Environmental Engineering

Fundamentals and Applications

Subhash Verma, Varinder S. Kanwar, Siby John

• Editore: CRC Press
• Anno: 2022
• ISBN:
  9781000533590
• Edizione: 1
• Argomento: Biowissenschaften
• Categoria: Umweltwissenschaft

Presenting an in-depth coverage, this textbook brings together and integrates key topics including water resources, wastewater, air, and solid waste in a single volume.

The textbook introduces a unique approach that emphases on the water and wastewater treatments with its distribution system and engineering. It begins by discussing the public health and sanitation, then covers the wastewater collection system and design, wastewater characteristics, natural purification water, different wastewater treatments, industrial and rural wastewater. Finally, the emerging technologies in the reuse/recycle of waste and processes to conserve the environmental resources are discussed.

The text will be useful for senior undergraduate and graduate students in the fields of civil and environmental engineering. Pedagogical features including solved problems, exercises and multiple-choice questions are interspersed throughout the book for better understanding.

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• Discusses latest technologies and engineering design in water and wastewater management.

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• Focusses on reuse and conservation of natural resources.

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• Comprehensively covers topics on air pollution and noise pollution.

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• Explains important topics including coagulation and flocculation, sedimentation, filtration, disinfection, water softening and water distribution.

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• Includes pedagogical features including solved examples, exercises and multiple-choice questions with answers for better understanding of concepts.

1Introduction

DOI: 10.1201/9781003231264-1

Environmental engineering as an undergraduate course, in general, deals with water and wastewater, air and noise pollution, and solid and industrial wastes. The study of the environment and how it interfaces with society and technology is a frontier area in today’s engineering education. This book covers all the main topics in environmental engineering. The first section deals with water supply and treatment, followed by a section on wastewater collection and treatment. The third section covers solid waste and environmental pollution, including air and noise. Different sections can be selected to meet the requirements of a given course.

1.1 Water

Water is essential for life and no life is possible without water. Water is one of the most abundant and essential constituents of all living things. Almost 70% of human body weight is due to water present in the tissues. Besides being essential for life, water is used for many other purposes: for drinking and personal needs, in agriculture and industry, and for transportation and recreation. In India, about 70% of the total water available is used in agriculture, 20–22% in industry, and only 8% for domestic use.

1.1.1 Historical Perspective

Historically, many civilizations developed around water bodies that could support their agriculture, transportation and water for domestic use. Based upon what we know, the human search for water must have begun in prehistoric times. Though it is only speculation, it seems some individuals may have conveyed water through trenches dug into the earth. Thousands of years probably passed before our recent ancestors learnt to build cities with piped water supplies.

The earliest recorded knowledge of water treatment is in Sanskrit medical lore and inscriptions on walls in Egypt. Sanskrit writings in India that date back to 2000 BC describe water purification by boiling it in copper vessels, exposing it to sunlight, filtering it through charcoal, then cooling it in earthen pots. There is mention of digging wells in Rig Veda as far back as 4000 BC.

The first engineering report on water supply and treatment was written in 97 AD by S. J. Frontinus, a water commissioner from Rome, who produced two books on the subject. In the 17th century, the English philosopher Francis Bacon wrote of experiments in purifying water by filtration, boiling, distillation and clarification by coagulation. The first known illustrated description of sand filters was published in 1685 by Luc Porzio, an Italian physician. A comprehensive article on the water supply of Venice was published in 1863 in the Practical Mechanic’s Journal.

Henry Darcy patented filters in France and England in 1856. He came up with Darcy’s law for groundwater flow and a design for filters. Filtered water was piped to homes for the first time in 1807 in Glasgow, Scotland. In around 1890, rapid sand filters were developed, and coagulation was later introduced to improve their performance. Techniques for water clarification and its filtration were improved and modified thereafter, followed by the introduction of chlorination for disinfection in 1905. Thanks to the technical and scientific developments of the late 20th and early 21st centuries, engineers can meet the quantity and quality challenges of supplying water.

The drains and sewers of Nippur and Rome are among some of the great structures built to carry away run-off from storms and flush streets. The need for the regular cleaning of Rome and the flushing of its sewers was well recognized by commissioner Frontinus. However, since then, no marked progress in sewage was made for some time. The history of the improvement of sanitation in London probably gives a clearer picture of what happened in the middle of the 19th century. In 1855, British parliament passed an act and subsequently the Commission of Sewers was formed to take responsibility for establishing an adequate sewerage system.

Edwin Chadwick (1800–1890), an administrator in the UK, introduced the idea of sanitation. Chadwick called for street and house cleaning by means of a supply of water and improved sewage collection. He specifically outlined the provision of services and advice from civil engineers and not physicians. Chadwick proposed the following engineering solutions:

1. A supply of drinking water to every house.
2. The collection of wastewater via a network of pipes.
3. The spread of wastewater into agricultural land away from the city.

1.1.2 Hydrologic Cycle

About 75% of the Earth’s surface is covered with water, and because of this it is often called the water planet. Most of the water (about 97%) is in the seas and other saline water bodies (salt water). This water is too salty to be used for drinking and irrigation. Thus, only a tiny fraction (about 3%) of Earth’s water can be called fresh water. Of this, a little more than 2% is locked up in glaciers, soil or atmospheric moisture, or is buried so deep that its extraction becomes cost-prohibitive. Therefore, for daily use and use in industry and agriculture, humans depend on less than 1% of the fresh water readily available in rivers, lakes, streams and groundwater.

Water in nature is in a constant state of motion, as depicted in the hydrologic cycle shown in Figure 1.1. The water cycle is driven by energy from the sun. The major components of the cycle are the evaporation of water from sea or land, its precipitation as rain or snow over the oceans and land, and its return from the land to the sea via streams and rivers. With slight variations, the water content of the sea remains constant.

Figure 1.1Hydrologic Cycle

As urban development expands, so does the need for municipal water systems. Thus, in urban areas, water also goes through a cycle to serve the needs of municipal establishments, known as the urban water cycle. Water is pumped from rivers or groundwater, treated, and distributed via pipe networks. After use, water is then discharged into sanitary sewers and treated before being discharged into receiving water bodies. All these systems, including water treatment, water distribution, wastewater collection and wastewater treatment, are engineered systems. Basic knowledge of these systems is essential for workers in civil, environmental and public health engineering. In addition, environmental engineers deal with solid waste and air pollution.

1.2 Wastewater Treatment

Wastewater is water carrying waste. In the past, when populations were more scattered and lifestyles were simple, natural purification was good enough to treat waste discharges. As our lifestyles changed and areas became more urbanized, it became beyond the capacity of natural systems to purify this waste. Therefore, to protect our water resources and natural environment, it is pertinent that man-made or engineered systems are in place.

In a developing country such as India, most of the urban areas inhabited by slums are plagued by acute problems related to the indiscriminate disposal of sewage. Even though a substantial amount of money is allocated to wastewater treatment, disposal is still in a dismal state. According to the Central Pollution Control Board, the estimated deficit in wastewater treatment in India is about 72%. It is not uncommon to find that a large portion of resources is spent by local governments manning sewerage systems for their operation and maintenance (O&M). Despite this, there has been a decline in the standard of services with respect to the collection, transportation, treatment and safe disposal of treated sewage, as well as measures for ensuring the safeguard of public health and the environment.

Sewerage and sewage treatment are a part of public health and sanitation and, according to the Indian Constitution, fall within the purview of the State List. Since this is non-exclusive and essential, the responsibility for providing these services lies within the public domain. In developed countries, water and wastewater treatment fall under the jurisdiction of municipal governments. This activity, being of a local nature, is entrusted to the urban local bodies (ULBs), which undertake the task of sewerage and sewage treatment service delivery with their own staff, equipment and funds. In a few cases, part of said work is contracted out to private enterprises. Cities and towns that have sewerage and sewage treatment facilities are unable to keep up with the increased burden of providing such facilities efficiently to the desired level. The leading cause of water pollution is the unintended disposal of untreated, partly treated and non-point sources of sewage, and its effect on human health and the environment is of great importance.

1.2.1 Need for Wastewater Treatment

Sanitation can be perceived as the conditions and processes relating to people’s health, especially the systems that supply water and deal with human waste. Such a task would logically cover other matters such as solid wastes, industrial and other special/hazardous wastes, and storm water drainage. However, the most potent of these pollutants is sewage.

When untreated sewage accumulates and is allowed to become septic, the decomposition of its organic matter leads to nuisance conditions, including the production of malodorous gases. In addition, untreated sewage contains numerous pathogens that dwell in the human intestine tract. Sewage also contains nutrients that can stimulate the growth of aquatic plants and may contain toxic compounds or compounds that are potentially mutagenic or carcinogenic. For these reasons, the immediate and nuisance-free removal of sewage from its sources of generation, followed by its treatment, reuse or disposal into the environment in an eco-friendly manner, is necessary to protect public health and the environment.

1.2.2 Wastewater Treatment Technologies

In the development of wastewater treatment technologies, the basic principles of engineering, such as hydraulics, are applied to solve issues associated with collection and conveyance. The basic principles of microbiology, chemistry and engineering are applied to the t...

Indice dei contenuti

• Cover
• Half-Title Page
• Title Page
• Copyright Page
• Contents
• List of Figures
• List of Tables
• Preface
• About the Authors
• 1 Introduction
• 2 Sources of Water Supply
• 3 Water Wells
• 4 Water Demand
• 5 Water Quality and Treatment
• 6 Coagulation and Flocculation
• 7 Sedimentation
• 8 Filtration
• 9 Disinfection
• 10 Water Softening
• 11 Miscellaneous Water Treatment Methods I
• 12 Miscellaneous Water Treatment Methods II
• 13 Water Distribution
• 14 Pipeline Systems
• 15 Pumps and Pumping
• 16 Wastewater Collection System
• 17 Design of Sewers
• 18 Construction of Sewers
• 19 Lift Stations
• 20 Natural Purification
• 21 Wastewater Characteristics
• 22 Preliminary Treatment
• 23 Primary Treatment
• 24 Activated Sludge Process (ASP)
• 25 Stabilization Ponds
• 26 Attached Growth Systems
• 27 Anaerobic Systems
• 28 Biosolids
• 29 Advanced Wastewater Treatment
• 30 Industrial Wastewater Treatment
• 31 Sources of Air Pollution
• 32 Meteorological Aspects of Air Pollution
• 33 Air Pollution Control
• 34 Introduction to Solid Waste
• 35 Solid Waste Management
• 36 Hazardous Waste
• 37 Noise Pollution
• 38 Noise Pollution and Control
• 39 Environmental Impact Assessment (EIA)
• 40 Rural Sanitation
• Appendices
• Index