NOVELTY - The unit (350) has a separator (354) for receiving sewage. The draining slots are provided in the separator, so as to enable the liquid in sewage to drain out of the separator for obtaining partially drained solids in the separator. The separator and composting drum (358) are rotatably driven about the core assembly (352). A passageway is formed between the separator and composting drum. The partially drained solids are displaced towards the passageway when the separator is rotated. The passageway is adapted to transfer the partially drained solids to composting drum.    USE - Separator and composting unit of wastewater treatment system, used for separating human faeces, toilet paper, and kitchen waste from domestic wastewater.    ADVANTAGE - The solids can be easily separated from sewage and the separated solids can be easily composted. The separation rate of solids from sewage can be improved. The quality of the composted solids can be improved. The water content of the compost can be reduced. The separation of the solids allows for the capture of about 50% of the phosphorus present in the sewage and produces compost. The waste water treatment process can be simplified. The nutriment can be reused. The sludge hauling can be reduced. The odors can be reduced to a non repulsive level. The green gas emission (GGE) byproducts can be reduced. The core assembly is provided with holder structures to about against the front wall, so as to prevent the front wall from moving off the core assembly. The sloped walls are provided in the scraper structure, so as to reduce the accumulation of matter on the scraper structure and to reduce the risk of blockage of scraper structure. The inside perimeter portion of the hoop is not overlapped with the edges of circumference wall, such that the friction between the hoop and circumferential walls can be prevented effectively. The compost confined to a rolling composting drum allows good management practice.    DETAILED DESCRIPTION - The draining slots are extended along a circumference of the separator. The second circumference wall of separator is spaced apart from the first circumference wall, to define a gap between the walls. A gap insert is located in the gap and is fixed with respect to the core assembly. A first draining slot is formed between the gap insert and first circumference wall. A second draining slot is formed between the gap insert and second circumference wall. The gap insert is a hoop. The vanes are extended from the front wall to the back wall of separator. The second circumference wall is fixedly secured to the vanes. The vanes are configured to push the partially drained solids toward the passageway when the separator is rotated. A third draining slot is formed between the front wall gap insert and first circumference wall. The front wall gap insert and back wall gap insert are fixed with respect to the core assembly. The core assembly is provided with a trough to receive the partially drained solids. An auger is adapted to push the drained solids out of the through and into the passageway. The draining slot of the composting drum is extended along a circumference of the composting drum. The composting drum circumference wall is spaced apart from the composting drum front wall to define a composting drum gap. The composting drum gap insert is a composting drum hoop fixed with respect to the core assembly. The composting drum vanes are adapted to push the partially drained solids received from the separator toward the top portion of the sloped wall upon the separator being rotated. The partially drained solids are pushed towards the exit opening upon the composting drum being rotated. The composting drum exit opening is formed in the composting drum back wall.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the separator and composting system.    Separator and composting unit (350)    Core assembly (352)    Separator (354)    Composting drum (358)    Gear (360)