共查询到17条相似文献,搜索用时 140 毫秒
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研究了上流式厌氧复合床反应器(UASBF)处理垃圾渗滤液的启动期、负荷提高期、运行期的处理效果及CODCr负荷、pH、碱度对反应器运行的影响.结果表明,启动期最佳启动温度在35±1℃,进水pH6.8,CODCr浓度1000~1200 mg·L-1,水力停留时间(HRT)48h,容积负荷为0.5kgCODCr·m-3·d-1.提高期和运行期容积负荷为10kg CODCr·m-3·d-1,CODCr去除率为71.5%,氨氮去除率为57.5%,总磷去除率为64.8%,悬浮物达到去除率为55%. 相似文献
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石油焦基高比表面积活性炭对废水中CODCr的吸附能力 总被引:2,自引:0,他引:2
探讨了高比表面积活性炭(HSAAC)吸附水中CODCr时,活性炭用量、pH值和吸附时间等因素对CODCr吸附量和去除率的影响。实验结果表明,HSAAC用量越大,去除CODCr效果越好。当HSAAC用量为2.0g·L-1,pH=3时,去除率达到78%以上;在酸性条件下HSAAC对CODCr的去除效果较好;HSAAC对废水中CODCr的吸附发生在前30min;CODCr浓度低于60mg·L-1时,处理后CODCr的残余质量浓度低于地表水环境质量Ⅰ类标准(15mg·L-1)。用碱再生HSAAC,一次再生率达94.22%,二次再生率达到了86.90%。说明高比表面积活性炭在适宜条件下对CODCr具有较好的吸附性能和良好的再生效果。 相似文献
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光催化氧化降解制药废水中头孢曲松钠的研究 总被引:5,自引:1,他引:4
以二氧化钛(TiO2)为光催化剂,分别采用高压汞灯和反射镝灯为紫外光和模拟日光光源,对头孢曲松钠进行光催化降解,用紫外光谱跟踪其光催化降解过程。考察了光催化体系中光源、催化剂用量、光照时间、电子受体以及其他离子的存在对光催化降解过程的影响。结果显示,当反应物初始浓度500mg·L-1,在高压汞灯和反射镝灯条件下反应5小时后,在催化剂用量分别为2.5g·L-1和2.0g·L-1时对头孢曲松钠的降解效果最好,分别达到93.4%和73.8%。体系中加入电子受体能促进光催化反应速率,而一些无机离子如HCO3-、SO42-、Cl-等的存在显著降低了TiO2光催化剂的活性。实验结果有助于抗生素制药工业废水的光催化处理研究。 相似文献
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耐高浓度氨氮的异养硝化好氧反硝化菌株U1的鉴定及其脱氮特性 总被引:1,自引:1,他引:0
【背景】城市垃圾渗滤液是一种成分复杂的有机废水,含氮量高,如果未经处理直接排放到环境中会造成严重的环境污染。【目的】筛选可以耐受垃圾渗滤液中高浓度氨氮并高效去除污水中氮素的异养硝化好氧反硝化菌株,为解决垃圾渗滤液的氮素污染提供功能菌株。【方法】从垃圾渗滤液中筛选分离能耐受高氨氮浓度的菌株,通过测定各菌株的脱氮能力,筛选到一株脱氮能力最强的菌株,命名为U1,通过测定16S rRNA基因序列和生理生化特性确定该菌株为铜绿假单胞菌。进一步研究了菌株U1在不同初始氨氮浓度、碳源、转速、初始pH、碳氮比等单因素变量下的脱氮能力,并结合L9(34)正交试验研究了菌株U1的最佳脱氮条件。【结果】分离出一株铜绿假单胞菌并命名为U1。该菌株的最优脱氮条件为:初始氨氮浓度为1 000 mg/L,红糖和柠檬酸三钠的混合碳源,pH 6.0,C/N为10,转速为130 r/min,菌株U1的最大总氮去除率为64.37%,最大氨氮去除率为76.73%。对于总氮和氨氮含量分别是2 345 mg/L和1 473.8 mg/L的垃圾渗滤液,菌株U1最大总氮去除率为27.86%... 相似文献
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准好氧填埋渗滤液水质变化特性研究 总被引:14,自引:0,他引:14
在大型模拟填埋试验装置(21 m×3.8 m×6.0 m)上,研究了准好氧填埋渗滤液水质的主要指标CODCr、BOD、NH3+-N和pH的变化特性.结果表明,准好氧填埋结构下渗滤液CODCr、BOD浓度下降很快,没有出现在传统填埋场累积的现象,并且封场后39周分别降为173和30 mg·L-1;NH3+-N浓度下降更为显著,第39周降为1 mg·L-1,下降率达到99.6%,为渗滤液后续处理解决了NH3+-N浓度过高的难题;pH值在前2周略低于7,第3周后一直呈弱碱性.根据实验数据,拟合了准好氧填埋结构渗滤液污染物的衰减方程. 相似文献
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用溶胶-凝胶法在不同温度下煅烧,合成了系列LAVO4光催化剂,用XRD,FT-IR,SEM,BET,UV-Vis DRS对催化剂进行了表征,考察了其可见光催化降解罗丹明B的性质.结果表明,在200℃煅烧可合成t-LaVO4晶体,300℃以上煅烧有利于制备m-LAVO4.催化剂样品为多孔结构,比表面积大,可见光催化活性良好.300℃制各的样品具有最好的光催化活性,可见光催化6 h后,罗丹明B降解率达65.45%,比TiO4的降解率高48.07%.加入电子受体或调节初始溶液pH值为酸性(pH=3)都可大幅度提高m-LaVO4的可见光催化活性,m-LaVO4可见光催化反应2 h后,罗丹明B均可完全降解. 相似文献
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利用烧杯混凝试验,通过改变pH值、药剂投加量等方法开展了一系列混凝试验,比较了一种新型聚合混凝剂硫酸铝聚合氯化铝对以木浆为主的制浆造纸厂的综合废水的处理效果.结果表明,在最佳pH值和投药量条件下,新型聚合混凝剂的处理效果最好.当pH为8.29,药剂投加量为175mg·L-1时,即使不投加CPAM,处理后的废水CODCr去除率为87.4%,浊度去除率为96.4%,色度去除率为89.5%;出水CODCr和色度分别为90mg·L-1左右和约32倍,均达到了广东省《水污染物排放限值》(DB4426-2001)第二时段的一级标准. 相似文献
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通过室内好氧、厌氧2种培养,研究了3种不同填埋年限垃圾渗滤液在红壤和潮土中的生物降解动态.鲜样、天井洼样、水阁样垃圾渗滤液分别为填埋0年、4~5年和12年的垃圾渗滤液.结果表明,垃圾渗滤液在前7 d降解相对较快.在好氧培养条件下,红壤鲜样、天井洼样、水阁样渗滤液在前7 d的表观降解率为88.9%、60.5%、25.0%;潮土中的表观降解率更大,分别为96.6%、80.4%和65.0%;7 d后下降趋势均趋于平缓.在相同土壤中,填埋龄越短的垃圾渗滤液的表观降解率越大,在厌氧培养条件下的情况与此类似,但降解率不如好氧条件下高.在没有土壤介质参与的条件下(如低洼处积存的渗滤液),3种垃圾渗滤液自身降解速率均符合一级动力学方程.鲜样垃圾渗滤液降解的半衰期为12~16 d,其余垃圾渗滤液降解的半衰期为20~30 d.垃圾渗滤液一旦进入土壤环境,降解速率会大大加快.土壤处理垃圾渗滤液有一定的功效. 相似文献
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为获得能适合于烟道气条件下生长的微藻,找到一种高效的温室气体固定的方法,利用配置烟道气(CO2和O2的浓度分别为15%和2%)驯化稻田微藻混合试样,分离出对高浓度CO2条件有很强适应力的微藻ZY-1,并研究了在不同培养条件下微藻ZY-1的生长情况.微藻ZY-1在CO2浓度从10%~15%的范围内有较高生长力,在CO2浓度为10%时,生长最好.微藻ZY-1对温度、气体流速、pH值等物理条件也有很宽的适应范围,在温度为25~30.C、流速为0.25~0.75L·min-1、pH4~6范围内,生长基本稳定.在培养条件为10%CO2、25.C、pH5.0时,微藻ZY-1的生长率最高,CO2的固定率平均值为0.397%.可以认为,利用该藻固定烟道气温室气体具有一定的可行性. 相似文献
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Photo-irradiated titanium dioxide catalyzes site specific DNA damage via generation of hydrogen peroxide 总被引:5,自引:0,他引:5
Titanium dioxide (TiO2) is a potential photosensitizer for photodynamic therapy. In this study, the mechanism of DNA damage catalyzed by photo-irradiated TiO2 was examined using [32P]-5'-end-labeled DNA fragments obtained from human genes. Photo-irradiated TiO2 (anatase and rutile) caused DNA cleavage frequently at the guanine residue in the presence of Cu(II) after E. coli formamidopyrimidine-DNA glycosylase treatment, and the thymine residue was also cleaved after piperidine treatment. Catalase, SOD and bathocuproine, a chelator of Cu(I), inhibited the DNA damage, suggesting the involvement of hydrogen peroxide, superoxide and Cu(I). The photocatalytic generation of Cu(I) from Cu(II) was decreased by the addition of SOD. These findings suggest that the inhibitory effect of SOD on DNA damage is due to the inhibition of the reduction of Cu(II) by superoxide. We also measured the formation of 8-oxo-7,8-dihydro-2' -deoxyguanosine, an indicator of oxidative DNA damage, and showed that anatase is more active than rutile. On the other hand, high concentration of anatase caused DNA damage in the absence of Cu(II). Typical free hydroxyl radical scavengers, such as ethanol, mannnitol, sodium formate and DMSO, inhibited the copper-independent DNA photodamage by anatase. In conclusion, photo-irradiated TiO2 particles catalyze the copper-mediated site-specific DNA damage via the formation of hydrogen peroxide rather than that of a free hydroxyl radical. This DNA-damaging mechanism may participate in the phototoxicity of TiO2. 相似文献
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Qing Shi Dong Yang Zhongyi Jiang Jian Li 《Journal of Molecular Catalysis .B, Enzymatic》2006,43(1-4):44-48
P-doped TiO2 nanoparticles were prepared by the sol–gel method and characterized by XRD, BET, SEM, XPS and UV–vis spectrum. The results indicated that the doping of phosphorus could efficiently inhibit the grain growth and enhance the surface area of TiO2 nanoparticles. The doped phosphorus was present as the pentavalent-oxidation state, which can replace a part of Ti4+ in the crystal lattice of anatase. Because P5+ can accept photoelectron as the electron trap center, its doping reduces the recombination rate of photogenerated charge carriers. In addition, P-doped TiO2 nanoparticles also show stronger absorption in the visible light range than the pure sample, because of the formation of an impurity energy level within the band gap of TiO2. Correspondingly, P-doped TiO2 nanomaterials show higher ability of NADH photogenenration under visible-light irradiation than pure TiO2. 相似文献
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The adsorption of iron(III), lead(II) and cadmium(II) ions onto Schizomeris leibleinii, a green alga, was studied with respect to initial pH, temperature, initial metal ion and biomass concentration to determine the optimum adsorption conditions. Optimum initial pH for iron(III), lead(II) and cadmium(II) ions were 2.5, 4.5 and 5.0 at optimum temperature 30°C, respectively. The initial adsorption rates increased with increasing initial iron(III), lead(II) and cadmium(II) ion concentrations up to 100, 100 and 150 mg l−1, respectively. The Freundlich and Langmuir adsorption isotherms were developed at various initial pH and temperature values. The adsorption of these metal ions to S. leibleinii was investigated in a two-stage mixed batch reactor. The residual metal ion concentrations (Ceq) at equilibrium at each stage for a given ‘quantity of dried algae (X0)/volume of solution containing heavy metal ion (V0)’ ratio were calculated using Freundlich and Langmuir isotherm constants. The experimental biosorption equilibrium data for iron(III), lead(II) and cadmium(II) ions were in good agreement with those calculated by both Freundlich and Langmuir models. The adsorbed iron(III), lead(II) and cadmium(II) ion concentrations increased with increasing X0/V0 ratios while the adsorbed metal quantities per unit mass of dried algae decreased. 相似文献
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对绿色木霉接种到啤酒糟固态发酵产纤维素酶的培养基和培养条件进行优化,考察发酵物料起始含水量、发酵时间、起始pH值等发酵条件,以及啤酒糟培养基中添加麸皮、氮源种类对产酶的影响。结果表明,以啤酒糟为发酵基质接种绿色木霉生产纤维素酶是可行的。经单因素和正交试验获得最适固态发酵的培养条件为:起始pH 5~6,培养温度28~30℃,发酵4 d;最佳发酵培养基组合为:麸皮比例30%,培养基起始含水量50%,(NH4)2SO4添加量为2.0%~2.5%。 相似文献
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Ho Jin Kang Cheorun Jo Na Young Lee Joong Ho Kwon Myung Woo Byun 《Carbohydrate polymers》2005,60(4):547-551
Using citrus pectin a biodegradable film was prepared by a combination treatment of gamma irradiation (0, 10, 20, and 30 kGy) and CaCl2 immersion (0, 5, and 10%) cross-linking. The tensile strength of the pectin-based film was the highest in the 5% CaCl2 treatment at 20 kGy of an irradiation dose. The tensile strength of the film with CaCl2 was generally higher than that of the non-CaCl2 treatment. The elongation at break and water vapor permeability were the lowest at a CaCl2 of 5% among the irradiated treatments. The total organic carbon content produced from the Paenibacillus polymyxa and Pseudomonas aeruginosa showed that the film of the 20 kGy-irradiated film was lower than those of the 0, 10, and 30 kGy-irradiated films. In conclusion, irradiation of the film casting solution at 20 kGy combined with a 5% CaCl2 immersion resulted in film with improved mechanical properties and biodegradability. 相似文献