Severe droughts and mismanagement of water resources during the last decades have propelled authorities in the Kurdistan Region to be concerned about better management of precipitation which is considered the primary source of recharging surface and groundwater in the area of interest. The drought cycles in the last decades have stimulated water stakeholders to drill more wells and store uncontrolled runoff in suitable structures during rainy times to fulfill the increased water demands. The optimum sites for rainwater harvesting sites in the Qaradaqh basin, which is considered a water-scarce area, were determined using the analytical hierarchy process (AHP), sum average weighted method (SAWM), and fuzzy-based index (FBI) techniques. The essential thematic layers within the natural and artificial factors were rated, weighted, and integrated via GIS and multi-criteria decision-making (MCDM) approaches. As a consequence of the model results, three farm ponds and four small dams were proposed as future prospective sites for implementing rainwater harvesting structures. The current work shows that the unsuitable ratio over the study area in all methods AHP, SAWM, and FBI occupied 12.6%, 12.7%, and 14.2% respectively. The area under the curve (AUC) and receiver operating characteristics were used to validate the model outcomes. The AUC values range from 0.5 to 1, meaning that all MCDM results are good or are correctly selected. Based on the prediction rate curve for the suitability index map, the prediction accuracy was 72%, 57%, and 59% for AHP, SAWM, and fuzzy overlay, respectively. The final map shows that the potential sites for rainwater harvesting or suitable sites are clustered mainly in the northern and around the basin’s boundary, while unsuitable areas cover northeastern and some scatter zones in the middle due to restrictions of geology, distance to stream with the villages, and slope criteria. The total harvested runoff was 377,260 m3 from all the suggested structures. The proposed sites may provide a scientific and reasonable basis for utilizing this natural resource and minimize the impacts of future drought cycles.

Twenty daily time step–based SWAT simulation models for the Duhok, Adhaim and Dokan dam watersheds, in Iraq, were implemented using five land cover (LC) and digital elevation model (DEM) of different resolutions. The optimal LC and DEM for computing the most accurate streamflow for each watershed were specified. Results indicated that delineation of the flat watersheds is significantly affected by the DEM resolution and there was no evident trend on the computation of watersheds’ total areas, boundaries, number of subbasins and stream networks. Moreover, there is no significant trend between the increase in LC and DEM resolutions and accuracy of the computed streamflow. The most accurate streamflows for the Duhok, Adhaim and Dokan watersheds were computed using LC (DEM) of 30 m, 1000 m and 1000 m.

Stormwater biofilters, which are recommended for application in both Water-Sensitive Urban Design and Low Impact Development, can remove up to 80% or 90% of total metals found in stormwater. However, their winter operation is a common concern. That was addressed in this study by investigating the metal removal effectiveness of replicate laboratory biofilter mesocosms at 2°C, 8°C and 20°C. As recommended for cold climate bioretention, coarse filter media were implemented and in the top 100 mm layer topsoil was added to increase the sorption capacity. Cd, Cu, Pb and Zn concentrations measured in the biofilter effluent were far below those in the influent and this significantly improved the treated stormwater quality. Contrary to a common notion that coarse media in the main filter body impair dissolved metal sorption, satisfactory removals of dissolved metals were found in this study with most metal burdens retained in the top layer of the filter in which the sorption capacity was enhanced by topsoil. Some metal uptake by the plants was also detected. Temperature did not affect Cd, Pb and Zn removals in general, but Cu removals increased with decreasing temperatures. This was explained by increased biological activities in the filters at warmer temperatures, which may have led to an increased release of Cu with dissolved organic matter originating from root turnover and decomposition of organic litter and debris. Furthermore, plant uptake and biofilm adsorption may also be influenced by temperature. However, even in the worst case (i.e. at 20°C), Cu was removed effectively from the stormwater. Further research needs were identified including the effects of road salts on stormwater biofiltration during the winter period.

Iraq currently undergoing the problem of water shortage, although Iraq has two Rivers (Euphrates and Tigris) pass throughout most of its areas, and they have represented a major source of water supply. In the current research, to evaluate the quality of the Euphrates river in Iraq based on the values of total dissolved salts (TDS), the TDS concentrations were collected from sixteen sections along the river in the three succeeding years (2011, 2012, and 2013). The evaluation of the river was done depending on the classification of (W.H.O. (World Health Organization). (2003). Total Dissolved Salts in Drinking-water: Background document for development of W.H.O. Guidelines for Drinking-water Quality. World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland). of rivers for drinking uses. Inverse Distance Weighting Technique (IDWT) as a tool in the GIS was employed to establish the maps of the river that using interpolation/prediction for the TDS concentrations to each selected year and the average values of TDS for these 3 years. Based on the five categories of rivers’ classification of the TDS concentrations according to the (W.H.O. (World Health Organization). (2003). Total Dissolved Salts in Drinking-water: Background document for development of W.H.O. Guidelines for Drinking-water Quality. World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland), the Euphrates river was classified, and the maps of classification for the years 2011, 2012 and 2013 and the average values for 3 years were created. The average values for 3 years of TDS along the Euphrates river indicated that the sections from SC-1 to SC-4 as moderate-water-quality-Category-3, the sections from SC-5 to SC-10 as poor-water-quality-Category-4, while the sections between SC-11 to SC-16 as very poor-water-quality-Category-5. The interpolation maps showed that the Euphrates river in Iraq was ranged from moderate water quality (Category-3) to very poor water quality (Category-5).

Surface water and groundwater are significant for population and other activities due to the decreasing surface water flow toward Iraq. Therefore, there is a need to analyze groundwater’s quality and classification and its applicability as an alternative in various human activities in the study area. This study utilized the groundwater quality index model for drinking uses (GW.Q.I.) and entered the resulting values in the GIS environment. This model was applied to 56 wells in Al-Hillah city by measuring twelve variables in each well. The measured variables were calcium (Ca), magnesium (Mg), sodium (Na), chloride (Cl), sulfate (SO4), bicarbonate (HCO3), total hardness (TH), total dissolved solids (TDS), nitrate (NO3), and electric conductivity (EC). The prediction map of GW.Q.I. was produced in the GIS. Then, the distributing map was divided into six categories based on the suitability of groundwater for drinking uses. The areas’ values of six categories with their ratings were about 5 km2 (excellent), 122 km2 (good), 610 km2 (poor), 63 km2 (very poor), 36 km2 (contaminated), and 24 km2 (very contaminated). For the entire study area, the average value of the GW.Q.I. was 177, classified as poor for drinking uses.

Using solely an optical remotely sensed dataset to obtain an accurate thematic map of land use and land cover (LU/LC) is a serious challenge. The dataset fusion of multispectral and panchromatic images play a big role and provide an accurate estimation of LU/LC map simply because using a dataset from different spectrum portions with different spatial and spectral characteristics will improve image classification. For this study, the Landsat operational land imager multispectral and panchromatic images were adopted. This study aimed to investigate the effectiveness of using a panchromatic highly spatial resolution to refine the methodology for LU/LC mapping in Baghdad city, Iraq, by performing a comparison of classifications using different algorithms on multispectral and fused images. Different classification algorithms were employed to classify the data set; minimum distance (MD) and the maximum likelihood classifier (MLC). A suitable classification method was proposed to map LU/LC based on the outcome results. The result evaluation was conducted by applying a confusion matrix. An overall accuracy of a fused image using a principal component-based spectral sharpening algorithm and classified by the MLC classifier reveals the highest accurate results with an overall accuracy and kappa coefficient of 98.90% and 0.98, respectively. Results showed that the best methodology for LU/LC mapping of the study area is found from fusion of multispectral with panchromatic images via principal component-based spectral algorithm with MLC approach for classification.

A comparative study of indicator bacteria concentrations obtained by laboratory analysis of grab samples of storm water, which were collected manually or by automatic samplers, was carried out in two urban catchments. Samples were analyzed for four types of indicator bacteria, total coliforms, Escherichia coli (E. coli), enterococci, and Clostridium perfringens and further documented by measurements of total suspended solids (TSS) and turbidity. Analysis of complete data sets (N=198) indicated no statistically significant differences in the geometric means of all the constituent samples collected automatically or manually, but there were some small differences between the results produced by the two sampling methods applied. Total coliform concentrations were positively biased in samples collected by automatic samplers, but for the three remaining indicator bacteria (E. coli, enterococci, and C. perfringens), the opposite was true. Risk of sample cross-contamination in automatic samplers was assessed in the laboratory by sampling consecutively synthetic storm water with high and low concentrations of E. coli and enterococci. The first low-concentration samples preceded by high-concentration samples were cross-contaminated and the measured concentrations were positively biased. This cross-contamination was explained by storm-water residue in the sampling line. Such a residue remained in place even after line purging by compressed air, and its mass depended on the sampling line length (tested up to 5 m), as verified by measurements in the laboratory. The study findings should be helpful for improving field protocols for indicator bacteria sampling.

Inorganic chemicals in urban stormwater and snowmelt runoff originate from catchment geology and anthropogenic activities. The occurrence, partitioning and mobility of six minerals and six trace metal (TM) indicators of anthropogenic activities were studied in stormwater, snowmelt and baseflow in four urban catchments, and the sampling of inorganics was supplemented by measurements of electrical conductivity (EC), pH and total suspended solids (TSSs). Minerals occurred at concentrations several orders of magnitude higher (1–10² mg/L) than those of TMs (10⁻²–10² μg/L) and reflected the composition of local groundwater seeping into sewers. Concentrations of Ca, K, Mg and Na were enhanced by baseflow contributions and followed closely the electrical conductivity. Al and Fe minerals occurred in insoluble forms, and their pollutographs were similar to those of TMs, whose concentrations mimicked, to some extent, the flux of TSS. The TMs with the highest and lowest particulate fractions were Cr&Pb and Cu&Zn, respectively. The concentrations of total TMs in snowmelt were two to four times higher than those in stormwater, and both sources likely exceeded some of the stormwater effluent limits (for Cd, Cu and Zn) proposed in Sweden. Where such concentrations depended on water hardness, the risk of toxicity might be reduced by elevated hardness of the monitored snowmelt and stormwater. Recognizing the good ecological status of the study area receiving water, Lake Storsjön, some protection against polluted runoff and snowmelt may be needed and could be achieved by implementing stormwater management measures controlling TSS and TMs.

Al-Hawizeh Marsh is considered a major marsh in the south of Iraq with a longitude of 47° 32″–47° 45″ and latitude of 31° 30″–31° 42″, length of 80 km and width of 30 km, while the depth is from 1.5 to 4 m. It has a significant impact on the ecosystem and provides habitat for several types of living creatures. The surface water and the agricultural lands surrounding this marsh suffered from high level degrees of salinity. In the last decades, radical deterioration of water quality in this marsh happened because of the post-war-related events and several human activities. Landsat-8 data was used to predict and evaluate the spatial variation and map distributions of the salinity, SO₄ and CaCO₃ within Al-Hawizeh Marsh during the two seasons in the year 2017 based on the development of salinity and minerals mathematical equations. The evaluated values for salinity, SO₄ and CaCO₃ are found to be minimal in winter and maximum in autumn. The values of correlation coefficient (R²) between the real data and the equation results for the salinity, SO₄ and CaCO₃ during the two seasons are 0.95, 0.96 and 0.92, respectively.

Filtration can be a convenient technique for removing phosphorus (P) at on-site wastewater treatment facilities to recycle this non-renewable element. When testing potentially suitable materials for these filters, the properties of the influent and the method used to analyse measured effluent concentrations both affect the P binding capacity determined in filter tests and therewith filter longevity predictions. At present, there is a lack of robust methods for material investigation and filter test interpretation. This study was conducted to investigate the effect of inflow PO4-P concentrations (concentration) and hydraulic surface load (load) on P binding capacity and to analyse possible interpretations of laboratory filter tests. A 22 factorial experiment with replicates was performed on the calcium-based filter material Filtra P. The investigated concentrations ranged from 12 to 50 mg L-1 and loads from 419 to 1,023 L m-2 day-1. P binding capacity (calculated by mass balance including data until PO4-P breakthrough point) was negatively affected by concentration and positively affected by load, with the effect of concentration being slightly greater. Depending on the factors' settings and on the method of evaluation (i.e. analysing all pre-saturation data or considering only pre-breakthrough results), the total measured P binding capacity varied between 2.2 and 9.0 g kg-1. The part of the breakthrough curve between the breakthrough point and saturation contributed significantly to the measured P binding capacity, and it took about three times longer for the filters to become saturated than to reach breakthrough. Furthermore, a considerable amount of P that had reacted with the filter material was washed out of the filters as particle-bound P. This indicates that it is important to determine both the PO4-P and the particle-bound P phases in the filter effluent

Quantifying plant biomass and related processes such as element allocation is a major challenge at the scale of entire riparian zones. We applied sub-decimetre-resolution (5 cm) remote sensing using an unmanned aircraft system (UAS) in combination with field sampling to quantify riparian vegetation biomass at three locations (320-m river stretches) along a mining-impacted boreal river and estimated the amounts of Cd, Cu, and Zn stored in the dominant species. A species-level vegetation map was derived from visual interpretation of aerial images acquired using the UAS and field sampling to determine species composition and cover. Herbaceous and shrub biomass and metal contents were assessed by combining the vegetation maps with field sampling results. Riparian zone productivity decreased from 9.5 to 5.4 t ha-1 with increasing distance from the source of contamination, and the total amount of vegetation-bound Cd and Zn decreased from 24 to 0.4 and 3,488 to 211 g, respectively. Most Cu was stored at the central location. Biomass and metal contents indicated large variation between species. Salix spp. comprised only 17% of the total dominant-species biomass but contained 95% of all Cd and 65% of all Zn. In contrast, Carex rostrata/vesicaria comprised 64% of the total dominant-species biomass and contained 63% of all Cu and 25% of all Zn. Our study demonstrates the applicability of UAS for monitoring entire riparian zones. The method offers great potential for accurately assessing nutrient and trace element cycling in the riparian zone and for planning potential phytoremediation measures in polluted areas

A gully pot is often cleaned with the help of an eductor truck, which uses hydrodynamic pressure and a vacuum to loosen and remove the solids and standing liquid from a gully pot. This paper considers the polycyclic aromatic hydrocarbons (PAH) content in the gully pot mixture (water and sediment) after it has been discharged from the eductor truck. The results show that most PAH was attached to particles, and the dissolved phase represented approximately 22% of the total water concentration. No significant difference was found for the water phase between a housing area and a road, whereas a significant difference was found for NAP, ACE, FL, ANT, FLR, PYR, BaF, and BPY in the sediment at a 95% confidence level. Source identification showed that the PAH in the gully pot mixture came from mixed sources. Both the water and sediment phase exceed all or some of the compared guidelines. The result from this paper shows that not only the sediment needs to be discussed, but also the water phase created during the maintenance of different BMPs.

COD (chemical oxygen demand) has historically been considered to be an estimate of organic matter, and though this is no longer the case, for most kinds of water it is still a fair approximation. Landfill leachates may, however, be one of the exceptions. Landfill leachate contains many inorganic substances and, in certain circumstances, high concentrations of volatile organic compounds like acetic acid; the COD value may be affected by these conditions. Designed experiments were performed to determine how COD could be affected by the composition of landfill leachates. The factors studied include the content of iron(II), manganese(II), sulphide, ethanol, acetic acid, ammonia, and chloride as well as different aspects of the COD analysis design. The results show that up to about one-third of COD may be due to the inorganic components of leachates. The main conclusion from the experiments is that COD cannot be used solely as a measure of the organic matter of landfill leachate since inorganic substances as well as interactions between substances may interfere with the COD results.

In recent years, the problem of rising salinity levels in the Shatt al-Arab river in southern Iraq has been repeated, which has directly affected the living and health situation and the agricultural activity of these areas. Six sampling stations were selected along Shatt al-Arab to estimate the concentration of total dissolved solids (TDS) in the river; these stations included the following: Qurna, Labani, City Centre, Kateban, Corniche, and Sihan. In addition, three Landsat-8 satellite images which were taken at the same time as collected samples also used for detecting the salinity in the river. After processing of atmospheric correction and inserted remote sensing indices, the reflectance of water extracted from satellite images was used to express the spectral characteristics of different TDS concentrations. Correlation and regression were used to obtain accurate models for detecting the salinity depending on the spectral reflectance of Landsat 8 operational land image OLI. The results presented Pearson correlation (r) value of 0.70, 0.97, and 0.71, and correlation coefficient (R2) of 0.56, 0.94, and 0.85 between field data with spectral data of salinity index 2 (SI-2) derived from the green and blue bands of Landsat obtained in 2015, 2017, and 2018 respectively. In conclusion, remote sensing and GIS technologies coupled with spectral modeling are useful tools for providing a solution of future water resources planning and management, and also offer great undertaking as a means to improve knowledge of water quality and support water decision making.

Short-rotation tree forests are irrigated with landfill leachate to reduce both leachate volume and nutrient content. It is of interest both for leachate treatment and energy recovery to optimise the productivity of such plantations. This study's aim was to investigate the effects of irrigation on soil quality, tree growth and on emissions of landfill gas (LFG) produced in the wastes. Soils irrigated with leachate had a higher average nutrient and organic matter contents, and a lower dry solids content. Larger trees occur on plots irrigated with leachate, presumably due to the positive effect of water and nutrient supply. The willows used in this experiment seemed to be tolerant of high carbon dioxide concentrations, as no statistically effect arising from LFG emissions could be linked to tree growth. Methane oxidation levels between 50 and 950 mol m(-2) yr(-1) were observed. The positive correlation between soil methane oxidation capacity and tree presence is an interesting perspective on reduction of methane emissions by landfill's top cover vegetation type. Optimising methane oxidation using vegetation as a 'cover crop' could reduce the amount of methane discharged into the atmosphere.

Accumulations of mass loads of selected chemicals in roadside snowbanks were studied at five sites with various traffic densities in the City of Trondheim (Norway) by collecting snow samples throughout the winter period and analysing them for 13 water quality constituents: pH, EC, alkalinity, Cl, Na, TSS, Cd, Cr, Cu. Ni, Pb, W, and Zn. The resulting dataset was then supplemented by similar data collected earlier in the City of Luleå (Sweden). Regression analyses for individual sites indicated linear trends in unit-area constituent accumulations with time (0.65<R2<0.95) and supported the assumption of linearity in further analyses. Principal Component Analysis (PCA) of the combined Luleå/Trondheim data revealed cause-effect relationships between the chemical mass loadings (TSS and trace metals) and three predictors: snow age (SRT = snow residence time), traffic density (AADT = annual average density of traffic), and cumulative traffic volume (CTV = SRT • AADT). Cl and Na loads, originating from road salt applications in Trondheim only, did not display this trend. Two types of parsimonious models for predicting trace metal accumulations in winter-long roadside snowbanks were developed: (a) a linear regression model using CTV as a single predictor and predicting metal accumulations with a moderate certainty (0.37< R2<0.66), and (b) multiple regression models using SRT, AADT and SWE as predictors. The latter models indicated good correlations between the mass loads and the predictors (0.64<R2< 0.77) and produced slightly better prediction accuracies (0.44< R2 < 0.67) than the simpler model.

A bioretention media is a stormwater treatment option designed to reduce peak runoff volumes and improve water quality through soil infiltration and plant mitigation. To investigate the heavy metal removal in a bioretention media in a cold climate setting, a small pilot sized bioretention box was built in Trondheim, Norway. The system was sized using the Prince Georges County bioretention design method from 1993. Three runoff events, created using historical data, were undertaken in April 2005 and then again in August 2005. Both the peak flow reduction and the total volume reduction were significantly lower in April compared to August. Peak flow reduction was 13% in April versus 26% in August and the total volume reduction was 13% in April versus 25% in August. Metal retention was good for both seasons with 90% mass reduction of zinc, 82% mass reduction of lead and 72% mass reduction of copper. Plant uptake of metals was documented between 2 to 7%; however adsorption and mechanical filtration through the mulch and soil column were the most dominant metal retention processes. The metal retention was independent of the selected hydraulic loading rates (equivalent to 1.4–7.5 mm h−1 precipitation) showing that variable inflow rates during this set of events did not affect the treatment efficiency of the system.

Using a safe and easy-to-apply economicfocculant to replace alum is necessary to expandand enhance the water quality in rural regions wheretraditional water treatment is unavailable. The seedof Moringa oleifera is locally available in large volumes and is feasibly economical. A compatibility andapplicability research of the easily accessible localMoringa oleifera seed extract (MOSE) was conductedto examine its potential utilization to lessen variousdegrees of water turbidity at 30±2 °C. The studyconcerns the optimum dosage of MOSE to give highturbidity removal efciency in the water. Experimentswere carried out for nine turbidity samples: 5, 10,15, 30, 50, 70, 100, 200, and 300 NTU. The turbidityremoval efciency of up to 89% was achieved for highinitial turbid water 300 NTU. However, for low turbidwater, its potential efciency declined. The resultsdemonstrate that the de-oiled extract is substantiallymore efcient than the crude extract in agglomerating colloidal particles of low initial turbidity samplesand achieved up to 76% removal rate. The results ofthe ANOVA confrmed that the regression model wassignifcant at (p<0.05) for residual turbidity afterthe treatment process. The study also demonstratesthat a pseudo-frst-order kinetic model matched wellthe nature of the removal of colloidal particles withMOSE in water to form focs. The study also indicatesthat the characteristics of water treated with crudeMOSE produce little change in electrical conductivityand salinity. However, the hardness and alkalinity ofwater decreased signifcantly depending on the initialhardness and the amount of MOSE applied (p<0.05).

Evolving groundwater vulnerability from DRASTIC to modified DRASTIC methods helps choose the most accurate areas that are most delicate toward pollution. This study aims to modify DRASTIC with land use and water quality index for groundwater vulnerability assessment in the Halabja-Khurmal sub-basin, NE/Iraq. The Halabja-Khurmal sub-basin groundwater vulnerability index is calculated from nine hydrogeological parameters by the overlay weighting method. As a result, 1.3% of the total area has a very high vulnerability value and 46.1% with high vulnerability. The regions with high groundwater vulnerability have a high-water table and groundwater recharge. Nitrate concentration was used to validate the result, and the Pearson correlation and recession analysis between the modified DRASTIC index and nitrate concentration depicted a strong relation with 0.76 and 0.7, respectively.

In municipal planning of locations of snow deposits and investigations of the environmental effects of snow dumping, the partitioning of contaminants between particulate and dissolved matter is of great importance. This paper compares snow quality in two Swedish municipalities - Luleå and Sundsvall over time. The two municipalities have differences in used de-icing material and winter conditions. Because Luleå has a longer winter season and a lower average temperature, higher accumulations of chemicals were found in Luleå than in Sundsvall. A multiple regression analysis indicated relationships between the dissolved fraction of heavy metals and the concentration of suspended solids and chloride.

Sediment and porewater samples from an enclosed bay receiving stormwater discharge (Skutviken) near the centre of Luleå, northern Sweden were analysed for major and trace elements and 16 polycyclic aromatic hydrocarbons (PAHs). Among the studied metals Cd, Cu, Pb and Zn were enriched at Skutviken. Also, the PAH content was enriched, in particular for phenantrene, anthracene, fluoranthene and pyrene which are regarded as common constituents in stormwater. The use of trace metal ratios provided indications about pollutant sources for the sediment. Cs-137 dating was used to determine historical changes in metal and PAH fixation in the sediment. The bay Skutviken is enclosed through the construction of a road bank since 1962. The enclosure led to reduced water circulation in the bay that promotes the occurrence of anoxic conditions with sulphate reduction within the bay. As a consequence of these conditions, metals are trapped in the sediments as sulphides. This study suggests that enclosed bays with restricted water circulation may be efficient traps for urban pollutants, reducing the present-day input of pollutants to the sea. In areas with postglacial land uplift, where such bays are common, bay sediments are a potential future source of pollutants when uplift results in erosion and oxidation of the sedi

Osmium tetroxide (OsO4) is one of the most toxic air contaminants but its environmental effects are poorly understood. Here, for the first time, we present evidence of osmium uptake in a common herbivore (bank vole, Myodes glareolus) in boreal forests of northern Sweden. Voles (n = 22) and fruticose arboreal pendular lichens, the potential main winter food source of the vole, were collected along a spatial gradient to the west of a steelwork in Tornio, Finland at the Finnish-Swedish border. 187Os/188Os isotope ratios increased and osmium concentrations decreased in lichens and voles along the gradient. Osmium concentrations in lichens were 10,000-fold higher than those in voles. Closest to the steelwork, concentrations were highest in kidneys rather than skin/fur that are directly exposed to airborne OsO4. The kidney-to-body weight ratio was higher at the two localities close to the steelwork. Even though based on a small sample size, our results for the first time demonstrate that osmium is taken up, partitioned, and accumulated in mammal tissue, and indicate that high kidney-to-body weight ratios might be induced by anthropogenic osmium.

To prevent deterioration of receiving water bodies, phosphorus and total suspended solid (TSS) removal from stormwater is commonly targeted, e.g., by bioretention. However, their removal may vary due to ambient conditions and design features. In this study, the effect of a submerged zone with embedded carbon source (SZC), temperature, and (road) salt on phosphorus removal was investigated using a two-level full factorial design. A sand-based filter material was used. Overall, phosphorus and TSS removal percentages were high. Higher temperature (4.6 vs. 17.1 °C) caused higher outflow concentrations, thus lowering removal rates. The presence of salt deteriorated total phosphorus removal, whereas dissolved phosphorus removal was not affected. The impact of the SZC was statistically significant but not regarded to be of practical significance for P removal. In contrast, TSS removal was enhanced by a SZC. The results demonstrated that a relatively simple filter material could provide excellent P removal, avoiding the need for additives suggested in other studies.

Laboratory snow melting experiments were conducted with actual late-winter snow samples, collected just before the final snowmelt, in two similar northern Swedish cities, Luleå and Umeå, to investigate releases of the selected heavy metals (HM) (Cu, Pb, Zn, and Cd) and 16 USEPA PAHs from melting snow. Metal concentrations were determined in three fractions: total, dissolved, and truly dissolved (defined as the fraction passing through a 3-kMWCO ultrafilter). Total HM concentrations in snowmelt were rather high at both sites and reflected the accumulation of pollutants in the roadside snowbanks over a period of about 5 months: Cd = 0.43, Cu = 303, Pb = 41.9, Zn = 817 (μg/l), and TSS = 2000 (mg/l) in Luleå samples and Cd = 1.87, Cu = 905, Pb = 165, Zn = 3150 (μg/l), and TSS = 4800 (mg/l) in Umeå samples. The difference between metal and TSS concentrations at the two sites of similar characteristics was attributed to a smaller volume snowbank in Umeå. The dissolved HM concentrations represented relatively small fractions of the total concentrations (0.3–6.9% in Luleå and 0.01–3.1% in Umeå). The truly dissolved fraction represented 71–90% of the dissolved fraction in Luleå and 74–98% in Umeå. At both sites, the dissolved fractions exhibited preferential elution from the laboratory snow piles. The PAHs studied (16 US EPA PAHs) were mostly particulate bound, with only 5–12% of the total burden contributed by the meltwater, and most dissolved concentrations below the reporting limits. PAH concentrations in the Luleå samples were about one-third to one-fourth of those in Umeå. In general, the releases of PAHs from the snowbank were delayed, compared with releases of meltwater, and showed similar release patterns as TSS.

Choosing the appropriate sampling strategy is significant while estimating the pollutant loads in a snow pile and assessing environmental impacts of dumping snow into water bodies. This paper compares different snow pile sampling strategies, looking for the most efficient way to estimate the pollutant loads in a snow pile. For this purpose, 177 snow samples were collected from nine snow piles (average pile area − 30 m², height − 2 m) during four sampling occasions at Frihamnen, Ports of Stockholm’s port area. The measured concentrations of TSS, LOI, pH, conductivity, and heavy metals (Zn, Cu, Cd, Cr, Pb, and V) in the collected samples indicated that pollutants are not uniformly distributed in the snow piles. Pollutant loads calculated from different sampling strategies were compared against the load calculated using all samples collected for each pile (best estimate of mass load, BEML). The results/study showed that systematic grid sampling is the best choice when the objective of sampling is to estimate the pollutant loads accurately. Estimating pollutant loads from single snow column samples (collected at a point from the snow pile through the entire depth of the pile) produced up to 400% variation from BEML, whereas samples composed by mixing volume-proportional subsamples from all samples (horizontal composite samples) produced only up to 50% variation. Around nine samples were required to estimate the pollutant loads within 50% deviation from BEML for the studied snow piles. Converting pollutant concentrations in snow to equivalent concentrations in snowmelt and comparing it with available guideline values for receiving water, Zn was identified as the critical pollutant.

The aim of the study was to investigate how the quality of snow varies within a city. The study area is situated in the Luleå municipality, in northern Sweden (lat. 65°35'N and long. 22°10'E). For this study, the city was divided into three different types of areas: housing areas, city centre and outskirts. In one area of each type, sampling sites were selected. Snow samples were taken at nine occasions, once every fourteenth day in the city centre and in the housing area. Analyses were carried out for pH, conductivity, suspended solids and both the total and dissolved concentration of phosphorus and selected metals. It was concluded that traffic or activities related to traffic were a major source of heavy metals and phosphorus in urban snow, both in the city centre and in the housing area. Also, the type of area and the design of the street were important for the quality of snow. A clear relation was found between the pH and the quantity of suspended solids in the snow. Higher pH values were found in snow samples from sites with higher traffic loads, and lower pH values at sites, which were the no-traffic sites, with small quantities of particles. The particulate and dissolved substances in the snow behaved in different ways.

Cover systems can efficiently limit acid mine drainage generation from sulfidic mine wastes by controlling oxygen diffusion. Their performance relies on their high degree of saturation, as oxygen diffusion is substantially reduced in water or saturated medium. However, natural soils available in the mine vicinities do not necessarily have the hydrogeological properties required for the construction of sealing layers. A common strategy is to improve the characteristics of local soils using bentonite amendment, but this usually induces high costs and environmental footprint. An alternative is to reuse (or valorise) waste materials, such as mine wastes or industrial wastes like green liquor dregs (GLD). Blends of till and GLD can have advantageous properties regarding water retention capacity and hydraulic conductivity. In this study, the effective oxygen diffusion coefficient De of till-GLD blends was evaluated using 81 diffusion tests. Various quantities and different types of GLD were tested. The diffusion coefficient was found to vary greatly depending on the degree of saturation. Even though the GLD contained naturally a substantial amount of water, a high water content of the till was still required to reach a low De. Measurements were also compared with modified Millington-Shearer predictive model which could generally predict the diffusion coefficient within an acceptable range. Results also indicated that the till-GLD mixes should not be exposed to evaporation as significant performance loss may rapidly occur upon drying. Main experimental results are presented in this paper together with recommendations in terms of cover design using till-GLD mixes.

Composting municipal wastewater sludge may generate composting wastewater (acid washer water and tunnel wastewater) with high ammonium-nitrogen (NH 4-N) concentration; this kind of wastewater is usually generated in a rather small daily amount. A procedure of air stripping with catalytic oxidation was developed and tested with pilot-scale and full-scale units for synthetic disposal of the high NH4-N wastewaters from composting facilities. In air stripping, around 90% NH4-N removal efficiency was reliably achieved with a maximum of 98%. A model to describe the stripping process efficiency was constructed, which can be used for process optimization. After catalytic oxidation, the concentrations in the outlet gas were acceptable for NH3, NOX, NO2, and N2O, but the NH3 and N2O concentrations limited the feasible loading range. The treatment costs were estimated in detail. The results indicate that air stripping with the catalytic oxidation process can be applied for wastewater treatment in composting facilities

In the beginning of March 2006, polluted snow from a roadside in Luleå, in the north of Sweden, with a traffic intensity of approximately 7,400 vehicles per day, was collected. The snow was homogenously mixed and divided into samples of 30 litres. The initial volumes and densities of the snow samples were measured and calculated. The snow samples were melted in climate rooms, with four different experimental configurations, to investigate the influence of road salt, temperature, and surface slope upon the transport of total suspended solids (TSS) (three replicates for each experimental configuration). The total volume of snowmelt runoff was collected and analysed for pH, conductivity, and concentrations of TSS and chlorides. The results showed that measured concentrations, calculated mass loads, and performed statistical t-tests of TSS for the snowmelt of the four different configurations implied that the transported mass load of TSS was higher with the addition of road salt and at higher ambient temperatures. However, the results showed a lower mass load of transported TSS for the lower slope.