Industrial activities can produce valuable products as well as produce waste that can cause disturb and endanger survival of the living things. This research discusses distribution of lead (Pb) concentrations in Rhizophora mucronata mangrove roots which was studied through diffusion equation model and utilizes the Rhizophora mucronata mangrove roots as an alternative fuel. The production and testing of charcoal in this study used a simple household scale method by varying time of coking and testing of the gases resulting from charcoal containing harmful emission gases by the test method for survival experiment on insects. The result of this research is he finite difference method used in this study can poorly represent the process of lead absorption by mangrove roots as measured by a relatively high error. The lead concentration was distributed downwardly from root bark to center of the root and difference in distribution of lead concentration in each layer decreased from the first day to the thirtieth day. Solid fuel from Rhizophora mucronata mangrove roots according to or meet the standards of SNI 01-1682-1989, namely yield test value of 37.48%, moisture content test of 3.46%, test for the content of the volatile substance 25.87%, ash content test of 1.79%.