共查询到20条相似文献，搜索用时 15 毫秒
1.
Hong-zi Zhang Xu-wei Long Ru-yi Sha Guo-liang Zhang Qin Meng 《Journal of Zhejiang University. Science. B》2009,10(11):852-859
Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra-ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote the biodegradation of pe-troleum hydrocarbons by dispersing oil into aqueous environment. In the present study, we applied rhamnolipid-containing cell-free culture broth to enhance the biodegradation of crude oil and lubricating oil in a conventional aerobically-activated sludge system. At 20 ℃, rhamnolipids (11.2 mg/L) increased the removal efficiency of crude oil from 17.7% (in the absence of rham-nolipids) to 63%. At 25 ℃, the removal efficiency of crude oil was over 80% with the presence of rhamnolipids compared with 22.3% in the absence of rhamnolipids. Similarly, rhamnolipid treatment (22.5 mg/L) for 24 h at 20 ℃ significantly increased the removal rate of lubricating oil to 92% compared with 24% in the absence of rhamnolipids. The enhanced removal of hydrocarbons was mainly attributed to the improved solubility and the reduced interracial tension by rhamnolipids. We conclude that a direct application of the crude rhamnolipid solution from cell culture is effective and economic in removing oily contaminants from wastewater. 相似文献
2.
改性淀粉絮凝剂处理含油废水的试验效果 总被引：1，自引：0，他引：1
通过将玉米淀粉与氢氧化钠、三氯化铝和无水碳酸钠在恒温磁力搅拌器上搅拌、加热,使得玉米淀粉改性,制得改性淀粉絮凝剂,并研究了改性淀粉絮凝剂对含油废水的处理效果.试验结果显示,在搅拌速度与时间分别为快搅速度200 r/min,快搅时间0.5 min;慢搅速度100 r/min,慢搅时间3 min的情况下,使用改性淀粉絮凝剂处理含油废水时,COD去除率为77.94%、石油类去除率为61.2%、透光率为62.7%、SS去除率为79.96%;最佳反应条件为:投药量为12 mg/L、温度为5~30℃、pH值为6-8. 相似文献
3.
Biodegradation of crude oil by Pseudomonas aeruginosa in the presence of rhamnolipids 总被引：3，自引：0，他引：3
INTRODUCTION Oily wastewater, especially from oil field, hasposed a great hazard for terrestrial and marine eco-systems. The traditional treatment of oily wastewater,such as containment and collection using floatingbooms, adsorption by natural or synthetic materials,etc., can not degrade the crude oil thoroughly (Ollis,1992). So far, biodegradation suggests an effectivemethod. During biodegradation, crude oil is used asan organic carbon source by a microbial process,resulting in the brea… 相似文献
4.
Zhang Guo-liang Wu Yue-ting Qian Xin-ping Meng Qin 《Journal of Zhejiang University. Science. B》2005,6(8):725-730
The potential biodegradation of crude oil was assessed based on the development of a fermentative process with a strain ofPseudomonas aeruginosa which produced 15.4 g/L rhamnolipids when cultured in a basal mineral medium using glycerol as a sole carbon source. However,
neither cell growth nor rhamnolipid production was observed in the comparative culture system using crude oil as the sole
carbon source instead. As rhamnolipid, an effective biosurfactant, has been reported to stimulate the biodegradation of hydrocarbons,
1 g/L glycerol or 0.22 g/L rhamnolipid was initially added into the medium to facilitate the biodegradation of crude oil.
In both situations, more than 58% of crude oil was degraded and further converted into accumulated cell biomass and rhamnolipids.
These results suggest thatPseudomonas aeruginosa could degrade most of crude oil with direct or indirect addition of rhamnolipid. And this conclusion was further supported
by another adsorption experiment, where the adsorption capacity of crude oil by killed cell biomass was negligible in comparison
with the biologic activities of live cell biomass.
Project supported by Science Foundation from China Petroleum and Chemical Corporation, China 相似文献
5.
CAI Jing ZHENG Ping MAHMOOD Qaisar ISLAM Ejazul HU Bao-lan WU Dong-lei 《浙江大学学报(A卷英文版)》2007,8(7):1149-1156
The optimal operation conditions in an anoxic sulfide oxidizing (ASO) bioreactor were investigated. The maximal removal rates for sulfide and nitrate were found to be 4.18 kg/(m3·d) and 1.73 kg/(m3·d), respectively. The volumetrical volumetric loading rates (LRs) observed through decreasing hydraulic retention time (HRT) at fixed substrate concentration are higher than those by increasing substrate concentration at fixed HRT. The sulfide oxidation in ASO reactor was partially producing both sulfate and sulfur; but the amount of sulfate produced was approximately one third that of sulfur. The process was able to tolerate high sulfide concentration, as the sulfide removal percentage always remained near 99% when influent concentration was up to 580 mg/L. It tolerated relatively lower nitrate concentration because the removal percentage dropped to 85% when influent con- centration was increased above 110 mg/L. The process can tolerate shorter HRT but careful operation is needed. Nitrate conversion was more sensitive to HRT than sulfide conversion since the process performance deteriorated abruptly when HRT was decreased from 3.12 h to 2.88 h. In order to avoid nitrite accumulation in the reactor, the influent sulfide and nitrate concentrations should be kept at 280 mg/L and 67.5 mg/L respectively. Present biotechnology is useful for removing sulfides from sewers and crude oil. 相似文献
6.
INTRODUCTION Chromium is a commonly identified soils andgroundwater contaminant. Cr(VI) is toxic, carcino-genic, and has great subsurface mobility. In contrast,Cr(III) is relatively non-toxic and immobile. Muchresearch focused on the remediation of Cr(VI) such asadsorption by zeolites (Bowman, 2003) or silicas(Hideaki et al., 2002), chemical reduction by ferrousiron (Buerge and Hug, 1999; Fendorf and Li, 1996) orzero-valent iron (Powell and Puls, 1997; Alowitz andScherer, 2002), b… 相似文献
7.
To explore the applicability of anoxic-oxic （A/O） activated sludge process for petrochemical wastewater treatment, the relationship between bacterial community structure and pollutants loading/removal efficiencies was investigated by gas chromatograph-mass spectrometry （GC-MS）, polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE） and other conventional techniques. It showed that when the concentrations of the influent chemical oxygen demand （COD） and ammonia nitrogen （NH4＋^-N） were 420-560 mg/L and 64-100 mg/L, respectively, the corresponding average effluent concentrations were 160 mg/L and 55 mg/L, which were 1.6 and 2.2 times higher than those of the national standards in China, respectively, demonstrating the inefficient performances of A/O process. Analysis of GC-MS indicated that refractory pollutants were mainly removed by sludge adsorption, but not by biodegradation. PCR-DGGE profile analysis suggested that the biological system was species-rich, but there was apparent succession of the bacterial community structure in different locations of the A/O system. Variations of bacterial community structure and pollutant loadings had obvious influences on pollutants removal efficiencies. Thus, A/O process was inapplicable for the treatment of complicated petrochemical wastewater, and strategies such as the reinforcement of pre-treatment and two-stage A/O process were suggested. 相似文献
8.
The effectiveness of vitamin C in treating Cr(Ⅵ)-contaminated water is being evaluated. Cr(Ⅵ) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(Ⅵ) to essentially nontoxic Cr(Ⅲ). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(Ⅵ) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration.The reaction mechanism of Cr(Ⅵ) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(Ⅵ)-contaminated soils and groundwater. 相似文献
9.
通过驯化培养从受Pb2＋污染的土壤中分离到1株能在含Pb2＋浓度为300 mg.L-1液体培养基中生长的耐Pb2＋细菌菌株（B19）,对该菌株吸附Pb2＋能力及影响吸附Pb2＋的因素进行了探讨.结果表明：该菌株对Pb2＋的吸附速率较快,在5 min内,培养液中Pb2＋去除率达到76.4%,在30 min达到吸附平衡.pH、培养基、菌量、Pb2＋初始质量浓度对去除率有显著影响.在吸附时间为30 min,吸附温度为30℃,菌龄为3 d,牛肉膏蛋白胨培养基培养,pH5.5,Pb2＋质量浓度85 mg.L-1,菌量6 g.L-1时,其对Pb2＋去除率可达92.6%. 相似文献
10.
实验以B3（Pseudom-onas）、B6（Bacil-lus）、B7（Bacil-lus）、D4（Pseudom-onas）为石油降解菌,通过单因素实验,研究了培养时间、石油浓度、温度、溶氧量、初始pH值等因素对各单菌降解石油性能的影响,确定了各菌最适宜的石油降解条件.四株菌在纱布封口1、60 r/min振荡培养12 d较为适宜,它们适宜的降油石油浓度、温度和初始pH是：B3为4 000 mg/L、32℃、pH8.4,B6为3 000 mg/L、32℃、pH 7.3,B7为4 000 mg/L、26℃、pH7.3,D4为3 000 mg/L、26℃、Ph 7.3. 相似文献
11.
在研究猪分子标记遗传距离同杂种优势的关系时,对模板浓度和纯度、引物浓度、dNTP浓度、Mg2+浓度、不同商标的Tag酶等影响RAPD扩增的因素进行了系统的分析,在此基础上建立了适宜于本实验室研究的最佳RAPD技术体系:25(1反应体系中,含10×buffer2.5(I,MgCl21.75mmol/L,dNTPO25mmol/L,引物0.24(mol/L,Tag酶2U,模板50～100ng,1(g/(IBSA。反应程序为:94℃预变性5min,然后94℃变性1min,36℃退火1min,72℃延伸2min40个循环,最后在72℃延伸10min。 相似文献
12.
Virtual design and performance prediction of a silencing air cleaner used in an I.C. engine intake system 总被引：3，自引：0，他引：3
INTRODUCTION The primary function of an intake system is firstly to efficiently channel fresh air to the engine,and secondly to minimize intake noise emissions.There are a number of current approaches for devel-oping a more realistic method to improve intake sys-tem design.The objectives include more effective silencing performance to meet increasingly severe legislative targets for reduced noise on the one hand,with optimized engine performance and fuel economy accompanied by improvements… 相似文献
13.
Qian Jun-qing 《浙江大学学报(A卷英文版)》2001,2(2):209-213
Water extraction of soybean oil was studied to find the optimal conditions for recovery of oil preenriched protein and for
aqueous extraction of soybean oil. Orthogonal tests were employed in the procedures of oil pre-enrichment and aqueous extraction.
Soybeans were crushed to pass a 40 mesh sieve, soaked under the optimum conditions (solid/water=1/5(w/v), 40°C, pH 10, 3 h)
and water-ground to 100 mesh, stirred in 65 °C water for 20 min, and centrifuged at 1400 g to separate oil pre-enriched protein.
The protein yield was 17.8 g from 100 g soybeans, which contained 62.8% oil. The oil yield was 69.0%. Optimum conditions for
the aqueous extraction procedure were: solid-to-water ratio 1∶2, pH 9.0, time 30 min, stirring in boiling water bath, stationary
time 10 min, centrifuge at 3600 g for 10 min. Experimental values showed that the oil yield after aqueous extraction from
oil pre-enriched protein reached 88.3%, so the total oil extraction rate was 60.8%. 相似文献
14.
文章通过筛选适宜金线莲丛芽诱导、增殖和生根的培养基和研究影响试管苗移栽的条件，建立起金线莲组织培养的技术体系。结果表明：金线莲丛芽诱导以MS+6-BA30 mg/L +NAA05 mg/L +KT10 mg/L为最佳；丛芽增殖以MS+6-BA30 mg/L +NAA05 mg/L为最佳；生根以1/2MS+IBA10 mg/L +NAA10 mg/L水解酪蛋白05%+05%活性碳为最佳；在移栽中，以混合土（普通土：沙质土：有机肥=1∶1∶1）作为基质为较好，移栽成活率达到909% 相似文献
15.
16.
INTRODUCTION Environmental contamination by toxic metals isa serious problem worldwide due to their incrementalaccumulation in the food chain and continued per-sistence in the ecosystem. Conventional technologies,such as ion exchange or lime precipitation, are oftenineffective and/or expensive, particularly for the re-moval of heavy metal ions at low concentrations(below 50 mg/L). Furthermore, most of these tech-niques are based on physical displacement orchemical replacement, generating … 相似文献
17.
酱油渣中提取油脂和黄酮 总被引：1，自引：0，他引：1
[目的]探讨从酱油渣中提取油脂和黄酮类物质的最佳工艺参数,为酱油渣资源的进一步开发利用提供基础数据.[方法]在单因素实验的基础上,采用正交设计方法,研究各因素对油脂和黄酮提取率的影响.[结果]研究表明,油脂提取最佳条件为:酱油渣与异丙醇比例为1:13,超声温度50℃,超声时间30 min,该条件下油脂的提取率为34.76%;从脱脂酱油渣中提取黄酮的最佳条件为:50%乙醇、料液比1:30、超声时间15 min、提取温度60℃,在此条件下,黄酮的提取量为2.471 0 mg/g.[结论]利用超声波辅助提取技术从酱油渣中提取油脂和黄酮可行. 相似文献
18.
从太湖中成功筛选出一株能够同时降解微囊藻毒素-RR(MC-RR)和微囊藻毒素-LR(MC-LR)的土著细菌MC-LTH11.经鉴定,该菌属寡养单胞菌属,并含有mlrA基因.在含有藻毒素粗提物的培养基中,MCLTH11能够在6 d内将初浓度分别为37.13 mg/L的MC-RR和18.49 mg/L的MC-LR完全降解,并且降解速度受到pH值、温度、初始微囊藻毒素浓度和培养基种类的影响.此外,MC-LTH11能够在1 d内完全降解太湖水样中的微囊藻毒素.研究结果表明,寡养单胞菌MC-LTH11具备对微囊藻毒素污染水体的修复能力,并可能是太湖水华爆发后微囊藻毒素降解的重要因素. 相似文献
19.
高效液相色谱法测定草莓中维生素C含量 总被引：26，自引：0，他引：26
目的:建立一种高效液相色谱测定草莓中维生素C含量的新方法.方法:采用HYPERSIL-C18色谱柱,0.1%低浓度的草酸作流动相,流速为1.0 mL/m in,检测波长为254 nm.结果:维生素C在浓度为20~100 mg/L范围内有良好的线性关系,线性回归方程为y=9 361.6x-11 192,相关系数为0.999 3,方法回收率为97.4~102.1%,相对标准偏差小于3%.结论:本测定方法简便,快速,准确,稳定;适合于测定其它水果和蔬菜中维生素C的含量. 相似文献
20.
炼厂焦化废水是一类乳化较严重的废水,本文通过室内小试筛选出阳离子型焦化破乳剂JQ-104,试验结果显示,当焦化废水含油4235.6 mg·L-1,JQ-104投加量300 mg·L-1,废水含油去除率高达95.51%;另外,pH值对其有较大影响,最佳pH值范围为6-8.将JQ-104应用于现场工艺流程,除油效果明显,处理后出水稳定,含油浓度在200mg·L-1以内,减少了污油对环境的污染. 相似文献