Multiple-effect membrane distillation （MEMD） process for enriching semi-volatile organic acids from their individual aqueous solutions was performed by using a hollow fiber-based air gap membrane distillation （AGMD...Multiple-effect membrane distillation （MEMD） process for enriching semi-volatile organic acids from their individual aqueous solutions was performed by using a hollow fiber-based air gap membrane distillation （AGMD） module with the function of internal heat recovery. Aqueous solutions of glyoxylic acid, glycolic acid, lactic acid, pyrnvic acid, malonic acid and glutaric acid were used as model feed. For a feed of 1% （mass fraction）, each acid could be enriched for 8--20 times, which depended on the surface tension of the concentrate. The operation performance of MEMD process was characterized by permeation flux J, performance ratio PR and acid rejection rate R. The effects of cold feed-in temperature, heated feed-in temperature, feed-in volumetric flow rate and feed-in concen- tration on MEMD performance were experimentally evaluated. Maximum values of J, PR and R were 4.8 L/（h-m2）, 9.84 and 99.93%, respectively. Moreover, MEMD process demonstrated a fairly good stability in a long-term experiment lasting for 30 d when aqueous solution of 4% （mass fraction） lactic acid was used as a feed.展开更多
In the small country of Ecuador, all environmental risks of the production and consumption of fossil fuels can be observed by damages through oil exploration in the amazonite rainforest and two tank ship accidents clo...In the small country of Ecuador, all environmental risks of the production and consumption of fossil fuels can be observed by damages through oil exploration in the amazonite rainforest and two tank ship accidents close by Galapagos Islands causing death of 10,000 marine iguanas and other species. Now Ecuador plans to replace all environmentally dangerous diesel generators from all four inhabited Galapagos Islands by a hybrid system using 100% renewable energy for electricity production. Since 2010 a hybrid system of two Jatropha oil generators with an electrical power of 69 kW （kWel） and a photovoltaic plant with an electrical peak power of 21 kW （kWpeak） is successfully providing electricity from renewable energy for inhabitants and tourists of Floreana Island. After more than 15.000 engine operation hours of each engine there is no engine defect. For fuel supply, the so-called ＂Living Fence＂ concept collecting Jatropha seeds by farmers and families from already existing 6,000 km hedges on Ecuadorian mainland was chosen to comply with highest biofuel sustainability standards. The Jatropha oil is produced in a decentralized so-called CompacTropha oil mill container following the ambitious German fuel quality standard DIN51605. Since 2010 Floreana project successfully demonstrates that it is possible to replace diesel gen sets by generators fueled with pure Jatropha oil from decentralized sustainable production.展开更多
Natural organic fertilizers are receiving increased attention as a nutrient source for athletic turf fields. However, the performance of these fertilizers as an alternative to inorganic fertilizers is relatively untes...Natural organic fertilizers are receiving increased attention as a nutrient source for athletic turf fields. However, the performance of these fertilizers as an alternative to inorganic fertilizers is relatively untested. To address this issue, we initiated a study to evaluate turfgrass response to the use of pelletized poultry litter （PPL） as a nutrient source compared to inorganic fertilizer, and to compare core aeration and vibrating aeration. Four treatments were evaluated： synthetic fertilizer with vibrating aeration （VS）, synthetic fertilizer with core aeration （CS）, PPL with vibrating aeration （VP）, and PPL with core aeration （CP）. The PPL was applied at a nitrogen （N） rate equivalent to the synthetic fertilizer （assuming 50% availability of N）. Application of PPL did not produce significant changes in measured soil parameters during the 2.5 year study compared to the synthetic fertilizer. Minimal differences in tissue concentrations of Mn were observed. Remote sensing indicated that the CS treatment, which is the current management practice at the study site, produced the lowest turfgrass quality of all the treatments. Highest turf quality was achieved with the CP and VS treatments. Application of PPL resulted in greater turfgrass quality when compared to the same N rate of synthetic fertilizer, regardless of aeration method.展开更多
文摘Multiple-effect membrane distillation （MEMD） process for enriching semi-volatile organic acids from their individual aqueous solutions was performed by using a hollow fiber-based air gap membrane distillation （AGMD） module with the function of internal heat recovery. Aqueous solutions of glyoxylic acid, glycolic acid, lactic acid, pyrnvic acid, malonic acid and glutaric acid were used as model feed. For a feed of 1% （mass fraction）, each acid could be enriched for 8--20 times, which depended on the surface tension of the concentrate. The operation performance of MEMD process was characterized by permeation flux J, performance ratio PR and acid rejection rate R. The effects of cold feed-in temperature, heated feed-in temperature, feed-in volumetric flow rate and feed-in concen- tration on MEMD performance were experimentally evaluated. Maximum values of J, PR and R were 4.8 L/（h-m2）, 9.84 and 99.93%, respectively. Moreover, MEMD process demonstrated a fairly good stability in a long-term experiment lasting for 30 d when aqueous solution of 4% （mass fraction） lactic acid was used as a feed.
文摘In the small country of Ecuador, all environmental risks of the production and consumption of fossil fuels can be observed by damages through oil exploration in the amazonite rainforest and two tank ship accidents close by Galapagos Islands causing death of 10,000 marine iguanas and other species. Now Ecuador plans to replace all environmentally dangerous diesel generators from all four inhabited Galapagos Islands by a hybrid system using 100% renewable energy for electricity production. Since 2010 a hybrid system of two Jatropha oil generators with an electrical power of 69 kW （kWel） and a photovoltaic plant with an electrical peak power of 21 kW （kWpeak） is successfully providing electricity from renewable energy for inhabitants and tourists of Floreana Island. After more than 15.000 engine operation hours of each engine there is no engine defect. For fuel supply, the so-called ＂Living Fence＂ concept collecting Jatropha seeds by farmers and families from already existing 6,000 km hedges on Ecuadorian mainland was chosen to comply with highest biofuel sustainability standards. The Jatropha oil is produced in a decentralized so-called CompacTropha oil mill container following the ambitious German fuel quality standard DIN51605. Since 2010 Floreana project successfully demonstrates that it is possible to replace diesel gen sets by generators fueled with pure Jatropha oil from decentralized sustainable production.
文摘Natural organic fertilizers are receiving increased attention as a nutrient source for athletic turf fields. However, the performance of these fertilizers as an alternative to inorganic fertilizers is relatively untested. To address this issue, we initiated a study to evaluate turfgrass response to the use of pelletized poultry litter （PPL） as a nutrient source compared to inorganic fertilizer, and to compare core aeration and vibrating aeration. Four treatments were evaluated： synthetic fertilizer with vibrating aeration （VS）, synthetic fertilizer with core aeration （CS）, PPL with vibrating aeration （VP）, and PPL with core aeration （CP）. The PPL was applied at a nitrogen （N） rate equivalent to the synthetic fertilizer （assuming 50% availability of N）. Application of PPL did not produce significant changes in measured soil parameters during the 2.5 year study compared to the synthetic fertilizer. Minimal differences in tissue concentrations of Mn were observed. Remote sensing indicated that the CS treatment, which is the current management practice at the study site, produced the lowest turfgrass quality of all the treatments. Highest turf quality was achieved with the CP and VS treatments. Application of PPL resulted in greater turfgrass quality when compared to the same N rate of synthetic fertilizer, regardless of aeration method.
