Impacts of a high-discharge submarine sewage outfall on water quality in the coastal zone of Salvador (Bahia, Brazil)

MARINE POLLUTION BULLETIN

卷:106

Article

Roth, F.^1,2,3  Lessa, G. C.⁴  Wild, C.^1,2  Kikuchi, R. K. P.⁵  Naumann, M. S.¹ 

[1] Leibniz Ctr Trop Marine Ecol ZMT, Coral Reef Ecol Grp, D-28359 Bremen, Germany

[2] Univ Bremen, Fac Biol & Chem, D-28369 Bremen, Germany

[3] KAUST, Red Sea Res Ctr, Thuwal 239556900, Saudi Arabia

[4] Fed Univ Bahia UFBA, Inst Geosci, Dept Oceanog, BR-40170110 Salvador, BA, Brazil

[5] Fed Univ Bahia UFBA, Inst Geosci, Dept Oceanog, Coral Reef & Global Changes Res Grp RECOR, BR-40170110 Salvador, BA, Brazil

关键词: Marine pollution;    Oceanic Disposal System of Rio Vermelho;    Carbon and nitrogen stable isotopes;    Biological oxygen demand;    Shelf hydrodynamics;    Health threat;   

DOI  :  10.1016/j.marpolbul.2016.03.048

来源: Elsevier

【 摘 要 】

Carbon and nitrogen stable isotopic signatures of suspended particulate organic matter and seawater biological oxygen demand (BOD) were measured along a coastal transect during summer 2015 to investigate pollution impacts of a high-discharge submarine sewage outfall close to Salvador, Brazil. Impacts of untreated sewage discharge were evident at the outfall site by depleted delta C-13(org) and delta N-15 signatures and 4-fold increased BOD rates. Pollution effects of a sewage plume were detectable for more than 6 km downstream from the outfall site, as seasonal wind- and tide-driven shelf hydrodynamics facilitated its advective transport into near-shore waters. There, sewage pollution was detectable at recreational beaches by depleted stable isotope signatures and elevated BOO rates at high tides, suggesting high bacterial activity and increased infection risk by human pathogens. These findings indicate the urgent necessity for appropriate wastewater treatment in Salvador to achieve acceptable standards for released effluents and coastal zone water quality. (C) 2016 Elsevier Ltd. All rights reserved.

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