Portable toilet system and mechanisms

A solid/liquid separation system (300) for a portable toilet (10) comprising:

• a waste holding tank (170) having at least one waste holding tank inlet (172), a bottom wall (173), and at least one sidewall (174);
• a plurality of first perforated plates (305) connected to the sidewall of the waste holding tank below the waste holding tank inlet;
• a first separation chamber (310) comprising a first vertical wall (311), and an overflow shelf (312) connected to a first vertical wall top surface (313), said first vertical wall having a first vertical wall height (314) and being connected to the bottom wall and the at least one sidewall of the waste holding tank;
• a second separation chamber (320) comprising a second vertical wall (321), and a plurality of second perforated plates (322) connected to a second vertical wall top surface (323) and located below the overflow shelf, said second vertical wall having a second vertical wall height (324) and being connected to the bottom wall and the at least one sidewall of the waste holding tank;
• a third separation chamber (330) comprising a third vertical wall (331) having a third vertical wall height (332) and being connected to the bottom wall and the at least one sidewall of the waste holding tank;
• a fourth separation chamber (340) comprising a fourth vertical wall (341), and at least one third perforated plate (342) connected to a fourth vertical wall top surface (343), said fourth vertical wall having a fourth vertical wall height (344) and being connected to the bottom wall and the at least one sidewall of the waste holding tank;
• and wherein
• each first perforated plate of the plurality of first perforated plates is angled in a first direction to direct at least a portion of a fluid flow from the waste holding tank inlet towards the first separation chamber;
• the overflow shelf is angled in a second direction opposite the first direction;
• each second perforated plate of the plurality of second perforated plates is angled in a third direction opposite the second direction;
• the at least one third perforated plate is angled in a fourth direction opposite the third direction;
• the second vertical wall height is less than the first vertical wall height;
• the third vertical wall height is less than the second vertical wall height;
• and
• the fourth vertical wall height is less than the third vertical wall height.