Environmental aspects Pollution 36 Water 33 Purification 30 Heavy metals 26 Refuse and refuse disposal 25 Analysis 22 Management 22 Sewage 22 Energy consumption 21 Production management 19 Waste disposal 19 Measurement 18 Industrial management 17 Renewable energy sources 16 Design and construction 15 Environmental management 15 Safety measures 15 Biodiesel fuels 14 Economic aspects 14 Health aspects 14 Manufacturing industries 13 Palm oil industry 13 Pesticides 13 Waste minimization 13 Air 12 Carbon dioxide 12 Product life cycle 12 Sanitary landfills 12 Sustainable development 12