共查询到20条相似文献,搜索用时 15 毫秒
1.
污水处理工艺对污泥热处理特性的影响 总被引:1,自引:0,他引:1
通过10℃/min时的热重分析,对五种不同性质污泥分别在氮气和氧气气氛下的热解和燃烧特性进行了研究。结果表明,污水处理工艺的“好氧+厌氧”、“厌氧+好氧”过程以及污泥的厌氧消化均使污泥中的有机物结构复杂,导致污泥热解时有机物的分解和析出温度升高,且“好氧+厌氧”过程使污泥中有机物结构更复杂;而对污泥的燃烧过程和燃尽点无影响,但使着火温度升高。利用šatava-šesták 方程对污泥热解、燃烧的反应机理进行了研究。结果表明,五种污泥热解时均呈现为挥发分扩散和随后的化学反应机理函数,而燃烧时则为化学反应和随后的扩散过程。 相似文献
2.
Nath NC Sarker S Ahammad AJ Lee JJ 《Physical chemistry chemical physics : PCCP》2012,14(13):4333-4338
Three electrode structures with different spatial arrangements of carbon nanotubes (CNTs) in the mesoporous TiO(2) layer were employed in dye-sensitized solar cells to study the effect of surface states at the interface formed by the incorporation of CNTs. It was found that the decay of open circuit voltage (V(oc)) was significantly minimized by avoiding the direct contact of nanotubes to the conducting substrate by introducing a thin buffer layer of TiO(2) while maintaining the superior electron collection efficiency from the incorporation of nanotubes. 相似文献
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Fe-doped TiO2, Ti1–xFexO2 (x = 0.00, 0.02, 0.04, 0.06, 0.08, and 0.10), photocatalysts have been successfully synthesized via citric acid–assisted autocombustion method. The synthesized photocatalysts were characterized using different characterization techniques, such as X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDX), and x-ray photoelectron spectroscopy (XPS). The XRD diffraction patterns revealed that synthesized photocatalysts have the anatase phase of TiO2. The DRS analysis indicates a slight increment in absorbance in the visible light region by the Fe doping in TiO2. The FT-IR spectra reveal the various stretching and bending vibrational bands of the Ti–O lattice. The XPS spectra confirm the presence of elements titanium, oxygen, and iron in the synthesized samples and determine binding energy of elements. TEM analysis shows the shape of the synthesized photocatalyst, and it was used to calculate the average particle sizes of undoped and Fe-doped TiO2 (Ti0.96Fe0.04O2) photocatalysts using a histogram. The photocatalytic activities of synthesized photocatalysts were determined by photodegradation of dye (Direct Blue 199), contaminating carpet industry wastewater in the photochemical reactor and open pan reactor. The maximum photodegradation activity was shown by the Ti0.96Fe0.04O2 photocatalyst among all the synthesized undoped and Fe-doped photocatalysts. The synthesized photocatalyst (Ti0.96Fe0.04O2) had better photocatalytic activity when compared to both, undoped TiO2 and Aeroxide (Degussa) P-25. The used Fe-doped TiO2 photocatalyst (Ti0.96Fe0.04O2) was regenerated five times and investigated for its photocatalytic activity. 相似文献
4.
Yun JH Ng YH Huang S Conibeer G Amal R 《Chemical communications (Cambridge, England)》2011,47(40):11288-11290
The CuInS(2) (CIS) nanoparticles were wrapped uniformly throughout the inner and outer walls of TNTs (TNT) by using square wave pulsed-electrodeposition. This structure enables the CuInS(2)-TiO(2) (CIS-TNT) to exhibit p-n junction diode behavior and enhanced photoelectrochemical properties. 相似文献
5.
New membranes based on sulfonated polycarbonate (SPC) and polyvinylidene fluoride (PVDF) were prepared. SPC was obtained by treating polycarbonate (PC) with acetyl sulfate. The ion exchange capacity (IEC) of the sulfonated polymer was 0.6753 meq/g. Scanning electron microscopy revealed that the SPC/PVDF membranes constituted heterogeneous blends. Porosimetric measurements by liquid–liquid displacement indicated that there is no substantial change in pore-size distribution due to growing SPC content. Membrane performance was assessed using an oil–water emulsion. Results indicated that the membranes present lower fouling as SPC content increases. When using the resistances-in-series model to quantify fouling, membranes containing 20% of SPC did not present irreversible fouling. 相似文献
6.
P. R. Rela M. H. O. Sampa C. L. Duarte F. E. Costa V. Sciani 《Radiation Physics and Chemistry》2000,57(3-6):657-660
Electron beam irradiation processing is an available technology to treat sludge, groundwater, surface water and industrial and municipal wastewater. The use of this technology into environmental areas has moved slowly because industry and government are always conservative in the adoption of new processes, especially when they can not observe the efficiency and cost effectiveness of a treatment in a full scale facility.
In this direction the hydraulic system where the water is presented to the electron beam governs the efficacy of this technology. The present work is based on the development of the irradiation device, an up-flow delivery system that alleviates the dependence of energy transfer to the stream with the beam accelerating voltage (penetration capability).
In this work a series of experiments were performed to establish the relationships between accelerating voltage ranging from 0.5 to 1.5 MeV, current, water flow and deposited dose in order to optimize the operating parameters and the selection of a cost-effective commercial electron beam. 相似文献
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Every year, a large amount of wastewater is discharged from various industries into the environment, and various methods are used to treat wastewater to reduce the amount of pollutants. Electrocoagulation (EC) is an electrochemically based technique that generates coagulant species in situ from the electrodissolution of sacrificial anodes, usually made of iron or aluminum destabilizes suspended, dissolved, or emulsified pollutants by using an electric current. It has a potential in removing various kinds of pollutants including organic and inorganic contaminants for various types of wastewater. The effectiveness of EC process depends on various parameters including pH, electrode, operation time, and current density. The goal of this study is to review the most relevant literatures that were published recently. The main challenges associated with the EC process are electrode passivation and energy consumption. EC compared with other common methods has advantages such as reducing energy consumption and reducing operating costs. 相似文献
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Lucia Dančová Igor Bodík Andrea Blšťáková Zuzana Jakubčová Miloslav Drtil 《Chemical Papers》2008,62(5):451-457
Possibilities of membrane technology and the use of membrane processes in wastewater treatment were investigated. The main
focus was the monitoring of the starting phase of a domestic wastewater treatment plant. Experimental part of the study was
realized at the municipal wastewater treatment plant (WWTP) Devínska Nová Ves — Bratislava during the period from February
2005 to September 2006. The system was stable without any external chemical treatment of the membrane modules and the permeate
quality was very high. Observed decrease of COD and BOD5 values ranged between 91 % and 98 %. The process of nitrification was very successful considering its high efficiency (>
95 %).
Presented at the 34th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 21–25 May
2007. 相似文献
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Preparation of magnetic chitosan microspheres and its applications in wastewater treatment 总被引:1,自引:0,他引:1
The methods of preparation of magnetic chitosan microspheres have been introduced. In addition, their applications in the
wastewater treatment, based on different kinds of wastewater, have been reviewed, and their mechanisms have been discussed.
Supported by the Key Natural Science Foundation of China (Grant No. 50633030) 相似文献
14.
《Arabian Journal of Chemistry》2020,13(3):4797-4810
This paper evaluated the efficiency and reusability of multiwall carbon nanotubes (MWNTs) on removal of cationic and anionic dyes under effect of pH, dose of MWNTs and concentration of dyes. The characterization of MWNTs is characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), Raman spectra and BET (Brunauer, Emmett and Teller) surface area. SEM and TEM analyses showed that MWNTs had size within nano scale range of 10–50 nm. The experimental results indicated that the efficiency of removal of MWNTs increase under condition of normal pH, at contact time 60 min with agitation speed 240 rpm and initial concentration of dyes 10 mg/l. Under these optimal conditions, the removal reached 98.7% and 97.2% for anionic dyes and cationic dyes, respectively. For economic use, MWNTs can be used more than one time where the same experiments with the already used MWNTs was repeated and it was found that the percent removal is almost the same. 相似文献
15.
针对食堂餐饮废水,建立微生物燃料电池实验系统,研究微生物燃料电池废水处理与同步发电性能。首先使用Fe(NO3)3溶液作为阴极电解液进行实验,证明餐饮废水生物降解及产电的可行性;分别采用NaCl溶液和K3[Fe(CN)6]溶液作为阴极电解液进行对比实验,研究不同运行环境下微生物燃料电池的发电性能和污水净化效果。结果表明,采用NaCl溶液和K3[Fe(CN)6]溶液作为阴极电解液时的COD去除率分别是30%和22%左右,平均电流密度分别为5.6和5.2mA/m2。在污水稀释比为2∶1、NaCl电解液浓度为0.4mol/L的情况下,微生物燃料电池系统的发电性能和净水效果达到最佳状态,稳态电流密度为8.8mA/m2,COD去除率为33.3%。 相似文献
16.
Kleerebezem R 《Applied biochemistry and biotechnology》2003,109(1-3):3-13
Operational practice of high-rate anaerobic bioreactors such as upflow anaerobic sludge bed (UASB) reactors is generally based
on maximization of the biomass concentration and, in the case of more than one reactor compartment, operation in parallel.
In this article, a modeling approach is used to postulate that the treatment performance of anaerobic bioreactors can be improved
by simple operational measures. To achieve minimized effluent soluble substrate concentrations, operation of two reactors
in series combined with active exchange of biomass between both reactors is suggested. In this way, substrate concentrations
lower than the minimum achievable concentration in a completely mixed reactor can be achieved. It is furthermore suggested
that maximized biomass concentrations (and solid retention times [SRTs]) do not necessarily lead to minimized effluent concentrations
of organic material. At elevated SRTs, the soluble microbial products resulting from biomass turnover are shown to represent
the main fraction of soluble organic material in the effluent of the reactor, limiting treatment efficiency. 相似文献
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Highly efficient plastic substrate dye-sensitized solar cells using a compression method for preparation of TiO(2) photoelectrodes 总被引:2,自引:0,他引:2
Yamaguchi T Tobe N Matsumoto D Arakawa H 《Chemical communications (Cambridge, England)》2007,(45):4767-4769
The efficiency of a plastic-substrate dye-sensitized solar cell was much improved by a new method consisting of a press method without heat treatment, light confinement effect of TiO(2) film and water-based TiO(2) paste; this device shows the highest light-to-electrical energy conversion efficiency based on plastic-substrate dye-sensitized solar cells, 7.4% under 100 mW cm(-2) (1 sun) AM1.5 illumination. 相似文献
19.
《Arabian Journal of Chemistry》2020,13(4):5084-5095
Present study deals with the treatment of coking wastewater (CWW) using Fenton oxidation process for the degradation of pollutants containing chemical oxygen demand (COD), phenol and cyanide. The experiments were performed in batch mode to study the effect of operating parameters like initial pH (pHi), temperature (T), oxidant H2O2 amount, catalyst mass loading (Cw) and treatment time (tR). The response surface methodology (RSM) gave optimum value of pH, H2O2, Cw and tR as 3, 0.3 M, 1.85 g/L (0.0266 M) and 1.52 h. At this optimum operating condition maximum 84.66% COD, 88.46% phenol and 79.34% cyanide reduction were achieved from initial value of COD (CODi) = 2810.0 mg/L, phenoli = 283.0 mg/L and cyanidei = 18.88 mg/L. Results reflect that Fenton oxidation is an effective process for the reduction of pollutants present in CWW. The CWW treated by Fenton oxidation having average value COD = 590.0 mg/L, phenol = 39.49 mg/L and cyanide = 5.2 mg/L was further treated by adsorption process as second stage treatment, and these values were reached to COD = 199.0 mg/L, phenol = 0.0 mg/L and cyanide = 2.36 mg/L. The response surface methodology (RSM) was used for the designing and optimization of the experiments. Analysis of variance (ANOVA) suggested the high regression coefficient R2 = 0.999 and 0.993 for COD and phenol removal respectively. The two stage treated CWW can be recycled and reused in same industry for various purpose. 相似文献
20.
Sousa AC Lucio MM Bezerra Neto OF Marcone GP Pereira AF Dantas EO Fragoso WD Araujo MC Galvão RK 《Analytica chimica acta》2007,588(2):231-236
This paper proposes a method for determination of chemical oxygen demand (COD) in domestic wastewater. The proposed method is based on near-infrared reflectance (NIRR) measurements of seston collected from wastewater samples by filtration. The analysis does not require any special reagent, catalyst or solvent. Inherent baseline and noise features present in NIRR spectra are removed by a Savitzky-Golay derivative procedure followed by wavelet denoising. The resulting wavelet approximation coefficients are used for partial-least-squares modelling and subsequent prediction of COD values in new samples. The model is calibrated by using COD values obtained according to the American Public Health Association (APHA) reference method. The proposed method is applied to effluent samples from the anaerobic ponds of the Mangabeira municipal wastewater treatment plant in the city of João Pessoa (Paraíba, Brazil). By comparing the NIRR prediction results with the APHA reference values, a root-mean-square error of prediction (RMSEP) of 19 mg O2 L−1 and a correlation of 0.97 were obtained. Such results are deemed adequate in view of the joint estimate of the standard error of the reference method, which was calculated as 21 mg O2 L−1. 相似文献