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Wendi XU Shuhai GUO Gang LI Fengmei LI Bo WU Xinhong GAN 《Frontiers of Environmental Science & Engineering》2015,9(6):1096-1107
A combined treatment technology (DEF-BIO) using the direct electro-Fenton (DEF) process and bioremediation (BIO) was established in this study. The performance of the DEF-BIO process on the remediation of a pyrene (PYR)-contaminated soil was evaluated in a slurry reactor. The appropriate order of application was to conduct the DEF process followed by BIO, evaluated through analysis of the degradation characteristics of each process individually. In addition, the application time of the DEF process affected the efficiency of the combined process. The optimum time to apply the DEF process was determined through an analysis of the induced changes in PYR intermediates, pH, soil organic matter (SOM) and bacteria. The optimum application time of the DEF process was 6 h. All the induced changes were beneficial for the BIO phase. The removal of PYR was 91.02% for DEF–BIO after 72 h, and the efficiency was almost 50% increased, compared with the individual DEF and BIO treatments. Therefore, the combined process of DEF–BIO process may be an efficient and promising method for the remediation. 相似文献
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采用分步化学沉淀法分别脱除并回收磷酸铁生产废水中的高浓度磷酸根和硫酸根。实验结果表明:在以n(Fe~(3+))∶n(PO_4~(3-))=1.0的比例加入硫酸铁、反应时间为40 min、反应温度为25℃、废水初始p H为8.17、反应30 min时二次调节废水p H至5.50的条件下,磷酸根去除率可达98%以上,所得沉淀中Fe和P的质量分数分别为36.77%和18.81%,成分简单,回收价值高;采用氢氧化钙作为沉淀剂,在n(Ca~(2+))∶n(SO_4~(2-))=1.0的条件下可将废水中硫酸根质量浓度由78.62 g/L降至2.16 g/L,硫酸根去除率为97.3%,硫酸钙回收量为120.2 g/L;最终出水的磷酸根质量浓度小于0.5 mg/L,满足GB 8978—1996《污水综合排放标准》的一级标准。 相似文献
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我国开采原油的稠油比重大、胶质含量高、环境风险突出,亟需解决石油污染土壤中胶质组分的解毒问题.由于胶质结构复杂、难以降解,所以对胶质结构变化的研究较少,其降解率也并不足以说明胶质污染土壤的修复效果,因此本文着重分析了修复过程中胶质结构与毒性的变化,为污染土壤修复体系提供重要指标.本文从辽河油田原油中提取胶质配制污染土,并加入构建的混合菌群.设计微生物修复(Bio)、电动-微生物修复(EK+Bio1)、电动-微生物补充营养修复(EK+Bio2)及间断电动-微生物修复(EK+Bio3)共4种处理.结果表明,胶质平均降解率EK+Bio2EK+Bio3EK+Bio1Bio,降解率最高为9.67%,为Bio处理的3.05倍(3.15%).元素分析结果表明,修复前后胶质平均化学式为C_(106)H_(157)N、C_(96)H_(174)N,碳氢比降低,不饱和度降低.光谱分析与~1H-核磁共振结果表明,修复后胶质碳链变短,芳香环、羧基与酚类结构数量减少.根据B-L法计算胶质芳碳率(f_A)由0.28减少到0.11,可推测胶质的结构模型.MicroResp~(TM)与小麦种子发芽实验结果表明,修复后土壤中微生物活性增强,小麦种子发芽率大大提高,说明结构的变化使胶质毒性降低.因此,电动-微生物修复使胶质结构发生变化,并在一定程度上有效削减了胶质毒性,较好的对胶质污染土壤进行了修复. 相似文献
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Electro-bioremediation is an innovative method to remedy organic-polluted soil. However, the principle of electrokinetic technology enhancing the function of microbes, especially the relationship of electric intensity and biodegradation efficiency, is poorly investigated. Petroleum was employed as a target organic pollutant at a level of 50 g/kg (mass of petroleum/mass of dry soil). A direct current power supply was used for tests with a constant direct current electric voltage (1.0 V/cm). The petroleum concentrations were measured at 3275–3285 nm after extraction using hexane, the group composition of crude oil was analyzed by column chromatography. The water content of soil was kept 25% (m/m). The results indicated the degradation process was divided into two periods: from day 1 to day 40, from day 41 to day 100. The treatment of soil with an appropriate electric field led the bacteria to have a persistent effect in the whole period of 100 days. The highest biodegradation efficiency of 45.5% was obtained after treatment with electric current and bacteria. The electric-bioremediation had a positive effect on alkane degradation. The degradation rate of alkane was 1.6 times higher in the soil exposed to electric current than that treated with bacteria for 100 days. A proper direct current could stimulate the microbial activities and accelerate the biodegradation of petroleum. There was a positive correlation between the electric intensities and the petroleum bioremediation efficiencies with a coefficient of 0.9599. 相似文献
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采用热活化法辅以加压超声浸渍技术将硅酸盐水泥颗粒(PC)和Fe2O3负载于稻壳生物炭(RHC)的表面,得到了具有优异除磷效能和高选择性吸附性能的Fe2O3/PC功能化复合多孔炭材料(Fe-PC/RHC).基于磷吸附容量和磷去除率,对PC和Fe3+负载进行量的优化;选取优化炭进行比表面积、孔径分布、物相结构、表面结构、微观形貌和零电位点表征测定.结果表明:复合炭材料表面均匀分散着硅酸钙盐、硅酸铁盐和Fe2O3等矿物活性颗粒,对其比表面积、孔结构和吸附性能具有增强作用;当RHC:PC=0.8:1(质量比),Fe3+:RHC=2:1(2 mmol·g-1)时制备的炭材料Fe2-PC/RHC,投加0.2 g,处理100 mg·L-1的磷酸盐溶液,在pH=6~8的条件下表现出了优异的吸附性能;铁盐的掺杂能有效调控介质pH值从11.09降低至7.71,zeta电位从2.82提高到7.57;准二级动力学模型和Langmiur模型更适用于描述Fe2-PC/RHC吸附磷酸盐的过程,吸附4 h后逐渐趋于平衡,饱和吸附量为69.92 mg·g-1;在几种常见阴离子和阳离子共存的情况下,Fe2-PC/RHC对磷酸盐仍然表现出了优异的选择性吸附;结合吸附前后材料的表征结果,化学吸附是主要的除磷机理,此外还可能存在配体交换和静电吸引. 相似文献
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如何科学设定火源功率是研究高速列车火灾防治的基础和关键,目前大多数研究均基于假定火灾设计,缺乏系列全尺寸火灾基础试验数据,对此国内外研究尚处于空白。本文以CRH1为研究对象,采用全尺寸火灾试验,分别对车厢座椅、行李、窗帘等车厢内主要可燃物引燃特性、质量损失速率、烟气释放速率、温度场分布等火灾参数及燃烧行为特性进行定量分析;在此基础上,运用热释放速率分段线性叠加、质量损失速率计算及t2稳定火源模型等方法计算分析,最终创造性提出高速列车车厢火源功率应为37MW,进而为高速列车火灾危险性分析及火灾综合防治技术研究提供科学理论依据。 相似文献
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Liu J Yu H Song H Qiu J Sun F Li P Yang S 《Journal of environmental monitoring : JEM》2008,10(8):975-978
A novel, simple and sensitive liquid chromatography-hydride generation online coupled with atomic fluorescence spectrometry (LC-HG-AFS) method was developed for simultaneous determination of p-arsanilic acid (p-ASA) and roxarsone in feed. 20% Methanol aqueous was used as extraction reagent, after preprocessing samples by ultrasonic oscillation, then injected into the chromatography Waters symmetry shield RP18 analytical column (150mm x 4.6mm, 5 microm), finally detected by an atomic fluorescence spectrometer. The calibration curves of analyses were linear over a range of concentrations (0.2-4mg L-1 and the correlation coefficients were higher than 0.9990. The limits of detection were 0.2 mg L-1. The method has been validated by linearity, precision and recovery. p-ASA and roxarsone in feed can be successfully and simultaneously determined using the developed method without a tedious pretreatment procedure. 相似文献
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通过丁二酸酐与γ-氨丙基三甲氧基硅烷改性后的纳米SiO2(即可分散的纳米二氧化硅,简称DNS)反应,合成了羧基化的DNS,再经过与壳聚糖脱水生成酰胺的过程,合成了改性壳聚糖。通过红外光谱和扫描电镜对改性壳聚糖进行表征。研究了壳聚糖及改性壳聚糖微粒吸附Ni2+时溶液pH值、时间、吸附剂用量和Ni2+初始浓度等对吸附率的影响,并确定了最佳条件为:pH=7,吸附时间为120 min,吸附剂的投加量为0.3 g。改性壳聚糖比壳聚糖具有更强的吸附Ni2+的能力,吸附率达67.01%。 相似文献