Phytoremediation of Heavy Metals ( Cu , Zn , and PB ) Contaminated Water Using Water Hyacinth ( Eichornia Crassipes ) 1
Water samples contaminated with heavy metals (Zn, Cu and Pb) were subjected to phytoremediation method using water hyacinth (E. crassipes) for the period of 8 weeks. The study involved the preparation of the heavy metals solutions in different concentrations (their pH values supplemented) into eight 40L plastic containers, with six containers having the solutions of heavy metals (Zn, Cu and Pb in their replicates) while two plastic containers served as the control. Thereafter, the experiment was monitored and analyzed for 8 weeks for metal accumulation by the plant. Water analysis was carried out to know the concentration of heavy metals present in the water during these periods and the plants were also analyzed using Atomic Absorption Spectrophotometer. The results obtained were further interpreted using SPSS (T-test) to determine the mean concentration obtained from week 1 to week 8.The results obtained for Zn were 0.28 ,0.23 ,0.13 ,0.04 ,BDL,0.02 ,BDL,BDL .Also the results obtained for Cu from week 1 to week 8 were 0.04 ,0.07 ,0.03, BDL ,BDL ,BDL ,BDL ,BDL. More so, the results obtained for Pb from week 1 to week 8 were 0.13, 0.45, 0.05, BDL, BDL, BDL, BDL, BDL. At the end of the 8 weeks of remediation, it was observed that the concentrations of the metals in the water were below the detection limit but accumulated in the plant. Also, the results of the Bioconcentration factor (BCF) showed that the investigated plant (E.crassipes) hyperaccummulated Zn than other heavy metals. Therefore, heavy metal uptake by E. crassipes using phytoremediation technology seems to be a prosperous way to remediate heavy metal contaminated environment.
A review on the phytoremediation of petroleum hydrocarbon.
Oil spillage as a result of petroleum industry activities and pipe-line vandalization by saboteurs is a frequent occurrence in oil-producing regions of the world. Conventional oil spill clean-up techniques involve physical and chemical processes that do more damage to the aquatic ecosystem than the oil spill itself. Consequently, the need arises to evolve or develop a more environment-friendly technique that will not only clean-up the environment but also restore the aquatic ecosystem to its status before the oil spill. Phytoremediation, which involves the use of plant to detoxify polluted site, appears to be promising in this regard. It is environment-friendly as well as cost-effective but may take more time than the conventional methods because it is a natural process.
Impacts of climate and land use changes on flood risk management for the Schijn River, Belgium
Abstract Flooding is the most common natural disaster in Europe. Modern flood risk management relies not only infrastructure development but also on governmental and non-governmental actors applying legal, economic and communicative water management instruments. Within the European Union (EU), flood management closely relies on policy set at the EU and national levels. It is now recognized that a sound understanding of climate change is required in addition to current management by taking into account land use change and socio-political context, as climate and land use changes have major impacts on hydrological responses. This paper investigates the hydrological behavior due to urbanization under current and future climate scenarios of high summer and high winter rainfall for 20 sub-catchments of the Schijn River, located in the Flanders region near Antwerp, Belgium. As urbanization increases and existing rainfall-runoff models neglecting the specific behavior of urban runoff, a hydrological model was developed based on a basic reservoir concept and applied to the existing rainfall-runoff model (PDM) flow to examine the specific urban contribution. Results revealed that peak flow for urban runoff and the total peak flow (i.e. rural and urban runoff) were significantly higher (i.e. ranges from 200% to 500%) than the existing rainfall-runoff model (PDM) flows, because of faster and more peaked urban runoff response. The impact of climate change on current and future conditions was also assessed by estimating peak flows with respect to return periods from the flood frequency curve. The predicted peak flow of high summer future climate scenario was significantly higher (i.e. ranges from 200% to 250%) than that of the current climatic condition for this region. Furthermore, hourly peak flow and daily volume ratios of 100-year return period for the highest, lowest and average impervious area were projected for the time horizon of the year 2100. It is concluded that climate change impacts contribute the most in producing peak flow in coming years, while increased urbanization takes the second place for both hourly and daily values. Results on urbanization effect and climate change impact assessment are useful to the water managers for spatial planning, emergency planning and insurance industry.