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.
The central vacuole is a cellular organelle found in plant cells. It is often the largest organelle in the cell. It is surrounded by a membrane and functions to hold materials and wastes. It also functions to maintain the proper pressure within the plant cells to provide structure and support for the growing plant.
In plant cells, however, there is generally a large single central vacuole. Comprising approximately 90% of an mature plant cell, the central vacuole provides structure and support to the cell by maintaining turgor pressure, which is essentially fluid pressure that keeps the cells rigid.acuoles are essentially membrane-bound sacs found in the cytoplasm. In animal cells, vacuoles are relatively small, and are used as temporary storage areas for materials and for transport purposes.