Vízügyi Közlemények, 2002 (84. évfolyam)
1. füzet - Rövidebb tanulmányok, közlemények, beszámolók
160 Barna József ban több kis regionális rendszerből és egyedi szennyvíztisztítókból álló - létesítmények fölös iszapját egy helyen, együttesen kezelni hasznosítás céljából, pl. komposztálással. Másik megoldás egy megfelelő műszaki védelemmel ellátott földgödörben öszszegyüjtött, 10-14% szárazanyag tartalmú kezelt szennyvíziszapnak a talajba juttatása injektálással, vagy egyéb módszerrel. A szennyvizek és szennyvíziszapok mezőgazdasági felhasználásának és kezelésének szabályairól szóló 50/2001. (IV. 3.) Korm. rendelet előírásainak betartása mellett mindegyik eljárás hasznosításnak minősül. * * * Construction and operation problems of large regional waste water treatment systems by József BARNA C.E. In the field of waste water treatment Hungary has a lot to do in the accession process to the European Union. In the field of the protection of the environment the key issues, that lag behind the requirements of the EU, are the waste water treatment and the solid waste management. Of these two waste water treatment is the more expensive but less showy task. The data of the end of the year of 2000 indicate (Table I.) that of the 3,154 settlements of Hungary 854 had sewer systems. In the national scale 55.4% of the homes were connected to sewers and 58.5% of the thus collected sewage water received biological treatment, before their discharge into a recipient water body. These data indicate well that there is a substantial lag in the development of waste water collection and treatment and the work to be done is enormous. The ftill construction of all sewerage and sewage treatment facilities of Hungary could be made within 10 years (by 2012) on the expenditure of two-third or three-fourth of the sum estimated as the total cost, if good concepts and plans were used. This would result in a saving of 250-300 billion Hungarian Forints and this sum could be spent on other environmental purposes in an economic manner. In selecting the type of the waste water treatment plant and its capacity one should consider first the population or the population equivalent. In the EU countries the per capita sewage water generation rate is usually considered as 0.12 m 3/day. In Hungary this value is in the range of 0.08-0.12 m 3/capita/day. In the country, where people use less water it is sufficient to calculate with 0.08 m 3/capita/day, while in the cities the proposed design value is 0.12 m 3/capita/day. If there is an industrial plant in a settlement, then a population equivalent value shall be determined for that plant. The more simple and smaller the sewage treatment plant, the lower the per-capita construction and operation costs of sewage treatment. The individual treatment plants are the least expensive and most economic plants, which also comply with the requirements of both the environmental protection and the sewage treatment techniques. Whenever possible its is desirable to follow the principle of one plant for one settlement. Gravitational and pressure sewer systems are more favourable used by the planners, than the vacuum systems. The only advantage of vacuum sewer systems over the gravity and pressure systems is the required depth of the sewer pipes. For the gravity system the sewer must run at 2 m depth, while for the vacuum system the sewer must be 1.0 meter below frost depth. Thus the advantage is in the saving of earth-work volume. It has now advantage over the pressure system, as the laying depth of the vacuum and pressure sewers is the same.
