Phytoremediation development in Sweden

Abstract

The contaminated air, water and soil have been major environmental issues during the last decades in Sweden. The phytoremediation technologies with ecological and economic benefits may help to alleviate those problems, especially related to heavy metal and organic pollutants. There is paucity of literatures on comprehensive understanding of phytoremediation technology development in Sweden. The Environmental Science and Engineering Group (ESEG) at Linnaeus University has been working on the relevant topics for decades and achieved some important findings. This study aimed at providing a systematic insight on the phytoremediation development in Sweden through literature reviews as well as summarizing the doctoral theses presented by ESEG. Herein suggestions and recommendations for phytoremediation development are given, especially those projects and research in Sweden and other countries with similar climate situation, which can benefit the works for site managers and engineers as well as ecologists and biochemists. The study presents useful findings: 1) The majority of phytoremediation research in Sweden is focused on wetlands. Some are working on soil remediation, and very few on air purification. Submerged plant species in wetlands have been shown to be more effective at removing heavy metals than free-floating and terrestrial plants. Willow is the most popular species used in soil remediation, and there are many different clones. There are some other potential plants for phytoremediation, including Poplar, Silver Birch, Alfalfa, Spinach, Fireweed, Reed Canary grass, Scots pine, Rapeseed, etc. 2) Composting, bacteria, and iodides are examples of additions that can help improve phytoremediation efficiency. 3) Both biomass yields and contaminants accumulation concentration in plant must be considered when evaluating phytoremediation efficiency. 4) The efficacy of the phytoremediation function will be influenced by factors such as plant selection, climate situation, additions of substrate, soil properties, etc. Furthermore, the concentration of contaminants varies between plants as well as between different parts of the plant. 5) Management and maintenance are essential for a successful phytoremediation operation. It is critical to protect plants against disease, fungi, insects, pests and so on.