Water Pollution and Groundwater Quality improvement

Hydrological and Water Quality Characterisation of a Tropical Riverine Wetland: Nabajjuzi-Masaka, Uganda

by Najib Lukooya Bateganya

Abstract
In East Africa where wetlands are becoming essential systems for waste water treatment and potable... more Abstract
In East Africa where wetlands are becoming essential systems for waste water treatment and potable water supply, hydrological characterisation is crucial to understand the dynamics of their functioning on a spatial and temporal scale. Beside ecosystem services, basic ecological properties such as vegetation structure and nutrient cycling of wetland ecosystems depend on hydrology. Nabajjuzi wetland, in central Uganda, East Africa is internationally recognised as a Ramsar site and currently used for potable water supply in addition to other essential ecological and social economic services to the riparian communities. To contribute to the limited and scanty information of this ecosystem, the study focussed on hydrological and water quality characterisation using a water-nutrient mass balance as the major output. Also, the flow dynamics of Fe and allochthonous suspended solids loading into the wetland were investigated.

Results show that the water balance of Nabajjuzi wetland is dominated by surface flow, which is influenced by rainy and dry periods. During peak flow, the estimated hydraulic retention time was found to be 1 month compared to 1.5 months during the low flow period. Also, water loss flux due to evapotranspiration in this region is high and in Nabajjuzi wetland, it is twice the daily rate of abstraction. Analysis of long term flow data also revealed that the current water abstraction rate can potentially result in hydrological stress to the system during extremely low flow periods. However, the wetland N and P loading is very low compared to other urban disturbed wetlands. Consequently, high concentration of Fe and suspended solids loading are the major constraints to the surface water quality hence potable water supply. Generally, there is need for a more comprehensive hydrological-water quality study and careful planning of the future catchment land use strategies. This can enhance management and conservation of the wetland to guarantee the crucial ecosystem services it provides.

Keywords: Hydrology, Riverine wetland, Hydrological gradient, Surface-flow, Nutrients, Iron, Mass-balance, Lake Victoria basin.

The influence of plants on nitrogen removal from landfill leachate in discontinuous batch shallow constructed wetland with recirculating subsurface horizontal flow

by Antonio Albuquerque

A. Białowiec, L. Davies, A. Albuquerque, P. Randerson
Ecological Engineering, 2012, V. 40, 44-52

Three discontinuous batch shallow constructed wetland systems with recirculating subsurface horizontal flow with reed,... more Three discontinuous batch shallow constructed wetland systems with recirculating subsurface horizontal flow with reed, willow, and without plants were used to assess the removal of nitrogen from landfill leachate in relation to hydraulic retention time and climatic conditions. In all systems redox potential in the beds increased asymptotically from negative anoxic conditions to +67 (reed bed), −2 (willow bed), and +17 mV (control bed), reaching a plateau in two wk. During the first 24 h after feeding the beds all forms of nitrogen decreased significantly. It has been shown that plants release O2 and Norg which was then hydrolyzed to ammonia. Plant-available radiation significantly (p < 0.05) increased the release of Norg and removal of ammonia after the 9th day of the experiment. Low, and relatively constant concentrations of nitrite and nitrate indicated that denitrification had taken place in the beds.

Influence of stormwater infiltration on the treatment capacity of a LECA-based horizontal subsurface flow constructed wetland

by Antonio Albuquerque

L. Amado, A. Albuquerque, A. Espirito Santo
Ecological Engineering, 2012, V. 39, 16-23.

This research work evaluates the impact of stormwater infiltration on the removal of organics, solids, nitrogen and... more This research work evaluates the impact of stormwater infiltration on the removal of organics, solids, nitrogen and phosphorus in a LECA-based horizontal subsurface flow constructed wetland. Stormwater runoff for the period between January 2008 and June 2010 (30 months) was estimated for the drainage basin of the Vila Fernando wastewater treatment plant (constructed wetland system) and it was observed proportionality between the increase in surface runoff and the infiltration flow rate that reached the plant. The average stormwater infiltration rate that reached the plant was 67.4 m(3) d(-1) (77% of the influent flow rate into the plant). The 30 month monitoring campaign set up at one of the reed beds showed that stormwater infiltration led to a high variation of the hydraulic loading rate (HLR) throughout the bed, which affected its performance in the removal of organic matter, suspended solids and nitrogen. For a HLR below 20 cm d-1 the removal efficiencies for BOD5, COD and TSS doubled. The removal of nitrogen was too low and was associated with the weak development of nitrifying biofilm and the poor growth of reeds. However, it was observed a good relationship between the applied and removed loads for most of the parameters, which seems to indicate that the organic, solid, nitrogen and phosphorus loading rates influenced the respective removal rates. The use of a bed material with high specific surface area, such as LECA, can only improve the treatment capacity of horizontal subsurface flow systems if the organic and solid loading rates, as well as the HLR, can be effectively controlled.

Speciation of Arsenic, Chromium, and Vanadium in Red Mud Samples from the Ajka Spill Site, Hungary

by William Mayes

Burke, I.T., Mayes, W.M., Peacock, C.L., Brown, A.P., Jarvis, A.P., Gruiz, K. (2012) Speciation of arsenic, chromium and vanadium in red mud samples from the Ajka spill site, Hungary. Environmental Science and Technology. doi: 10.1021/es3003475.

Results are presented from X-ray absorption spectroscopy based analysis of As, Cr and V speciation within samples of... more Results are presented from X-ray absorption spectroscopy based analysis of As, Cr and V speciation within samples of bauxite ore processing residue (red mud) collected from the spill site at Ajka, Western Hungary. Cr K-edge XANES analysis found that Cr is present as Cr3+ substituted into hematite, consistent with TEM analysis. V K-edge XANES spectra have E½ position and pre-edge features consistent with the presence of V5+ species, possibly associated with Ca-aluminosilicate phases. As K-edge XANES spectra identified As present as As5+. EXAFS analysis reveals arsenate phases in red mud samples. When alkaline leachate from the spill site is neutralised with HCl, 94 % As and 71 % V is removed from solution during the formation of amorphous Al-oxyhydroxide. EXAFS analysis of As in this precipitate reveals the presence of arsenate Al-oxyhydroxide surface complexes. These results suggest that in the circumneutral pH, oxic conditions found in the Torna and Upper Marcal catchments, incorporation and sorption respectively will restrict the environmental mobility of Cr and As. V is inefficiently removed from solution by neutralisation, therefore, the red mud may act as a source of mobile V5+ where the red mud deposits are not removed from affected land.

PATCH DYNAMICS OF HYDROLOGICALLY DISTINCT REFUGIA: RECOLONIZATION OF BENTHIC MACROINVERTEBRATES AFTER A RECORD DROUGHT IN A SPRING-FED SEMI-ARID LANDSCAPE

by Rosemary Burk

Published online at: https://www.benthos.org/Other-Publications/NABStracts/2010/7389.aspx

Authors: Burk, Rosemary A. and J. H. Kennedy

This study examines the role of spring-fed refugia during a supraseasonal drought and recolonization of benthic... more This study examines the role of spring-fed refugia during a supraseasonal drought and recolonization of benthic macroinveretebrates in Ash and Silver Creeks (Parker County: TX) over eighteen months. Ash Creek maintained flow for 2.0 km in contrast to other regional streams with minimal surface water and no flow. Recolonization at a downstream intermittent site was slow, compared to rates reported for other prairie streams, with taxonomic richness approaching the headwater site’s eight months post flow. Riffles, perennial and shaded disconnected pools were refugia for drought-sensitive aquatic insects and taxonomic richness by macrohabitat type was significantly different (ANOVA, F3,44=27.34, p<0.0001). SNK analysis demonstrated preferential invertebrate use of refugia grouping macrohabitats as: Riffles>Perennial pools = Shaded disconnected pools > Full sun disconnected pools. Rare relict taxa with low resilience, such as Lutrochus sp., Mayatrichia sp., and Neotrichia sp., would likely be displaced without lotic refugia. Conservation of groundwater is critical to preserving a spatial and temporal patchwork of refugia for benthic invertebrates that increases these variable ecosystems resilience to disturbances and is thought to maintain regional species diversity.

Democracy by Proxy: Environmental NGOs and Policy Change in Mexico

by Raul Pacheco-Vega

Characterising infiltration and contaminant migration beneath earthen-lined integrated constructed wetlands

by Mawuli Dzakpasu

Mawuli Dzakpasu, Miklas Scholz, Rory Harrington, Siobhán N. Jordan, Valerie McCarthy
Ecological Engineering 41 (2012) 41– 51. doi:10.1016/j.ecoleng.2012.01.010

Abstract
The concept of integrated constructed wetlands (ICW) uses in situ soils to construct and line their... more Abstract
The concept of integrated constructed wetlands (ICW) uses in situ soils to construct and line their cells. The integrity of soil materials, however, may provide a potential pathway for contaminants to flow into the subsoil. In this study, the rates of infiltration and contaminants loading occurring beneath a full-scale ICW treating domestic wastewater were evaluated over an 18-month period. The ICW is located at Glaslough in Co. Monaghan, Ireland. It consists of two sludge cells and a sequence of five shallow vegetated wetland cells. The ICW cells were lined with 500 mm thick local subsoil materials. Infiltration water was collected from zero-tension pan lysimeters, which were placed within the soil-liners of the first three ICW cells and analysed for water quality parameters such as chemical oxygen demand, ammonia-nitrogen, nitrate-nitrogen, and molybdate reactive phosphate. Infiltration rates were 4.3 × 10−9, 3.7 × 10−9 and 1.0 × 10−8 m s−1 from the first three ICW cells. The variation among locations was small. The apparent hydraulic conductivity of the soil liner, calculated with empirical water budgets, ranged between 3.5 × 10−9 and 9.8 × 10−9 m s−1across the cells. In the first two cells of the ICW, less than 0.5% of the influent contaminant loading to the cells was lost through infiltration to subsoil. Overall, the amount of infiltration and contaminant loading occurring beneath the ICW cells increased from the proximal cells to the distal one. Higher contaminant loading was recorded in the third cell, which received partially treated wastewater. This implies that each ICW cell has the potential to impact differently on the underlying groundwater and that the potential for groundwater contamination from ICW systems was minimal in the first ICW cells, when compared to the last one.

Fluoride in Groundwater: Causes, Implications and Mitigation Measures

by Elango L

Brindha, K. and Elango, L. (2011) Fluoride in Groundwater: Causes, Implications and Mitigation Measures. In:  Monroy, S.D. (Ed.), Fluoride Properties, Applications and Environmental Management, 111-136.

Groundwater flow and radionuclide decay-chain transport modelling around a proposed uranium tailings pond in India

by Elango L

L. Elango, K. Brindha, L. Kalpana, Faby Sunny, R. N. Nair and R. Murugan
Hydrogeology Journal
DOI: 10.1007/s10040-012-0834-6

Extensive hydrogeological investigations followed by three-dimensional groundwater flow and contaminant transport... more Extensive hydrogeological investigations followed by three-dimensional groundwater flow and contaminant transport modelling were carried out around a proposed uranium tailings pond at Seripalli in Andhra Pradesh, India, to estimate its radiological impact. The hydrogeological parameters and measured groundwater level were used to model the groundwater flow and contaminant transport from the uranium tailings pond using a finite-element-based model. The simulated groundwater level compares reasonably with the observed groundwater level. Subsequently, the transport of long-lived radionuclides such as 238U, 234U, 230Th and 226Ra from the proposed tailings pond was modelled. The ingrowths of progenies were also considered in the modelling. It was observed that these radionuclides move very little from the tailings pond, even at the end of 10,000 y, due to their high distribution coefficients and low groundwater velocities. These concentrations were translated into committed effective dose rates at different distances in the vicinity of the uranium tailings pond. The results indicated that the highest effective dose rate to members of the public along the groundwater flow pathway is 2.5 times lower than the drinking water guideline of 0.1 mSv/y, even after a long time period of 10,000 y.

Impact of tanning industries on groundwater quality near a metropolitan city in India

by Elango L

K. Brindha and L. Elango (2012)
Water Resources Management
DOI: 10.1007/s11269-012-9985-4

The contribution of trophic position to mercury content of pike (Esox lucius) in small boreal lakes.

by Jonathan Grey

Verh Int Verein Limnol 2006

The utility of carbon and nitrogen isotope analyses to trace contributions from fish farms to the receiving communities of freshwater lakes: a pilot study in Esthwaite …

by Jonathan Grey

Hydrobiologia 2004

A pilot study was conducted to assess the potential for stable isotope analyses to reveal the fate of waste pelleted... more A pilot study was conducted to assess the potential for stable isotope analyses to reveal the fate of waste pelleted food material from fish farms in freshwater food webs. Esthwaite Water (Cumbria, UK) was selected as the study site, as it hosts an established salmonid farm, and a wealth of complementary limnological data exists. Salmonid pellet feed consists of primarily marine-derived material and thus exhibits carbon and
nitrogen stable isotopic compositions distinct to most freshwater organic material. Comparison of the isotopic ratios of organisms at the cage site with an unaffected control site, supports incorporation of pelletderived material to the diet of planktonic and benthic communities.Moreover, after allowing for a number of
trophic transfers, stable isotope analyses revealed the predatory cladoceran Leptodora kindti also utilised pellet material, while roach were probably short-circuiting the food chain by directly consuming particulate pellet material, as well as via ingestion of their zooplankton prey. Isotope data substituted into a simple twosource mixing model suggested that approximately 65% of Daphnia, and >80%of roach body carbon may be derived from pellet material in the plankton, and that chironomid larvae may incorporate >50% in the sediment environs. However, contributions calculated from both d13C and d15N values were inconsistent, which may simply be due to the constraints of the model and parameters used, but may also reflect different
routing of isotopes from the original pellet source, via soluble or particulate routes.

Contaminant mobility and carbon sequestration downstream of the Ajka (Hungary) red mud spill: The effects of gypsum dosing

by William Mayes

Science of the Total Environment

A number of emergency pollution management measures were enacted after the accidental release of caustic bauxite... more A number of emergency pollution management measures were enacted after the accidental release of caustic bauxite processing residue that occurred in Ajka, western Hungary in October, 2010. These centred on acid and gypsum dosing to reduce pH and minimise mobility of oxyanion contaminants mobile at high pH. This study assessed the effectiveness of gypsum dosing on contaminant mobility and carbon sequestration through assessment of red mud and gypsum-affected fluvial sediments via elemental analysis and stable isotope analysis. There was a modest uptake of contaminants (notably As, Cr, and Mn) on secondary carbonate-dominated deposits in reaches subjected to gypsum dosing. C and O stable isotope ratios of carbonate precipitates formed as a result of gypsum dosing were used to quantify the importance of the neutralisation process in sequestering atmospheric carbon dioxide. This process was particularly pronounced at sites most affected by gypsum addition, where up to 36% of carbonate-C appears to be derived from atmospheric in-gassing of CO2. The site is discussed as a large scale analogue for potential remedial approaches and carbon sequestration technologies that could be applied to red mud slurries and other hyperalkaline wastes. The results of this work have substantial implications for the aluminium production industry in which 3–4% of the direct CO2 emissions may be offset by carbonate precipitation. Furthermore, carbonation by gypsum addition may be important for contaminant remediation, also providing a physical stabilisation strategy for the numerous historic stockpiles of red mud.

Flow pattern and hydraulic performance of the REDAC Gross Pollutant Trap

by Aminuddin Ab Ghani

Ab. Ghani, A. , Azamathulla, H. Md., Lau, T.L., Ravikanth, CH., Zakaria, N.A. Leow, C.S. & Mohd Yusof, M.A. (2011). Flow Pattern and Hydraulic Performance of the REDAC Gross Pollutant Trap, Journal of Flow Measurement and Instrumentation, Vol. 22, No. 3, pp. 215-224, ISSN 0955-5986

This paper discusses the flow pattern and hydraulic performance of a Gross Pollutant Trap (GPT), designed and patented... more This paper discusses the flow pattern and hydraulic performance of a Gross Pollutant Trap (GPT), designed and patented by River Engineering and Drainage Research Centre (REDAC) at Universiti Sains Malaysia. Stormwater problems have become more severe due to the increase in urbanization. The increase in the amount of impervious surface in urban areas produces more stormwater runoff, that is carried to the receiving bodies of water. The higher runoff volume also carries more pollutants (gross pollutants, sediments, and nutrients) from the contributing catchment area. Coarse sediments transported by stormwater runoff have negative effects on the receiving body of water and the aquatic environment by covering up aquatic habitats and clogging waterways. One of the challenges in designing a GPT for urban stormwater drainage is providing effective trapping without hindering the hydraulic function of the channel, thus, avoiding overspill or flooding. The current study presents a GPT design to meet these specific requirements of trapping efficiency and hydraulic function. The current GPT overcame the common problem of overspilling of gross pollutants in GPT by the introduction of additional overspill compartments that can handle excessive runoff and improve pollutant trapping in higher flow conditions. In laboratory testing, the prototype GPT was capable of achieving good trapping efficiency (over 80% for gross pollutants and over 60% for coarse sediments) without causing any overspill.

The impact of pumped water from a de-watered Magnesian limestone quarry on an adjacent wetland: Thrislington, County Durham, UK

by William Mayes

Environmental Pollution

Although quarrying is often cited as a potential threat to wetland systems, there is a lack of relevant, quantitative... more Although quarrying is often cited as a potential threat to wetland systems, there is a lack of relevant, quantitative case studies in the literature. The impact of pumped groundwater discharged from a quarry into a wetland area was assessed relative to reference conditions in an adjacent fen wetland that receives only natural runoff. Analysis of vegetation patterns at the quarry wetland site, using Detrended Correspondence Analysis and the species indicator values of Ellenberg, revealed a clear disparity between community transitions in the quarry wetland and the reference site. Limited establishment of moisture-sensitive taxa, the preferential proliferation of robust wetland species and an overall shift towards lower species diversity in the quarry wetland were explicable primarily by the physico-chemical environment created by quarry dewatering. This encompassed high pH (up to 12.8), sediment-rich effluent creating a nutrient-poor substrate with poor moisture retention in the quarry wetland, and large fluctuations in water levels.

Hydrogeochemistry of alkaline steel slag leachates in the UK

by William Mayes

Water, Air & Soil Pollution

Drainage from steel slag disposal sites can be extremely alkaline and a source of pollution to surface and ground... more Drainage from steel slag disposal sites can be extremely alkaline and a source of pollution to surface and ground waters. Data is presented detailing the hydrogeochemistry of seven highly alkaline (pH > 10) steel slag surface discharges in the UK. While there is the consistent presence of Ca–OH type groundwater in all the discharges, there are clear disparities in hydrochemical facies within and between sites, reflecting native hydrochemistry, source material and hydrogeological setting. The longevity of the pollution problem from steel slag disposal sites is highlighted at one site where the water quality records date back three decades. The consistent presence of Al, B, Ba, Fe, Sr, V and occasional presence of Cr, Mo, Ni, Pb were found at concentrations typically below surface water quality standards in the leachates. Some of the monitored metals (Al, Fe, Ni, V) were found to be lost from solution downstream of emergence in calcite-dominated precipitates which rapidly form at all sites at rates up to 100 g m−2 day−1. The low concentrations of potentially problematic trace elements in both solution and the sediments are discussed with regard development of economically viable passive treatment wetlands for highly alkaline industrial discharges.

A national strategy for identification, prioritisation and management of pollution from abandoned non-coal mine sites in England and Wales. I.:: Methodology …

by William Mayes

Science of the Total Environment

In regions affected by historic non-coal (principally metal) mining activity, government agencies are often faced with... more In regions affected by historic non-coal (principally metal) mining activity, government agencies are often faced with the challenge of deploying limited remedial resources at abandoned mine sites to achieve maximum improvements in the chemical and ecological quality of impacted ground and surface waters. As such, strategies for the defensible allocation of public funds require comprehensive and systematic frameworks by which to identify and prioritise polluting sites for remediation. This paper describes the development and initial findings of such a national initiative in England and Wales which allies catchment-scale environmental impact assessments using existing public archive data, with recognition of the uncertainty in impact appraisals arising from disparities in data availability between sites and regions. The methodology identifies polluting sites and takes account not only of the chemical and ecological impacts of mine water discharges on receiving watercourses, but also of socio-economic factors such as conservation and heritage concerns, which can both impede or complement efforts to remediate mine sites. Using a Geographic Information System database and a suite of spatial analyses employing Boolean operators, both the extent of the pollution problem from abandoned non-coal mines in England and Wales (6% of 7815 surface water bodies are affected nationally) and the insight that can be gleaned from systematic analyses of existing archive data are highlighted. The results of the nationwide survey can be used as a dynamic database to inform future remedial planning, in terms of prioritising impacted river basins and abandoned non-coal mine sites themselves for either remediation or future monitoring efforts. As the assessment framework is built upon existing water quality and ecological data and mine site/geological data, there is considerable scope for the approach to be applied elsewhere where the legacy of historic mining persists through the widespread pollution of the aquatic environment.

Heavy metal pollution recorded in Porites corals from Daya Bay, northern South China Sea

by Gilbert Price

Chen, T.-R., Yu, K.-F., Li, S., Price, G.J., Shi, Q., Wei, G.-J., 2010. Heavy metal pollution recorded in Porites corals from Daya Bay, northern South China Sea. Marine Environmental Research 70, 318-326.

We examined metal-to-calcium ratios (Fe/Ca, Mn/Ca and Zn/Ca) in the growth bands of two Porites corals from Daya Bay,... more We examined metal-to-calcium ratios (Fe/Ca, Mn/Ca and Zn/Ca) in the growth bands of two Porites corals from Daya Bay, South China Sea, in order to trace long-term trends in local ambient pollution levels. Although Fe and Mn did not show any obvious increasing trends over 32 years in the period 1976–2007, peak values of Fe/Ca and Mn/Ca occurred in the mid-late 1980s, temporally-coeval with the local construction of a nuclear power station. Furthermore, both corals showed rapid increases in Zn concentrations over the past 14 years (1994–2007), most likely due to increases in domestic and industrial sewage discharge. The Daya Bay corals had higher concentrations of metals than other reported corals from both pristine and seriously polluted locations, suggesting that acute (Fe and Mn) and chronic (Zn) heavy metal contamination has occurred locally over the past 32 years.

River Pollution in China and America: Problems, Solutions, and the Future

by Michelle Barrett

In the midst of being submitted as part of my academic work for the Master of Arts degree at Central Michigan University (in lieu of a thesis).

Estudio ecológico comparativo de la fauna macroentónica de las bahías de Guaymas y Bacochibampo, Sonora, Mexico

by Ernesto Marin

En proceso de ser digitalizado.
Este estudio se realizo en 1970-1971 como parte del requisito para el Titulo de Ingeniero Bioquímico, con especialidad en Ciencias marítimas y Tecnología de Alimentos, del ITESM, Unidad Guaymas, Sonora, México.
Se estudia la fauna a nivel de genero, y se analizan los ecotopos y ecotipos, así como la diferencia de los ecosistemas de ambas bahías. En esa fecha se encontro un alto nivel de contaminación de agua en la bahía de Guaymas, que según obsevamos hasta hace unos meses se ha revertido el proceso.