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1.
INTRODUCTION Catalytic reforming of naphtha or mixture of naphtha with a certain amount of cracking oil is a process of great interest to the petrochemical industry for the production of aromatic compounds that are raw materials for plastics, elastomers and resins manufacture. Catalytic reforming unit uses naphtha or cracking oil as feedstock to produce rich aromatic compounds and high octane value liquid products through reactions such as aromatization, cyclization, and hydrocracking. At… 相似文献
2.
HE Qiang ZHANG Yu-ping XU Jian-bin 《重庆大学学报(英文版)》2005,4(4):208-212
In this paper, the characteristics of integrated biological aerated filter （IBAF） applied to municipal wastewater treatment were studied in a pilot scale experiment. The experimental results showed that IBAF has high efficiencies in removing organic pollutants, such as CODCr and SS, in municipal wastewater. The removal rates of CODCr and SS can reach over 90% and 80%, respectively, when COD and SS in the influent are 234 mg L^-1 and 112 mg L^-1, hydraulic retention time （HRT） is 8 h, and the aerated intensity is in the range of （0.5 to 0.6） L m^-2 s^-1. 相似文献
3.
Development of an evaporation crystallizer for desalination of alkaline organic wastewater before incineration 总被引：2，自引：0，他引：2
A wastewater evaporation-desalination pretreatment method was introduced to remove the Na^＋ and K^＋ salts in volatile organic compounds （VOCs） wastewater before it was fed into the incinerator. VOCs in the wastewater were volatilized in the evaporation system and then the vapor was combusted in an incinerator. Simulated phenol wastewater containing sodium chloride was evaporated and concentrated and sodium chloride was crystallized in different parameters. The experimental results showed that the higher initial concentration of sodium chloride increases the ratio of volatilization of VOCs, which was due to the effect of “salting out” （a decrease in the solubility of the nonelectrolyte in the solution, or more rigorously, an increase in its activity coefficient, caused by the salt addition （Furter and Cook, 1967））. When evaporation speed was increased from 1.67 ml/min to 2.73 ml/min, the total removal coefficient of sodium chloride was about 99.88%-99.99%. This pretreatment procedure eliminates the slag phenomenon caused by Na^＋ and K^＋ salts during wastewater incineration, so the incinerator could operate continuously, and the wastewater evaporation could increase the heat value of wastewater, and the operation cost would be reduced. 相似文献
4.
A dielectric barrier discharge （DBD） reactor consisting of water-filled dielectric tube electrodes was used for the treatment ofwastewater. The inner dielectric tube, which acted as the discharging electrode, was filled with an aqueous electrolyte solution. The outer dielectric tube, which served as the other electrode, was in contact with the wastewater, which was grounded. The present reactor system was energy-efficient for the production of ozone, not only because the perfect contact between the aqueous electrode and the dielectric surface minimized the loss of the electrical energy, but also because the DBD reactor was cooled by the wastewater. In addition, the ultraviolet （UV） light produced in the DBD reactor was able to assist in the wastewater treatment since the quartz tube used as the dielectric material was UV-transparent. The performance of the present DBD system was evaluated using a synthetic wastewater formed from distilled water and an azo dye, amaranth. The experimental parameters were the concentration of the electrolyte in the aqueous electrode, the discharge power, the initial pH of the wastewater and the concentration of hydrogen peroxide added to the wastewater. The wastewater treatment system was found to be effective for achieving decomposition of the dye. 相似文献
5.
A treatability study of industrial wastewater containing chlorinated nitroaromatic compounds (CNACs) by a catalytic ozonation process (COP) with a modified Mn/Co ceramic catalyst and an aerobic sequencing batch reactor (SBR) was investigated.A preliminary attempt to treat the diluted wastewater with a single SBR resulted in ineffective removal of the color,ammonia,total organic carbon (TOC) and chemical oxygen demand (COD).Next,COP was applied as a pretreatment in order to obtain a bio-compatible wastewater for SBR treatment in a second step.The effectiveness of the COP pretreatment was assessed by evaluating wastewater biodegradability enhancement (the ratio of biology oxygen demand after 5 d (BOD5) to COD),as well as monitoring the evolution of TOC,carbon oxidation state (COS),average oxidation state (AOS),color,and major pollutant concentrations with reaction time.In the COP,the catalyst preserved its catalytic properties even after 70 reuse cycles,exhibiting good durability and stability.The performance of SBR to treat COP effluent was also examined.At an organic loading rate of 2.0 kg COD/(m3·d),with hydraulic retention time (HRT)=10 h and temperature (30±2) °C,the average removal efficiencies of NH3-N,COD,BOD5,TOC,and color in a coupled COP/SBR process were about 80%,95.8%,93.8%,97.6% and 99.3%,respectively,with average effluent concentrations of 10 mg/L,128 mg/L,27.5 mg/L,25.0 mg/L,and 20 multiples,respectively,which were all consistent with the national standards for secondary discharge of industrial wastewater into a public sewerage system (GB 8978-1996).The results indicated that the coupling of COP with a biological process was proved to be a technically and economically effective method for treating industrial wastewater containing recalcitrant CNACs. 相似文献
6.
Protoporphyrinogen oxidase inhibitor has become the focus research field as herbicides.Seven novel N-benzoxazolonyluracils were obtained by cyclization of 6-aminobenzoxazolone derivatives with ethyl 3-dimethylcarbamoylamido-4,4,4-trifluorocrotonate and then methylation or amination, and the reaction yields were between 59%-86%. The chemical structures of the compounds were identified by Elemental Analysis, MS and ^1H NMR. Biological results indicate that some compounds exhibit excellent control of broadleaf weeds at post-emergence by low dosage 18.75 ga.i/ha, but are not effective for grass weeds below dosage 37.5 ga. i/ha. In addition, these compounds show no damage at high-dosage 150 ga. i/ha to wheat and corn, but are unsafe to dicotyledonous plants such as cole, soybean and sorghum even at lower dosage 18.75 ga. i/ha. 相似文献
7.
A great deal of new words are emerging and coming into vogue.Most of the previous studies on Chinese new words focused on their classification,form and meaning,as well as the social motivations.This thesis chooses to study the concept metaphor of Chinese new metaphorical compounds from the cognitive perspective based on 396 new words in 2010 and aims to classify the new metaphorical words in a new way and pay attention to the analysis of word formation of new metaphorical compounds.Besides,this paper attempts to explore the understanding process of metaphorical new words. 相似文献
8.
The reuse of wastewater for the irrigation of farmlands is gaining popularity, and the nutrient leaching associated with wastewater irrigation is becoming a matter of concern. The variability of nitrogen and phosphorus fractions in wastewater-irrigated soil was investigated in both horizontal and vertical directions in Kongjiaxiang, Tongliao, Inner Mongolia, China. The results showed that wastewater irrigation resulted in the concentrations of available N and P being 40.36% and 66.49% higher, respectively, than those with groundwater irrigation. Different forms of N and P exhibited significantly different distribution patterns. Higher concentrations of NO3- and total available N, as well as of those of Ca-P and total available P were observed near wastewater irrigation channels. Ca-P has a spatial distribution pattern similar to that of available P. The concentrations of NO3- and NH4+ were the highest in top soil and decreased with depth. The complex interactions between nitrate leaching and nitrogen transformation processes (e.g., nitrification, denitrification, and mineralization) determined the vertical profile of NO3- . The significant amount of NH4+ loss inhibited its deep seepage. The Ca-bound compound contained more P than other inorganic fractions as a result of high Ca levels throughout the soil profile. The differences in the concentrations of Ca-bound P at different depths could be due to the upward flux or translocation of Ca from subsurface to surface soil and the sequestration of P. 相似文献
9.
Interaction of nonionic surfactant AEO9 with ionic surfactants 总被引：2，自引：0，他引：2
INTRODUCTION Long chain nonionic surfactants such as poly-oxyethylenated alcohols C12H25O(CH2CH2O)9H (AEO9), are widely used in the chemical industry in fabric detergency and tertiary oil recovery due to their excellent surface-active properties. In many practical applications, surfactants are used in formulations containing mixtures of different compounds, and synergism can often be observed. Synergism is de-fined here as the condition in which the properties of a mixture are better… 相似文献
10.
Urban wastewater treatment techniques could not be applied to improve the pollutant removal efficiency,due to its characteristics of closed and quiescent conditions of the static lake water.In this study,natural zeolite and coal cinder were chosen as filler compounds of the ecological filter.Static and dynamic experiments were carried out to study the remediation efficiency.Experimental data show that removal efficiency of ammonia nitrogen （NH ＋ 4 -N） reaches 85% in both static and dynamic patterns and its removal efficiency reaches 97% when the recycling period is 1 h in dynamic condition.The maximum removal efficiency of nitrite nitrogen （NO-2 -N） reached 98%,and the removal efficiency of total nitrogen （TN） is a maximum of 84%.The final effluent concentration of total phosphorus （TP） is 0.079 mg/L.Effluent recycling could improve the nutrient （N,P） removal efficiently.Dissolved oxygen （DO） concentration could remain high with the water cycling.The filter works efficiently on regulating pH to the standard level of healthy water. 相似文献
11.
陈红 《浙江大学学报(A卷英文版)》2004,5(6):727-732
Specific ATP content of volatile solids was measured to characterize the sludge activity in a sequential anaerobic/aerobic wastewater treatment system, with an upflow anaerobic sludge blanket (UASB) reactor and a three-phase aerobic fluidized bed (AFB) reactor. The wastewater COD level was 2000(3000 mg/L in simulation of real textile wastewater. The ATP content and the specific ATP contents of volatile solids at different heights of the UASB reactor and those of the suspended and immobilized biomass in the AFB reactor were measured. In the UASB reactor, the maximum value of specific ATP (0.85 mg ATP/g VS) was obtained at a hydraulic retention time (HRT) 7.14 h in the blanket solution. In the AFB reactor, the specific ATP content of suspended biomass was higher than that of immobilized biomass and increased with hydraulic retention time reaching a maximum value of 1.6 mg ATP/g VS at hydraulic retention time 4.35 h. The ATP content of anaerobes in the UASB effluent declined rapidly under aerobic conditions following a 2nd-order kinetic model. 相似文献
12.
INTRODUCTION limiting conditions, obligatory aerobic and an- aerobic bacteria will survive in a mixed culture Sequential anaerobic/aerobic wastewater treat- (Gerritse et al., 1992). Little is know about thement has received increasing attention for effective change in the activity of anaerobic bacteria whennutrient removal, enhanced de… 相似文献
13.
An expanded granular sludge bed (EGSB) reactor inoculated with anaerobic granular sludge was started up with its COD removal performance, self-balancing of pH, biogas production rate and characteristics of the granular sludge during the start-up period being investigated. The results indicated that the EGSB reactor can be started up successfully in 27 d by increasing the organic loading rate rapidly. The removal efficiency of COD was maintained above 93% with influent COD concentration of 25 000 mg/L and OL... 相似文献
14.
厌氧颗粒污泥同时反硝化与产甲烷的研究 总被引：1，自引：0，他引：1
文章通过向严格厌氧系统中投加硝酸盐后,系统对基质的降解情况来考察厌氧颗粒污泥的同时反硝化与产甲烷的可行性。试验结果表明,向厌氧颗粒污泥系统中投加硝酸盐后,反硝化优先进行,当反硝化完成后,产甲烷过程开始。在反硝化过程中,硝酸盐迅速被还原,有亚硝酸盐累积现象出现。向纯厌氧颗粒污泥系统中投加少量的好氧活性污泥后,反硝化速度加快,亚硝酸盐累积强度减弱。 相似文献
15.
污水厌氧生物处理研究回顾与展望 总被引：1，自引：0，他引：1
在世界能源紧缺和环境污染不断加剧的背景下,污水厌氧生物处理技术经济可行,该技术能适应社会和环境的可持续发展要求,势必成为21世纪污水处理领域的核心技术.本文回顾了污水厌氧生物处理技术的发展历程,同时指出了污水厌氧生物处理过程中存在的问题及当前研究热点,并对其未来发展趋势作以展望. 相似文献
16.
为了快速培养出能同时去除生活污水中化学需氧量(COD)和氮的微氧颗粒污泥,采用膨胀颗粒污泥床(EGSB)反应器接种污水处理厂剩余污泥,研究了微氧颗粒污泥的培养过程以及稳定运行条件下供氧量对处理效果和污泥性能的影响。结果表明,水力停留时间(HRT)为6h,微氧颗粒污泥的成功培养仅需1个月;供氧速率在2.83.2gO2/d,COD,NH3-N和总氮(TN)的去除率最高分别可达91%,85%和81%,脱氮速率达1.7gN/d,出水水质最佳;成熟的微氧颗粒污泥粒径集中在0.453.2gO2/d,COD,NH3-N和总氮(TN)的去除率最高分别可达91%,85%和81%,脱氮速率达1.7gN/d,出水水质最佳;成熟的微氧颗粒污泥粒径集中在0.452mm,当供氧速率低于2.3gO2/d时,颗粒污泥结构致密,供氧速率在2.32mm,当供氧速率低于2.3gO2/d时,颗粒污泥结构致密,供氧速率在2.33.2gO2/d时,污泥性能稳定,供氧速率增加到3.2gO2/d时,污泥沉降性能下降,并出现颗粒解体和丝状菌生长优势。 相似文献
17.
朱蕾 《渭南师范学院学报》2014,29(19):34-38
在处理制革废水中常用SBR工艺,试验探讨了不同HRT、进水pH、COD负荷、NH3-N浓度、活性污泥浓度的运行参数,研究SBR工艺处理制革废水的最优运行参数．结果表明：SBR反应器在进水COD为1500～2000mg／L、NH3-N为150～250mg／L、pH为7．5、运行污泥浓度在3．0g／L左右、曝气时间为18h时COD去除率能达到95％左右,NH3-N去除率达到97％左右,其出水能够达到一级出水标准． 相似文献
18.
进行了海绵铁内电解法作为印染废水预处理工艺的试验研究,试验结果表明：在pH=5-6、海绵铁投加量50g/L、反应时间60min及一定的搅拌强度条件下,可去除40%左右的色度、30%左右的COD,废水可生化性得到有效改善。研究表明,海绵铁内电解工艺用于印染废水预处理效果良好,具有一定的推广价值。 相似文献
19.
Mahmood QAISAR 《Journal of Zhejiang University. Science. B》2010,11(2):79-86
Bed expansion behavior and sensitivity analysis for super-high-rate anaerobic bioreactor (SAB) were performed based on bed expansion ratio (E), maximum bed sludge content (Vpmax), and maximum bed contact time between sludge and liquid (τmax). Bed expansion behavior models were established under bed unfluidization, fluidization, and transportation states. Under unfluidization state, E was 0, Vpmax was 4 867 ml, and τmax was 844–3 800 s. Under fluidization state, E, Vpmax, and τmax were 5.28%–255.69%, 1 368–4 559 ml, and 104–732 s, respectively. Under transportation state, washout of granular sludge occurred and destabilized the SAB. During stable running of SAB under fluidization state, E correlated positively with superficial gas and liquid velocities (ug and ul), while Vpmax and τmax correlated negatively. For E and Vpmax, the sensitivities of ug and ul were close to each other, while for τmax, the sensitivity of ul was greater than that of ug. The prediction from these models was a close match to the experimental data. 相似文献
20.
采用高温和酸分别对粉煤灰进行改性,对比了改性后的粉煤灰对焦化废水深度处理的效果,确定了最佳工艺条件。结果表明,焦化废水COD135~170mg/L,NH3-N 96~135mg/L,体积150mL,pH值5,改性粉煤灰投加量25g,粒径100~160目,吸附时间60min,石灰量0.25g,高温改性粉煤灰对焦化废水COD和氨氮的去除率分别达到了85.2%和89.6%,而酸改性粉煤灰对焦化废水COD和氨氮的去除效果劣于高温改性粉煤灰,去除率分别为78.3%和82.7%。 相似文献