Phytoremediation for heavy metal‐contaminated soils combined with bioenergy production

Abstract

In June 2007, a project started in Flanders (Belgium) in which we will apply phytoremediation to clean soils that are diffusely polluted with heavy metals. Uptake ranges of heavy metals by rape seed, maize and wheat will be enhanced by increasing the bioavailability of these heavy metals by the addition of biodegradable physico‐chemical agents and by stimulating the heavy‐metal uptake capacity of the microbial community in and around the plant. In addition, the harvested biomass crops will be converted into bioenergy by using different energy‐recovery‐techniques. The energy and heavy metal mass balances will be compared for four different energy‐recovery techniques (anaerobic digestion, incineration, gasification and production of biodiesel). The overall information obtained will result in an economic evaluation of the use of phytoremediation combined with bioenergy production for the remediation of sites which are diffusely polluted with heavy metals. In the present review we will first explain the most important research steps investigated in our phytoremediation project. Secondly, an overview of literature discussing the phytoremediation capacity of rape seed to clean soils that are contaminated with heavy metals and the possibilities to produce biodiesel from this (heavy metal polluted) rape seed will be discussed in more detail.

Santrauka

2007 m. birželá Flandrijoje (Belgija) pradëtas vykdyti projektas, kuriame mes pritaikysime fitoremediacijà siekdami išvalyti sunkiuosius metalus iš dirvožemio. Sunkiøjø metalø patekimas á rapsus, kukurûzus ir kvieèius bus suintensyvintas didinant šiø sunkiøjø metalø biopriimamumà dël pridedamø biodegraduojanèiø fizikiniø‐cheminiø priedø bei stimuliuojant mikrobiologiniø bendrijø pajëgumà augale ir aplink já sugerti sunkiuosius metalus. Be to, nuimta javø biomasë bus perdirbta á bioenergijà, taikant ávairias energijos gavybos technologijas. Energijos ir sunkiøjø metalø masës balansas bus palygintas pagal keturias skirtingas energijos gavybos technologijas (anaerobinis kompostavimas, deginimas, dujofikavimas ir biodyzelio gamyba). Visa gauta informacija leis ekonominiu požiûriu ávertinti fitoremediacijos, derinamos su bioenergi‐jos gamyba, taikymà valant sunkiaisiais metalais nevienodai užterštus plotus. Pateikiamoje apžvalgoje pirma aptarsime svarbiausius fitoremediacijos projekto etapus. Antra, detaliau apžvelgsime literatûrà apie rapsø pajëgumà išvalyti dirvožemá, užterštà sunkiaisiais metalais, ir galimybes gaminti biodyzelá iš (sunkiaisiais metalais užterštø) rapsø sëklø.

Keywords:

• phytoremediation
• heavy metals
• biomass
• energy recovery
• rape seed
• biodiesel

Reikšminiai žodžiai:

• fitoremediacija
• sunkieji metalai
• biomasë
• energijos gamyba
• rapsai
• biodyzelis

Keywords: