Neochetina eichhorniae and Neochetina bruchi have been used for over four decades as Eichhorniae crassipes classical biological control agents globally. Despite the success of bio-control against the water hyacinth gl...Neochetina eichhorniae and Neochetina bruchi have been used for over four decades as Eichhorniae crassipes classical biological control agents globally. Despite the success of bio-control against the water hyacinth globally at different levels and environmental sustainability, biological control against water hyacinth seems to have overlooked the socio-economic sustainability in assisting the ravaged communities, gain resilience and adapt to the challenges of the invasive alien species. This manuscript evaluates the potential to draw out more from biological control of the water hyacinth by evaluating the potential to utilize Neochetina eichhorniae and Neochetina bruchi as feed. The live insects of the two species were collected from the water hyacinth marts in the nearby L. Victoria in Siaya county, Kenya. Where they were then transferred for semi-cultivation in localized ponds for reproduction and closer monitoring. The ponds having been set up in completely randomized design while in the open within the same climatic region mimicked the water quality and most abiotic conditions of the lake necessary for the insects’ and host plant acclimatization and reproduction. The samples for proximate analysis were collected from these ponds as per the research and experimental design. The chemical compositions of the Neochetina bruchi, N. eichhorniae and their larvae composite, satisfactorily compared to basic fish feed requirements, specifically as a protein source having crude protein (CP) percentage per DM of 55.0350 ± 0.025, 54.4350 ± 0.035 and 62.2750 ± 0.025 respectively.展开更多
This study considers the effect of Eichhornia Crassipes Biodiesel(ECB)blends on the performances,combustion,and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode(D...This study considers the effect of Eichhornia Crassipes Biodiesel(ECB)blends on the performances,combustion,and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode(DFM)and equipped with an Exhaust gas recirculation technique(EGR).In particular,a single-cylinder,four-stroke,water-cooled diesel engine was utilized and four modes of fuel operation were considered:mode I,the engine operated with an ordinary diesel fuel;mode II,the engine operated with the addition of 2.4 L/min of lique-fied petroleum gas(LPG)and 20%EGR;mode III,20%ECB with 2.4 L/min LPG and 20%EGR;mode IV,40%ECB with 2.4 L/min LPG and 20%EGR.The operation conditions were constant engine speed(1500 rpm),var-iation of load(25%,50%,75%,and 100%),full load,with a compression ratio of 18,and a time injection of 23°BTDC(Before top died center).With regard to engine emissions,carbon dioxide(CO_(2)),carbon monoxide(CO),hydrocarbons(UHC),and nitrogen oxide(NOX)were measured using a gas analyzer.The smoke opacity was measured using an OPABOX smoke meter.By comparing the results related to the different modes with mode I at full load,the BTE(Brake thermal efficiency)increased by 20.17%,11.45%,and 12.66%with modes II,III,and IV,respectively.In comparison to the results for mode II,the BTE decreased due to the combustion of ECB blends by 7.26%and 6.24%for mode III and mode IV,respectively,at full load.In comparison to mode II,the Brake specific energy consumption(BSEC)increased with the ECB substitution.With ECB blends,there is a noticeable decrease in the CO,CO_(2),and UHC emissions at a partial load.Furthermore,the 20%ECB has no effect on CO emissions at full load.For modes II and IV,the CO_(2)increased by 33.33%and 19%,respectively,while the UHC emissions were reduced by 14.49%for mode III and 26.08%for mode IV.The smoke of mode III was lower by 7.21%,but for mode IV,it was higher by 12.37%.In addition,with mode III and mode IV,the NOx emissions increased by 30.50%and 18.80%,respectively.展开更多
From 20 January to 20 July 2023, a study was carried out on the Lobé Creek, a waterway subject to considerable natural and man-made pressures, with a negative impact on its biodiversity and habitats. The aim was ...From 20 January to 20 July 2023, a study was carried out on the Lobé Creek, a waterway subject to considerable natural and man-made pressures, with a negative impact on its biodiversity and habitats. The aim was to evaluate the growth rate of invasive aquatic macrophytes and their contribution to the use of organic fertilisers: a case of Eicchornia crassipes (Mart.) Solms, 1883 in the Lobé Creek (Littoral-Cameroon) with a view to its appropriate use in agronomy. The specific objective was to examine the impact of anthropogenic actions on Lobé Creek, characterise physico-chemical environment of the study area, and evaluate the growth rate of E. crassipes and its chemical composition with a view to producing an organic biofertiliser. The results show that E. crassipes represents a considerable threat to the populations of these localities. As for the physico-chemical parameters, the temperature values vary from 24 ± 1.41˚C to 26.5 ± 1.13˚C;pH from 6.3 ± 0.1 to 7.2 ± 0.07;conductivity and dissolved oxygen vary respectively from 40.7 ± 1.83 µS/cm to 19.6 ± 3.11 µS/cm and from 7.3 ± 0.14 mg/l to 5.8 ± 1.55 mg/l. Its average growth rate varies from 0.69 feet/day to 0.63 feet/day. With regard to the nitrogen, phosphorus and potassium content of water hyacinth plants, the results show that the average total nitrogen content ranges from 6.11 ± 1.59 g/kg to 5.2 ± 2.03 g/kg;total phosphorus, from 0.52 ± 0.54 g/kg to 0.88 ± 0.38 g/kg;and potassium, from 1.43 ± 0.45 g/kg to 2.61 ± 0.89 g/kg.展开更多
Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 mz was constructed on...Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 mz was constructed on an egg duck farm, and water hyacinth （Eichhornia crassipes） was chosen as an aquatic plant for the wetland and used as food for duck production. The objectives of this study were to test the role of water hyacinth in purifying nutrient-rich wastewater and its effects on the ducks＇ feed intake, egg laying performance and egg quality. This paper shows that the constructed wetland removed as much as 64.44% of chemical oxygen demand （COD）, 21.78% of total nitrogen （TN） and 23.02% of total phosphorus （TP）. Both dissolved oxygen （DO） and the transparency of the wastewater were remarkably improved, with its transparency 2.5 times higher than that of the untreated wastewater. After the ducks were fed with water hyacinth, the average daily feed intake and the egg-laying ratio in the test group were 5.86% and 9.79% higher, respectively, than in the control group; the differences were both significant at the 0.01 probability level. The egg weight in the test group was 2.36% higher than in the control group （P 〈 0.05）, but the feed conversion ratios were almost the same. The eggshell thickness and strength were among the egg qualities significantly increased in ducks fed with water hyacinth. We concluded that a water hyacinth system was effective for purifying wastewater from an intensive duck farm during the water hyacinth growing season, as harvested water hyacinth had an excellent performance as duck feed. We also discussed the limitations of the experiment.展开更多
Water hyacinth (Eichhornia crassipes (Mart.) Solms) is a prolific free floating aquatic macrohpyte found in tropical and subtropical parts of the earth. The effects of pollutants from textile wastewater on the anatomy...Water hyacinth (Eichhornia crassipes (Mart.) Solms) is a prolific free floating aquatic macrohpyte found in tropical and subtropical parts of the earth. The effects of pollutants from textile wastewater on the anatomy of the plant were studied. Water hyacinth exhibits hydrophytic adaptations which include reduced epidermis cells lacking cuticle in most cases, presence of large air spaces (7～50 μm), reduced vascular tissue and absorbing structures. Textile waste significantly affected the size of root cells.The presence of raphide crystals was noted in parenchyma cells of various organs in treated plants.展开更多
Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of a...Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth, have been received world-wide attention. In this study, the allelopathic activity of the invasive macrophyte, Eichhornia crassipes （water hyacinth）, on blue-green algae, Microcystis aeruginosa （PCC7806） was investigated using coexistence assay. Our results showed that water hyacinth had disparate effects on the growth ofM~ aeruginosa （PCC7806） under different initial algal densities. Under lower initial algal density （OD650 = 0.10 and OD650 = 0.05）, the algal growth was significantly inhibited by water hyacinth （inhibition ratio was 95.6% and 97.3%, respectively）. While it was stimulated at higher initial algal densities （OD650 = 0.20）. Water hyacinth inhibited the growth of algae mainly through its root system. Culture water from water hyacinth and aqueous methanol extracts from dry roots samples also showed inhibition effects on algal growth. The inhibition effects increased as the increase of crude extract concentration, suggest that water hyacinth may excrete inhibitory substances from root system and show allelopathic inhibitory potential to the growth ofM. aeruginosa.展开更多
6 -Hydroxy-stigmasta-4,22-diene-3-one 1,a novel steroid, was isolated from the Eichhornia Crassipes.Its structure was deter- mined by ~1H and ^(13)C NMR spectroscopy and further confirmed by authen- tic sample,which w...6 -Hydroxy-stigmasta-4,22-diene-3-one 1,a novel steroid, was isolated from the Eichhornia Crassipes.Its structure was deter- mined by ~1H and ^(13)C NMR spectroscopy and further confirmed by authen- tic sample,which was synthesized from stigmasterol 2.展开更多
文摘Neochetina eichhorniae and Neochetina bruchi have been used for over four decades as Eichhorniae crassipes classical biological control agents globally. Despite the success of bio-control against the water hyacinth globally at different levels and environmental sustainability, biological control against water hyacinth seems to have overlooked the socio-economic sustainability in assisting the ravaged communities, gain resilience and adapt to the challenges of the invasive alien species. This manuscript evaluates the potential to draw out more from biological control of the water hyacinth by evaluating the potential to utilize Neochetina eichhorniae and Neochetina bruchi as feed. The live insects of the two species were collected from the water hyacinth marts in the nearby L. Victoria in Siaya county, Kenya. Where they were then transferred for semi-cultivation in localized ponds for reproduction and closer monitoring. The ponds having been set up in completely randomized design while in the open within the same climatic region mimicked the water quality and most abiotic conditions of the lake necessary for the insects’ and host plant acclimatization and reproduction. The samples for proximate analysis were collected from these ponds as per the research and experimental design. The chemical compositions of the Neochetina bruchi, N. eichhorniae and their larvae composite, satisfactorily compared to basic fish feed requirements, specifically as a protein source having crude protein (CP) percentage per DM of 55.0350 ± 0.025, 54.4350 ± 0.035 and 62.2750 ± 0.025 respectively.
文摘This study considers the effect of Eichhornia Crassipes Biodiesel(ECB)blends on the performances,combustion,and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode(DFM)and equipped with an Exhaust gas recirculation technique(EGR).In particular,a single-cylinder,four-stroke,water-cooled diesel engine was utilized and four modes of fuel operation were considered:mode I,the engine operated with an ordinary diesel fuel;mode II,the engine operated with the addition of 2.4 L/min of lique-fied petroleum gas(LPG)and 20%EGR;mode III,20%ECB with 2.4 L/min LPG and 20%EGR;mode IV,40%ECB with 2.4 L/min LPG and 20%EGR.The operation conditions were constant engine speed(1500 rpm),var-iation of load(25%,50%,75%,and 100%),full load,with a compression ratio of 18,and a time injection of 23°BTDC(Before top died center).With regard to engine emissions,carbon dioxide(CO_(2)),carbon monoxide(CO),hydrocarbons(UHC),and nitrogen oxide(NOX)were measured using a gas analyzer.The smoke opacity was measured using an OPABOX smoke meter.By comparing the results related to the different modes with mode I at full load,the BTE(Brake thermal efficiency)increased by 20.17%,11.45%,and 12.66%with modes II,III,and IV,respectively.In comparison to the results for mode II,the BTE decreased due to the combustion of ECB blends by 7.26%and 6.24%for mode III and mode IV,respectively,at full load.In comparison to mode II,the Brake specific energy consumption(BSEC)increased with the ECB substitution.With ECB blends,there is a noticeable decrease in the CO,CO_(2),and UHC emissions at a partial load.Furthermore,the 20%ECB has no effect on CO emissions at full load.For modes II and IV,the CO_(2)increased by 33.33%and 19%,respectively,while the UHC emissions were reduced by 14.49%for mode III and 26.08%for mode IV.The smoke of mode III was lower by 7.21%,but for mode IV,it was higher by 12.37%.In addition,with mode III and mode IV,the NOx emissions increased by 30.50%and 18.80%,respectively.
文摘From 20 January to 20 July 2023, a study was carried out on the Lobé Creek, a waterway subject to considerable natural and man-made pressures, with a negative impact on its biodiversity and habitats. The aim was to evaluate the growth rate of invasive aquatic macrophytes and their contribution to the use of organic fertilisers: a case of Eicchornia crassipes (Mart.) Solms, 1883 in the Lobé Creek (Littoral-Cameroon) with a view to its appropriate use in agronomy. The specific objective was to examine the impact of anthropogenic actions on Lobé Creek, characterise physico-chemical environment of the study area, and evaluate the growth rate of E. crassipes and its chemical composition with a view to producing an organic biofertiliser. The results show that E. crassipes represents a considerable threat to the populations of these localities. As for the physico-chemical parameters, the temperature values vary from 24 ± 1.41˚C to 26.5 ± 1.13˚C;pH from 6.3 ± 0.1 to 7.2 ± 0.07;conductivity and dissolved oxygen vary respectively from 40.7 ± 1.83 µS/cm to 19.6 ± 3.11 µS/cm and from 7.3 ± 0.14 mg/l to 5.8 ± 1.55 mg/l. Its average growth rate varies from 0.69 feet/day to 0.63 feet/day. With regard to the nitrogen, phosphorus and potassium content of water hyacinth plants, the results show that the average total nitrogen content ranges from 6.11 ± 1.59 g/kg to 5.2 ± 2.03 g/kg;total phosphorus, from 0.52 ± 0.54 g/kg to 0.88 ± 0.38 g/kg;and potassium, from 1.43 ± 0.45 g/kg to 2.61 ± 0.89 g/kg.
文摘Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 mz was constructed on an egg duck farm, and water hyacinth （Eichhornia crassipes） was chosen as an aquatic plant for the wetland and used as food for duck production. The objectives of this study were to test the role of water hyacinth in purifying nutrient-rich wastewater and its effects on the ducks＇ feed intake, egg laying performance and egg quality. This paper shows that the constructed wetland removed as much as 64.44% of chemical oxygen demand （COD）, 21.78% of total nitrogen （TN） and 23.02% of total phosphorus （TP）. Both dissolved oxygen （DO） and the transparency of the wastewater were remarkably improved, with its transparency 2.5 times higher than that of the untreated wastewater. After the ducks were fed with water hyacinth, the average daily feed intake and the egg-laying ratio in the test group were 5.86% and 9.79% higher, respectively, than in the control group; the differences were both significant at the 0.01 probability level. The egg weight in the test group was 2.36% higher than in the control group （P 〈 0.05）, but the feed conversion ratios were almost the same. The eggshell thickness and strength were among the egg qualities significantly increased in ducks fed with water hyacinth. We concluded that a water hyacinth system was effective for purifying wastewater from an intensive duck farm during the water hyacinth growing season, as harvested water hyacinth had an excellent performance as duck feed. We also discussed the limitations of the experiment.
基金Project (No. 30070017) supported by the National Natural Science Foundation of China
文摘Water hyacinth (Eichhornia crassipes (Mart.) Solms) is a prolific free floating aquatic macrohpyte found in tropical and subtropical parts of the earth. The effects of pollutants from textile wastewater on the anatomy of the plant were studied. Water hyacinth exhibits hydrophytic adaptations which include reduced epidermis cells lacking cuticle in most cases, presence of large air spaces (7～50 μm), reduced vascular tissue and absorbing structures. Textile waste significantly affected the size of root cells.The presence of raphide crystals was noted in parenchyma cells of various organs in treated plants.
文摘Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth, have been received world-wide attention. In this study, the allelopathic activity of the invasive macrophyte, Eichhornia crassipes （water hyacinth）, on blue-green algae, Microcystis aeruginosa （PCC7806） was investigated using coexistence assay. Our results showed that water hyacinth had disparate effects on the growth ofM~ aeruginosa （PCC7806） under different initial algal densities. Under lower initial algal density （OD650 = 0.10 and OD650 = 0.05）, the algal growth was significantly inhibited by water hyacinth （inhibition ratio was 95.6% and 97.3%, respectively）. While it was stimulated at higher initial algal densities （OD650 = 0.20）. Water hyacinth inhibited the growth of algae mainly through its root system. Culture water from water hyacinth and aqueous methanol extracts from dry roots samples also showed inhibition effects on algal growth. The inhibition effects increased as the increase of crude extract concentration, suggest that water hyacinth may excrete inhibitory substances from root system and show allelopathic inhibitory potential to the growth ofM. aeruginosa.
文摘6 -Hydroxy-stigmasta-4,22-diene-3-one 1,a novel steroid, was isolated from the Eichhornia Crassipes.Its structure was deter- mined by ~1H and ^(13)C NMR spectroscopy and further confirmed by authen- tic sample,which was synthesized from stigmasterol 2.
