STUDY ON EFFECT OF SOIL WASHING WITH DIFFERENT WASHING CYCLES ON PARTICLE SIZE OF CONTAMINATED SOIL

Soil contamination by heavy metals is a major problem at many contaminated sites now a day. According to EPA’s list of priority pollutants cadmium, chromium, copper, lead, mercury, nickel, and zinc are the most hazardous heavy metals found at many soil contaminated sites. Many techniques are employed for the decontamination of soils. This consists of various physiochemical as well as biological methods. Among these process soil washing is a physiochemical method, which has a very high efficiency for heavy metal removal from contaminated soils. It is a simple, ex situ remediation technology. In this process by the addition of washing water, heavy metals can be transferred from the degraded sediment to wash solution. This process can be enhanced by addition of acid washing, chelating agents or surfactants. Particle size always plays an important role in the removal of heavy metals. In this research paper an attempt has made to soil washing technology for removal of Pb and Cr from contaminated soil with the help of different combination of EDTA and DI water cycle. Another attempt has also made to find out the effect of particle size i.e. soil, silt and clay on the soil washing.