Study of traffic-related pollution and its treatment with a particular focus on microplastics in tunnel wash and road runoff water.

Treatment of tunnel wash runoff water and road runoff water before it reaches the environment is recommended to limit the negative consequences of traffic-related pollution. The efficiency of existing water treatment systems to remove traffic-related microplastic (MP) has not been sufficiently documented. Expanding the knowledge about traffic-related MP and documenting the treatment efficiency of MP in road tunnel wash water (TWW) and road runoff (RRW) treatment systems were the objectives of the presented project. TWW from the Tåsen tunnel, Norway, and RRW from the Fossbekken sedimentation pond were investigated in summer and winter situations. Six commonly available polymer types, tire rubber tread particles (TRP), and road marking paints (RMP) were analyzed in the selected samples. About 0.12 and 0.26 µg/L of polymers were identified in winter and summer TWWs. Significantly higher tire rubber and road marking paint concentrations were identified in the winter sample compared to summer sample. Suspended particle concentration in the Fossbekken RRW treatment pond effluent was lower in the summer than in the winter sample. About 0.002 and 0.0008 µg/L polymer masses were identified in winter and summer samples, respectively. TRP in the winter and summer samples were 0.7 and 0.2 µg7/L, and 13.4 µg/L RMP was found in the winter sample, while it was only 0.008 µg/L in the summer sample.

Effects of a Novel Adsorbent on Membrane Fouling by Natural Organic Matter in Drinking Water Treatment.

Irreversible fouling of water filtration membranes reduces filter longevity and results in higher costs associated with membrane maintenance and premature replacement. The search for effective pretreatment methods to remove foulants that tend to irreversibly foul membranes is ongoing. In this study, a novel adsorbent (Heated Aluminum Oxide Particles (HAOPs)) was deployed in a fully automated pilot system to remove natural organic matter (NOM) from the surface water source used at the UniVann water treatment plant (WTP) in Ullensaker County, Norway. The pilot plant treatment process consists of passing the water through a thin layer of HAOPs that has been deposited on a mesh support. The HAOPs layer acts as an active packed bed which removes NOM from the water. Fluxes around 120 L/m2/h (LMH) at transmembrane pressure (TMP) below 10.7 psi (0.7 bar) were achieved over production cycles excessing 12 h. Treatment achieved always >85% colour removal and effluent colour <5 mg Pt/L (the target of treatment), and always <0.01 NTU turbidity and non-detectable suspended solids in the permeate. The HAOPs mixture after saturated with NOM is easy to remove by disruption of the HAOPs by rinsing the mesh surface, and the sludge is easily dewatered to higher of dry solids content.

Relative sensitivity of one freshwater and two marine acute toxicity tests as determined by testing 30 offshore E & P chemicals.

Acute toxicity of 30 offshore E & P (Exploration and Production) chemicals was measured using the three standard test organisms Daphnia magna (freshwater cladoceran), Acartia tonsa (marine copepod) and Skeletonema costatum (marine diatom alga). Test chemicals included 20 water-soluble and 10 (partially) non-soluble products. For 22 out of the 30 chemicals, the difference in sensitivity between the three tests varied within one order of magnitude. A very good correlation was found between the two marine tests (r = 0.96, P < 0.01, n = 30), and a correlation coefficient of r = 0.78 (P < 0.01, n = 30) was found between D. magna and both A. tonsa and S. costatum, individually. When the comparison of D. magna and A. tonsa sensitivity was based only on the water-soluble chemicals, a significantly higher correlation was obtained (r = 0.84, n = 20), indicating that the sample preparation method used for the (partially) non-soluble chemicals (the water accommodated fraction (WAF) method) induces additional variation between tests performed with different test media. (Partially) non-soluble chemicals are characterised by phase separation or precipitation at the concentrations used for testing. In a WAF-based test, each test concentration/exposure level is prepared separately, and following mixing and separation, only the water phase is used for testing. Toxicity is related to the amount of substance originally added to the mixing vessels. For 25 of the 30 chemicals, D. magna was found to be less sensitive than the marine copepod by a factor >2. The generally higher sensitivity of the marine toxicity tests compared to the Daphnia test emphasise the importance of using marine data for environmental hazard classification as well as for environmental risk assessment purposes.