Papers by Keyword: Carbon Source

Abstract: In this report, a strains of nitrifying bacteria HFX08 with low temperature and low carbon nitrogen ratio is separated from the activated sludge which is domesticated of the northern city sewage plant in winter. The optimum carbon source for the growth of the strain is sodium acetate, the source of nitrogen is potassium nitrate and the optimum growth temperature range is 10-20°C correspondingly.

Abstract: A SBR was used to treat power plant sewage based on SND when pH, DO(dissolved oxygen),MLSS, were 7.0-8.0, 0.5-1mg/L, 3000±200mg/L, respectively. Results indicated average removal efficiency of COD and NH₄⁺-N were 89% ,96.34%.Because of low COD/ NH₄⁺-N, average removal efficiency of TN(total nitrogen)was only 71.15%, effect of SND was not apparent. After improving COD/ NH₄⁺-N by adding carbon source intermittently, removal effects of COD and NH₄⁺-N were not reduced, and effluent NO₃^--N and NO₂^--N was not accumulated, average removal efficiency of TN was 95%, and efficiency of SND was enhanced obviously. The effluent of system was recycled effectively. It indicates that SBR based on SND is feasible in theory and technology which is applied to treat power plant sewage.

Abstract: Banana trees and poultry dung were used as the main source of compost. The experiment method was orthogonal experiment design (three factors, three levels). The C/N (Organic carbon/Nitrogen) ratio in the compost, the pile-turning interval and the initial moisture were influencing factors on the nitrogen variation during the compost process It is seen that the C/N ratio effectively influences the nitrogen variation; the initial moisture and the pile-turning interval do not have evident effect on the nitrogen variation. The study found that the C/N ratio is the key condition of affecting the nitrogen variation among the basic condition of the banana trees and the poultry dung compost progress. The gradient experiment shown that when the C/N ratio is 25/1, the initial moisture is 65% and the pile-turning interval is 48 hours, the compost progress has the least nitrogen loss.

Abstract: In order to enhance the electrochemical performance of LiMnPO4 cathode material, we optimized the synthesis conditions of LiMnPO4 using a simple solid state reaction. The influence of factors of the pre-sintering temperature, carbon source and molar ratio of Zn to Mn, as well as the electrochemical properties of obtained LiMnPO4 powder were studied. The precursor of Zn-doping LiMnPO4/C was characterized by Differential Scanning Calorimetry and thermogravimetry. The microstructure of the samples was characterized by X-ray diffraction (XRD). The optimized LiMnPO4 cathode has good electrochemical properties and its discharge capacity could reach 140.2 mAh g−1 at 0.02 C rate and 111.3 mAh g−1 at 0.1 C rate with satisfactory cycling performance. It implies that the synthesis of LiMnPO4/C composite with excellent electrochemical performances can be achieved by a simple solid state method, which will boost the practical application of LiMnPO4 cathode materials.

Abstract: LiFePO4/C composite was synthesized by an easy sol-gel method using FeC2O4•H2O as iron source, citric acid and ethylene glycol as carbon source. The results showed that citric acid was inclined to leave more carbon in the synthesized material than ethylene glycol was and the carbon content increased greatly with the increasing amount of citric acid. When ethylene glycol was applied as carbon source, it left only a few amount of carbon (1.6 wt%) in the material. By optimizing the addition of carbon source, LiFePO4/C particles with uniform carbon coating and a little carbon content was obtained. The LiFePO4/C composite synthesized with 1/1 ratio of ethylene glycol to cations demonstrated the best electrochemical performance with its capacity of 143 mAh/g at 0.1C and 110 mAh/g at 1C within the voltage range of 2.5-4.2V (vs. Li/Li+). The results will provide ideas for the improvement of overall properties of LiFePO4 material for its application in the field of electric vehicles.

Abstract: With nitrite or nitrate nitrogen as electron acceptor in the high salt conditons, halophilic denitrifying bacteria can transfer nitrite or nitrate to nitrogen, thereby purifying the high-salt wastewater. Halophilic denitrifying bacteria play an important role in the carbon and nitrogen removal of saline wastewater, such as petroleum, chemical industry, seafood processing and seafood farming. This article dissussed halophilic denitrifying bacteria screening, the main types and the corresponding morphological characteristics, then we focused on the research progress of main factors of halophilic denitrifying bacteria’s growth and nitrogen removal. Finally put forward the current problems of the research and development trend of halophilic denitrifying bacteria.

Abstract: The article reviewed the advanced methods of ecological floating bed including usage of non-biodegradable bio-carrier, choosen of excellent plants, ion-beam irradiation, immobilized bacteria and aeration. Based on the review, the authors present the idea using biodegrable materials as bio-carrier, which not only could enhance the biomass in the ecological floating bed, but also could overcome the insufficience in carbon source for biological denitrification.

Abstract: LiFePO₄/C cathode material with different carbon sources was synthesized by using a two-step carbothermal reduction method. The structure and electrochemical properties of the samples were characterized by XRD, SEM and galvano-static charge-discharge method. The effect of different carbon sources on the structure, morphology and its electrochemical properties of the LiFePO₄/C composite materials were investigated. The results showed that the properties of the samples depended on carbon sources, significantly. The sample synthesized by citric acid as carbon source had the best electrochemical performance. The reason of performance difference of the LiFePO₄/C composite materials caused by carbon source was discussed.

Abstract: Two-stage complete mixing ferment process was used for developing carbon source with primary sludge. The effects of hydrolysis retention time (HRT) and sludge retention time (SRT) on the ferment system were studied. The results showed that the effective HRT was between 32 h and 36 h, and the effective SRT was between 4 d and 7 d. Under above conditions, the average effluent SCOD was in the range of 980 mg/L and 1180 mg/L, and supernatant MLSS was in the range of 50 mg/L and 80 mg/L. And then, the separation effect of the sludge thickener was clearly. Acidogenic bacteria and methanogenic bacteria could be separated effectively in the conditions.

Abstract: Porous silicon nitride ceramics with high-porosity were fabricated by carbothermal reduction reaction between silicon dioxide and carbon. The influences of carbon sources on microstructure and phase composition of the samples were studied. The result showed that the resultant porous silicon nitride ceramics using nano-meter carbon powder (C(n)) had finer microstructure, more uniform pore structure than those using activated carbon powder (C(a)). In order to illuminate the reaction and growth mechanism of b-Si3N4 grains, a series of intermediate sintering processes were investigated. X-ray diffractometry showed a difference in phase composition for the samples using the different carbon sources.