The community of Figuig is located in a desert area, east of Morocco. It is characterized by an arid climate. Part of the aquifers of the area has a high salinity which creates even worst conditions for the use of the...The community of Figuig is located in a desert area, east of Morocco. It is characterized by an arid climate. Part of the aquifers of the area has a high salinity which creates even worst conditions for the use of the scarce water available in the area. Therefore, it is essential to develop new water resources, especially for agriculture. For this reason, reclaiming wastewater for agricultural use is an essential strategy to increase water resources. The studied system is a wastewater treatment plant （WWTP） with stabilisation ponds; it treats a part of the wastewater of Figuig. The monitoring of the WWTP will allow to the physico-chemical and biological characterization of the treated water, and then, to verify two principal points： （1） the physico-chemical and pathogen parasites elimination; （2） the possibility of the treated water reuse in agricultural irrigation. The reductions recorded at the WWTP show a relatively preferment operation with an average decrease of 3.17 Ulog for faecal coliforms and 50-60% for organic matter. It was observed that the taxonomic density is slow in the WWTP; observed species are generally Cyanobacteria, Euglénophycea and Chlorophycea characteristic of eutrophic water sources.展开更多
Although to date some technologies producing bio-based phosphorus(P) fertilizers have been proposed and implemented, the efficient use of the recovered products is still limited due to legislative constraints and lack...Although to date some technologies producing bio-based phosphorus(P) fertilizers have been proposed and implemented, the efficient use of the recovered products is still limited due to legislative constraints and lack of insights in the P release with time and in the corresponding mechanisms. The aim of this work was to evaluate the fertilizer performance in terms of P release and use efficiency of recovered struvite, FePO_4-sludge, digestate, and animal manure as compared to fossil reserve-based mineral triple superphosphate(TSP). First, product physicochemical characteristics and P fractions in the context of European fertilizer legislation were assessed. Next, a controlled greenhouse experiment was set up to evaluate plant reactions as well as changes of P availability in a sandy soil with high P status and a Rheinsand soil with low P status. Soil P fractions were determined in the extracts with water, ammonium lactate and CaCl_2, and in soil solution sampled with Rhizon soil moisture samplers. Based on all results, it is worth conducting long-term field trials to evaluate the P release effect of struvite and digestate as compared to animal manure and TSP on different soil types with varying P status. These products showed promise as sustainable substitutes for conventional P fertilizers and could contribute to a more efficient use of P in agriculture. A refined classification of P application standards/recommendations in terms of soil P status, soil texture, and fertilizer characteristics, next to the crop P demand, is recommended. Moreover, the additional use of Rhizon samplers for determination of direct available P, including dissolved organic P, is proposed for better understanding and categorization of different P fertilizers in environmental and fertilizer legislations.展开更多
Herein the biowaste by-product spent coffee grounds(SCGs)from coffee industry were incorporated into asphalt binders for performance enhancement.From the analysis of Fourier transform infrared spectroscopy(FTIR),diffe...Herein the biowaste by-product spent coffee grounds(SCGs)from coffee industry were incorporated into asphalt binders for performance enhancement.From the analysis of Fourier transform infrared spectroscopy(FTIR),differential scanning calorimetry(DSC),dynamic shear rheometer(DSR),and Brookfield viscosity rheometer,it is confirmed that SCGs have potential prospects as bio-waste modifiers in the application of sustainable pavements.Results demonstrated that the modification process was mainly based on physical reinforcement.Compared with that of the neat asphalt,the shearing stress-resistant ability and high-temperature performance of the SCGs modified binders with the appropriate addition presented a bit of improvement;whereas the binders with 1%and 3%SCGs exhibited remarkably enhanced low-temperature stability.However,notable weaknesses of practical performance were shown for the binder with excessive content of SCGs,indicating the necessity of proportion selecting before application.展开更多
This paper deals with the problem of nonconstant harvesting of prey in a ratio-dependent predator-prey system incorporating a constant prey refuge. Here we use the reasonable catch-rate function instead of usual catch...This paper deals with the problem of nonconstant harvesting of prey in a ratio-dependent predator-prey system incorporating a constant prey refuge. Here we use the reasonable catch-rate function instead of usual catch-per-unit-effort hypothesis. The existence, as well as the stability of possible equilibria, is carried out. Bionomic equilibrium of the system is determined and optimal harvest policy is studied with the help of Pontryagin＇s maximum principle. The key results developed in this paper are illustrated using numer- ical simulations. Our results indicate that dynamic behavior of the system very much depends on the prey refuge parameter and increasing amount of refuge could increase prey density and may lead to the extinction of predator population density.展开更多
文摘The community of Figuig is located in a desert area, east of Morocco. It is characterized by an arid climate. Part of the aquifers of the area has a high salinity which creates even worst conditions for the use of the scarce water available in the area. Therefore, it is essential to develop new water resources, especially for agriculture. For this reason, reclaiming wastewater for agricultural use is an essential strategy to increase water resources. The studied system is a wastewater treatment plant （WWTP） with stabilisation ponds; it treats a part of the wastewater of Figuig. The monitoring of the WWTP will allow to the physico-chemical and biological characterization of the treated water, and then, to verify two principal points： （1） the physico-chemical and pathogen parasites elimination; （2） the possibility of the treated water reuse in agricultural irrigation. The reductions recorded at the WWTP show a relatively preferment operation with an average decrease of 3.17 Ulog for faecal coliforms and 50-60% for organic matter. It was observed that the taxonomic density is slow in the WWTP; observed species are generally Cyanobacteria, Euglénophycea and Chlorophycea characteristic of eutrophic water sources.
基金supported by the European Commission under the Interreg IVb NWE Project Arbor(No.Interreg IVB 223G)the Environmental&Energy Technology Innovation Platform(MIP),Belgium+2 种基金the Natural Science and Engineering Research Council of Canada(NSERC)the Fonds de Recherche de Québec sur la Nature et les Technologies(FRQNT),CanadaPrimodal Inc.,Hamilton,Canada
文摘Although to date some technologies producing bio-based phosphorus(P) fertilizers have been proposed and implemented, the efficient use of the recovered products is still limited due to legislative constraints and lack of insights in the P release with time and in the corresponding mechanisms. The aim of this work was to evaluate the fertilizer performance in terms of P release and use efficiency of recovered struvite, FePO_4-sludge, digestate, and animal manure as compared to fossil reserve-based mineral triple superphosphate(TSP). First, product physicochemical characteristics and P fractions in the context of European fertilizer legislation were assessed. Next, a controlled greenhouse experiment was set up to evaluate plant reactions as well as changes of P availability in a sandy soil with high P status and a Rheinsand soil with low P status. Soil P fractions were determined in the extracts with water, ammonium lactate and CaCl_2, and in soil solution sampled with Rhizon soil moisture samplers. Based on all results, it is worth conducting long-term field trials to evaluate the P release effect of struvite and digestate as compared to animal manure and TSP on different soil types with varying P status. These products showed promise as sustainable substitutes for conventional P fertilizers and could contribute to a more efficient use of P in agriculture. A refined classification of P application standards/recommendations in terms of soil P status, soil texture, and fertilizer characteristics, next to the crop P demand, is recommended. Moreover, the additional use of Rhizon samplers for determination of direct available P, including dissolved organic P, is proposed for better understanding and categorization of different P fertilizers in environmental and fertilizer legislations.
文摘Herein the biowaste by-product spent coffee grounds(SCGs)from coffee industry were incorporated into asphalt binders for performance enhancement.From the analysis of Fourier transform infrared spectroscopy(FTIR),differential scanning calorimetry(DSC),dynamic shear rheometer(DSR),and Brookfield viscosity rheometer,it is confirmed that SCGs have potential prospects as bio-waste modifiers in the application of sustainable pavements.Results demonstrated that the modification process was mainly based on physical reinforcement.Compared with that of the neat asphalt,the shearing stress-resistant ability and high-temperature performance of the SCGs modified binders with the appropriate addition presented a bit of improvement;whereas the binders with 1%and 3%SCGs exhibited remarkably enhanced low-temperature stability.However,notable weaknesses of practical performance were shown for the binder with excessive content of SCGs,indicating the necessity of proportion selecting before application.
文摘This paper deals with the problem of nonconstant harvesting of prey in a ratio-dependent predator-prey system incorporating a constant prey refuge. Here we use the reasonable catch-rate function instead of usual catch-per-unit-effort hypothesis. The existence, as well as the stability of possible equilibria, is carried out. Bionomic equilibrium of the system is determined and optimal harvest policy is studied with the help of Pontryagin＇s maximum principle. The key results developed in this paper are illustrated using numer- ical simulations. Our results indicate that dynamic behavior of the system very much depends on the prey refuge parameter and increasing amount of refuge could increase prey density and may lead to the extinction of predator population density.
