Natural systems for the treatment and management of municipal and industrial
wastewaters and residuals feature processes that use minimal energy and minimal
or no chemicals, and they produce relatively lower amounts of residual solids.
This book is intended for the practicing engineers and scientists who are involved
in the planning, design, construction, evaluation, and operation of wastewater
The study of geology, soils in the selection of sites for water spreading or infiltration recharging system are rather more important than for any well recharging systems. The basic aspects, which are considered, are: Moving the water through the vadose zone Making the water move through aquifer away from infiltration recharge sites so as to raise water buildup of ground water mound or ridge Therefore, for infiltration recharge systems the following area characteristics are desirable...
Geographical Information Systems and Modeling of Saltwater Intrusion in the Capoterra Alluvial Plain (Sardinia, Italy)
G. Barrocu, M.G. Sciabica, L. Muscas
1. INTRODUCTION A comprehensive study of the Capoterra alluvial plain (Southern Sardinia, Italy) has been carried out by the Engineering Geology and Applied Geophysics Section of the Department of Land Engineering at Cagliari University, within the frame of the international projects MEDALUS and AVICENNE 73, funded by the European Union.
This volume consists of a collection of current studies on free electron lasers. Free
Electron Lasers covers the analysis of fundamentals and questions of design of these
devices functioning from the infrared to ultraviolet or xuv wavelength regimes. In
addition to the comparison with conventional lasers, analyses of some related topics
concerning near-field and cavity electrodynamics, compact and table-top
arrangements and strong radiation–induced exotic states of matter are presented.
Water-quality engineering is a specialty area in environmental engineering that includes
the subspecialties of water treatment, wastewater treatment, and water-quality control in
natural systems. This textbook is intended to encompass the latter subspecialty, and the
content of this book constitutes baseline knowledge expected of water-quality engineers
Compared to other ecosystems, wetlands have received an exceptional amount of
attention. Wetlands are valuable as sources, sink and transformers of a multitude
of chemical, biological and genetic materials. They stabilize water supplies, clean
polluted waters, protect shorelines, and recharge groundwater aquifers. They have
increasingly become recognized for their unique ecological functions in the
environment and are the focus of increased research by scientists and study
programs by schools, communities, and nature centers.
Within the overall transport process, attenuation processes may cause movement of the
chemical to differ from that of the bulk flowing groundwater, for example dispersion, sorption
and chemical or biological degradation of the chemical. Such attenuation processes
potentially act to mitigate the impact of chemicals and are a function of both the specific
chemical and geologic domain. Indeed, attenuation may vary significantly between individual
chemicals and within different geological settings.
All ground water sources should be
located a safe distance from sources of
contamination. In cases where sources are
severely limited; however, a ground water
aquifer that might become contaminated
may be considered for a water supply, if
treatment is provided. After a decision has
been made to locate a water source in an
area, it is necessary to determine the
distance the source should be placed from
the origin of contamination and the direction
of water movement. A determination of a
safe distance is based on specific local
factors described in the section on "Sanitary
It is important to understand at the outset the natural hydrochemical conditions that exist in
aquifer systems, as these provide the necessary baseline from which quality changes caused
by human impacts can be determined. The natural hydrochemical conditions may also affect
the behaviour of some pollutants. Because groundwater movement is typically slow and
residence times long, there is potential for interaction between the water and the rock material
through which it passes.
Water resources could in principle be managed by several users as common property resources. In the
absence of effective mechanisms for co-management at the watershed or river-basin level, however,
water resources often become open access. Conflicts often arise between upstream and downstream
users. Irrigators at the tail end of a large irrigation system may have the formal right to water, but their
share may be taken by farmers near the head of the system, who may even have switched to higher
value and more water consumptive crops through collusion with irrigation officials.
The design of an aquifer remediation operation is merely a case of practical
experience today. The contaminant is flushed out of the soil by means of a system of
injection and recovery wells. The time needed and the amount of water that has to be
flushed through the soil to reach a certain required concentration are both important.
The amount of water is expressed in terms of the so-called flush factor, which is
equal to the ratio of the volume of this water and the volume of the pores in the soil
to be flushed.
The time needed and the...
Every year, farm operators apply more than 12 million tons of nitrogen fertilizer and 8 million tons of phos-
phorus fertilizer to agricultural land in the U.S.
Unless carefully managed, much of it is carried off the fields
by runoff or percolates into drainage systems, eventually ending up in streams, rivers, lakes and underground
aquifers. Animal manure from livestock is also an important contributor to nutrient pollution, particularly phos-