which of the following technologies is/are not typically used alone for groundwater treatment?

What is the best book on in situ chemical oxidation for groundwater remediation?

Jan 24, 2002 · The stormwater treatment practices listed in this section, referred to as primary stormwater treatment practices, are capable of providing high levels of water quality treatment as stand-alone devices. A growing body of research on stormwater treatment practices throughout the United States, as well as field experience in Connecticut and other northeastern states, has …

Where does groundwater come from?

4.1.2 Pump and treat. Pump and treat is a common method for cleaning up groundwater contaminated with dissolved chemicals, including industrial solvents, metals, and fuel oil. Groundwater is pumped from wells to an above-ground treatment system that removes the contaminants. Pump and treat systems also are used to contain the contaminant plume.

How is groundwater impacted by PFAS treated?

Limited application technologies–Technologies that have been implemented on a limited number of sites, by a limited number of practitioners, and may not have been documented in peer-reviewed literature.These limited application technologies for liquids and solids are contained in the technology comparison Tables 12-1 and 12-2 (provided as separate PDF) and discussed in …

Can GAC be used to treat organic contaminants in groundwater?

Nov 08, 2018 · These rocks have different porosity and permeability characteristics, which means that water does not move around the same way in all rocks below ground. When a water-bearing rock readily transmits water to wells and springs, it is called an aquifer. Wells can be drilled into the aquifers and water can be pumped out.

Which of the following is a method of groundwater remediation?

The most basic type of groundwater remediation, uses air to strip water clean (air sparging). Another method, called pump and treat, physically removes the water from the ground and treats it by way of biological or chemical means. Both of these methods have proven successful in treating contaminated groundwater.

What types of technologies can be used for site remediation and how do they work?

TechnologiesThermal desorption.Excavation or dredging.Surfactant enhanced aquifer remediation (SEAR)Pump and treat.Solidification and stabilization.In situ oxidation.Soil vapor extraction.Nanoremediation.More items...

What is remediation technology?

Click on the section that you are interested in to read more. Remediation Technology Types. Air Sparging involves the injection of air or oxygen through a contaminated aquifer to remove volatile and semivolatile organic contaminants by volatilization.Jul 19, 2021

How are Pfas treated in groundwater?

Activated carbon treatment is the most studied treatment for PFAS removal. Activated carbon is commonly used to adsorb natural organic compounds, taste and odor compounds, and synthetic organic chemicals in drinking water treatment systems.Aug 23, 2018

What are examples 3 of types of remediation?

The main three types of environmental remediation and reclamationSoil remediation. There are many factors that affect the soil condition. ... Groundwater and Surface water remediation. ... Sediment remediation. ... Sources.

What is remediation and types of remediation?

Technical principles for remediation can be divided into physical, chemical and biological processes. Techniques frequently used are: containment, pump-and-treat, extraction, stabilization/solidification, soil washing, air stripping, precipitation, vitrification, thermal desorption, and bioremediation.

What are examples of remediation?

An action taken to remedy a situation. Remediation is the act of correcting an error or stopping something bad from happening. When a company that polluted takes steps to clean up the water supply, this is an example of remediation. The act or process of remedying.

What is reclamation and remediation?

Remediation involves containment, removal, or stabilization of contaminants from soil, groundwater and vapour. Reclamation involves physical reconstruction of soils and terrain on a disturbed site to achieve equivalent land use capability as to what existed before disturbance.Mar 14, 2018

Which of the following is the most reliable method of soil remediation?

For the remediation of soils polluted with organic compounds, incineration is the most widely used method.

Can PFAS be removed from groundwater?

The most common treatment approach for achieving PFAS risk removal is groundwater extraction and filtration. This approach involves interceptor wells that pump groundwater to the surface and filter out the PFAS using granular activated carbon or ion-exchange resins.Jan 28, 2022

What are PFAS used for?

PFAS are man-made chemicals that have been used in industry and consumer products worldwide since the 1950s. They have been used in non-stick cookware, water-repellent clothing, stain resistant fabrics and carpets, some cosmetics, some firefighting foams, and products that resist grease, water, and oil.

How is groundwater contamination treated?

Common RemediesPump and treat is a common method for cleaning up groundwater contaminated with dissolved chemicals, including industrial solvents, metals, and fuel oil. ... In situ treatment occurs when groundwater is treated in place without extraction from the aquifer.More items...•Mar 1, 2021

What are the different types of air strippers?

There are three main types of air strippers: packed column, low-profile sieve tray, and diffused aeration. All three styles are configured differently but work on the same principle to transfer VOCs from water to air (ACOE, 2001).

How does air sparge work?

Air sparged through the bottom of the tray or through a vent pipe in the bottom of the system passes in a countercurrent direction through the water to strip out VOCs. Typically, the tray-style strippers are modular and trays can be added or removed to properly size the system for flow capacity and stripping efficiency.

How does air stripping work?

Air stripping is an ex situ technology that removes volatile organic compounds (VOCs) from pumped groundwater or wastewater by passing the water over a media having a large surface area while exposing the contaminated water to uncontaminated air flow. It is most commonly used as part of a groundwater pump and treat remedy. The VOCs are transferred (i.e., volatilized) from the groundwater or wastewater to the vapor phase in the countercurrent air stream, where the vapor is either directly discharged or routed to an off-gas treatment system.

What is air stripping?

Air stripping is an established technology for the treatment of VOCs and has been used for several decades to support full-scale site remediation. Air stripping is used to separate halogenated and nonhalogenated VOCs, as well as oxygenates, from water, even when low levels of these contaminants are present.

What are the different types of ISCO reagents?

A variety of ISCO reagents are available on the market including hydrogen peroxide, sodium persulfate, potassium permanganate, sodium percarbonate, potassium permanganate, and sodium persulfate, which generally are applied in liquid form. 1 Oxidants normally shipped in solid form, such as potassium permanganate or sodium persulfate, are dissolved easily and mixed on site to form a solution having the required design concentration. Design considerations for the common oxidants are listed in the table below. The three most common oxidants are described in the paragraphs that follow.

What is ISCO in chemical remediation?

In site chemical oxidation (ISCO) is an in situ remediation technology that involves the injection of chemical oxidants into the subsurface, the most common of which are permanganate, persulfate, and hydrogen peroxide. ISCO is applicable to treat a wide-range of contaminants of concern (COCs) including chlorinated ethenes and ethanes, petroleum hydrocarbons and their constituents, 1,4-dioxane, energetics, pesticides, and phenols among others. ISCO also can facilitate the removal of non-aqueous phase liquids (NAPLs). It is important to select an appropriate oxidant, dosing, and activation agent (if needed) based on the COCs present since not all compounds can be treated effectively by a single oxidant.

What is ISCO used for?

ISCO is applicable to treat a wide-range of contaminants of concern (COCs) including chlorinated ethenes and ethanes, petroleum hydrocarbons and their constituents, 1,4-dioxane, energetics, pesticides, and phenols among others. ISCO also can facilitate the removal of non-aqueous phase liquids (NAPLs).

What is permanganate used for?

More recently, permanganate has been used as an oxidant to treat contaminated soil and groundwater. When permanganate reacts with organic contaminants, the contaminants are oxidized to carbon dioxide and the permanganate is reduced to a manganese dioxide salt and a potassium (or sodium) salt.

What is the concentration of permanganate?

Field applications of permanganate have generally consisted of 0.5 to 3.0% concentration of injected solution. Higher concentrations can be used, but sometimes lead to excessive manganese dioxide formation around injection points, which can clog both the injection point and the aquifer.

What is the solubility of sodium persulfate?

Persulfate (S 2 O 82-) is delivered in the form of sodium persulfate. Sodium persulfate has a water solubility of approximately 40% and results in a clear solution. It is very reactive and produces innocuous byproducts.

What temperature is persulfate activated?

It is most common to activate persulfate using elevated temperatures (35 to 40°C), creating strongly alkaline conditions (pH upwards of 10 or 12), with ferrous iron (Fe [II]), or with hydrogen peroxide (H 2 O 2) to generate sulfate free radicals, which facilitate contaminant destruction.

What are the different types of stormwater treatment?

Primary stormwater treatment practices can be grouped into five major categories: Stormwater Ponds: Stormwater ponds maintain either a permanent pool of water or a combination of a permanent pool and extended detention.

What are stormwater treatment practices?

Stormwater treatment practices are structural controls primarily designed to remove pollutants from stormwater runoff, but also can provide other benefits including groundwater recharge, peak runoff attenuation, and stream channel protection. As described in Chapter Three of this manual, stormwater treatment practices are one element of a comprehensive stormwater management strategy and should be selected and designed only after consideration of effective site planning/design and source controls, which can reduce the volume of runoff and the size and cost of stormwater treatment. This chapter introduces stormwater treatment practices that are acceptable for water quality treatment in Connecticut, either alone or in combination with source controls and other treatment practices. The following sections describe three categories of stormwater treatment practices: 1 Primary Stormwater Treatment Practices 2 Secondary Stormwater Treatment Practices 3 Stormwater Treatment Train.

What is a secondary treatment?

Conventional or “public-domain” (as opposed to proprietary) secondary treatment practices are practices that have traditionally been used to provide some water quality benefits, but that do not provide the same level of treatment or broad water quality functions as primary stormwater treatment practices.

Is there any data on stormwater treatment practices in Connecticut?

Currently, there is very limited performance data for stormwater treatment practices in the State of Connecticut. Performance data from the majority of previous monitoring studies conducted throughout the United States are limited by differences in design, performance goals, site parameters, storm events, flow and pollutant loadings, seasonal variations, monitoring methods, efficiency calculation methods or simply by the lack of or inadequate information. Several major initiatives are underway nationally to provide a more useful set of data on the effectiveness of individual stormwater treatment practices, and to better understand the relationship between treatment practice design and performance. These include:

Is stormwater treatment stand alone?

A number of stormwater treatment practices may not be suitable as stand-alone treatment because they either are not capable of meeting the water quality treatment performance criteria described in the previous section or have not yet received the thorough evaluation needed to demonstrate the capabilities for meeting the performance criteria. These practices, termed secondary stormwater treatment practices, generally fall into either of the following categories:

How can plants be used as a natural pump and treat system?

Plants can be used as natural pump-and-treat systems for remediation of contaminated sites, this phenomenon is known as phytoremediation. This provides several advantages over other physical or chemical methods of environmental clean-up, like cost-effectiveness, easy handling, etc. However, natural hyperaccumulator plant species can be grown only in specific environmental conditions, and mostly suffer with limitations of having low biomass, shallow root system, less efficiency for uptake, accumulation, and degradation of xenobiotics and slow rate of phytoremediation. The genetic manipulation of plants using genes from their native metabolic pathway or microbial detoxification pathways could present a potential approach for improving phytoremediation capability of plants. Tremendous efforts have been put in this direction in the last few years. The present chapter comprehensively describes the current progress in the field of plant genetic engineering for efficient removal of recalcitrant inorganic and organic pollutants, and major concerns associated with them. Taken together, these studies demonstrate the immense potential of plant transformation for enhanced phytoremediation efficiency.

How does a pump and treat system work?

Pump and treat systems also are used to contain the contaminant plume. Containment of the plume keeps it from spreading by pumping contaminated water toward the wells. This pumping helps keep contaminants from reaching drinking water wells, wetlands, streams, and other natural resources.

What is the purpose of pump and treat?

Pump and treat is a common method for cleaning up groundwater contaminated with dissolved chemicals, including industrial solvents, metals, and fuel oil. Groundwater is pumped from wells to an above-ground treatment system that removes the contaminants. Pump and treat systems also are used to contain the contaminant plume.

What is pump and treat?

Pump-and-treat is the most widely used remediation technique for contaminated groundwater. For this method, one or more extraction wells are used to remove contaminated water from the subsurface. Furthermore, clean water brought into the contaminated region by the flow associated with pumping removes, or “flushes,” additional contamination by inducing desorption from the porous media grains and dissolution of NAPL. The contaminated water pumped from the subsurface is directed to some type of treatment operation, which may consist of air stripping, carbon adsorption, or perhaps an aboveground biological treatment system. An illustration of a pump-and-treat system is provided in Fig. 19.5. Pump-and-treat and hydraulic control using wells are essentially the same technology; they just have different objectives. For containment, we usually want to minimize water and contaminant extracted, whereas for pump-and-treat, we want to maximize contamination extracted.

How does soil venting work?

Because air is much less viscous than water, much less energy is required to pump air. Thus it is usually cheaper and more effective to use soil venting rather than soil washing to remove volatile contaminants from the vadose zone. There are two key conditions for using soil venting. First, the soil must contain a gas phase through which the contaminated air can travel. This condition generally limits the use of soil venting to the vadose zone. In some cases groundwater is pumped to lower the water table, thus allowing the use of soil venting for zones that were formerly water saturated. Second, contaminants must be capable of transfer from other phases (solid, water, immiscible liquid) to the gas phase. This requirement limits soil venting to volatile and semivolatile contaminants. Fortunately, many of the organic contaminants of greatest concern, such as chlorinated solvents (trichloroethene, tetrachloroethene) and certain components of fuels (benzene, toluene), are volatile or semivolatile. Soil venting is the most widely used method for removing volatile contaminants from contaminated vadose-zone systems.

Can phytoremediation systems treat sinking contaminants?

Sinking contaminants would be impossible to treat with traditional phytoremediation systems. However, designed and constructed systems can target these contaminants in many situations. Obviously, tighter formations would enhance the viability of a designed and constructed system over a pump and treat system but opportunities are not limited to tight formations. While phytoremediation systems are limited in water use capacity, they still offer treatment-free water removal.

What is ex situ bioremediation?

For sites with very high concentrations of radionuclide contaminants or where pump and treat systems are in operation, an ex situ bioremediation strategy may be an effective and economically viable option. Ex situ treatment processes include enzymatically catalyzed biotransformation (e.g., U (VI) reduction), biosorption/bioaccumulation, and biodegradation of organic complexing agents such as EDTA. Biosorption is the accumulation of radionuclides on biomass particles and is independent of bacterial metabolism. Bioremediation is also being applied to industrial and medical waste streams to consolidate radioactive waste, thus decreasing both the storage cost and the risk of future environmental contamination. However, the radiation toxicity of radionuclides often prevents ex situ bioremediation from being effective for highly concentrated radionuclide wastes ( Tabak et al., 2005 ).

What is flocculation in wastewater treatment?

Precipitation/coagulation/ flocculation is a common pretreatment approach used in wastewater treatment plants for removing various particles and dissolved constituents. Coagulants, either commodity or proprietary chemicals, can be added to water (conventional technology) or generated by anode-cathode reactions of metal plates inserted into the water (electrocoagulation). Common examples include:

What is a treatment technology?

Treatment technologies exploit a contaminant’s chemical and physical properties to immobilize, remove, or destroy the contaminant. The stability and surfactant nature of PFAS make many treatment technologies ineffective, including those that rely on contaminant volatilization (for example, air stripping, soil vapor extraction) or bioremediation (for example, biosparging, biostimulation, bioaugmentation). Even aggressive technologies such as thermal treatment and chemical oxidation require extreme conditions beyond typical practices (for example, extreme temperatures, high chemical doses, extreme pH) to be effective or partially effective in destroying PFAS.

How to treat PFAS?

Treatment Description: Amendments are added to the soil and sediment to reduce the potential for PFAS to mobilize from soil and sediment to groundwater and surface water. For sorption purposes, PFAS-adsorbing materials (for example, activated carbon) can be applied through in situ soil mixing or ex situ stabilization (for example, pug mill mixing) to reduce the leachability of PFAS from contaminated soil/sediment through physical and/or chemical bonding.

What is GAC treatment?

Treatment Description: GAC is an effective sorbent media for organics that has historically been used to reduce contaminants in a variety of water treatment applications . The information contained in this section describes ex situ GAC treatment in which water is extracted and transferred from the source of contamination and directed through the treatment system.

Is PFAS microbial degradation?

A limited number of studies have tested microbial degradation of PFAS and many conflicting reports exist, all suggesting that more work needs to be performed to fully understand the biotic transformations of these compounds.

What is a ix?

Treatment Description: IX is an effective sorbent for other contaminants and has historically been used for a variety of water treatment applications (for example, nitrate, perchlorate, arsenic). To date, IX for PFAS removal from water is limited to ex situ applications.

What is RO water?

RO is a technology used to remove a large majority of contaminants (including PFAS) from water by push ing the water under pressure through a semipermeable membrane as described below. The most common membrane module configuration is spiral-wound, which consists of flat sheet membrane material wrapped around a central collection tube.

What is running water?

Running or moving water purifies itself to “drinking water quality” after flowing a specified distance. (True or False) 10. A well or spring groundwater source, located downhill of a septic tank, may have increased susceptibility to pollution.

Is water a microbiological source?

B: Regardless of its source, water can be susceptible to microbiological contamination at any time. For this reason, it is necessary to sample water periodically and to have it analyzed for health-related bacteriological contamination. 6.

Is groundwater safe to drink?

1. False: Groundwater does typically undergo a degree of natural filtration that tends to remove particles in suspension, including microorganisms. In addition, the bacteriological quality of groundwater often improves during storage in aquifers because conditions there are usually unfavorable for bacterial survival. However, dissolved minerals from subsurface materials can make some well or spring water unsafe to drink, or at least aesthetically displeasing.

Schematic

Introduction

• Air stripping is an ex situ technology that removes volatile organic compounds (VOCs) from pumped groundwater or wastewater by passing the water over a media having a large surface area while exposing the contaminated water to uncontaminated air flow. It is most commonly used as part of a groundwater pump and treat remedy. The VOCs are transferred ...

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Schematic

Introduction

Description

• ISCO is a remediation technology involving the injection and distribution of a chemical oxidant into the subsurface to transform COCs in groundwater and soil into innocuous byproducts. It can be considered for contaminant mass removal at sites where groundwater and/or porous media contain COCs such as petroleum hydrocarbons, chlorinated solvents, 1...

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