In the thermodynamics, for flotation separation of the SbAs bulk concentrate system there is no potential extent using butyl xanthate as collector. However in the kinetics, there exists 150 mV in reducing potential of...In the thermodynamics, for flotation separation of the SbAs bulk concentrate system there is no potential extent using butyl xanthate as collector. However in the kinetics, there exists 150 mV in reducing potential of butyl dixanthogen on the surface of stibnite and arsenopyrite. In this paper, their reducing kinetic difference of electrochemistry was confirmed by pure mineral flotation under controlled potential, the artificial SbAs bulk concentrate flotation separation and UVspectrophotometic analysis. The electrochemical separation of SbAs bulk concentrate has been carried out. qualified concentrate has been obtained. Sbconcentrate contains Sb 4944 %, As 044 %, Sbrecovery is 8783 % and Asconcentrate contains As 1096 %, Asrecovery is 9466 %.展开更多
A batch experiment was conducted to investigate the adsorption of trivalent chromium (Cr(Ⅲ)) from aqueous solutions by sugarcane pulp residue (SPR) and biochar. The results show that Cr(Ⅲ) adsorption by SPR ...A batch experiment was conducted to investigate the adsorption of trivalent chromium (Cr(Ⅲ)) from aqueous solutions by sugarcane pulp residue (SPR) and biochar. The results show that Cr(Ⅲ) adsorption by SPR and biochar is highly pH-dependent and Cr(Ⅲ) adsorption amount increases with the increase of pH. The adsorption kinetics of Cr(Ⅲ) fits well with the pseudo-second-order model. The maximum Cr(Ⅲ) adsorption capacities of 15.85 mg/g and 3.43 mg/g for biochar and SPR were calculated by Langmuir model. This indicates that biochar has a larger ability for Cr(Ⅲ) adsorption than SPR. The free energy change value (AG) reveals a spontaneous sorption process of Cr(Ⅲ) onto SPR and non-spontaneous sorption process onto biochar. The entropy change (AS) and enthalpy change (AH) are found to be 66.27 J/(mol'K) and 17.13 kJ/mol for SPR and 91.59 J/(mol-K) and 30.875 kJ/mol for biochar which further reflect an affinity of Cr(Ⅲ) onto SPR and biochar. It is suggested that biochar has potential to be an efficient adsorbent in the removal of Cr(Ⅲ) from industrial wastewater.展开更多
Sugarcane pulp residue (SPR), a waste from sugar-refinery, which possesses a large surface area, can be used for removing chromium (Cr(Ⅲ) and Cr(Ⅵ)) from wastewater. In this work, the kinetics, isotherms of...Sugarcane pulp residue (SPR), a waste from sugar-refinery, which possesses a large surface area, can be used for removing chromium (Cr(Ⅲ) and Cr(Ⅵ)) from wastewater. In this work, the kinetics, isotherms of Cr(Ⅲ) and Cr(V[) adsorption and their removal by SPR were investigated. The results show that the removal percentages of Cr(Ⅵ) and Cr(Ⅲ) increase with increasing SPR dosage and temperature and decrease with increasing SPR particle size and the initial concentration of chromium ions. However, the influence of pH value on the Cr(Ⅵ) removal differs from that of the Cr(Ⅲ) removal. The Cr(Ⅵ) removal percentage decreases with increasing pH values, while the Cr(Ⅲ) removal percentage increases with increasing pH value. The adsorption kinetics of Cr(Ⅵ) and Cr(Ⅲ) well fits with pseudo-second-order model. Langmuir adsorption isotherm can well describe the adsorption phenomena of chromium ions with the maximum adsorption capacity of 0.567 mg/g for Cr(Ⅵ) and 3.446 mg/g for Cr(Ⅲ). Moreover, SPR reveals higher adsorption capacity for Cr(Ⅲ) than that for Cr(Ⅵ), which implies that SPR has more potential application for Cr(Ⅲ)-containing wastewater treatment than that for Cr(Ⅵ)-containing wastewater treatment.展开更多
The ultra fine grinding and resin in pulp with pH value of 10 are used to extract gold from pyrite roster cinder. During leaching process, aluminium oxide ball is used as stirring medium, hydrogen peroxide as leaching...The ultra fine grinding and resin in pulp with pH value of 10 are used to extract gold from pyrite roster cinder. During leaching process, aluminium oxide ball is used as stirring medium, hydrogen peroxide as leaching agent and sodium hexametaphosphate as grinding agent. With AM 2б resin as absorber and sulfocarbamide as eluent, gold is recovered from cyanide pulp of pyrite roster cinder by resin in pulp. The effects of contact time, temperature and acidity etc. on the gold absorption are investigated by static methods and dynamic method respectively. The effects of flow rate of solution on dynamic adsorption and elution of gold are studied. The results show that AM 2б resin has good adsorbability in cyanide solution, and gold can be easily eluated from the loaded resin with 0.1mol/L hydrochloric acid and 1mol/L sulfocabamide. The adsorption rate and the elution of gold exceed 98%. When leaching time is 2 h, mass ratio of liquid to solid 4∶1, consumption of sodium cyanide 3 kg/t, concentration of hydrogen peroxide and sodium hexametaphosphate 0.05% respectively, adsorption time 30 min, temperature 10 30 ℃, volume of resin 3 mL, ratio of eluent to resin (10 20)∶1, velocity of eluent 1.5 mL/min, the leaching rate of gold reaches 85%. Compared with traditional leaching technology, it can reduce leaching time, avoid complex filter process, decrease sodium cyanide consumption and increase leaching rate of gold by 35%.展开更多
Instead of pure bacteria, induction mutation of activated sludge by ultraviolet (Uv) was studied and used to treat pulping wastewater by continuous- flow. The result showed the mutagenic activated sludge had remarkabl...Instead of pure bacteria, induction mutation of activated sludge by ultraviolet (Uv) was studied and used to treat pulping wastewater by continuous- flow. The result showed the mutagenic activated sludge had remarkable effect and application potential in pulping wastewater treatment. Comparing with common activated sludge, the mutagenic activated sludge was more suitable for lignose decomposition and had high decomposing efficiency.展开更多
To improve heating uniformity and anthocyanin content of the blueberry pulp under microwave heating,the intermittent variable power microwave heating technology was introduced in the study.The effects of technology pa...To improve heating uniformity and anthocyanin content of the blueberry pulp under microwave heating,the intermittent variable power microwave heating technology was introduced in the study.The effects of technology parameters in terms of high microwave intensity heating time,intermittent time,low microwave intensity and low microwave intensity heating time on the blueberry pulp quality parameters(heating uniformity,average moisture content,the highest temperature and anthocyanin content)were investigated by using the response surface method.The results showed that the longer heating time under different microwave intensities resulted in the poorer heating uniformity.The intermittent stage promoted heat and mass transfer within the pulp and reduced the temperature difference and moisture gradient within the pulp,which enhanced desired uniformity of temperature and moisture distribution before entering the low microwave intensity heating stage.Therefore,the longer the intermittent time,the greater the heating uniformity.The optimal parameters were developed as high microwave intensity of 4 W·g^(-1),high microwave intensity heating time of 9.86 min,intermittent time of 10 min,low microwave intensity of 2.2 W·g^(-1)and low microwave intensity heating time of 6 min.This research might provide guidance for microwave heating berry fruits.展开更多
The stability was studied of the pigment in red pulp plum (Prunus salicina Lindl). The results showed that the pigment had a high resistance to heat and it′s stability seemed to be affected greatly by pH, and red pu...The stability was studied of the pigment in red pulp plum (Prunus salicina Lindl). The results showed that the pigment had a high resistance to heat and it′s stability seemed to be affected greatly by pH, and red pulp plum was suitable to be applied for making acid food. Several kinds of metallic ions including Na + 、Zn 2+ had an effect of reinforcement on its tone, however Fe 3+ had a disruptive effect. Sucrose had no undesirable effect, but vitamin C had a significant undesirable effect. Also the preservative of sodium benzoate had a definite undesirable effect. The pigment showed strong resistance to reducer sodium sulfite but was very weak in resistance to oxidizer hydrogen peroxide.展开更多
文摘In the thermodynamics, for flotation separation of the SbAs bulk concentrate system there is no potential extent using butyl xanthate as collector. However in the kinetics, there exists 150 mV in reducing potential of butyl dixanthogen on the surface of stibnite and arsenopyrite. In this paper, their reducing kinetic difference of electrochemistry was confirmed by pure mineral flotation under controlled potential, the artificial SbAs bulk concentrate flotation separation and UVspectrophotometic analysis. The electrochemical separation of SbAs bulk concentrate has been carried out. qualified concentrate has been obtained. Sbconcentrate contains Sb 4944 %, As 044 %, Sbrecovery is 8783 % and Asconcentrate contains As 1096 %, Asrecovery is 9466 %.
基金Project(50925417) supported by the National Funds for Distinguished Young Scientist,ChinaProject(50830301) supported by the Key Program of National Natural Science Foundation of ChinaProject(51074191) supported by the National Natural Science Foundation of China
文摘A batch experiment was conducted to investigate the adsorption of trivalent chromium (Cr(Ⅲ)) from aqueous solutions by sugarcane pulp residue (SPR) and biochar. The results show that Cr(Ⅲ) adsorption by SPR and biochar is highly pH-dependent and Cr(Ⅲ) adsorption amount increases with the increase of pH. The adsorption kinetics of Cr(Ⅲ) fits well with the pseudo-second-order model. The maximum Cr(Ⅲ) adsorption capacities of 15.85 mg/g and 3.43 mg/g for biochar and SPR were calculated by Langmuir model. This indicates that biochar has a larger ability for Cr(Ⅲ) adsorption than SPR. The free energy change value (AG) reveals a spontaneous sorption process of Cr(Ⅲ) onto SPR and non-spontaneous sorption process onto biochar. The entropy change (AS) and enthalpy change (AH) are found to be 66.27 J/(mol'K) and 17.13 kJ/mol for SPR and 91.59 J/(mol-K) and 30.875 kJ/mol for biochar which further reflect an affinity of Cr(Ⅲ) onto SPR and biochar. It is suggested that biochar has potential to be an efficient adsorbent in the removal of Cr(Ⅲ) from industrial wastewater.
基金Projects(2006AA06Z374, 2007AA021304) supported by the National High-Tech Research and Development Program of ChinaProject(2008SK2007) supported by the Key Program of Science and Technology of Hunan Province, China
文摘Sugarcane pulp residue (SPR), a waste from sugar-refinery, which possesses a large surface area, can be used for removing chromium (Cr(Ⅲ) and Cr(Ⅵ)) from wastewater. In this work, the kinetics, isotherms of Cr(Ⅲ) and Cr(V[) adsorption and their removal by SPR were investigated. The results show that the removal percentages of Cr(Ⅵ) and Cr(Ⅲ) increase with increasing SPR dosage and temperature and decrease with increasing SPR particle size and the initial concentration of chromium ions. However, the influence of pH value on the Cr(Ⅵ) removal differs from that of the Cr(Ⅲ) removal. The Cr(Ⅵ) removal percentage decreases with increasing pH values, while the Cr(Ⅲ) removal percentage increases with increasing pH value. The adsorption kinetics of Cr(Ⅵ) and Cr(Ⅲ) well fits with pseudo-second-order model. Langmuir adsorption isotherm can well describe the adsorption phenomena of chromium ions with the maximum adsorption capacity of 0.567 mg/g for Cr(Ⅵ) and 3.446 mg/g for Cr(Ⅲ). Moreover, SPR reveals higher adsorption capacity for Cr(Ⅲ) than that for Cr(Ⅵ), which implies that SPR has more potential application for Cr(Ⅲ)-containing wastewater treatment than that for Cr(Ⅵ)-containing wastewater treatment.
文摘The ultra fine grinding and resin in pulp with pH value of 10 are used to extract gold from pyrite roster cinder. During leaching process, aluminium oxide ball is used as stirring medium, hydrogen peroxide as leaching agent and sodium hexametaphosphate as grinding agent. With AM 2б resin as absorber and sulfocarbamide as eluent, gold is recovered from cyanide pulp of pyrite roster cinder by resin in pulp. The effects of contact time, temperature and acidity etc. on the gold absorption are investigated by static methods and dynamic method respectively. The effects of flow rate of solution on dynamic adsorption and elution of gold are studied. The results show that AM 2б resin has good adsorbability in cyanide solution, and gold can be easily eluated from the loaded resin with 0.1mol/L hydrochloric acid and 1mol/L sulfocabamide. The adsorption rate and the elution of gold exceed 98%. When leaching time is 2 h, mass ratio of liquid to solid 4∶1, consumption of sodium cyanide 3 kg/t, concentration of hydrogen peroxide and sodium hexametaphosphate 0.05% respectively, adsorption time 30 min, temperature 10 30 ℃, volume of resin 3 mL, ratio of eluent to resin (10 20)∶1, velocity of eluent 1.5 mL/min, the leaching rate of gold reaches 85%. Compared with traditional leaching technology, it can reduce leaching time, avoid complex filter process, decrease sodium cyanide consumption and increase leaching rate of gold by 35%.
文摘Instead of pure bacteria, induction mutation of activated sludge by ultraviolet (Uv) was studied and used to treat pulping wastewater by continuous- flow. The result showed the mutagenic activated sludge had remarkable effect and application potential in pulping wastewater treatment. Comparing with common activated sludge, the mutagenic activated sludge was more suitable for lignose decomposition and had high decomposing efficiency.
基金Supported by the National Natural Science Foundation of China(32072352)。
文摘To improve heating uniformity and anthocyanin content of the blueberry pulp under microwave heating,the intermittent variable power microwave heating technology was introduced in the study.The effects of technology parameters in terms of high microwave intensity heating time,intermittent time,low microwave intensity and low microwave intensity heating time on the blueberry pulp quality parameters(heating uniformity,average moisture content,the highest temperature and anthocyanin content)were investigated by using the response surface method.The results showed that the longer heating time under different microwave intensities resulted in the poorer heating uniformity.The intermittent stage promoted heat and mass transfer within the pulp and reduced the temperature difference and moisture gradient within the pulp,which enhanced desired uniformity of temperature and moisture distribution before entering the low microwave intensity heating stage.Therefore,the longer the intermittent time,the greater the heating uniformity.The optimal parameters were developed as high microwave intensity of 4 W·g^(-1),high microwave intensity heating time of 9.86 min,intermittent time of 10 min,low microwave intensity of 2.2 W·g^(-1)and low microwave intensity heating time of 6 min.This research might provide guidance for microwave heating berry fruits.
文摘The stability was studied of the pigment in red pulp plum (Prunus salicina Lindl). The results showed that the pigment had a high resistance to heat and it′s stability seemed to be affected greatly by pH, and red pulp plum was suitable to be applied for making acid food. Several kinds of metallic ions including Na + 、Zn 2+ had an effect of reinforcement on its tone, however Fe 3+ had a disruptive effect. Sucrose had no undesirable effect, but vitamin C had a significant undesirable effect. Also the preservative of sodium benzoate had a definite undesirable effect. The pigment showed strong resistance to reducer sodium sulfite but was very weak in resistance to oxidizer hydrogen peroxide.