Diatomite is a kind of natural low-cost mineral material. It has a number of unique physical properties and has been widely used as an adsorbent in wastewater treatment. This study was conducted to investigate the aer...Diatomite is a kind of natural low-cost mineral material. It has a number of unique physical properties and has been widely used as an adsorbent in wastewater treatment. This study was conducted to investigate the aerobic biodegradation of coal gasification wastewater with and without diatomite addition. Experimental results indicated that diatomite added in the activated sludge system could promote the biomass and also enhance the performance of the sludge settling. The average mixed-liquor volatile suspended solids （MLVSS） is increased from 4055 mg.L^-1 to 4518 mg.L^-1 and the average settling volume （SV） are changed only from 45.9% to 47.1%. Diatomite additive could enhance the efficiency of chemical oxygen demand （COD） and total phenols removal from the wastewater. The COD removal increased from 73.3% to near 80% and the total phenols removal increased from 81.4% to 85.8%. The mechanisms of the increase of biomass and pollutants removal may correlates to the improvement of bioavailability and sludge settlement characteristics by diatomite added. Micrograph of the sludge in the diatomite-activated sludge system indicated that the diatomite added could be the carrier of the microbe and also affect the biomass and pollutant removal.展开更多
General pretreatment processes of ammonia stripping and phenols solvent extraction can reduce the concentration of toxic compounds of the coal gasification wastewater for the following biological treatment. However, s...General pretreatment processes of ammonia stripping and phenols solvent extraction can reduce the concentration of toxic compounds of the coal gasification wastewater for the following biological treatment. However, some emulsified coal tar still exists in the influent and many substances in coal tar are refractory and toxic to microorganisms. This study is mainly on the removal of emulsified coal tar by acidification demulsion. The experimental results show that the acidification process of the wastewater by pure hydrochloric acid can reduce the chemical oxygen demand （COD）, total organic carbon （TOC）, total phenolics and oil about 3.1%-11.3%, 6%-- 10.8%, 5.3%--8.6% and 25.2%--57.4% respectively with pH value in the range of 4 to 7. The analysis of molecular weight distribution indicates that compounds removed from the wastewater by this process are large molecular substances. The experiment also shows that the efficiency of COD removal in the demulsion process by different acids is different and the phosphoric acid is prominent. The preserved time of the wastewater also affects the efficiency of demulsion. Small amount low-cost solid additives including kaolin and diatomite can improve the rate of coal tar sedimentation and enhance the removal efficiency of organics in the phosphoric acidification process.展开更多
Printing and dyeing industry is a considerable source of environmental contamination. In this study treatment of printing and dyeing wastewater with a new type of sewage treatment agent, fly-ash coated with chitosan p...Printing and dyeing industry is a considerable source of environmental contamination. In this study treatment of printing and dyeing wastewater with a new type of sewage treatment agent, fly-ash coated with chitosan particles （FCCP）, was examined. The effects ofpH, stirring time, sedimentation time and temperature on color, COD, turbidity and NH3-N removal were determined. The optimum dosage of FCCP and the influence of individual factors on removal efficiency were tested. The optimum parameters determined using the L16 （45） orthogonal experiment were as follows： FCCP （weight ratio of chitosan to fly-ash 1：6） dosage, 4 g.L^-1; temperature, 35℃; pH, 4. The stirring time and sedimentation time were 20 min and 5 h, respectively. Under these optimum conditions, the color, COD and NH3-N removal ratios were 97%, 80% and 75%, respectively.展开更多
In order to design a new technological process system to take the polymeric ferric aluminum silicate sulfate（PFASS） and to apply it in wastewater processing, the chemical composition analysis was carried on to the F...In order to design a new technological process system to take the polymeric ferric aluminum silicate sulfate（PFASS） and to apply it in wastewater processing, the chemical composition analysis was carried on to the Fuxin gangue, adopted the orthogonal experiment method to obtain optimum response condition of with the acid pickling taking the aluminum in the gangue and with alkali extracting taking the silicon in the gangue, The experiments indicate that the sample chemistry content which tests elect completely conform to the preparation inorganic polymer water treatment coagulant request standard. Used the polymeric ferric aluminum silicate sulfate results in which with the system take as the coagulant of treatment wastewater, used the mercerizing degree, the wastewater pH value, the coagulation time, the coagulant throws increment factors and so on to test and verify its influence on the waste water processing. The result indicates that by using this craft production PFASS in waste water processing, after the processed waste water achieves the emission standard, the processing effect is good.展开更多
On the basis of flocculating settling experimentation on flotation waste coal in Wangfenggang coal preparation plant,influence of medical dosage and cationization (CD) of CPAM samples on coal slurry's flocculating...On the basis of flocculating settling experimentation on flotation waste coal in Wangfenggang coal preparation plant,influence of medical dosage and cationization (CD) of CPAM samples on coal slurry's flocculating effect was studied,difference of flocculating effect on coal slurry among different categories of polyacrylamide was discussed.Experi- mental results show that when the dosage of flocculant reaches 2-4 g/m^3 flotation waste, and the CD of CPAM is 5%,flocculating effect is the best,light transmittance of super- natant liquor reaches 93%.Taking 3types of sample CPAM,PAM and PHP,which formula weight vary a little,to deal with the same concn of coal slurry,when medicine dosage is 3 g/m^3,flocculating effect of CPAM is the best,light transmittance of supernatant liquor reaches 92%.展开更多
A filtration system used without chemical agents for the pretreatment of turbid coal mine drainage is described in this paper.The influence of different aperture sizes and different motor speeds was investigated durin...A filtration system used without chemical agents for the pretreatment of turbid coal mine drainage is described in this paper.The influence of different aperture sizes and different motor speeds was investigated during the study.The experimental results show that for aperture diameters of 0.4,0.6,or 0.8 mm smaller apertures provide more complete filtration.Rotations of 12,20,28,or 40 r/min show that higher speeds give more efficient filtration.Suspended solids decreased in both particle size and concentration after the filtration.The separated slime can be directly reused as a fuel.Efficient filtration pretreatment systems for coal mine drainage were investigated and the economic feasibility is analyzed in this article.展开更多
In this paper, the results of an extensive investigation of hydrothermal pre-treatment for synthesizing belite phase from reactive mixtures （CaO/SiO2 molar ratio of 2） consisting of one waste kinds （bottom ash-BA o...In this paper, the results of an extensive investigation of hydrothermal pre-treatment for synthesizing belite phase from reactive mixtures （CaO/SiO2 molar ratio of 2） consisting of one waste kinds （bottom ash-BA or fly ash-FA） from fluidised brown coal combustion in Slovakian power plant and CaO （analytical grade reagent） addition are summarized. Changes in structure and phase composition of hydrothermally synthesized belite precursors and subsequent calcinated products were compared with those of starting mixtures. Based on XRD diffraction patterns, the formation of the new profiles corresponding to CSH phases with low degree of ordering as belite precursors after hydrothermal treatment was confirmed. Calcination of hydrotermally treated products at 900℃ led to transformation of CSH phases to wollastonite, belite and gehlenite phase. Differences in phase composition of products before and after calcination depend upon waste quality and precursor＇s synthesis conditions. Bottom ash isn＇t suitable as raw material for synthesizing belite phase because of high CaO content fixed in anhydrite form （44.1%）. Coal fly ash with low CaO content in anhydrite form （4.2%） and its hydrothermal treatment in combination with subsequent heating offer opportunities for the utilization of coal fly ash as raw material for belite production.展开更多
Detailed experimental investigations were carried out for microwave pre-treatment of high ash Indian coal at high power level(900 W) in microwave oven. The microwave exposure times were fixed at60 s and 120 s. A rheol...Detailed experimental investigations were carried out for microwave pre-treatment of high ash Indian coal at high power level(900 W) in microwave oven. The microwave exposure times were fixed at60 s and 120 s. A rheology characteristic for microwave pre-treatment of coal-water slurry(CWS) was performed in an online Bohlin viscometer. The non-Newtonian character of the slurry follows the rheological model of Ostwald de Waele. The values of n and k vary from 0.31 to 0.64 and 0.19 to 0.81 Pa·sn,respectively. This paper presents an artificial neural network(ANN) model to predict the effects of operational parameters on apparent viscosity of CWS. A 4-2-1 topology with Levenberg-Marquardt training algorithm(trainlm) was selected as the controlled ANN. Mean squared error(MSE) of 0.002 and coefficient of multiple determinations(R^2) of 0.99 were obtained for the outperforming model. The promising values of correlation coefficient further confirm the robustness and satisfactory performance of the proposed ANN model.展开更多
Using the method of sedentary thermal experiment, the use of fly ash to remove Zn 2+ ,Cu 2+ and Pb 2+ in waste water was studied. Special attention was paid to the effects of pH and time degree of activity on absorbin...Using the method of sedentary thermal experiment, the use of fly ash to remove Zn 2+ ,Cu 2+ and Pb 2+ in waste water was studied. Special attention was paid to the effects of pH and time degree of activity on absorbing ability. The freundlich model applicable to the absorption data was set. Also the mechanism of absorption and ultra micro structure of fly ash with the help of TEM was put forward.展开更多
This paper briefly states the features and advantages of FCS （fieldbus control system）. In view of condensate water fined processing system of domestic 600 MW supercritical coal-fired generating units, it designed a...This paper briefly states the features and advantages of FCS （fieldbus control system）. In view of condensate water fined processing system of domestic 600 MW supercritical coal-fired generating units, it designed and developed a FCS for entirely process control, designed computer monitoring software and organized network monitor the change of data. At the same time, making the simulation device of the system, the FCS control system scheme is implemented on this device. It is verified by practice that the system control technology is advanced, safe, reliable and operation well. It provides a complete project for automation technology upgrade program in power plant. In addition, this device can be used in the power industry technical personnel training and teaching of colleges and universities. It is worth promotion and reference.展开更多
基金Supported by the Shanghai Committee of Education (07ZZ158)
文摘Diatomite is a kind of natural low-cost mineral material. It has a number of unique physical properties and has been widely used as an adsorbent in wastewater treatment. This study was conducted to investigate the aerobic biodegradation of coal gasification wastewater with and without diatomite addition. Experimental results indicated that diatomite added in the activated sludge system could promote the biomass and also enhance the performance of the sludge settling. The average mixed-liquor volatile suspended solids （MLVSS） is increased from 4055 mg.L^-1 to 4518 mg.L^-1 and the average settling volume （SV） are changed only from 45.9% to 47.1%. Diatomite additive could enhance the efficiency of chemical oxygen demand （COD） and total phenols removal from the wastewater. The COD removal increased from 73.3% to near 80% and the total phenols removal increased from 81.4% to 85.8%. The mechanisms of the increase of biomass and pollutants removal may correlates to the improvement of bioavailability and sludge settlement characteristics by diatomite added. Micrograph of the sludge in the diatomite-activated sludge system indicated that the diatomite added could be the carrier of the microbe and also affect the biomass and pollutant removal.
文摘General pretreatment processes of ammonia stripping and phenols solvent extraction can reduce the concentration of toxic compounds of the coal gasification wastewater for the following biological treatment. However, some emulsified coal tar still exists in the influent and many substances in coal tar are refractory and toxic to microorganisms. This study is mainly on the removal of emulsified coal tar by acidification demulsion. The experimental results show that the acidification process of the wastewater by pure hydrochloric acid can reduce the chemical oxygen demand （COD）, total organic carbon （TOC）, total phenolics and oil about 3.1%-11.3%, 6%-- 10.8%, 5.3%--8.6% and 25.2%--57.4% respectively with pH value in the range of 4 to 7. The analysis of molecular weight distribution indicates that compounds removed from the wastewater by this process are large molecular substances. The experiment also shows that the efficiency of COD removal in the demulsion process by different acids is different and the phosphoric acid is prominent. The preserved time of the wastewater also affects the efficiency of demulsion. Small amount low-cost solid additives including kaolin and diatomite can improve the rate of coal tar sedimentation and enhance the removal efficiency of organics in the phosphoric acidification process.
基金Supported by the Science and Technology Development Foundation of Foshan (No.2005060071)
文摘Printing and dyeing industry is a considerable source of environmental contamination. In this study treatment of printing and dyeing wastewater with a new type of sewage treatment agent, fly-ash coated with chitosan particles （FCCP）, was examined. The effects ofpH, stirring time, sedimentation time and temperature on color, COD, turbidity and NH3-N removal were determined. The optimum dosage of FCCP and the influence of individual factors on removal efficiency were tested. The optimum parameters determined using the L16 （45） orthogonal experiment were as follows： FCCP （weight ratio of chitosan to fly-ash 1：6） dosage, 4 g.L^-1; temperature, 35℃; pH, 4. The stirring time and sedimentation time were 20 min and 5 h, respectively. Under these optimum conditions, the color, COD and NH3-N removal ratios were 97%, 80% and 75%, respectively.
文摘In order to design a new technological process system to take the polymeric ferric aluminum silicate sulfate（PFASS） and to apply it in wastewater processing, the chemical composition analysis was carried on to the Fuxin gangue, adopted the orthogonal experiment method to obtain optimum response condition of with the acid pickling taking the aluminum in the gangue and with alkali extracting taking the silicon in the gangue, The experiments indicate that the sample chemistry content which tests elect completely conform to the preparation inorganic polymer water treatment coagulant request standard. Used the polymeric ferric aluminum silicate sulfate results in which with the system take as the coagulant of treatment wastewater, used the mercerizing degree, the wastewater pH value, the coagulation time, the coagulant throws increment factors and so on to test and verify its influence on the waste water processing. The result indicates that by using this craft production PFASS in waste water processing, after the processed waste water achieves the emission standard, the processing effect is good.
基金the Hi-Tech Research and Development Program of Huainan City(2005zd008)
文摘On the basis of flocculating settling experimentation on flotation waste coal in Wangfenggang coal preparation plant,influence of medical dosage and cationization (CD) of CPAM samples on coal slurry's flocculating effect was studied,difference of flocculating effect on coal slurry among different categories of polyacrylamide was discussed.Experi- mental results show that when the dosage of flocculant reaches 2-4 g/m^3 flotation waste, and the CD of CPAM is 5%,flocculating effect is the best,light transmittance of super- natant liquor reaches 93%.Taking 3types of sample CPAM,PAM and PHP,which formula weight vary a little,to deal with the same concn of coal slurry,when medicine dosage is 3 g/m^3,flocculating effect of CPAM is the best,light transmittance of supernatant liquor reaches 92%.
基金support through Special Basic Research Fund of China Central University(No.2011QH01)Innovative Experiment Projects for Undergraduates
文摘A filtration system used without chemical agents for the pretreatment of turbid coal mine drainage is described in this paper.The influence of different aperture sizes and different motor speeds was investigated during the study.The experimental results show that for aperture diameters of 0.4,0.6,or 0.8 mm smaller apertures provide more complete filtration.Rotations of 12,20,28,or 40 r/min show that higher speeds give more efficient filtration.Suspended solids decreased in both particle size and concentration after the filtration.The separated slime can be directly reused as a fuel.Efficient filtration pretreatment systems for coal mine drainage were investigated and the economic feasibility is analyzed in this article.
文摘In this paper, the results of an extensive investigation of hydrothermal pre-treatment for synthesizing belite phase from reactive mixtures （CaO/SiO2 molar ratio of 2） consisting of one waste kinds （bottom ash-BA or fly ash-FA） from fluidised brown coal combustion in Slovakian power plant and CaO （analytical grade reagent） addition are summarized. Changes in structure and phase composition of hydrothermally synthesized belite precursors and subsequent calcinated products were compared with those of starting mixtures. Based on XRD diffraction patterns, the formation of the new profiles corresponding to CSH phases with low degree of ordering as belite precursors after hydrothermal treatment was confirmed. Calcination of hydrotermally treated products at 900℃ led to transformation of CSH phases to wollastonite, belite and gehlenite phase. Differences in phase composition of products before and after calcination depend upon waste quality and precursor＇s synthesis conditions. Bottom ash isn＇t suitable as raw material for synthesizing belite phase because of high CaO content fixed in anhydrite form （44.1%）. Coal fly ash with low CaO content in anhydrite form （4.2%） and its hydrothermal treatment in combination with subsequent heating offer opportunities for the utilization of coal fly ash as raw material for belite production.
基金the sponsor CSIR (Council of Scientific and Industrial Research), New Delhi for their financial grant to carry out the present research work
文摘Detailed experimental investigations were carried out for microwave pre-treatment of high ash Indian coal at high power level(900 W) in microwave oven. The microwave exposure times were fixed at60 s and 120 s. A rheology characteristic for microwave pre-treatment of coal-water slurry(CWS) was performed in an online Bohlin viscometer. The non-Newtonian character of the slurry follows the rheological model of Ostwald de Waele. The values of n and k vary from 0.31 to 0.64 and 0.19 to 0.81 Pa·sn,respectively. This paper presents an artificial neural network(ANN) model to predict the effects of operational parameters on apparent viscosity of CWS. A 4-2-1 topology with Levenberg-Marquardt training algorithm(trainlm) was selected as the controlled ANN. Mean squared error(MSE) of 0.002 and coefficient of multiple determinations(R^2) of 0.99 were obtained for the outperforming model. The promising values of correlation coefficient further confirm the robustness and satisfactory performance of the proposed ANN model.
文摘Using the method of sedentary thermal experiment, the use of fly ash to remove Zn 2+ ,Cu 2+ and Pb 2+ in waste water was studied. Special attention was paid to the effects of pH and time degree of activity on absorbing ability. The freundlich model applicable to the absorption data was set. Also the mechanism of absorption and ultra micro structure of fly ash with the help of TEM was put forward.
文摘This paper briefly states the features and advantages of FCS （fieldbus control system）. In view of condensate water fined processing system of domestic 600 MW supercritical coal-fired generating units, it designed and developed a FCS for entirely process control, designed computer monitoring software and organized network monitor the change of data. At the same time, making the simulation device of the system, the FCS control system scheme is implemented on this device. It is verified by practice that the system control technology is advanced, safe, reliable and operation well. It provides a complete project for automation technology upgrade program in power plant. In addition, this device can be used in the power industry technical personnel training and teaching of colleges and universities. It is worth promotion and reference.
