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EN
At the current stage of discharge and treatment of municipal sewage and other types of wastewater in the territory of Ukraine, traditional technologies of biological treatment in aero-tanks by the process of aerobic oxidation involving active silt characterized by low efficiency are largely used. It was established that biological treatment and additional treatment of sewage involving hydrophytes are efficient. The research on wastewater quality and the efficiency of sewage treatment was conducted in three phases: Phase 1 – “the quality before treatment”, Phase 2 – “the quality after mechanical-biological treatment” at the existing municipal treatment plants, Phase 3 – “the quality after additional treatment by hydrophytes”. In order to determine the efficiency of using hydrophytes additional treatment, Eichhornia crassipes (water hyacinth) and the perennial aquatic plant Lemna minor were planted in one treatment pond. The results of the experiment made it possible to determine high efficiency of using hydrophytes for additional sewage treatment. In particular, the efficiency of additional treatment in the treatment ponds removing the residue of suspended pollutants for 40 days was 32%, toxic salts – 13.0–23.0%, oil products – 30.0%, biogenic substances – 68.5–83.3%. It caused a drop in the values of chemical and biological oxygen demand for 5 days by 89.6% and 61.2%, respectively. The efficiency of sewage treatment removing toxic salts and oil products reached 97.7%, whereas in the case of mineral and organic pollutants – up to 99%. That contributed to a considerable increase in the wastewater quality by the criteria for fisheries. In particular, high nutritional value of Eichhornia crassipes and Lemna minor allowed obtaining 12.5 tons of hydrophyte wet mass that can be used as green manure, feeds for farm animals, poultry and fish.
EN
Rawapening is one of Indonesia’s national priority lakes, which is experiencing environmental damage and urgently needs rehabilitation. The decline in water quality is caused by sedimentation and organic and inorganic waste that triggers eutrophication. Rehabilitation of Lake Rawapening is important to improve the health of freshwater resources. The ecological engineering approach is the most appropriate choice to rehabilitate these water conditions. The character of the macrophyte is the key factor for successful rehabilitation. Three macrophytes, Hydrilla verticillata (L. f.) Royle, Eichhornia crassipes (Mart.) Solms and Salvinia molesta D.Mitch., charactierized. Their characteristics, including growth rate, salt tolerance, dissolved oxygen production and consumption, nutritive value, and preferred food by herbivore fish were evaluated. The results indicated that H. verticillata has the highest growth rate, is the most tolerant to salinity change, produces more oxygen, has the highest nutritive value, and is the most preferred food for herbivore fish. H. verticilata is recommended as the best candidate to be used as a forcing function to drive the Rawapening lake into more economic and environmentally valuable for a resident. As the other two species also have high nutritive value, they can be recommended as a source of feed for animals as well. For better management, these two macrophytes required more often regular removal. Other economic and environmental values can also be achieved from E. crassipes and S. molesta.
EN
Rawapening Lake is one of Indonesia’s national priority lakes that is experiencing environmental problems which are urgently required to be solved due to its functions. The decline in the environmental quality of Rawapening Lake includes sedimentation, water pollution and excess of nutrients, especially Phosphorus (P) and Nitrogen (N) into the lake that induced uncontrolled growth of aquatic plants, one of which is water hyacinth (Eichhornia crassipes (Mart.) Solms). Many activities had been done to reduce the covering of water hyacinth in Rawapening Lake that tends to increase by the time, but no significant result has been achieved. Therefore, this research was conducted in order to study the growth rate of water hyacinth with mesocosm in Rawapening Lake as a baseline to develop suitable management. There were three different sites, namely: Site I in the floating net cage area (FNCA), Rowoboni Village, Site II in the natural area of Bejalen Village which is far from the aquaculture sites, and Site III in the upper reaches of the Tuntang river, Asinan Village. The research was performed in November-December 2019 with the measurements of growth rate, addition number clump and water hyacinth covering every week. The experiment was conducted in the 1 x 1 meter mesocosm, with three replication in every site. In every mesocosm water hyacinth with similar initial weight of 160 grams and number of leaves 6-7 strands were grown in the mesocosm. On day 7 (H7) the average wet weight of water hyacinth increased by 201%. In the fourth week (H28) the average wet weight of water hyacinth increased by 788% compared to the initial weight when planted. The highest relative growth rate (RGR) value of water hyacinth was at site III (7.26%/ day), followed by Site I (7.03%/day), and Site II (6.40%/day), respectively. The doubling time (DT) value of water hyacinth at the site I was 9.9 day, site II – 10.8 day, and site III – 9.6 day. One clump of water hyacinth weighing 160 grams was able to cover 1 m2 of mesocosm within 21 days. On the basis of these results, to manage water hyacinth blooms one has to consider its growth rate.
EN
The performance of electrically stimulated phytoremediation in the removal of lead, cadmium and copper was assessed in this study. A combination of phyto and electro remediation was attempted in this study for the remediation of the metals from water. Three tanks were setup with different operating conditions for this experiment: control A (only phytoremediation system), control B (only electro remediation) and treatment (combination of phyto and electro remediation). The electrically enhanced phytoremediation system and electro remediation system were operated 2h/day at voltages of 4V for 25 days continuously. In this experiment, the Eichhornia crassipes, an able phytoremediator exhibited efficient and fast removal of heavy metals from synthetic solution in electro assisted phytoremediation system. The electrically enhanced phytoremediation using aluminum sheet electrodes showed better and effective removal of Cd, Pb and Cu than aluminum rod electrodes. A more favorable and moderate increase of pH was noticed in electrically stimulated phytoremediation system. Eichhornia crassipes has tremendous potential to reduce maximum amount of cadmium (within 15 days), lead (within 15 days) and copper (within 10 days) under electrically stimulated condition. Under electrified condition, maximum amount of Cd and Cu was accumulated in the aerial parts of Eichhornia crassipes but maximum concentration of Pb was attained by roots. This indicates the high heavy metal accumulation capacity of Eichhornia crassipes under electrified conditions. The results showed that 4V voltage is probably suitable to stimulate the Eichhornia crassipes to synthesize more chlorophyll and voltage can improve growth and ability to resist adverse circumstances by promoting chlorophyll synthesis. Eichhornia crassipes stimulated by an electric field has grown better and assimilated more metal. Bioconcentration factor (BCF) an index of hyperaccumulation, indicates that electrically stimulated Eichhornia crassipes is a good hyper accumulator of Cd (BCF = 1118.18) and Cu (BCF = 1152.47) and a moderate accumulator of Pb (BCF = 932.26). Translocation ability (TA) ratio indicates that Eichhornia crassipes have the ability to translocate more amounts of Pb, Cd and Cu to its upper portion under electrified condition. The results imply that the electro-phytoremediation technique seems to be promising in the treatment of wastewater contaminated with heavy metals.
EN
Eichhornia crassipes is a floating macrophyte. It is capable of assimilating large quantities of toxic metals, some of which are essential for plant growth. Water Hyacinth grows rapidly in water with a high level of nutrients like nitrogen and phosphorous. The plants have been shown to absorb trace elements such as Silver (Ag), Lead (Pb), Cadmium (Cd) and Copper (Cu) reported by Lu et al [1]. The purpose of this study is to determine the distribution of heavy metals in different parts of the Water Hyacinth . Such a detail study has been taken for the first time. It is expected that the metal distribution within the plant species would be a representation of the concentration and distribution of the water in which it is found. Plants have the ability to accumulate non-essential and essential trace elements and this ability could be harnessed to remove pollutant metals from the environment. Aluminum, cadmium, calcium, copper, iron, lead, magnesium and zinc have been found in different amounts in roots, stems , leaves and flowers.
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