Abstract: An improved process for treating a waste liquid containing impurities which inhibit the biological treatment of the liquid providing a first and a second sorbent treatment zone. The waste liquid is treated in the first sorbent treatment zone with a sorbent material which has previously been used to treat the liquid in the second zone. The waste liquid is passed through a biological treatment system and is subsequently received in the second sorbent treatment zone. The liquid is treated in the second zone with fresh activated sorbent material. After use of the sorbent material in the second sorbent treatment zone, the sorbent material in the second zone is transferred to the first sorbent treatment zone.Systems for the practice of the above process are also disclosed.

Abstract: A sludge heat treat system wherein a tube in the tube heat exchanger consists of multiple set of small tubes spaced inside of larger tubes. At the end of each run there is a return bend that conveys the fluid on the inner tube around to the next tube in the tube exchanger and also conveys the outer tube fluid to the next tube system. The inner tube system is carrying sludges that are obtained in a sewage treatment plant or an industrial waste treatment plant or any other type of treatment plant where sludges are produced and it is desired to heat treat these in order to release the bound waters and thereby effect a dewatering of the sludge cake which is not possible without sludge heat treat systems. The outer tube conveys a liquid which is usually water which has been treated. The outer tube conveys a liquid which is usually treated water which gives up the heat from an outside source to the sludge on the inner tube in a consistent manner.