Paviršinių vandenų taršos komunalinėmis nuotekomis mažėjimo prognozė Nemuno vidurupio baseine

Abstract

Visos urbanizuotos šalys susiduria su paviršiniu vandenu tarša komunalin mis nuotekomis, Lietuva taip pat n ra išimtis. Straipsnyje nagrin jamas Nemuno vidurupio baseino taršos komunalin mis nuotekomis mažinimas nuoteku šalinimo sistemu pl tros kontekste. Pagal parengta Strategini plana igyvendinant centralizuotu nuoteku šalinimo sistemu pl tra, Nemuno vidurupio baseino teritorijoje galima likviduoti 51 taršos šaltini. Siekiant nustatyti, kiek sumaž s Nemuno vidurupio baseino upiu tarša, palyginti i aplinka išleistu teršalu kiekiai 2005 m. su prognozuojamais teršalu kiekiais 2010 m. ir 2020 m., kai prie nuoteku tinklu prisijungs visos baseino gyvenviet s, turincios daugiau kaip 500 gyventoju. Nustatyta, kad, igyvendinus baseino Strateginiame plane numatytus projektus, Nemuno vidurupio baseino upiu tarša komunalin mis nuotekomis iki 2020 m. sumaž s 87 %, pagal BDS7, bendraji azota, bendraji azota ir bendraji fosfora – 51 % ir 67 % atitinkamai. Siekiant ivertinti nuoteku sektoriaus valdymo schemos igyvendinimo poveiki aplinkai, buvo nagrin tos trys gyvenvieciu nuoteku valymo atvejai. Nustatyta, kad bendras taršos kiekis i paviršinius vandenis yra mažesnis valant nuotekas jungtinėse sistemose

All urbanised countries encounter pollution of surface waters by municipal sewage, Lithuania also is not an exception to this case. In the article decrease of pollution by municipal sewage in Nemunas Midland river basin is analyzed in the context of sewerage system extension. According to the prepared Strategic Plan, extension of centralized sewerage systems in the Nemunas Midland river basin will eliminate around 51 sources of pollution by municipal sewage. Seeking to estimate the extent of reduced pollution in the rivers of the Nemunas Midland river basin the comparison of pollution was made in 2005 and will be carried out in the future – in 2020, when all the basin settlements with more than 500 inhabitants are connected to wastewater collection systems. It was stated that after completion of the intended Strategic Plan projects the concentrated pollution of surface water bodies by 2020 will have been decreased by 87 % according to BOD7, by 51 % according to total nitrogen and by 67% according total phosphorus. In order to access the influence of water sector treatment scheme on the environment, three alternatives of waste water treatment were discussed. It has been established that pollution level is the lowest when sewage is cleaned in the joint waste water treatment system