Abstract. For more than a decade it has been known that shallow tube wells in Bangladesh are frequently contaminated with arsenic concentrations at level is harmful to human health. By now clear disaster of an unheard magnitude going on: the World Health Organization estimated long-term exposure groundwater, over 500 μg L−1, causes death 1 10 adults. Other studies show problems groundwater/drinking water occur many countries worldwide, such as USA and China. In Europe focus on currently...

Rapid sand filters (RSF) are an established and widely applied technology for groundwater treatment. Yet, the underlying interwoven biological physical-chemical reactions controlling sequential removal of iron, ammonia manganese remain poorly understood. To resolve contribution interactions between individual reactions, we studied two full-scale drinking water treatment plant configurations, namely (i) one dual-media (anthracite quartz sand) filter (ii) single-media (quartz in series. In...

Rapid sand filters are established and widely applied technologies for groundwater treatment. In these filters, main contaminants such as iron, manganese, ammonium oxidized removed. Conventionally, intensive aeration is employed to provide oxygen redox reactions. While effective, promotes flocculent iron removal, which results in oxide flocs that rapidly clog the filter. this study, we operated two parallel full-scale at different intensities resolve relative contribution of homogeneous,...

In this study, F− removal by Ca–Al–CO3 layered double hydroxides (LDHs) was investigated at environmentally-relevant concentration ranges (2–12 mg/L) to below the WHO guideline, with an emphasis on effect of LDHs' modification, as well effects initial concentration, adsorbent dose, pH, temperature and co-existing ions. LDHs, either untreated, calcined or microwave treated, showed affinity for from synthetic groundwater capacities 6.7–8.4 mg F−/g LDHs groundwater-relevant a higher capacity...

Rapid sand filters (RSF) are an established and widely applied technology for the removal of dissolved iron (Fe2+) ammonium (NH4+) among other contaminants in groundwater treatment. Most often, biological NH4+oxidation is spatially delayed starts only upon complete Fe2+ depletion. However, mechanism(s) responsible inhibition by or its oxidation (by)products remains elusive, hindering further process control optimization. We used batch assays, lab-scale columns, full-scale filter...

The ceramic silver-impregnated pot filter (CSF) is a low-cost drinking water treatment system currently produced in many factories worldwide. objective of this study to gather performance data provide scientific basis for organisations safely scale-up and implement the CSF technology. Filters from three production locations are included study: Cambodia, Ghana Nicaragua. microstructure material was studied using mercury intrusion porosimetry bubble-point tests. Effective pores were measured...

H2O2 residuals from advanced oxidation processes (AOPs) may have critical impacts on the microbial ecology and performance of subsequent biological treatment processes, but little is known. The objective this study was to evaluate how influence sand systems with an emphasis dissolved organic carbon (DOC) removal, activity change bacterial community evolution. results laboratory batch studies showed that 0.25 mg/L lowered DOC removal by 10% while higher concentrations at 3 5 promoted 8% 28%....

Arsenic (As) is a toxic element present in many (ground)water sources the world. Most conventional As removal techniques require pre-oxidation of neutral arsenite (As(III)) species to negatively charged arsenate (As(V)) oxyanion optimize and minimize chemical use. In this work, novel, continuous-flow system was developed that combines biological As(III) oxidation by bacteria with Fe electrocoagulation (EC), an Fe(0)-based electrochemical technology generates reactive Fe(III) precipitates...

Iron in anaerobic groundwater is commonly removed by oxidation followed sand filtration. This produces large volumes of iron(III)(hydr)oxide sludge with little value. Our research investigates the novel concept iron(II) recovery from as valuable mineral vivianite (Fe3(PO4)2 • 8 H2O) addition phosphate to water. We found that precipitated both synthetic and natural when saturation index (SI) was higher than 4. The SI can be increased elevating pH, which allows for iron removal at lower...

Slow Sand Filtration is popular in drinking water treatment for the removal of a wide range contaminants (e.g., particles, organic matter, and microorganisms). The Schmutzdecke slow sand filters (SSFs) known to be essential pathogen removal, however, this layer also responsible increased head loss. Since role deeper layers bacteria virus poorly understood, research investigated E.coli WR1 PhiX 174 at different depths full-scale SSF. Filter material from top (0–5 cm), middle (5–20 cm) deep...

Drinking water treatment plants (DWTPs) are designed to remove physical, chemical, and biological contaminants. However, until recently, the role of DWTPs in minimizing cycling antibiotic resistance determinants has got limited attention. In particular, risk selecting antibiotic-resistant bacteria (ARB) is largely overlooked chlorine-free where processes applied. Here, we combined high-throughput quantitative PCR metagenomics analyze abundance dynamics microbial communities, genes (ARGs),...

The need to improve the access safe water is generally recognized for benefit of public health in developing countries. This study's objective was identify critical parameters which are essential improving performance ceramic pot filters (CPFs) as a point-of-use treatment system. Defining production also relevant confirm that CPFs with high-flow rates may have same disinfection capacity pots normal flow rates. A pilot unit built Cambodia produce under controlled and constant conditions. Pots...

Ceramic pot filters are considered safe, robust and appropriate technologies, but there is a general consensus that water revenues limited due to clogging of the ceramic element. The objective this study was investigate potential high flow produce more without sacrificing their microbial removal efficacy. High filters, produced by increasing rice husk content, had higher initial rate (6-19 L h-1), LRVs for E. coli slightly lower than regular filters. This disadvantage was, however, only...

The objective of this study was to investigate whether arsenic-oxidising bacteria (AsOB) will grow and survive in rapid sand filters. Additionally, the interdependence other groundwater constituents (Fe(II), Mn(II), NH4) with biological As(III) oxidation investigated. For purpose monitored pilot-scale filter columns fed raw groundwater, as well treated (drinking water) spikes either As(III), Mn(II) or NH4. It concluded that rapidly developed columns. With a typical lag log phase, decreasing...

Cu and Ag have been used as bactericidal agents since ancient times, yet their antiviral capacity in water remains poorly understood. This study tested the effect of copper (Cu) silver (Ag) on model RNA DNA viruses MS2 PhiX 174 solution at pH 6-8. caused inactivation with similar rates 6 7 but was inert towards regardless pH. inactivated both viruses, causing denaturation loss capsid spikes 174. were dependent increased increasing At 8, 6.5 logs after 3 h only 10 min. The combined use...

In this paper we analyse the feasibility of low voltage iron electrocoagulation as a means municipal secondary effluent treatment with focus on removal microbial indicators, Antibiotic Resistant Bacteria (ARB) and nutrients. A laboratory scale batch unit equipped electrodes was used synthetic real from wastewater plant. Synthetic separately assayed spiked Escherichia coli WR1 bacteriophage ΦX174, while samples were screened before after for E. coli, Extended Spectrum Betalactamase-producing...

Abstract Nitrate leaching from agricultural soils is increasingly found in groundwater, a primary source of drinking water worldwide. This nitrate influx can potentially stimulate the biological oxidation iron anoxic groundwater reservoirs. Nitrate-dependent iron-oxidizing (NDFO) bacteria have been extensively studied laboratory settings, yet their ecophysiology natural environments remains largely unknown. To this end, we established pilot-scale filter on nitrate-rich to elucidate structure...