Environmental and Natural Resources Engineering

This chapter concerns the role of pollinators, especially bees, in relation to our agriculture and economy. Besides being a critical participant in the reproductive process of most flowering plants, the bees’ pollination services increase flowering crop yields, improve nutritional quality, and contribute significantly to the global economy. However, beekeepers that manage the domesticated European honey bee had noticed that huge numbers of their bees were dying in recent years, and apiculture is closely wedded to agriculture. Honey bees suffer from a variety of maladies attributed to pesticides, climate change, parasites, and disease, all of which contribute to increased bee mortality and catastrophic hive death such as Colony Collapse Disorder (CCD). A number of these issues appear to affect wild pollinators as well. In order to conserve and protect our pollinator resources, this chapter describes a number of major stressors that lead to bee mortality and offers suggestions to improve bee and ultimately general pollinator survival. Recommended actions for beekeepers include adoption of honey bee strains that are bred for specific climates and survival traits as well as maintaining diverse forage around the apiary. Farmers are recommended to maintain areas of wild plants for diverse foraging sources, where a healthy bee diet also aids in crop pollination. In order to protect food availability, control prices, and support agricultural sustainability, governments can review ongoing research concerning known bee and pollinator stressors and implement legislation and guidelines to control human-created stressors such as pesticides while encouraging pollinator-friendly land management.

The strategy for long-term planning and management of water resources is more and more being based on the renovation and utilization of wastewater for use in agricultural and landscape irrigation as well as in industrial production. Conventional wastewater treatment, even when it is economically feasible, is costly because of biosolids handling and tertiary sedimentation tanks. A newly developed flotation/filtration cell is an advanced water clarification package plant, using a combination of chemical flocculation, dissolved air flotation (DAF), and rapid granular filtration in one unit. The average processing time from start to finish is less than 15 min. This innovation replaces a conventional process requiring five separate tanks with a single, compact, and cheaper unit. The aim of this chapter is to discuss six applications that illustrate the versatility and effectiveness of the flotation/filtration cell, to demonstrate the performance of the compact unit in secondary and tertiary treatment of various wastewater effluents, and to illustrate the system’s usefulness for wastewater reclamation, recycling, and reuse.

Current practice in the secondary treatment of wastewater for pollution control calls for the use of biological oxidation to remove organic substances. When it comes to selecting the method of biological oxidation, a pollution control engineer has at his or her disposal a variety of treatment processes, among which activated sludge and trickling filters are the most popular. The function and limitations of the activated sludge processes are reviewed. The principles of biological oxidation and of the energy flow concept are described, and the relationship of synthesis and respiration is discussed in relation to the importance of activated sludge process control.

A contact bed, contact aerator, trickling filter, rotating disks, or other attached-growth systems consist of a bed of coarse contact media such as granite, limestone, clinkers, wood slats, plastic tubes, corrugated plastic sections, hard coal, or other material over which wastewater is distributed or contacted. Wastewater flows over the contact media on which a biological slime layer develops. Dissolved organic pollutants in the wastewater are transported into the slime layer, where biological oxidation takes place. Organic pollutants are removed by the biological slime film, which consists of various microorganisms. In the outer portions of the film, organic pollutants are degraded by aerobic and facultative bacteria. Transfer of oxygen in slime layer and liquid film, transfer of substrate in liquid film and slime layer, types of trickling filters, performance models, and design procedures are discussed. This book chapter also introduces recent advances in biological wastewater treatment processes involving the use of dissolved air flotation for primary flotation clarification, secondary flotation clarification, tertiary flotation clarification, flotation sequencing batch reactor, and flotation sludge thickening.

The endocrine system regulates all biological processes in the body from conception through adulthood and into old age, including the development of the brain and nervous system, the growth and function of the reproductive system, as well as the metabolism and blood sugar levels. Endocrine disruptors are chemicals that either mimic endogenous hormones, interfere with pharmacokinetics, or act by other mechanisms resulting in adverse effects such as compromised reproductive fitness, functional or morphological birth defects, cancer, and altered immune functions.

Recently, public concern has focused on the possible hormonal effects of some environmental pollutants on wildlife and humans. These chemicals, referred to collectively as endocrine disruptors, comprise a wide range of substances including pesticides (methoxychlor), surfactants (nonylphenol), plasticizers (diethylphthalate), and organohalogens (polychlorinated biphenyls or PCBs and dioxin).

The feasibility of using the various techniques for the removal of the endocrine disruptors will depend on the size of the system and the cost-effectiveness. The two major concerns regarding technologies for small systems are affordability and technical complexity (which determine the needed skills for the system operators). The removal processes of these chemicals from water supply include granular activated carbon; powdered activated carbon; coagulation/filtration; and lime softening.

Thermal pollution is produced by industries such as electric power plants, pulp and paper mills, chemical facilities, and other process industries that use water and subsequently discharge water with elevated temperature. The receiving streams, rivers, lakes, and other waters can dramatically alter the native environment. Often, elevated water temperature will be detrimental to native species of plants and animals. As water warms, the solubility of oxygen decreases. In addition to promoting competitive species of plants and animals, warmed waters may lead to aesthetic and odor problems if anaerobic conditions are created. For these and many other reasons, the discharge of warm process water is widely regulated by governmental agencies in developed nations. The authors introduce both cooling ponds and cooling towers in detailed. The cooling pond topics covered are mechanism of heat dissipation, cooling pond types and design, completely mixed cooling, recirculation cooling, surface temperature prediction, longitudinal mixing, heat dissipation evaluation, once-through cooling ponds, seasonal weather variation, pond location, cooling, etc. The cooling tower topics covered are mechanism of cooling tower’s heat dissipation, cooling tower types and designs, natural draft atmospheric cooling towers, natural-draft wet hyperbolic cooling towers, design examples, hybrid draft cooling towers, induced, mechanical or forced wet cooling towers, cooling tower performance, operational problems and solutions, and reuse of thermal discharge.

This chapter introduces the basic hydrology, water resources, and a dissolved air flotation (DAF) boat plant for lake water treatment. Specific coverage includes special features of water and their relationship to life on earth, hydrology, evaporation, transpiration, evapotranspiration, infiltration, percolation, runoff, ground water, impact of pollution on lakes, thermal impacts on the aquatic environment, toxics in water resources, goals of water pollution control, dissolved air flotation boat plant for lake restoration, glossary, and a list of authors’ recent publications.

Cadmium (Cd) is often found in industrial sludge, fly ash, slag, and flue gas, and it presents serious risks to the environment and biota. Stabilizing and detoxifying Cd in waste streams is thus of great importance. The use of various low-cost and attainable ceramic matrices (amorphous SiO₂, γ-Al₂O₃, α-Fe₂O₃, and Fe₃O₄) to interact with Cd-containing waste is a promising method of Cd stabilization. Heating mixtures of cadmium oxide (CdO) and ceramic matrices at various molar ratios and temperatures (600–1000 °C) for 3 h could achieve the goal of Cd incorporation. Phase transformation was assessed using X-ray diffraction (XRD), and the efficiency of Cd incorporation was quantified through Rietveld analysis of the obtained XRD patterns. The XRD results show that Cd can be crystallochemically incorporated into CdSiO₃, Cd₂SiO₄, Cd₃SiO₅, CdAl₄O₇, and CdFe₂O₄ phases. The treatment temperature greatly affected the Cd incorporation reactions. The Cd incorporation efficiency was quantified and expressed as a transformation ratio according to the weight fractions of crystalline phases in the sintering products. To evaluate the metal stabilization effect of the Cd detoxification process, a series of constant-pH leaching tests was conducted. A remarkable reduction in Cd leachability was achieved by forming different Cd-hosting crystalline products, particularly spinel phase CdFe₂O₄. Overall, the efforts to stabilize Cd by sintering with ceramic matrices suggest a promising strategy for the detoxification of Cd in wastes.

Vegetable oils are mainly extracted from soybean, sesame, sunflower, corn, canola, and cotton seeds. Their yields, compositions, and physical and chemical properties determine their usefulness in various applications aside from edible uses. Crude oils obtained by pressing of such vegetable seeds are not usually considered to be edible before the removal of various nonglyceride compounds through an operation known as refining. The vegetable oil refinery uses various types of physical and chemical processes to offer a premium quality of oil. The refining processes remove undesirable materials, such as phospholipids, monoacylglycerols, diacylglycerols, free fatty acids, color and pigments, oxidized materials, etc., but may also remove valuable minor components, such as antioxidants and vitamins (carotenes and tocopherols). The major steps involved in chemical refining include degumming, deacidification, deodorization, and neutralization processes. During these processes, a high amount of water is used, and highly polluted effluents are formed. The treatment of vegetable oil refinery wastewaters has been a major problem of environmental concern in developing countries for the last decades due to their complex nature consisting of water and soluble and insoluble substances that contain fats and oil, carbohydrates, phenolic compounds, and suspended solids. Therefore, a suitable wastewater treatment prior to their discharge into the receiving bodies is required. Numerous treatment technologies have been applied to treat oily wastewaters. Coagulation/flocculation, electrocoagulation, reverse osmosis, flocculation/membrane filtration, air flotation, microfiltration, and enzymatic catalysis are the most common ones. However, due to the complex nature and low biodegradability of the oily wastewater, some of these technologies may not be efficient in treating such wastewaters, while others may be of high cost and generally require a pretreatment. As a result, in this chapter, the processes involved in the vegetable oil refining, the environmental impacts of those processes, the characterization of the waste produced during the processes, waste reduction at source, recovery from waste, and treatment technologies are discussed.

Among the plants and animals inhabiting the earth, there are very few taxonomic categories that do not contain some organisms capable of producing human sickness or of causing economic loss, or that simply may be classified as nuisances, i.e., a “pest.” Control of undesirable pests (i.e., certain plants, insects, animals, and microbes) includes both the management of the pest occurrence (e.g., the rodent) as well as any vector organisms that may carry a pathogen (e.g., a malaria-carrying mosquito). Such control or management of the occurrence of pests is addressed by both environmental approaches and that of pesticides. As a necessary precursor to the application of pesticides, successful strategies are employed in the environmental control of undesirable organisms through manipulation of the physical and ecological factors within the pest habitat. Together, this approach is regarded as Integrated Pest Management (IPM). Pesticide approaches encompass a wide arrange of organic and inorganic chemistries, which for many years have been developed to both great success and unintended damage to nontarget organisms, including humans. Specific pests and vectors are to be discussed within this chapter that highlight the economic impact of such agents on human health and agricultural productivity.

The authors have reviewed six technical books published by the Water Environment Federation (WEF), Alexandria, VA, USA, in 2014–2018. These six books are (1) Wastewater Biology: The Microlife, Third Edition, 2017; (2) Guidelines for Grit Sampling and Characterization, 2016; (3) Activated Sludge and Nutrient Removal, Manual of Practice No. OM-9, Third Edition, 2018; (4) The Nutrient Roadmap, 2015; (5) Wet Weather Design and Operation in Water Resource Recovery Facilities, 2014; and (6) Operation of Water Resource Recovery Facilities Study Guide. (2018). All six reviewed books are in the professional area of wastewater treatment and resources recovery. In each book review, the authors introduce the publisher, authors, editors, and previous old editions of the book if they exist. Each book is reviewed and discussed in terms of its technical coverage, professional level, area of applications, affordability to readers, advantages, disadvantages, suitability for international distribution, recommended readership, possible improvements, etc.

This chapter presents the technical terms and acronym terms in the wide academic areas of environmental engineering and natural resources management. The authors have tried their best to selectively cover the subject areas in the Handbook of Environmental Engineering (HEE), Volume 19 (Environmental and Natural Resources Engineering), Volume 20 (Integrated Natural Resources Management), Volume 21 (Environmental Flotation Engineering), and Volume 22 (Integrated Natural Resources Research).