EOX concentrations in sediment in the part of the Bothnian Bay affected by effluents from the pulp and paper mills at Kemi, Northern Finland

Abstract

The Bothnian Bay, which is the northernmost part of the Gulf of Bothnia in Northern Finland, is affected by effluents discharged from point sources such as the pulp and paper mills of Stora Enso Oyj Veitsiluoto Mill and Oy Metsä-Botnia Ab Kemi Mill at Kemi, and the Kemi municipal sewage plant, as well as the River Kemijoki. In this paper we discuss, how modernisation of the wastewater treatment plant at the mills, and process investments in the Best Available Techniques (BAT) for effluent treatment, have decreased the effluent discharges of biological oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (Tot-P), total nitrogen (TOT-N), total suspended solids (TSS) and adsorbable organically bound halogens (AOX) from the mills since 1988. One specific aim of the study was to determine the EOX (Extractable Organically Bound Halogens) concentrations in bottom sediment of the Bothnian Bay in order to assess whether the EOX concentrations reflect the reduction in discharges of chlorinated compounds. According to the monitoring program carried out every third year between 1997-2006, the decreasing trend in EOX concentrations in the top 2 cm of the bottom sediment reflect the decrease in organochlorine discharges (AOX) from the mills. In 1997 the EOX concentrations in bottom sediment varied between 3-70 microg of Cl g(-1) (dry weight), and in 2006 between 3.3-32 microg of Cl g(-1) (dry weight).

Assessing the Trend of the Trophic State of Lake Ladoga Based on Multi-Year (1997–2019) CMEMS GlobColour-Merged CHL-OC5 Satellite Observations

“…On the other hand, it is well documented that, better waste management practices by paper mills, settlements and agricultural activities have improved the water quality of rivers and lakes [49,50]. For example, the Stora Enso Veitsiluoto Mills at Kemi, northern Finland [51,52] and the Kaukas paper mill on southern Lake Saimaa have been able to improve local water quality through better water management processes [53]. It is worthy to note that the closing of paper mills was a major factor to improved water quality in the absence of better waste management practices, e.g., [51,52,54].…”

Potential Application of Lignite as Adsorbents in Industrial Wastewater Treatment: A Mini Review

“…There are also synthetic dyestuffs used extensively in textile and printing industries. Some of these compounds can be degraded by microorganisms in the activated sludge plant; however, a biorefractory portion of the effluent, which consists of high molecular weight oxidized organic compounds, is often an important fraction of the waste (Bijan and Mohseni 2005;Pöykiö et al 2008).…”