5. Sludge treatment, reuse and disposal. Sludge is produced from the treatment of wastewater in on-site (e.g. septic tank) and off-site (e.g. activated sludge) systems. This is inherently so because a primary aim of wastewater treatment is removing solids from the wastewater.
Definition of central. 1  1 : containing or constituting a center. 2  2 : of primary importance : essential, principal the central character of the novel. 3  3a : situated at, in, or near the center the central part of the stateb : easily accessible from outlying districts a central location for the new theater.
The definition of character is the person in a story the definition  of setting is when and where the story takes place the plot is a  series of related events that make up â¦ a story and the resolution is  when characters problems are solved. + 9 others found this useful. Rick Van de Houten. Stanie Clement.