Impact Of Leachate On Soil-Plant System

Landfill leachate is an increasing problem for the world, regulators and the environment. Leachate emissions from landfill sites are of concern, primarily due to their toxic impact when released into the environment, and the potential for landfill sites to generate leachate for many hundreds of years following closure. Nowadays, the treatment effect of different processes and their combinated process can meet the emission standard, but the high expenses are difficult to accept for some underdevelopment districts. Consequently, economically and environmentally sustainable disposal options base on land treatment are in growing demand.One potential option is the use of soil-plant based remediation schemes. This paper focus on the influence of irrigation of landfill leachate on the soil plant systems. Three soils were purple soil, yellow soil and humus soil which are difference in the physical-chemical porperties. The results showed that irrigating with leachate, soil pH,electrical conductivity and organic content increased, and be direct proportion with the concentration of leachate increased. When compared to control, treated with raw leachate, humus soil pH and electrical conductivity had the highest increment, and increasted by 153% and 1500%,organic content increased 13.5g.soil nitrogen,effect-nitrogen and effect-phosphor were increased with concentration of leachate increased, but total phosphor had micro-reaction. The activity of peroxidase and urease of the three types of soils had been elevated in different degrees irrigation. Soil accumulation on heavy metals were unobvious, the absorbability was: Cr>Pb>Zn> Cu>Cd.Soil acted as a natural filter, yielding sustained water quality improvements, and indirectly enhancing soil quality and N, P availability to plants. Studied on effects of leachate application on soil-plant systems had concluded that, landfill leachate can be effectively decontaminated by land application. Soil buffer action decreased addition of leachate to soil pH. Electrical conductivity,organic content also been increased after irrigated with landfill leachate. The activities of soil enzymes had been elevated obviously in low degrees irrigation, but peroxidase were reduced in yellow soil. Plants growth responds positively after the short-term addition of leachate to soil. The use ratio of plants on N were decrease with hing degrees irrigation, and the Dianthus chinensis absorpted more than Salvia splendens L. Compare with soil systems, the absorption of plants on heavy metals were stronger.