Mahmoudian,F , , Hamidian,A H , , Khorasani,N , and Haghpanah,P . "Risk assessment of ground water pollution by heavy metals in leachate of acidic sludge from motor oil recycling and linear recommendation)Case study: Garmsar(", Journal of Natural Environment, 66, 4, 2014, 435-443. doi: 10.22059/jne.2014.36629