The need for safe drinking water in rural Ghana inspired Katherine Alfredo, a graduate student at the University of Texas at Austin to propose a project for a Fulbright Fellowship. The purpose of the fellowship was to map the extent of the fluoride concentration in the Bongo District of the Upper Eastern Region for use by local authorities and eventually use the data collected in the development of a cost-effective defluoridation filter for existing capped wells.
In rural areas, groundwater is plentiful, but natural geographic contamination by inorganic contaminants like iron, manganese and fluoride render government sponsored boreholes useless. Fluoride in the Upper East, Upper West and Northern regions of Ghana often exceeds the general WHO recommended limit of 1.5 mg/liter.
Katherine began her research by observing and recording local water usage habits. She conducted borehole water usage counts on centrally and non-centrally located borehole sites tracking the quantity of water collected daily. Coupling this data with familial compound water usage surveys she was able to begin understanding the volumetric demand placed on each borehole daily and how that volume translates to the household level.
A one-liter sample of water was retrieved for testing and used for all the water quality tests. An aliquot of the sample water was placed in an Ultrameter II 6P to measure pH, ORP, conductivity, total dissolved solids and temperature.
Conductivity readings from the Ultrameter II will be used to simulate influent water containing excessive levels of fluoride in Katherine’s laboratory. Using Bongo as a design test case, Katherine plans to adjust the ionic strength of her synthetic influent to reflect that seen in the Bongo District.
Ultrameter II TDS readings were used as a quality indicator of water as it was dispensed from a borehole. The amount of all dissolved solids is important in determining the potential for interference and competition for adsorption sites on the aluminum adsorbents. Preventing any ions from competing for active sites on alumina surfaces will greatly increase the efficiency of filtration.
ORP readings taken by the Ultrameter II gave a good indicator of the general biological activity in the water. Additional testing was performed using two 2 mL tubes filled with sample water to measure nitrate/nitrite and ammonia using test strips. In another 2 mL tube a 1:1 dilution of the sample was created using distilled water to measure alkalinity using test strips.
Using a 0.45 micron filter, a 30 mL or 60 mL sterile plastic bottle was completely filled for fluoride concentration testing later in the laboratory.
Each capped borehole, new borehole, or nonfunctional borehole that was visited had its corresponding borehole identity recorded in a handheld GPS device. After each governance was covered, eight capped boreholes were chosen for water quality testing to be compared to the nearby functional boreholes.
At the time of Katherine’s departure, she had reported the pH and fluoride concentration of each well to the two water and sanitation government agencies in the Bongo area—The Community Water and Sanitation Agency and The Bongo District Assembly Water and Sanitation Team.
Katherine continues to analyze data recorded in Ghana and experiment with cost-effective solutions for fluoride removal in rural communities.
Expert Manages Storm Water Discharge in Active Construction Sites With Ultrameter II 6P: MyronLMeters.com
Mike Alberson, an expert in storm water pollution prevention, uses the Myron L Ultrameter II 6P to meet new and existing state and federal requirements for storm water monitoring. He checks for the presence of pollutants by testing the levels of total dissolved solids (TDS) and conductivity. He also tests storm water pH levels in accordance with NPDES guidelines implemented in California in 2010 that mandate pH testing for all Risk Level 2 and 3 sites.
Though TDS and conductivity do not indicate the presence of any specific contaminant, monitoring these parameters is a good way to determine an increase in the concentration of dissolved chemical constituents generally. High conductivity or TDS levels are a red flag to Alberson to investigate potential sources of pollution.
Chemicals used in landscaping, such as herbicides, pesticides and fertilizers, as well as materials such as cement, can all potentially dissolve into storm water runoff. Additionally, acidic or basic pollutants impact the quality of water by altering the pH of the runoff. Monitoring is required because altering the pH alters the types and amounts of all chemical constituents in runoff and, thereby, its toxicity. Changes in pH also impact the ecosystem directly when they exceed the narrow range required by biota to live in the receiving waters. The new California NPDES requirements have set a pH range limit of 6.5 to 8.5 pH Units
The State Water Quality Board’s overall goal in implementing increased monitoring and reporting requirements is to evaluate the effectiveness of Best Management Practices (BMPs) on effluent pollution and the impact that construction activities have on receiving waters. Developers and inspectors like Alberson are continually challenged with preventing potential pollutants from leaving the project sites, and when that happens, they need to remediate any adverse affects on the environment.
As a prerequisite to construction, the Developer of Plan must generate and gain approval of BMPs and Storm Water Pollution Prevention Plans (SWPPPs) which take into account the nature of the project’s building schedule, phasing of the project, building materials, the projected rainfall, the percentage of impervious cover on the project and the impact that potential storm water runoff could have on receiving waters. The plans must also address the required monitoring and critical indicators of specific pollutants projected to discharge from the project site.
The site storm water inspector has to ensure that the necessary BMPs are implemented throughout the length of the project, as defined by the project SWPPP plan, which addresses project-specific site conditions and risk level determinations. Alberson uses the meter frequently on Barnhart Balfour Beatty projects as most fall into a category of Risk Level 2, which now requires pH monitoring along during a rain event of 0.5 in. or more.
New California requirements have required all SWPPP developers and inspectors to be certified by the state since Sept. 2, 2011 via a special course given by designated State Trainers of Record (TOR). Alberson is designated as a TOR and offers California’s new Qualified SWPPP Practitioner and Qualified SWPPP Developers courses.
As a trainer, Alberson passes on knowledge gained from his own experience. Through the years, he has seen inspectors send water samples off to laboratories for analysis, the results of which would not be known for up to two weeks. In addition, the pH of these samples would change in the time it took to get the samples to the labs for analysis. Alberson now trains developers and inspectors to use the Myron L Ultrameter II to immediately measure pH, thereby ensuring storm water runoff on project sites is precisely monitored for potential pollutants in real time.
In his own work as an inspector, Alberson has used the Myron L Ultrameter II to respond to potential pollution issues as they arise. For example, at Barnhart Balfour Beatty’s Otay Ranch Village #6 Elementary School project in Otay Mesa, Calif., he developed a remediation solution that prevented environmental contamination from high pH runoff resulting from a required lime treatment of the campus soil. By performing onsite testing following a rain event, Alberson was able to determine the potential runoff had a pH level of 12.5. He decided to immediately utilize a retention pond with carbon dioxide percolation control techniques. His remediation tactic worked using the meter to continuously monitor the pH until it was at a level acceptable for release into the receiving waters.
The magic button says:
“Give resale pricing to those who enter the code “GIMMERESALE” at checkout.”
Thus spake the magic button. Good until June 30, 2014 on Ultrameters only.
The Ultrameter III 9P Titration Kit allows for fast, accurate alkalinity, hardness & LSI titrations in the field.
The Ultrameter III 9P is based on the tried and tested design of the Ultrameter II 6P and measures conductivity, resistivity, TDS, pH, ORP, free chlorine and temperature quickly and accurately. The 9P also features new parameters that allow the user to perform titrations in the field. The Ultrameter III 9P has a unique method of performing alkalinity, hardness and LSI titrations that makes field monitoring fast and feasible.
How does it work?
The 9P titrations are based on conductometric titration methods that are possible with the 9P’s advanced conductivity cell and microprocessor based design. Titrations are chemically equivalent to standard methods using colorimetric techniques, but replace color change identification of equivalence points with changes in conductivity, thereby replacing a subjective, qualitative assessment with a quantitative one. This means the instrument determines the equivalence point instead of the user and the method of analyzing the equivalence point is objective, rather than subjective.
What is a conductometric titration?
A conductometric titration is performed just like a colorimetric titration, only the equivalence point is determined by a change in conductivity rather than a change in color. This is based on the fact that changes in ionic concentration that occur as constituents react with reagents change the electrical conductivity of the solution.
A simple example can be given of the titration of a strong acid with a strong base. The acid solution, before the addition of the base, has a very high conductance owing to the concentration and mobility of the small hydrogen ions.
With the addition of the base, the hydroxide reacts with the hydrogen to form water, thus reducing the hydrogen ion concentration and effectively lowering the conductivity of the solution. The conductivity continues to decrease until all the hydrogen ions are consumed in the reaction, but then sharply increases with the next addition of base, which contains highly conductive hydroxide ions. The solution conductivity then continues to increase with each base addition. The equivalence point in this example would be a clearly defined minimum point of lowest conductivity (see Figure 2).
Not all solutions will give a plot with an equivalence point that is as easy to distinguish as the sharp upturn found in a strong acid-base titration, however. The 9P plots several reagent additions beyond any changes in conductivity and matches the derived curve to the behavior of solutions of known concentration.
Is a conductometric titration a standard method?
(Standard method comparison to methods listed in the Standard Methods for the Examination of Water and Wastewater published by the American Public Health Assn., the American WaterWorks Assn. and the Water Environment Assn.)
Myron L’s conductometric titration methods are chemically equivalent to standard methods that use the same procedure, but with pH indicators. That means that they use the same reagents in the same sequence with the same theoretical approach. The difference lies in the 9P’s ability to determine the equivalence point based on numerical data, rather than subjective observation of a color change.
The alkalinity titration is modeled after standard method 2320. The sample is titrated with sulfuric acid and conductivity changes are recorded at each titration point.
The hardness titration is modeled after standard method 2340. To reduce the affects of high alkalinity in the form of bicarbonate, acid is first added to the sample. This shifts the bicarbonate toward carbonic acid, then carbon dioxide (reference the carbonic acid equilibrium), which is gassed off the sample. The sample is buffered above pH 10 (effectively pH 12) by the addition of sodium hydroxide. EDTA reagent is then added incrementally, with conductivity measured after each addition.
The LSI titration uses a simplified version of the thermodynamic equations for the determination of the scaling tendency of water developed in 1936 by Dr. Wilfred Langelier. The user simply titrates for alkalinity and hardness, then measures pH and temperature, and the 9P generates the saturation index value automatically.
Conductometric vs. Colorimetric
The benefits of determining the equivalence points by conductometric titrations are that the user does not have to interpret any results. The 9P does it for you using objective measurements. And the 9P is a faster method. For example, a typical colorimetric titration for hardness can take up to 30 drops of reagent, while the 9P method for the same concentration only requires six to eight drops. Colorimetric distinctions are sometimes hard to make, as well, especially when adding reagents drop by drop while trying to carefully observe the precise point at which the color changes—and that can lead to inaccurate data. This is especially true in colored or turbid solutions.
The conductometric method can also be used with very dilute solutions or for solutions for which there is no suitable indicator. The conductometric titration method gives you empirical results that are calculated for you, eliminating potential sources of error. And the measurements can be stored in memory for later data transfer using the optional U2CI software and bluDock Bluetooth hardware installed on the 9P . This makes data analysis and reporting seamless.
What else can the Ultrameter III 9P do?
Alkalinity, hardness, pH and temperature values used to compute the saturation index of a sample can be manipulated in the LSI Calculator function, allowing you to perform on the spot analysis of water balance scenarios. You can use historical or theoretical data to populate the required values in the calculator.
And the 9P titration kit comes with all required accessories, reagents, and calibration solutions (see Figure 6). Streamline your field testing with an Ultrameter III 9P from MyronLMeters, where you can save 10% when you order online.
Myron L Meters is the premier online retailer of accurate, reliable, and easy-to-use Myron L meters like the Ultrameter III 9P. Save 10% when you order online at MyronLMeters.com. Find out more about the Ultrameter III 9P in our Myron L Meters – Ultrameter III 9P Titration Kit Overview video.