Willows for energy and phytoremediation in Sweden

Abstract

hort-rotation willow coppice is cultivated in Sweden to produce biomass for energy. The crop is commercially grown, mainly on agricul-tural land, and the biomass produced is used in district heating plants for com-bined heat and power production.In recent years, nutrient-rich waste products – mainly urban wastewater, landfill leachate, industrial wastewaters (e.g. log-yard runoff), sewage sludge and wood-ash – have been successfully applied to the willow coppice to reduce, through plant uptake, the content of pol-lutants and/or excess nutrients in water and soils, and to facilitate microbial degradation of organic pollutants. This process is known as phytoremediation.The benefits of such practices are both environmental and economic: this method of treating waste products (which here can be considered more as resources than as wastes) is more cost effective than conventional treatments, and the nutrients contained in the waste products serve as low-cost fertilizers to increase biomass production. This article provides an overview and exam-ples of the use of short-rotation willow coppice in phytoremediation systems for treating different kinds of waste in Sweden.