Biofuels from sewage sludge- A review

Municipal sewage sludge is a solid, semisolid, or liquid muddy looking residue that results after plain old sewage (human and other waste from households and industries) is treated at a waste water treatment plant. Recent restrictions on the use of sewage sludge, however, have resulted in increased disposal problems. Sludge contains a variety of organic and inorganic compounds in the waste water. Organic materials present in the waste water are detergents, pesticides, fats, oil and grease, colorings, solvents, phenols etc. Municipal waste water management is estimated about 38254 million liters per day of wastewater is generated in urban centers comprising cities and towns having population of more than 50,000. This is the current situation we need to find more solution to control the wastes is converted harmless uses and remedies. Waste water after treatment are used for irrigation purposes or utility water and sludge can be used in pisciculture, irrigation, forestry, and horticulture. Nowadays the extraordinary human knowledge has resulted in the use of sewage sludge to produce energy in the form renewable biofuels. Such, bio fuels are biodiesel, bio ethanol, biogas (bio H2, bio CNG, bio LNG) and bio solids. The paper reviews the various biofuels production processes from municipal waste water sewage sludge.