Hidrológiai Közlöny 1989 (69. évfolyam)

3. szám - Szabó Tamás: Szemlecikk – A nyomás és vákuum alatti szennyvízcsatornázás

150 HIDROLÓGIAI KÖZLÖNY 1989. 69. ÉVFOLYAM. 3. SZÄM The problem has become so acute that the 92d Congress specifically directed the Environmental Protection Agency (EPA) to conduct a comprehensive program of reasearch and investigation eliminating pollution from sewage in rural and other, areas where cellection of sewage in conventional, community-wide sewage collect;jn systems is impractical, uneconomical or otherwise infeasible, or where soil condi-' cions or other factors preclude the use of septic tank and drainage field systems. The situation and the problems in Europe are simiar to the US. Although sewage pumping has been practiced for many years is municipal systems in the form of lift stations and force mains to avoid excessive depthes of cut, wholesale use of small diameter pressure collection systems did not emerge until the latter part of the 1960's. The most highly instrumented study of pressure; sewers was performed on a group of 12 homes in Albany (Fig. 1 and 2). Valuable information was reported on design and construction methods and on the operational characteristics and maintenance requirements at the newly of pressure sewer systems were made — for example — of Phoenixville and of the Granview Lake. In Europe the pressure sewer systems began with the patent of hydropneumatic system, gained by Wilhelm Zander. Gesellschaft für Rein und Abwassertechnik. Braunschweig, in 1965 (Fig. 3). The best instrumented study of hydropneumatic pressure sewers was performed at Hamburg, operated with pneumatic units at each connection. A other study — nomed „Niederdruckentwässerung", and equiped with centrifugal pumps — was in the island Neuwerk. The „Electroiux — Liliendahl Vacuum Sewage System" was originally a watersawing toilet system. Nhis concept uses separate black and gray collection mains. Black water refers to toilet wastes and gray water includes all other domestic wastewater. Vacuum systems depend on a central vacuum source maintaining 450 to 650 mm of mercury on smalldiameter collection mains. A gravity vacuum interface valve separates atmospheric pressure from the vacuum in the mains. The interface unit may be installed or „on line" on the gravity drain, or „off line" in the buffer tank. In the United States several companies started marketing vacuum equipment in the 1970's There are significant differences among the designs of the four types: Liliendahl-Electrolux, Colt Envirovac, Airvac and Vas-Q-Tec. (Fig. 5, 6. 7). In the U. S and Europe hundreds of vacuum sewer systems work and there are well — known systems in Australia and Japan too. The „Electrolux Vacuum Toilet System" is used for trains, ships and air-liners (Fig. 8). The newest Evak Vacuum Sewage Collection System — developed in Sweden — uses a new type of valve and collection station (Fig. 9). Keywords: pressure and vacuum sewers, sewage collection, environmental protection SZABÓ TAMÁS szakmai munkásságának összefoglalóját a Hidrológiai Közlöny 1988/3. számának 153—160. oldalán közöltük.