Natural Water Treatment Systems Research Articles

Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context: Saph Pani

Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context is based on the work from the Saph Pani project (Hindi word meaning potable water).The book aims to study and improve natural water treatment systems, such as River Bank Filtration (RBF), Managed Aquifer Recharge (MAR), and wetlands in India, building local and European expertise in this field. The project aims to enhance water resources and water supply, particularly in water stressed urban and peri urban areas in different parts of the Indian sub-continent. This project is co-funded by the European Union under the Seventh Framework (FP7) scheme of small or medium scale focused research projects for specific cooperation actions (SICA) dedicated to international cooperation partner countries.Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context provides:an introduction to the concepts of natural water treatment systems (MAR, RBF, wetlands) at national and international levelknowledge of the basics of MAR, RBF and wetlands, methods and hydrogeological characterisationan insight into case studies in India and abroad.This book is a useful resource for teaching at Post Graduate level, for research and professional reference.First published 2016Revised edition with the addition of Chapter 19, 2016Original EditionISBN: 9781780407104 (Paperback)ISBN: 9781780407111 (eBook)This Revised EditionISBN: 9781780408392 (eBook)ISBN: 9781780408385 (Print)DOI: 10.2166/9781780408392

Cultural ecosystem services of multifunctional constructed treatment wetlands and waste stabilization ponds: Time to enter the mainstream?

Natural water treatment systems have long been recognized as sources of ancillary benefits in the form of cultural ecosystem services. To date, there is a lack of quantitative understanding of the extent and welfare impact of such benefits. This paper investigates 166 natural treatment systems worldwide and provides the first quantitative assessment of their recreational and educational benefits. The public use is highly influenced by the type of recreational activities, presence of recreational and educational facilities, and accessibility of the systems. Using value transfer techniques, we estimate the mean and median monetary values of recreational benefits in 8397 and 530€/ha/year, respectively. We compare such value flows with operation and management costs and other ecosystem services provided by these systems.

Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context: Saph Pani

This version of the book Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context: Saph Pani, has been revised due to the addition of a new chapter. The new 2016 edition is available herehttp://wio.iwaponline.com/content/15/97817804083922016 Revised EditionISBN: 9781780408385 (Paperback)ISBN: 9781780408392 (eBook)

Influence of Wastewater Discharge on the Metabolic Potential of the Microbial Community in River Sediments.

To reveal the variation of microbial community functions during water filtration process in river sediments, which has been utilized widely in natural water treatment systems, this study investigates the influence of municipal wastewater discharge to streams on the phylotype and metabolic potential of the microbiome in upstream and particularly various depths of downstream river sediments. Cluster analyses based on both microbial phylogenetic and functional data collectively revealed that shallow upstream sediments grouped with those from deeper subsurface downstream regions. These sediment samples were distinct from those found in shallow downstream sediments. Functional genes associated with carbohydrate, xenobiotic, and certain amino acid metabolisms were overrepresented in upstream and deep downstream samples. In contrast, the more immediate contact with wastewater discharge in shallow downstream samples resulted in an increase in the relative abundance of genes associated with nitrogen, sulfur, purine and pyrimidine metabolisms, as well as restriction-modification systems. More diverse bacterial phyla were associated with upstream and deep downstream sediments, mainly including Actinobacteria, Planctomycetes, and Firmicutes. In contrast, in shallow downstream sediments, genera affiliated with Betaproteobacteria and Gammaproteobacteria were enriched with putative functions that included ammonia and sulfur oxidation, polyphosphate accumulation, and methylotrophic bacteria. Collectively, these results highlight the enhanced capabilities of microbial communities residing in deeper stream sediments for the transformation of water contaminants and thus provide a foundation for better design of natural water treatment systems to further improve the removal of contaminants.

Characterization of a macrophyte microcosm as a surface water treatment system for antibiotics

Natural water treatment systems provide for a means to manage nutrient (and carbon) cycles while improving water quality. We present chemical engineering design characteristics from an example flow through and model tertiary water treatment microcosm. This research demonstrates that aquatic macrophytes (Pistia stratiotes and Eichhornia crasippes) can degrade concentrations (0–10 mg/L) of oxytetracycline (OTC). First order OTC degradation rate coefficients (0.07–4.5/day) can be adjusted by altering; agitation, pH, temperature, and aeration mass flows in exudate treatment strategies when simulated wastewater was fed at 10 L/day. Further, we suggest that electronic paramagnetic resonance can be used to aid in hypothesis testing that external elicitation with phytohormones can be used to promote biological based oxidative bursts with methyl jasmonate during water treatment. Finally, we suggest there is a lack of research that considers macrophytes in more holistic natural and human use cycles. © 2015 American Institute of Chemical Engineers Environ Prog, 34: 1605–1612, 2015

Enhancement of phosphorus sorption onto light expanded clay aggregates by means of aluminum and iron oxide coatings

Phosphorus (P) loading from non-point or point sources increases the eutrophication risk of natural waters. The functioning of constructed wetlands (CWs) used as natural water treatment systems can be improved by means of additional materials adsorbing soluble P. In this study, light expanded clay aggregates (LECA) and LECA coated with aluminum (Al) oxide (Al-LECA) or iron (Fe) oxide (Fe-LECA) were tested for their efficiency as P sorbents in the pH range 3–8. The oxide coatings duplicated the actual sorption capacity calculated from the sorption isotherms at the P concentration in the equilibrium solution of 20μgL−1, assumed to be the allowable P level in purified water. In the oxide-coated LECAs the sorption was fast and followed both the first- and second-order Lagergren kinetic models, suggesting that the formation of a binuclear surface complex was feasible. In LECA, sorption was markedly slower and followed the first-order kinetic model, indicating that retention occurred through a monodentate attachment. These findings were in harmony with the degree of P saturation (DPS) of the sorbent surfaces at the highest P addition level (200μgL−1), DPS being decisively higher for LECA than for the oxide-coated sorbents. Accordingly, at higher pH values the competition by hydroxyl ions diminished the sorption in LECA relatively more than that in the coated sorbents. In agreement with the acidity of Al3+ being 100 times lower than that of Fe3+, at elevated pH the sorption by Al-LECA proved to be less reversible than that by Fe-LECA. The results provide evidence that in CWs Al-coated sorbents are superior to Fe-coated ones that are also redox-sensitive and may lose their sorption properties in anoxic conditions.

Observations of mean and turbulent flow structure in a free‐floating macrophyte root canopy

Lay AbstractFree‐floating aquatic plants, or macrophytes, often grow in dense mats, and their feathery, unanchored roots form canopies below the water surface that can affect water flow and water quality. This study examines the physical interactions of an invasive species of free‐floating macrophyte, water hyacinth (Eichhornia crassipes), and the surrounding water to better understand how free‐floating macrophyte root canopies affect hydrodynamics. Experiments in an open‐channel flow chamber were conducted to examine the flow fields through and around root canopies. Acoustic Doppler velocity measurement revealed that water flow was deflected around the root canopy and was reduced within the canopy. Interestingly, the vertical pattern of the velocity in the roots was similar to what has been observed in leaf canopies of terrestrial and submerged aquatic vegetation. In these cases, an unstable velocity profile (one with an inflection point) gives rise to water column turbulence, which was observed at distances >50% of the length of the root canopy, culminating in a large wake region immediately downstream. Although mixing caused by turbulence increased outside the root canopy, it did not increase within the canopy, and so there was limited exchange of water between the root canopy and the open water. Because of this, we expect the time that water resides within the root canopy to be dominated by the slow mean flow velocity, rather than turbulence. This result helps to explain why the root canopies of free‐floating macrophytes can suffer from low levels of dissolved oxygen (hypoxia) and poor water quality, and suggests ways in which to improve the operational efficiency of natural water treatment systems relying on these types of plants.

Role of biodegradation in the removal of pharmaceutically active compounds with different bulk organic matter characteristics through managed aquifer recharge: Batch and column studies

Natural water treatment systems such as bank filtration have been recognized as providing effective barriers in the multi-barrier approach for attenuation of organic micropollutants for safe drinking water supply. In this study, the role of biodegradation in the removal of selected pharmaceutically active compounds (PhACs) during soil passage was investigated. Batch studies were conducted to investigate the removal of 13 selected PhACs from different water sources with respect to different sources of biodegradable organic matter. Neutral PhACs (phenacetine, paracetamol, and caffeine) and acidic PhACs (ibuprofen, fenoprofen, bezafibrate, and naproxen) were removed with efficiencies greater than 88% from different organic matter water matrices during batch studies (hydraulic retention time (HRT): 60 days). Column experiments were then performed to differentiate between biodegradation and sorption with regard to the removal of selected PhACs. In column studies, removal efficiencies of acidic PhACs (e.g., analgesics) decreased under conditions of limited biodegradable carbon. The removal efficiencies of acidic PhACs were found to be less than 21% under abiotic conditions. These observations were attributed to sorption under abiotic conditions established by a biocide (20 mM sodium azide), which suppresses microbial activity/biodegradation. However, under biotic conditions, the removal efficiencies of these acidic PhACs were found to be greater than 59%. This is mainly attributed to biodegradation. Moreover, the average removal efficiencies of hydrophilic (polar) neutral PhACs (paracetamol, pentoxifylline, and caffeine) with low octanol/water partition coefficients (log K ow less than 1) were low (11%) under abiotic conditions. However, under biotic conditions, removal efficiencies of the neutral PhACs were greater than 98%. In contrast, carbamazepine persisted and was not easily removed under either biotic or abiotic conditions. This study indicates that biodegradation represents an important mechanism for the removal of PhACs during soil passage.

A systematic approach to determine herbicide removals in constructed wetlands using time integrated passive samplers

Natural water treatment systems such as wetlands are increasingly being recognised for their role as part of a multi-barrier system for water recycling. Natural wetland systems have the ability to provide effective treatment for a wide range of organic chemicals. However, techniques are required to validate the performance of these treatment processes in the field. This paper provides a new method for evaluating wetland systems using passive samplers and applies a statistical method for use in advanced water treatment processes. Three years of stormwater quality passive sampler data for diuron, simazine and atrazine is provided to determine herbicide removal between the inlet and outlet regions of a constructed wetland. Mean removal rates over the three year period for diuron, simazine and atrazine were 43, 54 and 50% respectively. The results show that this method coupled with passive samplers is amenable to wetland system barrier characterisation where opportunities for process validation is not feasible.