wastes 538 recycling of wastes 227 waste disposal services 202 house-hold wastes 75 environment 68 industrial wastes 62 treatment 61 more ... environment protection 52 biological wastes 45 secondary raw materials 40 toxic waste 37 environmental pollution 34 composts 33 waste incinerators 33 storage of wastes 31 sorting 31 agricultural wastes 28 biofuels 27 dumps 24 legal regulations 23 hazardous wastes 21 unconventional energy sources 20 odpadové hospodářství 20 provisions 20 synthetic polymers 19 radioactivity 18 combustion 18 permanently sustainable development 17 health harmful substances 17 waste water treatment 16 less ...