Landfilling in Tropical Climates - an Analysis of Issues to Be Solved

On! a! global! level,! landfilling! is! still! the! main! method! to! dispose! of! waste.! In! particular! low:! and! middle:income! countries! almost! exclusively! depend! on! landfilling,! due! to! its! low! costs! and! convenient! operation! and! management.! Regulations!and!guidelines!exist!for!landfills!in!moderate!climates!(Western!Europe,! United! States).! These! guidelines,! nevertheless,! cannot! be! applied! in! tropical! countries,!as!the!behaviour!of!landfills!there!is!different.!! The! aim! of! the! present! thesis! was! to! provide! an! overview! over! the! problems! concerning! landfilling! in! tropical! countries.! A! special! focus! was! laid! on! the! characteristics!of!emissions!of!tropical!landfills!since!a!good!understanding!of!these! is! of! paramount! importance.! The!methodology! used!was! an! analysis! of! literature! reporting!on!problems! for! landfills! in! tropical! climates!as!well! as! a! comparison!of! the!specific!characteristics!of!landfill!emissions.! The!results!can!be!summarized!as!follows:!The!specific!behaviour!of!tropical!landfills! refers! mainly! to! landfill! emissions! and! waste! mechanics.! Leachate! quantities! are! much! higher! than! in! temperate! climates! and! vary! depending! on! the! season.! This! variation! is!also!observed! for! its! composition.! Leachates!of! the!dry! season!have!a! much! higher! concentration! of! pollutants! than! those! produced! during! the! rainy! season.! The! higher! precipitation! of! the! tropics! leads! to! a! higher! rate! of! waste! decomposition! in! the! landfill.! This! influences! methane! production,! which! occurs! faster,!in!larger!quantities!and!lasts!for!a!shorter!time!than!in!temperate!landfills.!! The!mechanical!stability!of!landfills!is!another!issue!that!is!influenced!by!the!higher! moisture! level! of! tropical! landfills.! Almost! all! dump! slide! disasters! occurred! after! periods!of!extreme!precipitation!or!due!to!an!increased!moisture!level!in!the!waste.! To!prevent!future!disasters,!the!climate!zone!is!a!factor!that!has!to!be!considered! when!designing!a!landfill.! Possible!solutions!to!a!few!of!the!issues!analysed!include!an!adequate!design!of!the! landfill!cover,!a!system!for!storing!and!recirculating!leachates!and!finally,! it!will!be! necessary! to! develop! an! international! landfill! classification! that! considers! the! climate,!the!development!level!of!the!country!as!well!as!the!type!of!waste!that!shall! be! deposited.! According! to! these! landfill! classes,! appropriate! national! and! international!guidelines!could!be!designed!that!fit!for!every!country!of!this!planet.!