Abstract: A wastewater treatment apparatus having a fixed film media apparatus having insertable high surface area polymer cartridges providing growth surfaces for autotrophic or heterotrophic bacteria and a protective shielding surface which isolates the biofilm from turbulence within the wastewater treatment system. A method of placement of said media apparatus within the aeration and/or clarifier section of the wastewater treatment apparatus.

Abstract: A wastewater treatment apparatus having a fixed film media apparatus having insertable high surface area polymer cartridges providing growth surfaces for autotrophic or heterotrophic bacteria and a protective shielding surface which isolates the biofilm from turbulence within the wastewater treatment system. A method of placement of said media apparatus within the aeration and/or clarifier section of the wastewater treatment apparatus.

Abstract: An adaptor for use with a light-communication device including a frame and a light guide on the frame. The light guide has a first light port assembly to receive a light signal from a light-communication device, a second light port assembly to output a light signal received by the first light port assembly, and a light transmission element for directing a light signal in a predetermined path between the first and second light port assemblies. The adaptor may be used in a system with two or more light-communication devices. Also provided is a method for communicating light signals between light-communication devices.

Abstract: A battery charger includes a first portion of a charging circuit with first and second terminals, a detector for detecting a selected signal sequence in the charging circuit, and a regulator for switching from a first output level to a second output level in the charging circuit in response to the detector detecting the selected signal sequence. A communication unit has a port for a rechargeable battery and includes a second portion of the charging circuit through the battery port with third and fourth terminals connectable with the first and second terminals and fifth and sixth terminals connectable to terminals of a rechargeable battery when in the port. The communication unit also has a switch in the second portion of the charging circuit controlled by a processor, with the processor adapted to control the switch according to the selected signal sequence when a battery is in the port which requires the second output level.