Groundwater contamination via nitrate leaching has been observed in many countries. The denitrification performance of a poly(3-hydroxybutyrate-co-hydroxyvalerate) (PHBV)–ceramsite-based reactive barrier system was evaluated in continuous upflow bioreactors. Artificial groundwater spiked with nitrate (44.75–57.25 mg NO3−-N/L) was tested under different hydraulic retention times (HRT; 5.2 h and 2.6 h). The continuous experiment for 35 days showed that more than 95% NO3−-N was removed. The maximum denitrification rate was determined to be 241 mg NO3−-N/(L· d), and NO2−-N concentration was below 0.1 mg/L in the effluent at the substrate:ceramsite mass ratio of 1:40. Rapid biodegradation of PHBV granules caused an initial excess release of dissolved organic compound (DOC), and shortening HRT from 5.2 h to 2.6 h can result in a sharp decrease of DOC. The minimum DOC concentrations were determined to be 20–33 mg/L in the effluent when the HRT was set at 2.6 h. So the PHBV granules may be a suitable solid-phase carbon source for enhancing denitrification in nitrate-contaminated groundwater.
To determine whether NO3−, concentration pulses in surface water in early spring snowmelt discharge are due to atmospheric NO3−,, we analyzed stream δ,15N-NO3−, and δ,18O-NO3−, values between February and June of 2001 and 2002 and compared them to those of throughfall, bulk precipitation, snow, and groundwater. Stream total Al, DOC and Si concentrations were used to indicate preferential water flow through the forest floor, mineral soil, and ground water. The study was conducted...
Inappropriate farming techniques and 4 years of drought (1992–1995) produced conditions for high nitrate concentration in an aquifer located in the Province of Seville (Southwest Spain). The objectives of this study were to study groundwater components and to determine the relationship between the cropping system and nitrate concentrations in groundwater. From October 1994 to May 1996, 16 groundwater samples were obtained from a network of 35 sample points. Groundwater concentrations were analysed by multivariate...
Cameron Highlands has a long history of intensive horticulture especially vegetable and flower cultivation. This industry uses large amounts of nutrients and pesticides. Several simulation models were used to assess the movement of pesticides and nutrients in relation to agronomic practices in farm plots cultivated with cabbage and chrysanthemum. It was shown that most of the pesticides are absorbed by the topsoils which are enriched by organic fertiliser, and are not leached beyond the top 10 cm layer. Methamidoph...
The Sanitation Districts of Los Angeles County (Sanitation Districts) operate the Palmdale Water Reclamation Plant (WPR) to provide wastewater treatment and disposal services for a city of 140,000. The Palmdale WRP is a secondary treatment system that uses oxidation ponds for BOD stabilization. Partial removal of nitrogen occurs within the facility, primarily as a result of assimilation by algae that subsequently settle to the pond bottom. Recent detections of nitrate nitrogen (NO3-N) in local groundwater have...
Bench-scale laboratory tests were conducted to evaluate and compare the enhanced bioremediation of pentachlorophenol (PCP) in groundwater under anaerobic and aerobic conditions. While tests under both conditions showed a significant reduction of PCP over the 3-month test period (greater than 90 percent reduction compared to 40 percent in controls), removal to concentrations below the 10 μg/L method detection limit was only observed under aerobic conditions in the time allowed. The results of the laboratory...
With the passage of the 1990 Clean Air Act Amendments, many chemical and metal industries and utility producers will now be required to further limit the amount of NOX (Nitrogen Oxides) produced. NOX is a precursor to ozone in the atmosphere, and is believed to be a major contributor to acidic deposition (acid rain).
Formation of ozone:
NO2 + Hv NO + O (Photochemical Reaction)
O + O2 + M O3 + M, where M - Energy accepting third body.
NOX is produced in a variety of different processes, including combustio...
Available carbon source is essential to enhance the biological nutrient removal (BNR) in wastewater treatment. Volatile fatty acids (VFAs) accumulated in the thermophilic aerobic digestion (TAD) supernatant under the microaerated operation is the potential carbon source for denitrification and phosphorus removal. This study investigated the use of VFAs recovered from the TAD supernatant in the BNR processes. Batch tests (2.8 L/batch, simulating the anaerobic, anoxic and aerobic conditions in sequences) and...
ABSTRACT
As water and sewer costs are expected to increase over the next decade, membrane technology will continue to be a viable and economical option in the recovery and reuse of water. This paper describes the mechanism of membrane effected separation (specifically reverse osmosis, ultrafiltration and microfiltration), membranes commercially available, membrane element configurations, and how complete membrane systems are designed. The paper also discusses case histories of a variety of proven applications,...
Untitled Document
Summary:
A granular activated carbon system developed by Calgon Corp., is being used
to remove various toxic materials from contaminated groundwater at the U.S.
Army's huge Rocky Mountain Arsenal near Denver, Colo. The pilot containment/treatment
project, which went into full operation in late August, 1978, has been described
as one of the largest efforts in the world to treat contaminated groundwater.
It consists of a 1,500-foot-long underground water barrier...
Geographic Information Systems (GIS) hold great potential as a tool for managing environmental site remediation data. While noting the location of contaminated sites in GIS is commonplace, GIS has played only a minor role in review and analysis of chemical data gathered during an investigation or monitoring activity. The New Jersey Department of Environmental Protection Site Remediation Branch (NJDEP SRP) has undertaken a project making the use of GIS for this purpose a reality within their organization. Through...
Abstract
Foundry production needs high quality of quartz sand. After production, most of the sand is recycled and used again, but there is still a certain quantity which cannot be used. This paper presents the results of the researches made with a view to utilization of waste sand from foundry production. It is possible to use such material in building materials production and building construction.
Introduction
The development of foundry production in the territory of Yugoslavia dates from the beginnings of...
Abstract
This paper presents results of the EU-project `DISCO` (Disassembly and Recycling of Pure Materials from Consumer Goods). The project concentrated on the development of new concepts for disassembly and quality sorting of specific electronic products, which have a standard design in relation to the number and type of selected components (`key-products` like keyboards, telephones or calculators). Since during recycling already minor contaminations of pure materials result in the degradation of sorted...
The Surface Coatings Resins Business Unit of Akzo Nobel in Louisville, KY, has chosen the Macro Porous Polymer - Extraction technology for treating process wastewater. The MPPE unit with a capacity of 20 gpm removes xylene and ethyl benzene from 200 ppm to less than 20 ppb. The new system assures compliance with local discharge regulations, while improving economy, reliability, and flexibility in the water treatment area.
The Louisville Resins operation manufactures a variety of resins for coatings manufacturers,...
The application of agri-environment contracts concerning 1 farmer in every 7 and delivering environmental services over 20% of European farmland, marks a very significant step towards sustainability. The target set in the 5th Environmental Action Programme of 15% coverage by 2000 has thus already been exceeded. The requirement on Member States to apply the regulation throughout their territories according to their needs has stimulated a very rapid expansion of initiatives and measures, which otherwise may have...
SCREENING AND GRINDING
When materials from CR&R and other generators are unloaded, a preliminary screening separates out nonorganic contaminants. Even though there are source separated programs in places like Temecula and Lake Elsinore, there is the occasional appearance of plastic and glass that needs to be sorted out. Next, Bodlak’s crews put materials through a Vermeer tub grinder that can process up to 200 tons (or 720 cubic yards) a day.
After the initial grinding, water is sprayed onto the piles,...
Introduction
Pollution Prevention Guidelines to provide technical advice and guidance to staff and consultants involved in pollution-related projects. The guidelines represent state-of-the-art thinking on how to reduce pollution emissions from the production process. In many cases, the guidelines provide numerical targets for reducing pollution, as well as maximum emissions levels that are normally achievable through a combination of cleaner production and end-of-pipe treatment. The guidelines are designed to...
This document is an attempt to compile worldwide research efforts and applications in the field of permeable reactive barriers (PRB). The listing will evolve as input is received. Apologies are made for any inadvertent omissions or errors. Typically, many people are responsible for a project; however, for simplicity, a single contact is provided for each project. Research projects are organized by the type of contamination treated (organics or inorganics) and by the type of reaction process (sorption, precipitation...
Introduction:
As for in situ solidification/stabilization (S/S), ex situ S/S contaminants are physically bound or enclosed within a stabilized mass (solidification), or chemical reactions are induced between the stabilizing agent and contaminants to reduce their mobility (stabilization). Ex situ S/S, however, typically requires disposal of the resultant materials. Under CERCLA material can be replaced on site.
There are many innovations in the stabilization and solidification technology. Most of the innovations...
In general, no single technology can remediate an entire site. Several treatment technologies are usually combined at a single site to form what is known as a treatment train. A system diagram of a common treatment train for halogenated VOCs is illustrated below. A ground water pumping system is used to pull contaminated water from the subsurface. The VOC contaminated water is pumped to a liquid phase granulated activated carbon (GAC) adsorption system. The GAC system removes VOCs in the water and the effluent is...
A treatment train is the combination of different treatment technologies. A system diagram of a common treatment train for nonhalogenated VOCs is illustrated below. A soil vapor extraction system is used to pull VOC vapor from the contaminated soil. An air sparging system delivers air below the water table to enhance bioremediation. After passing through a liquid/vapor separator, the VOC contaminated water and gas are pumped to a liquid phase granulated activated carbon (GAC) adsorption system. The GAC system...
Introduction
The utilization of fungal biodegradation involves the controlled usage of these specially cultivated fungi to treat contaminants.
White Rot Fungus
White rot fungus has been reported to degrade a wide variety of organopollutants because of its lignin-degrading or wood-rotting enzymes. Two different treatment configurations have been tested for white rot fungus, in situ and bioreactor. An aerobic system using moisturized air on wood chips is used in a reactor for biodegradation. A reactor was used...
Information presented for SVOCs may also be appropriate for many of the contaminants presented in this subsection.
The term `explosive waste` commonly is used to refer to propellants, explosives, and pyrotechnics (PEP), which technically fall into the more general category of energetic materials. These materials are susceptible to initiation, or self-sustained energy release, when present in sufficient quantities and exposed to stimuli such as heat, shock, friction, chemical incompatibility, or electrostatic...
Air sparging involves injecting a gas (usually air/oxygen) under pressure into the saturated zone to volatilize groundwater contaminants and to promote biodegradation in saturated and unsaturated soils by increasing subsurface oxygen concentrations. Vola tilized vapors migrate into the vadose zone where they are extracted via vacuum, generally by a soil vapor extraction system. The term biosparging is sometimes used interchangeably with air sparging to highlight the bioremediation aspect of the treatment process...
Customer comments
No comments were found for Denitrification of nitrate-contaminated groundwater in columns packed with PHBV and ceramsites for application as a permeable reactive barrier. Be the first to comment!
