP的降解率分别为59.61%,37.39%,31.50%;添加铜和H2O2对PAEs的降解有抑制作用。  相似文献   

3.
彭娜  王开峰  涂常青  黎忠 《化工环保》2011,31(5):464-468
采用黄酒糟对模拟染料废水中的活性艳红和亚甲基蓝进行吸附.在染料初始质量浓度100 mg/L、黄酒糟加入量10 g/L、吸附时间2 h的条件下,当活性艳红废水初始pH 为2.0 ~10.0 时,黄酒糟对活性艳红的吸附率为94.0% ~95.7%;当亚甲基蓝废水初始pH 为11.0 ~12.0 时,黄酒糟对亚甲基蓝的吸附率...  相似文献   

4.
采用可见光分解(光解)-氯碱氧化法去除模拟废水中的Fe(CN)63-。考察了光解过程中反应时间、初始Fe(CN)63-质量浓度和初始废水pH对Fe(CN)63-去除效果及表观反应速率常数(k(Fe(CN)63-))的影响,以及光解-氯碱氧化法对Fe(CN)63-模拟废水中总氰化物(TCN)的去除效果。实验结果表明:在初始Fe(CN)63-质量浓度6.7 mg/L、初始废水pH 12、反应时间8.0 h的条件下,Fe(CN)63-的去除率为83%,光解过程符合表观一级动力学模型;在初始Fe(CN)63-质量浓度6.7 mg/L、初始TCN质量浓度4.90 mg/L、初始废水pH 12、反应时间12.0 h的条件下,采用光解-氯碱氧化法可使Fe(CN)63-模拟废水的TCN质量浓度降至0.14 mg/L,低于GB 16171—2012的要求(0.2 mg/L),该过程的限速步骤为Fe(CN)63-的光解破络过程。  相似文献   

5.
以模拟含油废水为处理对象,用辣根过氧化物酶(HRP)去除水中的油,研究了HRP催化氧化柴油反应的工艺条件。实验结果表明,当柴油质量浓度为120mg/L时,在H2O2质量浓度为250mg/L、HRP的酶活性浓度为0.8U/mL、废水pH为7.4、温度为27℃、反应时间为3h的最佳工艺条件下,除油率可达60.89%。实验还考察了壳聚糖和聚乙二醇(PEG)对HRP催化过程的影响。实验结果显示,壳聚糖对HRP催化过程的影响很小,PEG则有很好的强化作用,在PEG质量浓度为160mg/L时,除油率可达79.31%。  相似文献   

6.
采用自制的负载型CuO-ZnO-CeO2/γ-Al2O3催化剂,常温常压下通过紫外辐照-催化湿式氧化技术处理酸性大红GR模拟染料废水。考察了催化剂加入量、H2O2加入量、废水pH、反应时间、初始酸性大红GR质量浓度等对废水脱色率的影响。实验得到最佳工艺条件为初始酸性大红GR质量浓度200mg/L,催化剂加入量10.0g/L,H2O2加入量2.0mL/L,废水pH4,反应时间2h。最佳工艺条件下废水脱色率达99.33%。  相似文献   

7.
铱涂层钛电极电催化氧化降解喹啉   总被引:2,自引:1,他引:1  
采用电催化氧化降解模拟焦化废水中的喹啉,研究了电极种类、废水初始质量浓度、废水pH、极板间距和电流密度对喹啉去除率的影响.实验结果表明,在以铱涂层钛电极为阳极、废水中喹啉初始质量浓度为100 mg/L、废水pH为9、电流密度为20 mA/cm2、极板间距为1 cm、反应时间为720 min时,喹啉去除率达88.1%.并...  相似文献   

8.
从制革废水中分离得到1株好氧反硝化菌ZY1,并对ZY1的反硝化能力进行了研究。通过16S rDNA序列分析,确定ZY1为地衣芽孢杆菌(Bacillus licheniformis)。在初始NO2--N质量浓度为80 mg/L、DO为5.7 mg/L、废水温度为30℃、废水pH为8.0、废水中Cr3+质量浓度为110 mg/L、反应时间为24 h的条件下,ZY1菌对NO2--N的降解率大于98%。  相似文献   

9.
生物刺激与生物强化联合修复柴油污染土壤   总被引:1,自引:0,他引:1       下载免费PDF全文
高闯  张全 《化工环保》2015,35(2):142-146
从柴油污染土壤中筛选分离出一株高效降解柴油的菌株CY-1,考察了自然衰减修复、生物刺激修复、生物强化修复以及生物刺激-生物强化联合修复等4种修复方法对土壤中柴油的降解能力及降解过程中几种土壤微生物酶活性的变化。实验结果表明:该菌为假单胞菌属;采用生物刺激-生物强化联合修复初始柴油质量分数为2.70%的柴油污染土壤,经过31 d的降解,柴油质量分数降至1.09%,柴油去除率达59.6%;经生物刺激-生物强化联合修复,土壤脱氢酶活性和荧光素二乙酸酯水解酶活性最高;通过生物刺激处理可使土壤脲酶活性和磷酸酶活性达到最高。  相似文献   

10.
电化学法处理高盐苯酚废水的研究   总被引:9,自引:0,他引:9  
对在氯盐电解质中用电化学方法处理含酚废水进行了研究,着重探讨了盐的种类与浓度、反应温度与溶液:pH、电流密度、苯酚初始浓度及阴阳极转换频率对苯酚去除率的影响。在Na2SO4的浓度为0.2mol/L,NaCl的浓度为0.1mol/L、苯酚初始质量浓度为200mg/L、电流密度为0.04A/cm^2、温度为35℃、pH为12.5、阴阳极转换频率为5min/次及反应时间为200min的条件下,苯酚的去除率为99.5%,COD去除率为5%,CIO^-把苯酚氧化成了其他有机化合物。  相似文献   

11.
The burning rate of a slick of oil on a water bed is calculated by a simple expression derived from a one-dimensional heat conduction equation. Heat feedback from the flame to the surface is assumed to be a constant fraction of the total energy released by the combustion reaction. The constant fraction (χ) is named the burning efficiency and represents an important tool in assessing the potential of in situ burning as a counter-measure to an oil-spill. The total heat release, as a function of the pool diameter, is obtained from an existing correlation. It is assumed that radiative heat is absorbed close to the fuel surface, that conduction is the dominant mode of heat transfer in the liquid phase and that the fuel boiling temperature remains constant. By matching the characteristic thermal penetration length scale for the fuel/water system and an equivalent single layer system, a combined thermal diffusivity can be calculated and used to obtain an analytical solution for the burning rate. Theoretical expressions were correlated with crude oil and heating oil, for a number of pool diameters and initial fuel layer thickness. Experiments were also conducted with emulsified and weathered crude oil. The simple analytical expression describes well the effects of pool diameter and initial fuel layer thickness permitting a better observation of the effects of weathering, emulsification and net heat feedback to the fuel surface. Experiments showed that only a small fraction of the heat released by the flame is retained by the fuel layer and water bed (of the order of 1%). The effect of weathering on the burning rate decreases with the weathering period and that emulsification results in a linear decrease of the burning rate with water content.  相似文献   

12.
The simultaneous adsorption of copper (Cu), cadmium (Cd), nickel (Ni), and lead (Pb) ions from spiked deionized water and spiked leachate onto natural materials (peat A and B), by-product or waste materials (carbon-containing ash, paper pellets, pine bark, and semi-coke), and synthetic materials (based on urea-formaldehyde resins, called blue and red adsorbents) or mixtures thereof was investigated. The adsorbents that gave the highest metal removal efficiencies were peat A, a mixture of peat B and carbon-containing ash, and a mixture of peat A and blue. At an initial concentration of 5 mg/l for each metal, the removal of each species of metal ion from spiked water and spiked leachate solutions was very good (>90%) and good (>75%), respectively. When the initial concentration of each metal in the solutions was twenty times higher (100 mg/l), there was a noticeable decrease in the removal efficiency of Cu2+, Cd2+, and Ni2+, but not of Pb2+. Langmuir monolayer adsorption capacities, qm, on peat A were found to be 0.57, 0.37, and 0.36 mmol/g for Pb2+, Cd2+, and Ni2+, respectively. The order of metal adsorption capacity on peat A was the same in the case of competitive multimetal adsorption conditions as it was for single-element adsorption, namely Pb2+ > Cd2+ ≥ Ni2+. The results show that peat alone (an inexpensive adsorbent) is a good adsorbent for heavy metal ions.  相似文献   

13.
采用结构化/非结构化混合网格技术、多孔介质模型及k-ε两方程湍流模型,对某袋式除尘器及进出口管道内的气体流场进行了数值计算.计算结果表明,合理布置导流板后,袋式除尘器两箱体流量偏差为1.8%;除尘器下游滤袋单元处理气量偏大,中游滤袋单元处理气量较小,最大流量与最小流量偏差为22.3%;靠近除尘器进口处灰斗内存在气流回流特性,易造成粉尘的二次附着现象.  相似文献   

14.
The chemical recycling of poly(lactic acid) (PLA) to its monomer is crucial to reduce both the consumption of renewable resources for the monomer synthesis and the environmental impact related to its production and disposal. In particular, the production of lactic acid from PLA wastes, rather than from virgin raw materials, it is also possible to achieve considerable primary energy savings. The focus of this work is to analyse deeply the PLA hydrolytic decomposition by means of a kinetic model based on two reactions mechanism. To this end, new experimental data have been gathered in order to investigate a wider temperature range (from 140 to 180 °C) and to extend the water/PLA ratio up to 50 % of PLA by weight. The reported results clearly highlight that more than 95 % of PLA is hydrolyzed to water-soluble lactic acid within 120 min, when it is hydrolyzed within 160–180 °C. Furthermore, the kinetic constant is highly influenced by reaction temperature. The proposed “two reactions” kinetic mechanism complies satisfactorily with the experimental data under analysis.  相似文献   

15.
对富拉尔基发电总厂5号炉的设计条件进行了分析,针对燃用低硫煤,飞灰比电阻高,场地较小,除尘效率要求高的情况,在电除尘器的设计上采取有效措施,达到了排放要求。  相似文献   

16.
Establishing carbon balances has been proven to be an applicable and powerful tool in testing biodegradability of polymers. In controlled degradation tests at a 4-L scale with the model polymer poly(-hydroxybutyrate) (PHB), it was shown that the degree of degradation could not be determined with satisfactory accuracy from CO2 release alone. Instead, the course of degradation was characterized by means of establishing carbon balances for the degradation of PHB withAcidovorax facilis and a mixed culture derived from compost. Different analytical methods for determining the different carbon fractions were adapted to the particular test conditions and compared. Quantitative determination of biomass and residual polymer were the main problems in establishing carbon balances. Amounts of biomass derived from protein measurements depend strongly on assumptions of the protein content of the biomass. Selective oxidation of biomass with hypochlorite was used as alternative, but here problems arose from insoluble metabolic products. Determination of soluble components with the method of chemical oxygen demand (COD) also includes empirical assumptions but seems acceptable if the dissolved carbon fraction is in the range of some 10% total carbon. Results confirm both analytical assays and theoretical approaches, in ending up at values very close to 100%, within an acceptable standard deviation range under test conditions comparable to standard test practice.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.  相似文献   

17.
The degradation of cellulose (a substantial component of low- and intermediate-level radioactive waste) under alkaline conditions occurs via two main processes: a peeling-off reaction and a basecatalyzed cleavage of glycosidic bonds (hydrolysis). Both processes show pseudo-first-order kinetics. At ambient temperature, the peeling-off process is the dominant degradation mechanism, resulting in the formation of mainly isosaccharinic acid. The degradation depends strongly on the degree of polymerization (DP) and on the number of reducing end groups present in cellulose. Beyond pH 12.5, the OH- concentration has only a minor effect on the degradation rate. It was estimated that under repository conditions (alkaline environment, pH 13.3-12.5) about 10% of the cellulosic materials (average DP = 1000-2000) will degrade in the first stage (up to 105 years) by the peeling-off reaction and will cause an ingrowth of isosaccharinic acid in the interstitial cement pore water. In the second stage (105-106 years), alkaline hydrolysis will control the further degradation of the cellulose. The potential role of microorganisms in the degradation of cellulose under alkaline conditions could not be evaluated. Proper assessment of the effect of cellulose degradation on the mobilization of radionuclides basically requires knowing the concentration of isosaccharinic acid in the pore water. This concentration, however, depends on several factors such as the stability of ISA under alkaline conditions, sorption of ISA on cement, formation of sparingly soluble ISA-salts, etc. A discussion of all the relevant processes involved, however, is far beyond the scope of the presented overview.  相似文献   

18.
Six film samples of low-density polypropylene (LDPE)/linear LDPE (LLDPE)/high-density polypropylene (HDPE) with varying ratios of LDPE (20–45 ... wt%) and LLDPE (25–50 wt%) having a fixed amount of HDPE at 30 wt% were prepared by blown film extrusion technique. The samples were aged at four different temperatures, 55°, 70°, 85°, and 100°C, for four different time periods in the interval of between 150 hours and up to 600 hours. The change in the structure of various constituents and the formation of various oxygenated (peroxy and hydroperoxy) and unsaturated groups during thermo-oxidative degradation was discussed by infrared spectroscopy. The visiosity-average molecular weight was found to have decreased slowly in the initial aging hours and temperatures, whereas it decreased by 10% with its previous value tensile strength that is, 100°C when aged for 600 hours. The tensile strength of the sample first increased by 67% at 55°C and 89% at 70°C up to 450 hours, whereas the values increased by 52.5% at 85°C and 33.9% at 100°C when aged for 150 hours and then decreased. The percentage elongation at break increased by 2.7% at 55°C and 10.7% at 70°C for 150 and 300 hours of aging, respectively, whereas the percentage decreased when aged at 85°C and 100°C for up to 600 hours of aging. The values of gel content (percent) increased and initial degradation temperature decreased with aging time and temperature.  相似文献   

19.
Octenyl succinate starch of degree of substitution (ds) 0.03, 0.07, and 0.11 was synthesized in an aqueous medium. These compounds were then tested for the susceptibility to enzymatic degradation. The multiple-enzyme regime of -amylase, amyloglucosidase, and pullulanase was chosen for the evaluation. This combination of enzymes had been proven to degrade 99.5% of unmodified starch to glucose and hence was chosen for this study. It was found that even small amounts of subsituent caused a considerable decrease in the extent of degradation. The net extent of degradation decreased with increasing ds. Surprisingly, the amount of glucose from all three substituted substrates was quite similar, suggesting the effect small amounts of subtituent had on the enzymatic activity.  相似文献   

20.
The effects of temperature on the release of chemical components of six solid organic materials under conditions of oversaturation were investigated in this paper. The six materials were peat moss (PM), weathered coals (WC), charred rice husks (CRH), sawdust (Sd), turfgrass clippings (TC), and chicken manure (CM). Significant differences were observed in the available nitrogen and phosphorus content of the aqueous extracts of organic materials at different temperatures. The available nitrogen content in aqueous extracts of PM and WC at 25 °C was higher than that registered at 15 °C and 35 °C. Available nitrogen content in the aqueous extracts of CRH, Sd, TC, and WC at 35 °C was higher than at 15 °C and 25 °C. The available phosphorus content in the aqueous extracts of organic materials at 35 °C was higher than that available at 15 °C and 25 °C, with the exception of Sd. In addition, the release of available phosphorus in the aqueous solution of organic materials at different temperatures varied constantly for 108 h. The release of potassium (K+) and sodium (Na+) ions in the aqueous extracts of organic materials was basically steady over time, with the exception of CM. High temperature (35 °C) may significantly hasten the release of K+ from organic substrates (except for WC) with low temperatures significantly inhibiting release of K+ in Sd and CRH. High temperatures (35 °C) might significantly facilitate the release of Na+ in CM and TC. However, no significant differences were manifested in the release of Na+ from organic substrates at different temperatures, with the exception of CM and TC. Moreover, no significant differences were observed in the release of calcium, magnesium and iron ions with time, nor were there any significant differences in the contents of iron ions in the aqueous extracts of organic materials at different temperatures. The results indicate that multiple mediums should be pretreated in water for a week before being used for planting. They should be used when all mineral elements of organic materials are steady and ignoring the effect of organic mediums.  相似文献   

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