Adsorptive Iron Removal from Groundwater


Book Description

A pilot study conducted at the Gilze water treatment plant of Water Supply North West Brabant demonstrated that adsorptive filtration has several potential advantages over floc filtration, namely: longer filter runs due to slower head loss development; better filtrate quality; shorter ripening time; and less backwash water use. In existing groundwater treatment plants, the high iron (II) adsorption capacity of the iron oxide coated filter media makes it potentially possible to switch the governing mode of operation from floc filtration to adsorptive filtration. To achieve this two options can be considered: iron (II) adsorption under anoxic conditions followed by oxidation with oxygen-rich water; and adsorption of iron (II) in the presence of oxygen and simultaneous oxidation. The first option might be attractive specifically when two filtration steps are available.




Fluoride Removal from Groundwater by Adsorption Technology


Book Description

In the Eastern corridor of Northern region of Ghana, presence of high fluoride concentration in the groundwater has made many drilled boreholes unusable for drinking. Little is, however, known about the factors contributing to the occurrence of high fluoride in this part of Ghana and it's spatial distribution. Treatment of the fluoride-contaminated groundwater by adsorption is also hampered by the lack of suitable adsorbents that are locally available. Based on principal component analysis, and saturation indices calculations, this thesis highlights that, the predominant mechanisms controlling the fluoride enrichment probably include calcite precipitation and Na/Ca exchange processes, both of which deplete Ca from the groundwater, and promote the dissolution of fluorite. The mechanisms also include F-/OH-anion exchange processes, as well as evapotranspiration processes which concentrate the fluoride ions, hence increasing its concentration in the groundwater. Spatial mapping showed that the high fluoride groundwaters occur predominantly in the Saboba, Cheriponi and Yendi districts. The thesis further highlights that, modifying the surface of indigenous materials by an aluminium coating process, is a very promising approach to develop a suitable fluoride adsorbent. Aluminum oxide coated media reduced fluoride in water from 5. 0 ± 0.2 mg/L to ≤ 1.5 mg/L (which is the WHO health based guideline for fluoride), in both batch and continuous flow column experiments in the laboratory. Kinetic and isotherm studies, thermodynamic calculations, as well as analytical results from Fourier Transform Infrared Spectroscopy and Raman spectroscopy, suggest the mechanism of fluoride adsorption onto aluminium oxide coated media involved both physisorption and chemisorption processes. Field testing in a fluoritic community in Northern Ghana showed that the adsorbent is also capable of treating fluoride-contaminated groundwater in field conditions, suggesting it is a promising defluoridation adsorbent. The adsorbent also showed good regenerability potential that would allow re-use, which could make it practically and economically viable. Additional research is, however, required to further increase the fluoride adsorption capacity of developed adsorbent.




Application of Nanotechnology in Water Research


Book Description

Details the water research applications of nanotechnology in various areas including environmental science, remediation, membranes, nanomaterials, and water treatment At the nano size, materials often take on unique and sometimes unexpected properties that result in them being ‘tuned’ to build faster, lighter, stronger, and more efficient devices and systems, as well as creating new classes of materials. In water research, nanotechnology is applied to develop more cost-effective and high-performance water treatment systems, as well as to provide instant and continuous ways to monitor water quality. This volume presents an array of cutting-edge nanotechnology research in water applications including treatment, remediation, sensing, and pollution prevention. Nanotechnology applications for waste water research have significant impact in maintaining the long-term quality, availability, and viability of water. Regardless of the origin, such as municipal or industrial waste water, its remediation utilizing nanotechnology can not only be recycled and desalinized, but it can simultaneously detect biological and chemical contamination. Application of Nanotechnology in Water Research describes a broad area of nanotechnology and water research where membrane processes (nanofiltration, ultrafiltration, reverse osmosis, and nanoreactive membranes) are considered key components of advanced water purification and desalination technologies that remove, reduce, or neutralize water contaminants that threaten human health and/or ecosystem productivity and integrity. Various nanoparticles and nanomaterials that could be used in water remediation (zeolites, carbon nanotubes, self-assembled monolayer on mesoporous supports, biopolymers, single-enzyme nanoparticles, zero-valent iron nanoparticles, bimetallic iron nanoparticles, and nanoscale semiconductor photocatalysts) are discussed. The book also covers water-borne infectious diseases as well as water-borne pathogens, microbes, and toxicity approach.




Manganese Removal from Groundwater


Book Description

In The Netherlands, Belgium and other European countries, manganese is removed by conventional groundwater treatment with aeration and rapid (sand) filtration. Such a treatment process is easy to operate, cost effective and sustainable, because it does not make use of strong oxidants such as O3, Cl2, ClO2 and KMnO4 with the associated risk of by-product formation and over or under dosing. However, application of aeration-filtration is also facing drawbacks, especially the long ripening time of filter media. Due to the long ripening time, water companies have to waste large volumes of treated water, making this process less sustainable. Also, costs associated with filter media ripening (man power, electricity, operational and analysis costs) are high. Therefore decreasing the filter ripening time, regarding manganese removal is a big issue. Although already extended research has been carried out into manganese removal, the controlling mechanisms, especially of the start up face of filter media ripening, are not fully understood yet. The emphasis of this thesis is to provide a better understanding of the mechanisms involved in the ripening of virgin filter media, regarding manganese removal and how to shorten or completely eliminate the long ripening period of filters with virgin material. This thesis therefore highlights the role of the formation of a manganese oxide coating on virgin filter media. Characterization and identification revealed that the responsible manganese oxide for an effective manganese removal was Birnessite. It was found that Birnessite, formed at the beginning of the ripening process was of a biological origin. Based on the knowledge that manganese removal in conventional groundwater treatment is initiated biologically, long ripening times may be reduced by creating conditions favouring the growth of manganese oxidizing bacteria, e.g., by limiting the back wash frequency and / or intensity. Additionally, this thesis also shows that the use of freshly prepared manganese oxide, containing Birnessite, can completely eliminate filter media ripening time.




Groundwater Geochemistry


Book Description

This book contains both practical and theoretical aspects of groundwater resources relating to geochemistry. Focusing on recent research in groundwater resources, this book helps readers to understand the hydrogeochemistry of groundwater resources. Dealing primarily with the sources of ions in groundwater, the book describes geogenic and anthropogenic input of ions into water. Different organic, inorganic and emerging contamination and salinity problems are described, along with pollution-related issues affecting groundwater. New trends in groundwater contamination remediation measures are included, which will be particularly useful to researchers working in the field of water conservation. The book also contains diverse groundwater modelling examples, enabling a better understanding of water-related issues and their management. Groundwater Geochemistry: Pollution and Remediation offers the reader: An understanding of the quantitative and qualitative challenges of groundwater resources An introduction to the environmental geochemistry of groundwater resources A survey of groundwater pollution-related issues Recent trends in groundwater conservation and remediation Mathematical and statistical modeling related to groundwater resources Students, lecturers and researchers working in the fields of hydrogeochemistry, water pollution and groundwater will find Groundwater Geochemistry an essential companion.







Handbook of Natural Zeolites


Book Description

"Handbook of Natural Zeolites provides a comprehensive and updated summary of all important aspects of natural zeolites science and technology. The e-book contains four sections covering the relevant scientific background, established technologies, recent "







Heavy Metals In Water


Book Description

This book highlights the latest research on dissolved heavy metals in drinking water and their removal.




Environmental Arsenic in a Changing World


Book Description

The Congress "Arsenic in the Environment" offers an international, multi- and interdisciplinary discussion platform for research and innovation aimed towards a holistic solution to the problem posed by the environmental toxin arsenic, with significant societal impact. The Congress has focused on cutting edge and breakthrough research in physical, chemical, toxicological, medical, agricultural and other specific issues on arsenic across a broader environmental realm. The Biennial Congress "Arsenic in the Environment" was first organized in Mexico City (As2006) followed by As2008 in Valencia (Spain), As2010 in Tainan (Chinese Taiwan), As2012 in Cairns (Australia), As2014 in Buenos Aires (Argentina) and As2016 in Stockholm (Sweden). The 7th International Congress As2018 was held July 1-6, 2018, in Beijing, P. R. China and was entitled Environmental Arsenic in a Changing World. The Congress addressed the broader context of arsenic research aligned on the following themes: Theme 1: Arsenic Behaviour in Changing Environmental Media Theme 2: Arsenic in a Changing Agricultural Ecosystem Theme 3: Health Impacts of Environmental Arsenic Theme 4: Technologies for Arsenic Immobilization and Clean Water Blueprints Theme 5: Sustainable Mitigation and Management Arsenic in drinking water (mainly groundwater) has emerged as an issue of global health concern. During last decade, the presence of arsenic in rice, possibly also other food of plant origins, has attained increasing attention. This is particularly true in the Asian countries, where the use of high arsenic groundwater as source of irrigation water and drinking water has been flagged as severe health concern. This has been accentuated by elevating arsenic concentrations in deep groundwater recharged from shallow high arsenic groundwater, which may have further detrimental effects on public health. Notably, China has been in the forefront of research on arsenic biogeochemical cycling, health effects of arsenic, technologies for arsenic removal, and sustainable mitigation measures. The Congress has attracted professionals involved in different segments of interdisciplinary research on arsenic in an open forum, and strengthened relations between academia, research institutions, government and non-governmental agencies, industries, and civil society organizations to share an optimal ambience for exchange of knowledge.