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Fu K.,Hainan Provincial Research Academy of Environmental science | Fu K.,South China University of Technology | Yue P.,Hainan Provincial Research Academy of Environmental science | Li H.,South China University of Technology | And 2 more authors.
Asian Journal of Chemistry | Year: 2013

To improve the ammonium exchange capacity of the medical stone, its modifications in different solutions have been tested, respectively. The ammonium-exchange isotherms of the modified medical stone have been determined and compared. The renewable ammonium exchange capacity of the medical stone has been further studied. The results indicated that the ammonium exchange of medical stone increased as the average pore diameter and the BET surface area increased, after the medical stone were soaked with HCl and H2SO 4 solutions. The modified method soaking with NaCl solution was superior to them, because the sodium content of this modified medical stone increased, leading to a more improved ammonium exchange capacity. The ammonium exchange capacity decreased with modified ion in the order Na+ > K+ > Mg2+ > Ca2+. When the ammonium concentration was 150 mg/L, the ammonium exchange capacity of medical stone modified with 98 °C NaCl solution increased 80.4 %. For the ammonium exchange isotherms of medical stones, the Freundlich isotherm model yielded a much better fit than that of Langmuir isotherm model. After three times regeneration, the ammonium uptake of medical stone was changed little. Its exchange capacity was stable. Copyright © 2013 Asian Journal of Chemistry. Source


Fu K.,Hainan Provincial Research Academy of Environmental science | Fu K.,South China University of Technology | Li Z.,South China University of Technology | Xia Q.,South China University of Technology | Zhong T.,Hainan Provincial Research Academy of Environmental science
Asian Journal of Chemistry | Year: 2012

The removal of ammonium from aqueous media using Chinese Dalian clinoptilolite has been investigated. To improve the ammonium exchange of the clinoptilolite, its modifications in aqueous NaCl solution at different temperatures and under different power levels of ultrasonication have been tested. The ammonium-exchange isotherms of the clinoptilolite have been determined. The effects of solution pH and the different modifications of the clinoptilolite on ammonium exchange have been further studied. The results showed that a pseudo-second-order model gave a better correlation for all of the kinetic data as compared to Vermeulen's model or an intraparticle diffusion model. The optimal pH of solutions for ammonium exchange with clinoptilolite has been identified to be between 3 and 9. Natural clinoptilolite soaked in aqueous NaCl solution at 98 °C had the highest sodium content, leading to an improved ammoniumexchange capacity. The ammonium-exchange capacity of clinoptilolite could be improved by increasing the temperature at which it was soaked in aqueous NaCl solution, but it could not be improved by increasing the power level of ultrasonication continuously. All of the ammonium-exchange equilibrium isotherms, with both natural and modified clinoptilolite, conformed well to the Freundlich model. Source


Xing Q.,Guangxi University | Xing Q.,Hainan Provincial Research Academy of Environmental science | Chen J.,Guangxi University | Chen J.,Shandong Polytechnic University | And 4 more authors.
Asian Journal of Chemistry | Year: 2013

In this study, a series of pot experiments were conducted to investigate irrigation impacts on coriander biomass and quality using effluent from natural rubber processing plants treated at various stages with different levels of nutrients. The results showed that, irrigating with both the UASB anaerobic effluent and the aerobic effluent significantly increased the yield and nutrient contents of coriander. Among those, the efficiency of 50 %-diluted anaerobic effluent was better than compound fertilizer. Skim latex effluent without dilution should not be used to irrigate coriander whereas diluted skim latex effluent made the yield and nutrient contents of coriander increased significantly. The more diluted the skim latex effluent, the better growth the coriander. The 10 %-diluted skim latex effluent was similarly fertile as the 50 %-diluted aerobic effluent. Our study also suggested that: (1) untreated skim latex effluent could be used to irrigate crops and vegetables after being diluted to appropriate pH level. (2) Zero discharge of effluent from natural rubber processing plant would achievable if applying high-concentration skim latex effluent to irrigation and recycling low-concentration effluent. © 2013 Asian Journal of Chemistry. Source


Fu K.,Hainan Provincial Research Academy of Environmental science | Ren X.Y.,Hainan Provincial Research Academy of Environmental science | Ren X.Y.,Hainan Provincial Environmental Monitoring Center | Lin J.Q.,Hainan Provincial Research Academy of Environmental science | And 2 more authors.
Advanced Materials Research | Year: 2013

The environmental impacts of the dregs disposal in cement kiln and conventional production were contrastively evaluated by life cycle assessment (LCA) in this study. The results showed that the environmental load ratio of both cement productions followed the order of energy depletion potential (EDP) > depletion potential (ADP) > global warming potential (GWP) > acidification potential (AP) > human toxicity (HT) > photochemical ozone creation potential (POCP). The comprehensive environmental load of disposal dregs was 14.465×10-12/a, which was 3.98% lower than that of the conventional cement production. Moreover, the reduced percentage of the environmental load followed the order of HT> AP> POCP> EDP> ADP> GWP, which indicated that the reduced percentage of human toxicity and acidification reached 10.62% and 10.06% respectively. Thus, considering the environmental benefits, it would be a better method to dispose dregs instead of limestone in cement kiln. © (2013) Trans Tech Publications, Switzerland. Source

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