Contaminated Soil

Ex Situ Bioremediation Technologies

Bioremediation Background

In many cases, it is necessary to move the contaminated soil or groundwater to a site where a suitable treatment system can be engineered. Contaminated soil may be excavated and moved to landfills to thermal treatment systems, e.g., incinerators or to a variety of bioremediation systems including biopiles, windrows for composting, landfarms, and soil slurry reactors. All have their merits. The choice of which technology to use often is driven by the required performance criteria, i.e., the...

Phyto- And Zootoxic Metals

Images Lead Metal Biomagnification

FIGURE 1.20 Metabolic pathway for the aerobic biod gradation of 1-CDD (140). A and B, sites of attack by the initial dioxygenase. FIGURE 1.21 Gene organization for dioxin metabolism in Sphingomonas sp. strain RW1. Six fragments of the RW1 genome which are probably involved in dibenzofuran and dioxin degradation are shown. Genes coding for the initial dioxin dioxygenase (boxed) are indicated. FIGURE 1.21 Gene organization for dioxin metabolism in Sphingomonas sp. strain RW1. Six fragments of the...

Renewable Resources

Plant and animal sources have provided industrial raw materials, such as timber, paper, vegetable oils, tallow, and many others, for centuries. Following the first production of crude oil, however, this abundant and cheap resource quickly became the principal raw material for a burgeoning chemical industry. Only in times of conflict, when resources take on a strategic importance, has there been any significant return to natural raw materials. Today, with increasing attention being paid to...

Contaminants Biodegraded By Bioventing

Bioventing Iumages

Bioventing has found its niche in the in situ treatment of fuel spills (322). Whereas fresh gasoline may be too volatile to be treated by true bioventing, bioventing has been used many times for the full-scale bioremediation of diesel (88) and kerosene (35) spills. It has also been used successfully on PAHs (187) and a mixture of acetone, toluene, and naphthalene (174). Bioventing is not considered appropriate for the treatment of PCBs and other chlorinated hydrocarbons. However, deliberate en...

The Need For Bioremediation

The major reasons for the control of water and soil pollution and the consideration of bioremediation are first and foremost, public health concerns second, environmental conservation and finally, the cost of decontamination. Clean water is essential to agriculture and industry, and for most countries water is a finite resource which has to be kept free of pollutants. Maintenance of safe potable water supplies is a major health concern around the world. The arguments for uncontaminated soil are...

Rcra Contaminated Soil

The Resource Conservation and Recovery Act (RCRA) (42 U.S.C. 6901 et seq. 2000 ), enacted in 1976, implemented a comprehensive program to regulate the treatment, storage, and disposal of solid and hazardous waste within the United States. When enacted, the goals of RCRA were as follows to protect human health and the environment from the hazards posed by waste disposal to conserve energy and natural resources through waste recycling and recovery to reduce or eliminate, as expeditiously as...

References

Lutze, and H. E. Nuttall. 1998. Reduction ofU(VI) to U(IV) by indigenous bacteria in contaminated ground water .J. Contam. Hydro . 35 217 233. 2. Abdelouas, A., W. Lutze, andE. H. Nuttall. 1998. Chemical reactions of uranium in groundwater at a mill tailings site. J. Contam. Hydrol. 34 343-361. 3. Abdelouas, A., W. Lutze, and H. E. Nuttall. 1999. Uranium contamination in the subsurface characterization and remediation, p. 433-473. In P. C. Burns andR. Finch (ed.),...

Deoxygenation

Whereas toxicity is a pollution effect with major implications for human health, deoxy-genation is much more an ecotoxicological effect. Deoxygenation of water has serious consequences for the biota of surface water and contaminated soils. Groundwater and soil pore water deoxygenation slows natural attenuation of contamination to negligible levels. The problem of water deoxygenation stems fundamentally from the limited aqueous solubility of oxygen. Moreover, the solubility of oxygen in water is...

Factors Affecting Bioremediation

Phage Reduction Assay

Bioavailability is extremely important to biodegradation of organic pollutants. It is frequently observed that the rate of removal of compounds from soils is very low even though the compounds are biodegradable. However, the substrates in these instances may not be in a form that is readily available to the microorganisms. Biodegradation of hydrophobic pollutants may take place only in the aqueous phase for example, naphthalene (143) is utilized by pure cultures of bacteria only in the...

Extraction Procedures For Metals

For the determination of metal in soils and other solid media, acid digestion is commonly used to break down the sample matrix. The acids commonly used are nitric, hydrochloric, sulfuric, and perchloric acid, and for organic-rich matrices, an oxidizing agent such as hydrogen peroxide can be applied. Samples can be digested either under reflux, on a hot plate, or with the aid of microwave heating. After digestion is complete, samples are filtered through hardened ashless filter paper prior to...

Blower Sizing For Soils Vapor

Biosparging

Where E is pore volume exchange time (in hours), 0 is total porosity (in cubic centimeters of vapor per cubic centimeter of soil), and Q is total vapor flow rate (cubic meters of vapor per hour). Oxygen Radius of Influence. The radius of influence is defined as the maximum radius to which oxygen has to be supplied to sustain maximal biod gradation. Radius of influence is the most important factor that directs engineering design of full-scale bioventing systems once the soil gas permeability and...

Tetrachlorobipheny

Pentachlorophenol 2,4,6-trichlorophenol FIGURE 1.12 Structures of two examples of chlo-rophenols PCP and trichorophenol. the triazole fungicides (Fig. 1.14). The insolubility and hydrophobicity of some chloroaro-matics make them useful industrial solvents. The chlorobenzenes exist as a group of 12 compounds. Historically, the chlorobenzenes were used in the synthesis of DDT, but now the most important use is in the synthesis of aniline dyes and a variety of pesticides. Biod gradation of...

Failures Of Nutrient Biostimulation

Biostimulation has been used successfully in bioremediation much more often than it has failed. The reasons for failure, however, are usually unclear, and understanding these reasons may be crucial to the acceptance of bioremediation as a full-scale technology. Possible reasons advanced by Alexander (10) are high levels of nitrogen and phosphorus already present in the soil which may make further fertilization futile, the presence of nitrogen and phosphorus in the pollutants (also see reference...

Windrow Forming And Turning

Windrow Formation

Comments similar to those for bed construction pertain to windrow composting and bio-pile construction, except that for windrows there is no added complication of installing piping runs for aeration. Mixing can be done during windrow formation. For example, if wood chips are to be used for bulking, and the soil-to-chips volume ratio has been calculated, then the wood chips can be laid out on the windrow bed along with, say, pellet NPK fertilizer, then the moist soil, and any additional...

Landfarm Operation

The main activities of landfarm operation are placing of contaminated material, aeration, watering, fertilization, and removal of treated material. The most important of these is aeration. The soil amendments are as for other ex situ bioremediation technologies. The critical issues, as always, are water and oxygen. FIGURE 5.13 Photograph of experimental landfarm plots at an oil sludge storage facility, Perm, Russia. The left half of the plot has been sown with common Russian grasses. One plot...

Biodesulfurization Of Gasoline

Conventional hydrodesulfurization of gasoline is an expensive and energy-intensive process requiring high temperature and pressure see reference 61 . Expensive processes are required to generate hydrogen and to convert the main by-product, hydrogen sulfide, into elemental sulfur. The conventional process saturates olefins in the gasoline, which results in a lowered octane rating. Biodesulfurization BDS offers potential cost savings because the process operates at ambient temperature and...

Lca Techniques

An LCA can be conducted at different levels, depending on the purpose and application. At its simplest, an assessment of environmental aspects can be based on limited and usually qualitative inventory. A so-called screening LCA or streamlined LCA covers the whole life cycle, with the aim of providing essentially the same results as a detailed LCA, but with a significant reduction in expense and time. In order to ensure that the overall result gives a true picture of the impact, a quality check...

Assessment In Practice

Novo-zymes has published data on their process for removing residual hydrogen peroxide after bleaching prior to dyeing (bleach cleanup). This step uses the enzyme catalase, which has the following advantages it has no adverse ef fects on dyestuffs, there is no need to heat or rinse prior to dyeing, there is no risk of harmful overdosing, and there is no formation of byproducts in wastewater. Catalase is biodegradable and is not toxic for aquatic organisms. A...

Successes And Failures Of Bioaugmentation

The current situation is that there are many recorded successes and failures of bioremedia- tion treatment of soil contaminants (90). Some examples of successful bioaugmentation for degradation of recalcitrant pollutants are use of pure cultures of bacteria for atrazine (287), a consortium for atrazine (230), a pure culture for 2,4,6-trichlorophenol (17), a pure culture for pentachlorophenol (70), and activated soil for pentachlorophenol (33). In some cases where bioaugmentation has been...

Production Of Ammonium Acrylate

Ammonium acrylate is conventionally manufactured by the chemical conversion of acrylo-nitrile to acrylic acid, which is subsequently neutralized with ammonia. The first biological process, based on two sequential enzyme catalysts, nitrile hydratase and amidase, had the disadvantage that there existed the possibility of a buildup of the toxic intermediate acrylamide. A breakthrough came with the discovery of a species of Rhodococcus possessing a nitrilase enzyme which was capable of converting...

Formulations Of Inorganic Nutrients

Adas and Bartha (24) observed dramatic mineralization of crude oil upon stimulation with ni trogen and phosphorus, but limited stimulation with either one singly. Subsequent studies have shown the need for nitrogen and phosphorus as the primary nutrient additions in bioremediation. Nearly always, the supply of potassium, sulfur, magnesium, calcium, iron, and trace elements is greater than the demand (10). Common commercial NPK fertilizers are used, but the influence of potassium is often...

Biostimulation

Contamination Scanning

An alternative to increasing numbers of biode-grading microorganisms on the site is the practice of biostimulation. Biostimulation aims at FIGURE 5.30 Scanning electron micrograph of bacteria emerging from bulges in a PVA immobilization gel. Such evidence suggests that it should be possible to manufacture engineered slow-release bioaugmentation. FIGURE 5.30 Scanning electron micrograph of bacteria emerging from bulges in a PVA immobilization gel. Such evidence suggests that it should be...

Alternative Electron Acceptors

Denitrifying bacteria can be rapidly stimulated when supplied with a source of carbon and nitrate. Typically, acetate is supplied as a growth substrate, and nitrate and or sulfate is supplied as an alternative electron acceptor to oxygen for the bioremediation of CAH (e.g., see references, 284 and 285). Providing nitrate to the subsurface is less expensive than maintaining aerobic conditions, and as nitrate is highly soluble, it is easier to maintain a residual concentration in groundwater...

Microtiter Platebased Mpn Techniques

Bacterial Contamination Plate Images

As a result of the limitations of traditional solid-agar-based enumeration methods, liquid culture methods have been developed by employing the most-probable-number (MPN) FIGURE 6.2 Bacterial colonies growing on an agar plate with a thin film of phenanthrene applied by the spray-plate technique. The cleared halo surrounding colonies is evidence of phenanthrene biotransformation. FIGURE 6.2 Bacterial colonies growing on an agar plate with a thin film of phenanthrene applied by the spray-plate...

The Evolution Of Bioremediation

Microorganisms, especially bacteria, have benefited from time, evolving into many types with exceedingly diverse metabolic capabilities which can be utilized in bioremediation. Bacteria have existed on the planet for perhaps 3 billion years or so. Given their small size, large surface-to-volume ratio, very high rate of growth and division, and genome plasticity, bacteria evolve quickly. Yet it is only within approximately the last century that a vast array of synthetic chemicals which appear to...

Microbial Methods For Monitoring Bioremediation

For bioremediation to be considered as a remediation technology, it is critical to establish that there is an adequate active microbial population that is capable of attacking the specific contaminant(s). If the site has the requisite values for water content and pH, has porosity within the desirable range, and is contaminated with only petroleum hydrocarbons, then there is a very good chance that there will be an active population of hydrocarbon-oxidizing microorganisms in the soil and that...

Demonstrating Efficacy Of Bioremediation For Marine Oil Spills

It has been a major challenge to provide statistically significant evidence that bioremediation is truly effective in removing oil from a shoreline. It sounds relatively simple surely one measures the amount of oil in two representative sections of shoreline, applies fertilizer to one, and returns after some reasonable time to measure the amount of oil remaining. However, there are several reasons why this is complex. The major one is that the heterogeneity of the natural world leads to huge...

Process Assessment And Sustainable Development

Deciding whether or not to adopt a new industrial process, be it based on biotechnology or conventional physics and chemistry, requires a number of important decisions. However, the point at which these decisions are made is only the crossroads at which many different pieces of information converge and from which the process will travel down one of a number of alternative routes. An essential rationale for the use of biotechnology is that it is thought to bring increased sustainability and...

Gypsum Reduction In Zinc Refining

Budel Zink BV has operated a zinc refinery at Budel-Dorplein in The Netherlands since 1973. Over 200,000 tons of zinc is produced annually. The conventional roast-leach-elec-trowin process produces various wastewater streams containing sulfate and zinc. Until mid-2000, these streams were treated conventionally by neutralization with milk of lime, resulting in the production of gypsum which was stored on-site. The Dutch government indicated that they would prohibit further storage of residues...

Introduction

A combination of economic, environmental, and social pressures, the so-called triple bottom line, is driving companies in a wide spectrum of industries to explore and use alternative manufacturing processes and to develop novel, environmentally friendly products. In essence, industry is turning to preemptive bioremedia-tion as a strategy to reduce potential environmental problems and liabilities and make industrial products and processes more sociably acceptable in an age of ecoactivism....

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BOX FIGURE 8.1.1 Flow scheme (left) and photograph (right) of a pilot plant for removal of mercury from wastewater by mercury-resistant bacteria. The plant includes pH adjustment to pH 7, nutrient amendment, the bioreactor (volume, 1 m3), a buffering tank, and a polishing carbon filter. Continuous automated Hg measurement is performed at the inflow, after the bioreactor, and at the outflow. pH is measured before and after adjustment to pH 7. Other parameters determined continuously are chlorine...

Date Samples 120489 Sample 89cem 377 Photo Date 010390

FIGURE 6.3 Illustration of a five-tube MPN result for a marine sediment sample obtained by the sheen screen method. The 10 2 and 10 3 dilutions are all positive for crude oil emulsifications, four of five of the 10 4 dilution tubes are scored positive, and one of five of the 10 5 dilution tubes scored positive. Courtesy of Ed Brown, University of Northern Iowa. 10'2 10'3 104 105 106 107 10'8 109 FIGURE 6.3 Illustration of a five-tube MPN result for a marine sediment sample obtained by the sheen...

Contaminants Treated By Biosparging

In a manner analogous to the comparison between SVE and bioventing, air sparging and biosparging are suited to the treatment of different contaminants, although there is inevitable overlap. Air sparging utilizes higher airflow velocities and the treatment is therefore dominated by volatilization, with some incidental biod gradation. The lower flow velocities of biosparging favor biod gradation over volatilization. Biosparging is most often used at sites with groundwater contamination by middle...

Defining Contaminated Land

The public's perception of contaminated land has a tendency to be shaped by catastrophic accidents, such as the infamous Love Canal in the United States, where the dumping of toxic wastes into a waterway endangered the health of residents of an estate subsequently developed on the area, or the Lekkerkerk incident in The Netherlands, in which 800 residents were evacuated from homes that had been built on a former refuse tip near Rotterdam (45). Highprofile incidents such as these have led to...

Bioremediation And Its Place In The World

The past century witnessed a vast increase in global pollution. Industrial development, population growth, urbanization, and a disregard for the environmental consequences of releasing chemicals into the environment all contributed to the modern pollution situation. A huge range of industries, including most notably the oil and gas industry, contributed to the problem Table 1.1 . There was a large increase in the diversity of organic compounds that are industrially produced and which were...