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.
Definition of Character in Fiction. In a work of fiction, a character is depicted through both narrative and dialogue. Characters can be flat, minor characters or round and major, developed with depth. The persona is revealed by how a character responds to conflict, by dialogue, and through descriptions. Characters in fiction can have many roles and purposes, all of them dictated by the writer's intent and style. A few possible character roles include: Protagonist: Also sometimes called the hero or heroine of the story, the protagonist is the main character. In some cases, the reader experiences the story through eyes of the protagonist; in other cases, the protagonist may be only one of many characters whose perspective is described.