A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigat...A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The waste resin bonded sand was first reclaimed by a thermal method and the waste clay bonded sand was reclaimed by a wet method. Then, hot thermal reclaimed sand and the dehydrated wet reclaimed sand were mixed in certain proportions so that the hot thermal reclaimed sand dried the wet reclaimed sand leaving some water. The thermal reclamation efficiency of the waste resin bonded sand was researched at different heat levels. The optimized wet reclamation process of the waste clay bonded sand was achieved by investigating the effects of wet reclamation times, sand-water ratio and pH value on the reclaimed sand characteristics. The composite reclamation cost also was calculated. The research results showed that the properties of the mixed reclaimed sand can satisfy the application requirements of foundries; in which the temperature of the thermal reclamation waste resin bonded sand needs to be about 800 oC, the number of cycles of wet reclamation waste clay bonded sand should reach four to five, the optimal sand-water ratio of wet reclamation is around 1:1.5, and the pH value should be adjusted by adding acid. The mass ratio of hot thermal reclaimed sand to dehydrated wet reclaimed sand is about 1:2.5, and the composite reclaimed sand cost is around 100 yuan RMB per ton.展开更多
Thermal plasma technology provides a stable and long term treatment of mixed wastes through vitrification processes. In this work, a transferred plasma system was realized to vitrify mixed wastes, taking advantage of ...Thermal plasma technology provides a stable and long term treatment of mixed wastes through vitrification processes. In this work, a transferred plasma system was realized to vitrify mixed wastes, taking advantage of its high power density, enthalpy and chemical reactivity as well as its rapid quenching and high operation temperatures. To characterize the plasma discharge, a temperature diagnostic is realized by means of optical emission spectroscopy （OES）. To typify the morphological structure of the wastes samples~ scan- ning electron microscopy （SEM）, and X-ray diffraction （XRD） techniques were applied before and after the plasma treatment.展开更多
The aim of this research work was to enhance the fermentative production of exopolysaccharide(EPS)with mixed fruit waste as a key substrate.Xanothomonas campestries was isolated from spoiled orange and its EPS product...The aim of this research work was to enhance the fermentative production of exopolysaccharide(EPS)with mixed fruit waste as a key substrate.Xanothomonas campestries was isolated from spoiled orange and its EPS production efficiency was determined using EPS medium.Prior to optimisation,the production was 3.4 g/L,upon optimizing the medium the production improved to 9.2 g/L.The medium formulation was studied by sequential addition of medium components and replacement of sugar with mixed fruit waste.In formulated medium,the production enhanced to 11.1 g/L.For further optimisation,the response surface methodology was used,which resulted in the enhancement of production to 14.5 g/L.The scale-up study was undertaken in a 10 L shake flask and fermenter.In 10 L flask EPS,production was 14.45 g/L in 100 h,whereas in 10 L fermenter it was 21.10 g/L in 60h only.The optimisation studies gave nearly 500%(6.2fold)enhanced EPS production and dwindle in fermentation time.Replacement of sucrose with fruit waste extract made the process environment-friendly;omission of L-cystine and use of 50%reduced amount of sodium acetate in the medium lowered the production cost of EPS.The developed process resulted in the utilization of fruit waste and was also useful in solving the fruit waste disposal problem.展开更多
基金supported by the National Natural Science Foundation (Grant numbers:50575085,51075163 and 51375187)
文摘A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The waste resin bonded sand was first reclaimed by a thermal method and the waste clay bonded sand was reclaimed by a wet method. Then, hot thermal reclaimed sand and the dehydrated wet reclaimed sand were mixed in certain proportions so that the hot thermal reclaimed sand dried the wet reclaimed sand leaving some water. The thermal reclamation efficiency of the waste resin bonded sand was researched at different heat levels. The optimized wet reclamation process of the waste clay bonded sand was achieved by investigating the effects of wet reclamation times, sand-water ratio and pH value on the reclaimed sand characteristics. The composite reclamation cost also was calculated. The research results showed that the properties of the mixed reclaimed sand can satisfy the application requirements of foundries; in which the temperature of the thermal reclamation waste resin bonded sand needs to be about 800 oC, the number of cycles of wet reclamation waste clay bonded sand should reach four to five, the optimal sand-water ratio of wet reclamation is around 1:1.5, and the pH value should be adjusted by adding acid. The mass ratio of hot thermal reclaimed sand to dehydrated wet reclaimed sand is about 1:2.5, and the composite reclaimed sand cost is around 100 yuan RMB per ton.
文摘Thermal plasma technology provides a stable and long term treatment of mixed wastes through vitrification processes. In this work, a transferred plasma system was realized to vitrify mixed wastes, taking advantage of its high power density, enthalpy and chemical reactivity as well as its rapid quenching and high operation temperatures. To characterize the plasma discharge, a temperature diagnostic is realized by means of optical emission spectroscopy （OES）. To typify the morphological structure of the wastes samples~ scan- ning electron microscopy （SEM）, and X-ray diffraction （XRD） techniques were applied before and after the plasma treatment.
基金We are grateful to the Department of Science and Technology(DST),New Delhi,India awarding INSPIRE Fellowship to Dr.Kinjal.H.Upadhyay.Dr Bhargav C Patel for correction of text and plagiarism check.
文摘The aim of this research work was to enhance the fermentative production of exopolysaccharide(EPS)with mixed fruit waste as a key substrate.Xanothomonas campestries was isolated from spoiled orange and its EPS production efficiency was determined using EPS medium.Prior to optimisation,the production was 3.4 g/L,upon optimizing the medium the production improved to 9.2 g/L.The medium formulation was studied by sequential addition of medium components and replacement of sugar with mixed fruit waste.In formulated medium,the production enhanced to 11.1 g/L.For further optimisation,the response surface methodology was used,which resulted in the enhancement of production to 14.5 g/L.The scale-up study was undertaken in a 10 L shake flask and fermenter.In 10 L flask EPS,production was 14.45 g/L in 100 h,whereas in 10 L fermenter it was 21.10 g/L in 60h only.The optimisation studies gave nearly 500%(6.2fold)enhanced EPS production and dwindle in fermentation time.Replacement of sucrose with fruit waste extract made the process environment-friendly;omission of L-cystine and use of 50%reduced amount of sodium acetate in the medium lowered the production cost of EPS.The developed process resulted in the utilization of fruit waste and was also useful in solving the fruit waste disposal problem.
