Preface

Over hundreds of years, the Industrial Revolution has caused serious worldwide contami‐ nation problems since humans started to develop industrial processes. The environmental consequences of rapid industrialization have included air, water, and upper soil layers be‐ ing contaminated with many potentially harmful pollutants due to the industrialization process, which has introduced a large number of products that nature cannot, or can only very slowly, decompose or degrade.

Decision-makers, scientists, occupational health and safety authorities, and individual citi‐ zens generally accept and understand that soil contamination can have negative consequen‐ ces on ecosystems, but the impacts of such soil contamination on our health and the health of other living species are not so well understood. The ability to detect potential contami‐ nants in this environmental matrix can help us identify emerging health threats to living organisms and ecosystems.

Diverse sources contribute to soil pollution, generating a large proportion of toxicities for living species. Over many decades, urban development, industrial and man-made pollu‐ tants, farming, mining, military activities, and accidents have introduced excessive amounts of contaminants into the environment, causing a decline in the health of soil with uncertain future uses. Each type of soil contaminant is characterized by its origin or what type of product it was before it became waste. The most frequent contaminants of soil are heavy metals such as arsenic, lead, cadmium, chromium, copper, and mercury, among others. As‐ bestos contamination in the soil is of concern in a number of locations, because it can be released into the air. Similarly, dioxins and dioxin-like chemicals are a group of structurally and chemically related polychlorinated compounds that are persistent for a long time in soils. Another source of contamination is organic (carbon-based) pollutants, which include numerous types of chemicals of organic origin or that could be produced by living organ‐ isms or are based of matter formed by living organisms. Common organic chemical pollu‐ tants include crude oil and refined petroleum products, solvents, chlorinated solvents, polyaromatic hydrocarbons, polychlorinated biphenyl ethers, alcohols, trihalomethanes, phenols, plastics, pesticides, detergents, and organometallic compounds, among others, and some are referred to as persistent organic pollutants, which do not break down quickly in the environment.

It is a matter of international concern, and several public and private administrations em‐ ploy a wide variety of technologies to ensure the decontamination and recovery of affected sites. However, cleaning up contaminated sites is a long and expensive process. Thus, envi‐ ronmental remediation is an important focus of the green economy, and a wide variety of innovative technologies must be employed to remove pollution or contaminants from waste areas to restore the environment and protect the health of living species, including humans.

This single volume comprises seventeen high-quality chapters, organized in two sections, describing several issues related to soil contamination. The first section, "Contamination Sources," comprises nine excellent chapters, starting with a comprehensive appraisal of the use of in-field and edge-of-field technologies to virtually eliminating nutrient migration from cropland and protecting water systems. This is followed by a second chapter review‐ ing the problem existing in greenhouses using traditional methods of cultivation, where soil pollution is mostly due to the use of excessively high doses of fertilizers. The third chapter presents an update describing the effects of different fertilizers, especially municipal wastes, inorganic fertilizers, and a mixture of both fertilizers, on soil fertility and plant productivity. The fourth chapter is an interesting study showing strategies on the management of Cu-con‐ taminated Mediterranean agricultural soils by evaluation of the effect of Cu and its interac‐ tion with soil properties on biomass production in two horticultural species. The fifth chapter is an interesting overview about the methods employed to measure microbial diver‐ sity in contaminated sites, and it focuses on the identification of several groups of microor‐ ganisms present in soils contaminated with polycyclic aromatic hydrocarbons. The sixth chapter presents a review about cyanotoxins as contaminants of emerging concern in soil, identifying sources of contamination, determining their fate and effects in the soil, and un‐ derstanding their bioaccumulation in agricultural plants used for feed and food and the con‐ sequences on animal and human health. The seventh chapter depicts the main sources of soil contamination in forest and industrial areas of Bulgaria, including soil acidification and eutrophication processes as well as accumulation of heavy metals in forest and industrial soils. The eighth chapter summarizes the evolution of groundwater systems and soil envi‐ ronments and presents an analysis of the main factors contributing to soil salinization and the erosion of underground structures in northern China. Last, the ninth chapter of this sec‐ tion provides a review of the literature on the key functional description of the use of munic‐ ipal wastewater for agricultural irrigation, including the mid- and long-term effects of irrigation by wastewater on plant, soil, and human health.

The second section of this book, "Soil Remediation," emphasizes integrated remediation ap‐ proaches for detecting potentially biohazardous contaminants. The tenth chapter evaluates the degradation of the herbicide atrazine in a clay loam soil microcosm using fungal enzyme extracts alone or in coculture to determine the kinetic parameters of the adsorption-desorp‐ tion of atrazine in soil. The eleventh chapter presents the results of a number of beneficial conclusion studies employing plant growth–promoting rhizobacteria and enzyme activities and discussing different heavy metal pollutions and remediation processes. The twelfth chapter presents a review of the processes and technologies that allow the simultaneous re‐ moval/destruction/immobilization of more than one class of contaminants in soils, focusing on dual decontamination of at least two different pollutants: one being an inorganic com‐ pound and the other an organic compound. The thirteenth chapter aims to highlight the im‐ portance of evaluating radionuclide distribution for the selection of proper in situ or ex situ remediation strategies, focusing on remediation methods based on radioactive pollutant re‐ distribution. The fourteenth chapter is an interesting overview about the environmental role of earthworms in the formation of soil properties and presents a set of studies where earth‐ worms were employed to analyze the effect of tropho-metabolic activity on the maintenance of remediated artificial soil stability against the impact of soil contamination by copper. The

fifteenth chapter describes the implementation of electroremediation techniques as attractive options for dealing with environmental problems caused by contamination by organic and inorganic compounds. The sixteenth chapter is an excellent review about the potential of surfactants in the bioremediation of contaminated soil using an ex situ approach, with con‐ siderations given to the practical aspects of field components. Finally, this book ends with a chapter highlighting the current status of bioaugmentation, biostimulation, and bioattenua‐ tion techniques, which have been applied in polycyclic aromatic hydrocarbon-contaminated agricultural soils during the last decades.

innovative technologies must be employed to remove pollution or contaminants from waste areas to restore the environment and protect the health of living species, including humans. This single volume comprises seventeen high-quality chapters, organized in two sections, describing several issues related to soil contamination. The first section, "Contamination Sources," comprises nine excellent chapters, starting with a comprehensive appraisal of the use of in-field and edge-of-field technologies to virtually eliminating nutrient migration from cropland and protecting water systems. This is followed by a second chapter review‐ ing the problem existing in greenhouses using traditional methods of cultivation, where soil pollution is mostly due to the use of excessively high doses of fertilizers. The third chapter presents an update describing the effects of different fertilizers, especially municipal wastes, inorganic fertilizers, and a mixture of both fertilizers, on soil fertility and plant productivity. The fourth chapter is an interesting study showing strategies on the management of Cu-con‐ taminated Mediterranean agricultural soils by evaluation of the effect of Cu and its interac‐ tion with soil properties on biomass production in two horticultural species. The fifth chapter is an interesting overview about the methods employed to measure microbial diver‐ sity in contaminated sites, and it focuses on the identification of several groups of microor‐ ganisms present in soils contaminated with polycyclic aromatic hydrocarbons. The sixth chapter presents a review about cyanotoxins as contaminants of emerging concern in soil, identifying sources of contamination, determining their fate and effects in the soil, and un‐ derstanding their bioaccumulation in agricultural plants used for feed and food and the con‐ sequences on animal and human health. The seventh chapter depicts the main sources of soil contamination in forest and industrial areas of Bulgaria, including soil acidification and eutrophication processes as well as accumulation of heavy metals in forest and industrial soils. The eighth chapter summarizes the evolution of groundwater systems and soil envi‐ ronments and presents an analysis of the main factors contributing to soil salinization and the erosion of underground structures in northern China. Last, the ninth chapter of this sec‐ tion provides a review of the literature on the key functional description of the use of munic‐ ipal wastewater for agricultural irrigation, including the mid- and long-term effects of

The second section of this book, "Soil Remediation," emphasizes integrated remediation ap‐ proaches for detecting potentially biohazardous contaminants. The tenth chapter evaluates the degradation of the herbicide atrazine in a clay loam soil microcosm using fungal enzyme extracts alone or in coculture to determine the kinetic parameters of the adsorption-desorp‐ tion of atrazine in soil. The eleventh chapter presents the results of a number of beneficial conclusion studies employing plant growth–promoting rhizobacteria and enzyme activities and discussing different heavy metal pollutions and remediation processes. The twelfth chapter presents a review of the processes and technologies that allow the simultaneous re‐ moval/destruction/immobilization of more than one class of contaminants in soils, focusing on dual decontamination of at least two different pollutants: one being an inorganic com‐ pound and the other an organic compound. The thirteenth chapter aims to highlight the im‐ portance of evaluating radionuclide distribution for the selection of proper in situ or ex situ remediation strategies, focusing on remediation methods based on radioactive pollutant re‐ distribution. The fourteenth chapter is an interesting overview about the environmental role of earthworms in the formation of soil properties and presents a set of studies where earth‐ worms were employed to analyze the effect of tropho-metabolic activity on the maintenance of remediated artificial soil stability against the impact of soil contamination by copper. The

irrigation by wastewater on plant, soil, and human health.

X Preface

The editors of *Soil Contamination - Current Consequences and Further Solutions* are enormously grateful to all the contributing authors for sharing their knowledge and insight in this inter‐ disciplinary book project. They have made an extensive effort to arrange the information included in every chapter. The publication of this book is of high importance for researchers, scientists, and engineers in diverse fields with expertise in soil science, health, toxicology, and other disciplines who contribute and share their findings to take this area forward for future investigations.

**Marcelo L. Larramendy PhD and Sonia Soloneski PhD**

School of Natural Sciences and Museum National University of La Plata La Plata, Argentina

**Contamination Sources**

#### **Edge of Field Technology to Eliminate Nutrient Transport from Croplands: Specific Focus on Denitrification Bioreactors Edge of Field Technology to Eliminate Nutrient Transport from Croplands: Specific Focus on Denitrification Bioreactors**

Michael Aide, Indi Braden and Sven Svenson Michael Aide, Indi Braden and Sven Svenson Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/64602

#### **Abstract**

Tile drainage effluent from agriculture fields is beneficial to production agriculture; however, nitrate and phosphate transport from production fields to surface water resources is an environmental concern. The David M. Barton Agriculture Research Center (Cape Girardeau County, Missouri, USA) has a 40 ha controlled subsurface tile drainage/irrigation technology with associated denitrification bioreactor. Nitratebearing effluents from the controlled subsurface tile drainage/irrigation technology under a corn (*Zea mays* L.)-soybean (*Glycine max* L) rotation is sufficient to be an environmental concern. Nitrate-bearing effluent passage through the denitrification bioreactor typically promotes sufficient nitrate reduction (denitrification) that the bioreactor effluent water is less than 10 mg NO3-N/L. Phosphorus, ammonium-N, and sulfate-S concentrations are not appreciably influenced by denitrification bioreactor passage.

**Keywords:** bioreactors, nitrate, controlled drainage, water quality, denitrification
