Environmental problems are one of the main problems for developing countries like Indonesia, especially the problem of lead waste (Pb) from industry. If the dangerous heavy metal Pb is discharged into the environment, it can cause various problems in the environment and certainly can threaten human life. If the lead is released into the water around the industry it will certainly be able to flow into the river, even to the sea. Bioaccumulation of Pb in water can cause the formation of toxic organometallic compounds in the body of marine fish, which can allow these compounds to enter the food chain, and can disturb both the environment and human health. Meanwhile, on the other hand there is an event that has long happened that until now and is considered a disaster, namely the Lapindo mudflow. The purpose of this study is to find out how to reduce the content of heavy metals Pb produced from industrial waste by adding synthetic zeolites made from Lapindo mud. Zeolite is a substance that can function as an adsorbent for various types of waste, one of which is heavy metal. In this study, qualitative and quantitative tests were carried out on the influence of the mass of zeolite based on Lapindo mud to the binding of Pb heavy metal ions. Qualitative data analysis is done by describing the results of observations of the presence of white deposits that are formed as the final results of qualitative tests. Quantitative data analysis is performed by weighing the mass of white deposits that are formed. Based on the results of the study, obtained a relationship that is the greater the mass of zeolite, the greater the decrease in levels of heavy metal Pb in liquid waste. According to the results obtained in this study. In this study, the best zeolite mass used in adsorbing Pb metal ions was 2 grams. In the treatment with 2 grams of zeolite mass it has the best ability to absorb heavy metal Pb up to 90.15%.