WASTE DESIGN FOR HOUSEHOLDS WITH RESPECT TO WATER, ORGANICS AND NUTRIENTS

Waste design couples handling and treatment of waste with the producti on and control of waste materials. This integrated approach will allow for a reduced use of non renewable resources in waste treatment The p aper discusses the use of waste design for households and its impact o n the composition of household wastewater. This will allow for the des ign of a wastewater with characteristics quite different from those no rmally found. The separation of toilet wastes or just urine can reduce the amount of nitrogen and phosphorus in the wastewater to a level wh ere no further nutrient removal is needed. The BOD and COD load to was tewater can be significantly reduced by separating toilet wastes and p art of the kitchen wastes. The phosphate content of detergents influen ces the phosphorus load significantly. Kitchen wastes can be diverted to the solid waste system or the compostable fraction of solid wastes can be incorporated into the wastewater by use of garbage grinders. Th e change in pollutant load can be achieved separately or in combinatio n with water savings. It is thus possible to reduce or increase the ov erall concentration of pollutants, and to design wastewater with a giv en COD/TN or COD/TP ratio, which is of significant influence on biolog ical nutrient removal processes. (C) 1997 IAWQ. Published by Elsevier Science Ltd.