Abstract: A system for providing emergency alerting capability to persons at or near a remote banking terminal (ATM) or night-depository, in such a manner as to minimize risk to the possible victim and maximize the emergency response authorities' ability to monitor and respond to the situation. The device consists of a covert control and two-way communication unit attached to an Automatic Teller Machine or a night-depository. The unit is activated by a button or switch on the ATM, or by a remote radio receiver link from a keyed small radio transmitter. Upon activation, the unit dials a 911 emergency response office, establishing two-way voice communication from covert microphones at the ATM, and to a speaker hidden at the ATM. During communication, the unit is controlled by the emergency response operator.

Abstract: A method for the secondary treatment of sewage (and apparatus therefor) having a step in which sewage is circulated in a system having a riser and a downcomer communicating with each other at their upper and lower ends and in which an oxygen-containing gas is supplied to the sewage as it passes through the downcomer. The method is intended for use in the aeration and/or digestion steps of the secondary treatment of sewage. The riser and downcomer are preferably located in a shaft extending into the ground for at least 40 meters below a basin containing the sewage.

Abstract: A method for the secondary treatment of sewage (and apparatus therefor) having a step in which sewage is circulated around a system having a riser and a downcomer communicating with each other at their upper and lower ends and in which an oxygen-containing gas is supplied to the sewage as it passes through the downcomer. The method is intended for use in the aeration and/or digestion steps in the secondary treatment of sewage. The riser and downcomer are preferably located in a shaft extending into the ground for at least 40 meters below a basin containing the sewage.

Abstract: A method and apparatus for treating wastewater by circulating it around a system comprising a downcomer and a riser communicating with each other at their lower ends, the level of the wastewater in the downcomer being above the level of the wastewater in the riser and providing a hydrostatic pressure head which causes circulation of the wastewater around the system, supplying a gas containing free oxygen to the wastewater as it passes through the downcomer, and pumping the wastewater up from, or from near, the top of the riser to a part of the downcomer, at or near the top thereof, which has, for at least a part of its length, a cross-sectional area which is less than the cross-sectional area of the remainder of the downcomer below the said part.

Abstract: A method and apparatus for the treatment of wastewater in which the wastewater is circulated around a system comprising a downcomer and a riser communicating with each other at their lower ends, the level of the wasterwater in the downcomer being maintained above the level of the wastewater in the riser and providing a hydrostatic pressure head which causes circulation of the wastewater around the system at a pre-selected rate, a gas containing free oxygen is supplied to the wastewater as it passes through the downcomer, and the wastewater is pumped from, or form near, the top of the riser back into the downcomer (or vessel communicating therewith) at a position(s) above the highest level to which the wastewater in the downcomer can fluctuate during normal operation of the system when operating at maximum load.

Abstract: Solids-liquid separation, wherein a solids-liquid mixture containing dissolved oxygen-containing gas is circulated around a circulatory system comprising a downcomer and a riser, part of the mixture in the riser being introduced into a flotation chamber in which the hydrostatic pressure gradually decreases as the mixture flows upwards, with consequent release from solution of gas bubbles which carry solid particles to the top of the mixture.

Abstract: A method and apparatus for continuously circulating a mixture comprising a liquid and a gas around a system comprising a riser and a downcomer and a gas disengagement section in which liquid flows downwardly at a velocity which does not exceed 0.2 meters per second and is being injected into a lower section of the riser. The method and apparatus are particularly useful for conducting aerobic fermentations.