ABSTRACT
The aim of this study is to evaluate the purifying ability of 3 parallel planted filters (PF1, PF2 and PF3) composed of three plants (Phragmites australis (Cav) Trin ex Steud, Typha latifolia L., Cyperus papyrus L.) on leachates from a landfill of industrial waste in Pointe-Noire (Republic of Congo). This landfill site includes a technical landfill for ordinary industrial waste (OIW) and a technical landfill for hazardous and soiled industrial waste (SIW). In order to assess purifying ability, we sampled 14 samples over 8 weeks, with 7 samples of the raw leachates from the technical landfill center, and 7 samples of leachates cleaned after passing through the tryptic vegetable filter. The physico-chemical analyzes made it possible to determine the following parameters: TOC, COD, NO3-,PO42-, Ni, Cd, CrVI, Zn, Cu and Pb. The results showed a significant decrease in organic pollution with abatement rates in TOC and COD greater than 90%. The average removal efficiency is respectively 45.97% for nitrates and 40.2% for phosphates. The abatement rates for heavy metals range from 41.2% to 60.9% for nickel, from 52.2% to 68.5 % for cadmium, from 49% to 71.7% for chromium VI, from 59% to 74.6% for zinc, from 50.9 % to 65 % for copper and from 61.4% to 75.1% for lead. However, additional analyzes are needed to confirm the hypperaccumulator nature of these plant filters in particular absorption isotherms and kinetics of extraction of heavy metals of Phragmites australis (Cav) Trin ex Steud, Typha latifolia L., Cyperus papyrus L.)
ABSTRACT
The increasing demand for energy, limited resources of fossil fuel, as well as pollution of the environment and changes in the global climate have raised more interest about the renewable resources. The use of renewable resources has become a very important part of European Union policy. The aim of the paper was to analyse reed resources in Latvia, its dynamics, volume and quality to produce clean energy. The use of reeds as a renewable energy resource contributes in minimizing fossil fuel consumption. The paper presents the results of a research of reed resources in lakes of Latgale (a region in Latvia). The investigation of reed resources showed that in the region they are scattered and rational usage of them is connected with environmental aspects. The greatest amounts of reed resources are concentrated in the biggest lake in Latvia - Lubana Lake and near to it. Studies show ed that the reed areas in Lubana Lake and Kvapanu ponds have doubled since 1997 and as a result these water reservoirs are becoming overgrown. Using direct measurement methods and metering from distance, it was stated that the total reed resources of greatest Lake - Lubanas are about 6830 tons year-1 in area of 734 hectares and are situated in 701 reed blocks. The aggregated reed resources of Latgale region are 18 000 tons year-1 of dry biomass. The investigation proved that reed resources of the region are sufficient to replace up to 21 thousand tons of different fossil fuels. The physical properties of the reed were measured. Carbon quantity, ash content and structure, moisture content proved that reeds are a profitable fuel for heat energy production. Balanced harvesting of reed gives a positive influence on environment.