Hampton University Water Quality Research and Monitoring Laboratory
A Resource for Water Pollution Prevention Programs in the Hampton Roads Area
As the largest estuary in the US, the Chesapeake Bay supports tourism, transportation, fishing, recreation, and other economic activities, affecting almost 20 million people. Therefore, maintaining a healthy bay is a major priority of all seven jurisdictions in the bay watershed – the states of Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia, and the District of Columbia. The pollution of the bay and its rivers can be traced to urban runoffs; farmland drainage; air pollution from factories, power plants and automobile emissions; wastewater treatment; industrial discharges; and marine transport and other marine related activities. Together, they produce pollution that impairs the water with toxic heavy metals, persistent organic compounds, pesticides and herbicides, paints, solvents, nutrients; and pharmaceutical and personal care products.
Nutrients (phosphorus and nitrogen) and sediments have been given a top priority as these pollutants are thought to have a systemic and pronounced decline in the quality of the water of the bay. Nitrates and phosphates are the key nutrients for plant growth. However, high levels of these nutrients in a body of water can cause algal blooms, a condition that leads to a degraded aquatic environment. Each of the seven states is required by the EPA to have a plan that limits the amounts of these pollutants entering the bay waters on a daily basis, a plan that is commonly referred to as the total maximum daily load or TMDL. The TMDL is one of the provisions of the Clean Water Act (CWA) designed to restore and maintain the quality of water resources around the nation. TMDL programs establish pollutant levels that cannot be assimilated by a body of water and therefore must not be exceeded by pollution discharges.
A sustainable and effective TMDL plan will require the cooperation of municipalities and other jurisdictions working in concert with the community, civic organizations, and educational institutions to develop pollution prevention measures, monitor the quality of the water periodically, and implement corrective measures where impairment is detected. Situated along the banks of the Virginia Peninsula near the mouth of the Chesapeake Bay, Hampton University is among several entities in the area that continue to play very prominent roles in preventing pollution of the Chesapeake Bay and its rivers. The university’s environmental stewardship is well demonstrated in its curriculum offerings, participation in community sponsored pollution prevention and clean-up initiatives; sponsorships of environmental workshops and seminars; and courses and degree programs that offer integrated educational experiences and training for students and others interested in environmental careers.
HU has teamed with the City of Hampton Department of Public Works to look for new ways and technologies to prevent water pollution. This partnership is especially timely as the City undertakes major initiatives to address local community water quality issues as well as respond to established requirements related to the reduction of nutrients entering the Chesapeake Bay. Partnership efforts and resources are directed to two key areas: (1) preservation and improvement of the performance of wetlands, and (2) prevention of pollution from storm water outfalls. Collaboration with HU researchers provides the City of Hampton access to state-of-the-art chemical measurement facilities while HU students and faculty gain training and future career opportunities in water quality and related environmental professions.
Hampton University’s commitment to local water quality issues is best exemplified by the recently established Water Quality Research and Monitoring Laboratory. This facility supports research in water quality, provides training and service learning opportunities for students, and serves as a resource for the immediate Hampton Roads community. The laboratory includes a wide array of chemical measurement tools and devices ranging from wet-chemical apparatus to sophisticated instruments that represent the state-of-the-art chemical measurement technology that is available in the market today. This technology includes Inductively Coupled Plasma Atomic Emission Spectroscopy, High Performance Liquid Chromatography, Mass Spectrometry, Ion Chromatography, and Atomic Absorption Spectroscopy. Their capabilities are described below.
Water Quality Laboratory Facilities
|Inductively Coupled Optical Emission (ICP) Spectrometry is a powerful tool for the determination of trace elements in aqueous samples. Coupled with liquid chromatography, the system provides element speciation capability based on ICP’s utility as an element-selective detector for the chromatographic system. Speciation information is essential in addressing questions related to the fate and bioavailability of chemical pollutants.|
|Ion Chromatography (IC) is the technique of choice in the determination of ions that are commonly found in natural water, including chloride, fluoride, nitrite, nitrate, bromide, phosphate, sulfide, and sulfate.|
|Mass spectrometry (MS) is used to obtain analytical information of chemical entities (molecules and atoms) based on their masses. Coupled with liquid chromatography (LC/MS), MS represents a powerful analytical technology for the separation and detection of chemicals in the low ppb concentration range. The Varian 500 LC/MS system in HU’s water quality lab is being used to develop analytical methods for emerging contaminants (pharmaceutical products, personal care products, and organic pollutants).|
|High Performance Liquid Chromatography (HPLC) is among the most commonly used chromatographic techniques to separate organic compounds, organic ions, and biomolecules. This tool is being used in the water quality laboratory in conjunction with the LC/MS system to develop analytical methods for emerging contaminants (pharmaceutical products and personal care products).|
|The Wet–chemistry unit of the laboratory encompasses bench-top analytical tools used for routine measurements, sample treatment and processing, and physical characterization.|
Measurement sensitivity and the ability to provide information on the different forms of a pollutant in a sample are two key requirements of environmental measurement techniques. Commonly known as speciation, the process of identifying and quantifying the various species of an analyte provides important analytical data that is used in the evaluation of the impact of the contaminant on environmental or biological systems. For elemental analytes, it is not sufficient to only determine the total concentration of that element but all the different entities containing that element. The aim in HU’s Water Quality Laboratory is to develop analytical methods that have the capability to identify and quantify trace concentrations (ppb to ppt range) of contaminants; have speciation capabilities; and can be used to identify and quantify contaminants that are not routinely tested in environmental samples, including pharmaceuticals (antibiotics, steroids) and persistent organic pollutants (POPs), some of which are classified as potential endocrine disruptors.
Most often, speciation is accomplished by interfacing a chromatographic system with an element selective detector as is done in HU’s Water Quality Lab where the ICP is interfaced with high performance liquid chromatography/ion chromatography (ICP-HPLC/IC). Because of its multi-element capability, ICP rivals and sometimes is preferred over its forerunner, and the more widely used atomic absorption spectroscopy (AAS), a sequential single element technique. The HPLC/IC configuration provides a powerful capability that can be used in a variety of applications in the pharmaceutical industry, environmental analyses, and clinical studies. The immediate focus of the research in HU’s Water Quality Laboratory is toxic heavy metals, nutrients, and emerging contaminants (pharmaceutical compounds and personal care products). There is a need for scientific data on the behavior of these materials once they are introduced in the environment. Often they exist in very small concentrations, requiring ultrahigh measurement sensitivity for their detection and quantification. This analytical capability is now available in HU’s Water Quality Lab as described above.
Speciation of Phosphates
A hyphenated ICP-LC configuration has significantly improved our ability to conduct phosphorus speciation measurements. Phosphorus can exist in aqueous media in several different forms, with orthophosphate (PO43-) being the form that can readily be absorbed by plants and other biological systems. All other forms (polyphosphates, condensed phosphates, etc.) must be converted to this form before they can become bioavailable. The conversion process can vary widely depending on prevailing environmental conditions. For example, phosphorus immobilization has been demonstrated to be an important factor in phosphorus removal in some wetlands. Wetlands provide an environment in which all the various forms of phosphorus interconvert, the eventual sink being sediments or soils, often in the forms of insoluble precipitates formed with a variety of cations, such as Ca5(Cl,F)(PO4)3, and Ca5(OH)(PO4)3. It is believed that microbial interaction is the first process that occurs following the addition of anthropogenic phosphorus in a wetland, and not the macrophytes that may be present. The role of microorganisms in wetland phosphorus removal is being investigated to determine if microbes can be stimulated to enhance phosphorus accumulation. With knowledge of prevailing environmental conditions, predictions can be made as to the form and amount of phosphorus species present and the likelihood of their conversion to orthophosphate, using ICP-LC.
By interfacing HPLC with ICP, an analytical technique is produced that can speciate the chromatographic effluents containing a targeted element. All the chemical entities containing the element of interest are measured with equal efficiency. A case in point is the determination of arsenic. Arsenic is considered to be a key environmental pollutant. High levels of arsenic can cause cancers of the skin, bladder, lung, as well as neurological and cardiovascular problems. The inorganic arsenite, monomethylarsonous acid, and dimethylarsinous acid are known to be highly toxic. It is important to know the conditions under which the transformation of one species to another occurs and the concentrations of those contaminants in environmental systems as exemplified above for two inorganic arsenic species (arsenic-III and arsenic-V).
|Arsenic speciation As(III)/As(V)|
One of the key features of ICP is its capability for element speciation when interfaced with LC or IC, allowing the separation and quantification of various species of an element that may be in the sample to be determined separately, as shown for two arsenic species.
The addition of a mass spectrometer to the HPLC results in a powerful analytical tool with a wide range of versatility. The HPLC-MS system can provide molecular information of the molecular species that are separated on the HPLC column. This is made possible by coupling the HPLC with the MS via an electrospray (ES) or atmospheric pressure sample ionization (APCI) units.
|LC/MS system||Mass spectrum for tylosin, an antibiotic|
The online coupling of HPLC with ES-MS (HPLC-ESMS) not only allows the identification of unknown speciation fractions but will also provide an analytical tool for chemical compounds that are not well documented, as is the case for the antibiotic, tylosin.
Example of Research Findings
Environmental impacts of Biosolids
Biosolids is a term used to describe the solid material resulting from the treatment of domestic sewage to render it safe for land application. Several steps involving chemical, biological, and physical treatment of the material are taken to produce Biosolids, a form that is suitable for land application. The composition of the resulting material depends on the wastewater constituents and the treatment processes employed. Depending on their level of pollutant content, Biosolids can be used for both non-food agriculture and food-agriculture. The impact of Biosolids on soils and the potential for ground water contamination is highly influenced by their nature, treatment, the method of application on land, and the characteristics of the receiving soils. Biosolids can be applied directly on agricultural soils or after they are composted.
Using composted Biosolids produced by HRSD and distributed as fertilizer with the name “Nutri-Green”, the chemistry of the material was investigated to determine the impact it might have when used as fertilizer on agricultural soils. While the economic value of Biosolids stems from its nutrient content, this material has other properties that lend it useful in addressing other environmental pollution problems, including lead pollution. Lead is a toxic metal that was used for many years in paint and other products found in and around our homes. It can also be emitted into the air from industrial sources, leaded gasoline where this product is still being used, and drinking water from plumbing materials. Because of serious health risks associated with lead, measures have been taken to phase-out lead-based paints, leaded gasoline, plumbing materials, and other lead containing products. Lead abatement measures have also been initiated to remediate lead-contaminated soils using mechanical and chemical processes. Research conducted in HU’s Water quality Lab found “Nutri-Green”, the HRSD supplied Biosolids, to have a high affinity for lead (Fig 1). This research was reported in an article that was published in the December 2011 issue of the Journal of Environmental Science and Health, Part A, Vol. 46, Issue 14, 1625-1631.
Figure 1.Breakthrough curve for lead, copper, and cobalt loaded on Biosolids packed column, showing the affinity of Biosolids for lead over other metals.
Its affinity for lead makes Biosolids a viable candidate for lead abatement of lead polluted sites. The HU team studied the mechanisms involved in lead uptake by Biosolids, and the factors that may come into play when this material is applied on land. However, while Biosolids have the attractive features of soil remediation and soil amendment, its impact on the quality and safety of ground water is an issue that has not been extensively explored. It was found for example that the adsorption of lead on Biosolids proceeds with a release of calcium and a decrease in soil pH, increasing the soil-calcium content and making the soil more acidic(Figures 2 and 3). Preliminary studies also point to the potential of phosphate leaching out of this material, serving as a source of ground water pollution. This is an on-going investigation in HU’s water quality research lab.
For questions regarding the Water Quality Research Laboratory please contact Dr. I.T. Urasa, PI firstname.lastname@example.org