BBC Inside ScienceNational Insect Week, Venus' electric field, Green mining, Wimbledon grass scienceAlgae: cleaning Welsh rivers

Wales has 1300 rivers with illegal levels of heavy metals. Toxic metals like lead, zinc and copper are a legacy from the many (now defunct) mines in the area. Natural Resources Wales and Innovate UK set a competition to look for technology that would clean up these rivers. One of the two winners is Steve Skill from Swansea University, who is now trialling a system where an algae-covered matrix extracts the toxins from polluted water as it flows past it.