Phosphorus removal from irrigation return flow using an iron oxide filter and denitrifying pine bark bioreactor treatment train.

Development of low-cost aqueous P removal methods is imperative for water resource protection. This study assessed the contribution of an iron oxide (FeOx) filter for P sorption paired with a denitrifying pine bark bioreactor, quantifying the effect of treatment order on P removal. FeOx filters were placed upstream (order 1) or downstream (order 2) of pine bark bioreactors receiving a continuous flow of simulated irrigation return flow after constructed floating wetland treatment.

Continuous co-treatment of mine drainage with municipal wastewater.

Acid mine drainage (AMD) and municipal wastewater (MWW) are commonly co-occurring waste streams in mining regions. Co-treating AMD at existing wastewater facilities represents an innovative solution for simultaneous AMD reclamation and improved MWW treatment. However, unknowns related to biological processes and continuous treatment performance block full-scale use.

Phosphorus uptake and release patterns in overwintering constructed floating wetlands.

Understanding nutrient cycling patterns in plants deployed within constructed floating wetlands (CFWs) is critical for improving CFWs' design and management practices. This study evaluated phosphorus (P) uptake and release patterns during fall/winter plant senescence and spring regrowth. Two mesocosm-scale CFW experiments were conducted characterizing plant growth, plant tissue P levels, and water quality (nutrients and phytoplankton).

A simple multilevel sampler for synchronous collection of stratified waters.

Stratified water collection plays a crucial role in water quality monitoring, as most water bodies are not perfectly mixed systems. In order to precisely collect stratified waters, we developed an inexpensive, simple, and high-resolution sampler to simultaneously collect and measure physical and chemical parameters along vertical water profiles. The water sampler predominantly consists of two parts: (1) an apparatus for measuring sampling depth below the water and (2) water sampling units secured below the water.

Pollutant co-attenuation via in-stream interactions between mine drainage and municipal wastewater.

Municipal wastewater (MWW) and mine drainage (MD) are common co-occurring sources of freshwater pollution in mining regions. The physicochemical interactions that occur after mixing MWW and MD in a waterway may improve downstream water quality of an impaired reach by reducing downstream concentrations of nutrients and metals (i.e.

Mine drainage precipitates attenuate and conceal wastewater-derived phosphate pollution in stream water.

Hydrous ferric-oxide (HFO) coatings on streambed sediments may attenuate dissolved phosphate (PO) concentrations at acidic to neutral pH conditions, limiting phosphorus (P) transport and availability in aquatic ecosystems. Mesh-covered tiles on which "natural" HFO from abandoned mine drainage (AMD) had precipitated were exposed to treated municipal wastewater (MWW) effluent or a mixture of stream water and effluent. Between 42 and 99% of the dissolved P in effluent was removed from the water to a thin coating (~2 μm) of HFO on the mesh.

Spatiotemporal water quality variability in a highly loaded surface flow wastewater treatment wetland.

This study evaluates spatiotemporal relationships between water quality parameters (WQPs), nutrients, suspended solids, and biochemical oxygen demand (BOD) concentrations within an engineered wastewater treatment wetland system in the Georgia Piedmont, USA. We explored factors related to treatment efficiency within a heavily loaded 630-m surface flow wetland system over a 2-yr period. Relationships between temperature, dissolved oxygen (DO), and oxidation-reduction potential (ORP) were observed; relationships were also seen between these WQPs and nutrient concentrations.

Identification and quantification of contributions to karst groundwater using a triple stable isotope labeling and mass balance model.

Although karst groundwater systems provide critical ecosystem services in many regions worldwide, anthropogenic contamination has seriously degraded groundwater quality. Properly elucidating geochemical processes, quantifying contributions of natural and anthropogenic end members, and then protecting karst aquifer systems remain challenging from scientific and engineering aspects. To identify the hydrochemical processes and quantifying contributions of end members (especially, contamination end members), 49 samples were collected from cave waters (CW), artesian springs (AS), and gravity springs (GS) in a karst watershed in Guiyang, China.

Abatement of circumneutral mine drainage by Co-treatment with secondary municipal wastewater.

Acid mine drainage is a persistent and problematic source of water pollution. Co-treatment with municipal wastewater at existing wastewater treatment plants has several advantages; however, potential impacts on plant physicochemical and biological processes have not been well explored. The primary purpose of this bench-scale study was to examine the impact of co-treatment by combining a mild acid mine drainage at various ratios with municipal wastewater, followed by sludge settling and supernatant comparative analysis using a variety of effluent water quality parameters.

Preliminary Assessment of Ferrate Treatment of Metals in Acid Mine Drainage.

We report a preliminary assessment of ferrate [Fe(VI)] for the treatment of acid mine drainage (AMD), focused on precipitation of metals (i.e., iron [Fe] and manganese [Mn]) and subsequent removal.

Tracing and quantifying contributions of end members to karst water at a coalfield in southwest China.

Karst water, which provides 25% of the world's drinking water, is especially vulnerable to anthropogenic contamination. Such is the case in southwestern China with trace element pollution in important karst aquifers. Approximately 20% of the total study area consisted of abandoned mine tailings with elevated concentrations of Fe, S, Mn, As, Cu, and Cr.

Metal-contaminated potato crops and potential human health risk in Bolivian mining highlands.

This study assessed metals in irrigation water, soil and potato crops impacted by mining discharges, as well as potential human health risk in the high desert near the historic mining center of Potosí, Bolivia. Metal concentrations were compared with international concentration limit guidelines. In addition, an ingested average daily dose and minimum risk level were used to determine the hazard quotient from potato consumption for adults and children.

Passive Biological Treatment of Mine Water to Reduce Conductivity: Potential Designs, Challenges, and Research Needs.

The remediation of mine water to preserve receiving water quality has advanced substantially over the past half century, but prospective regulations to limit the conductivity of mining-impacted waters pose a significant new challenge. Conventional approaches to reduce high levels of conductivity in these mine waters are often costly, requiring high levels of maintenance and significant inputs of energy and refined chemicals. In contrast, passive biological treatment (PBT) systems are a relatively low-cost, low-maintenance treatment technology for mine waters that have been used for over three decades.

Removal of Less Commonly Addressed Metals via Passive Cotreatment.

The viability of removing less commonly addressed metals (e.g., Cd, Cu, Ni, and Pb) in a passive cotreatment concept was tested using a microcosm-scale, three-stage batch reactor system in which acid mine drainage from an abandoned adit on Cerro Rico de Potosí and raw municipal wastewater from Potosí, Bolivia, were introduced at a 5:1 ratio.

Possible health effects of living in proximity to mining sites near Potosí, Bolivia.

Objective: The goal of this study was to determine the health effects of living downstream from mines in the Potosí region of Bolivia.

Methods: Histories, physical examinations, and urinalyses were completed on adults recruited from mining and nonmining villages in Bolivia. Blood concentrations of Cd, Hg, and Pb were determined in a subset of participants.

Hydrogen and oxygen isotopic composition of karst waters with and without acid mine drainage: impacts at a SW China coalfield.

Karst water resources, which are critical for the support of human societies and ecological systems in many regions worldwide, are extremely sensitive to mining activities. Identification and quantification of stable isotope (δ(2)HH2O andδ(18)OH2O) composition for all sources is essential if we are to fully understand the dynamics of these unique systems and propose successful remediation strategies. For these purposes, a stable isotope study was undertaken in two similar watersheds, one impacted by acid mine drainage, and the other not.

Novel passive co-treatment of acid mine drainage and municipal wastewater.

A laboratory-scale, four-stage continuous-flow reactor system was constructed to test the viability of high-strength acid mine drainage (AMD) and municipal wastewater (MWW) passive co-treatment. Synthetic AMD of pH 2.6 and acidity of 1870 mg L(-1) as CaCO3 equivalent containing a mean 46, 0.