Barbara B. Martin

Inhibition of Water Fern Salvinia minima by Cattail (Typha domingensis) Extracts and by 2-Chlorophenol and Salicylaldehyde

The allelopathic potential of a cattail species (Typha domingensis) towards the common water fern (Salvinia minima) was studied in a short-term bioassay. Aqueous extracts of cattail plants (roots, stems, and leaves) as well as two of its phenolic compounds (2-chlorophenol and salicylaldehyde) were found to inhibit the growth of Salvinia when incorporated in the growth medium. After a period of seven days, chlorophyll concentration, fresh weight, dry weight, and number of fronds of Salvinia were compared and correlations were found among the different parameters. The results suggest an inhibitory effect by components of Typha, especially of the root fractions. Results from pure chemicals are in qualitative and quantitative agreement with those obtained from the cattail extracts.

Removal of aqueous arsenic using iron attached to immobilized ligands (IMLIGs)

The present study describes the synthesis of the iron(III) salt of a commercially available immobilized ligand, IMLIG, Octolig-21 and its use to remove arsenic from aqueous solutions. The synthesis was accomplished by treating an aqueous suspension of Octolig-21 with an equal weight of ferrous sulfate heptahydrate under nitrogen. The ferrous salt was then collected by sieving and allowed to oxidize to the iron (III) salt by exposure to air, and treatment with dilute sodium hydroxide converted the composite to the hydroxide. Using standard test water containing 300 ppb As and column chromatography, reduction of the arsenic concentration to 3 ppb or less in the effluent was achieved, using a pair of columns (4.5 cm id; 1780 mL and 2019 mL, respectively) in tandem. Subsequently, the Fe(III)-Octolig composite was tested for capacity, and it was calculated that with an input of 50 ppb As, it could take up to a year for the effectiveness to be exhausted.

Cloud‐point extraction of chromium(III) ion with 8‐hydroxyquinoline derivatives

Abstract Cloud‐point extraction, a less‐common extraction method, was used to extract chromium(III) ion from aqueous solution. Using a nonionic surfactant solution and 8‐hydroxyquinoline (or a derivative), a chromium(III) complex and unreacted chelating agent were extracted into the micellar phase at a temperature above the cloud‐point temperature within two hours. The molar ratio, pH, temperature and hydrophobicity of the chelating agent were factors determining the extraction efficiency. Extraction efficiency was improved to 99 %, and chromium concentration was reduced from 55 ppm to less than 1 ppm when excess chelating agent was used at pH 5.5 at 70°C.

Comparison of effectiveness of removal of nuisance anions by metalloligs, metal derivatives of Octolig®

The present study describes the effectiveness of removal of selected aqueous anions by several metalloligs, i.e., metal derivatives of a commercially available immobilized ligand, IMLIG, Octolig®. This material consists of polyethylenediamine moieties covalently bound to a high-surface area silica gel (CAS Registry number = 404899-06-5). The metals involved are copper, cobalt, iron, nickel, manganese, and thorium. The nuisance anions, studied as aqueous solutions, were arsenate, orthophosphate, selenite, sulfate, nitrate, and nitrite. All six metalloligs tested were able to remove arsenate (280 ppb, > 99% removal) effectively. The effectiveness for other anions varied, but all anions were removed by one metallolig or another. For example, for Colbaltilig, in deionized water samples, removal was 96% for 20.9 ppm NO3-N, 98% for 29.6 ppm sulfate (as sodium sulfate). For Cuprilig, removal was 98% for 9.82 ppm boron as boric acid, > 99% for Cr as 212 ppm dichromate, 97% for P as 10 ppm HPO4-P, and 90% for sulfate as 29 ppm sulfate. Removal of nitrate by Cobaltilig appeared to be adversely affected by the presence of sulfate. Manganilig and Nickelig were able to remove > 97% of 10 ppm P as Na2HPO4. Mechanisms of interaction are proposed that suggest six types of behavior and several classes of materials are represented by these metalloligs.

Removal of nuisance aqueous anions with Ferrilig

The present study describes an improved synthesis of Ferrilig, an iron(III) salt of a commercially available immobilized ligand, IMLIG, called Octolig®. The resulting composite, called “Ferrilig” was used to remove arsenate, chromate, molybdate, and selenite ions from aqueous solutions by means of column chromatography. The synthesis of Ferrilig was accomplished by treating an aqueous suspension of Octolig®-21 with an equal weight of ferrous sulfate heptahydrate under nitrogen. The ferrous salt was then collected by sieving and allowed to oxidize to the iron (III) salt by exposure to air; treatment with dilute sodium hydroxide converted the composite to the hydroxide. Using 300 ppb As (as Na2HAsO4·7H2O) and column chromatography, the arsenic concentration in the effluent was less than the detection limit (< 2 ppb). Chromium as sodium chromate, molybdenum as (NH4)6 Mo7O24·4H2O, and selenium as Na2Se03, were removed with fair success. The elements, their initial concentrations and their percentage removal (parenthetically) were: As (280 ppb, 99%), Cr (50.6 ppm, 95.5%), Mo (50.7 ppm, 94.6%), Se (258 ppm, 99.9%).

Cloud‐point extraction of trace copper in lipophilic complex form

Abstract A less‐common extraction procedure, cloud‐point extraction, was used with a lipophilic chelating agent (LEX® 54) to extract copper ion from aqueous solution. Surfactant solutions [0.2–2.2 %(w/w) of nonylphenoxypoly(ethylenoxy)ethanol] with a cloud‐point of 48–52°C, was used in conjunction with a lipophilic chelating agent, dodecyl benzoylacetone, RC6H4CO‐CH2COCH3, to form a copper complex that would be extracted into the micellar phase. Extraction was optimal in a pH range of 5–11 with 95.5–98.6% of the copper extracted. The partition coefficient increased with increasing copper concentration and was in excess of 1000 when the initial copper concentration was 80 ppm. Unlike the cloud‐point temperature and the extraction rate, extraction efficiency was only slightly related to surfactant concentration.

Potential management of Florida red tide through selective photodynamic action

Abstract The unarmoured dinoflagellate, Gymnodinium breve (or Ptychodiscus brevis) was used to test the effectiveness of the photodynamic action of hematoporphyrin. Four systems were compared: light control and dark control (organisms in light and dark, respectively, for 24 hours) versus dark and light test (organisms plus 8 x 10‐5 M porphyrin in dark and light, respectively, for 24 hours). Essentially total destruction was observed for the last system (light test) and no statistically significant differences were observed among the other three systems. The effect of concentration of porphyrin was tested in preliminary experiments using the (10‐4.1, 10‐5.1, 10‐6.1, 10‐7.l M) and the lowest concentration had no discernable effect.

Design of removal agents for prevention of lithium intoxications Chelating tendencies of model β-diketones

Abstract Previous studies have shown the value of lithium salts in the treatment of the manic phase of the manic-depressive syndrome. However, the danger of side effects is real, and it is necessary to find a method for removing excess serum lithium. Dipivaloymethane has been shown to be specific for lithium in aqueous extractions of lithium from mixtures of sodium and potassium ions; other β-diketones, because of certain steric effects may also be specific. In this study, formation constants of dipivaloylmethane and dibutyrylmethane with lithium and other alkali-metal ions were determined to define the specifity for lithium and to explore the possibility of the utility of these and other β-diketones as model compounds for use as lithium control agents.

AGRICULTURAL PHARMACEUTICALS IN THE ENVIRONMENT: A NEED FOR INVENTIVENESS

Some 70% of the pharmaceuticals produced in the US (16,000 tons in 2000) are added to food animal diets to control bacteria and enhance growth rates. These practices and the ramifications are reviewed against a backdrop of diet selection, especially corn-rich diets for cattle. A heavy reliance on tetracyclines, for example, has propagated antibiotic-resistant bacteria. Also, acidosis and related problems, arising from corn-rich diets, require antibiotics that would not be needed on a diet of forage. In addition, the reliance on two important pharmaceuticals, monensin and tetracyclines, has led to antibiotic-resistant bacteria. A need for creative solutions and inventiveness is evident. Practices that would reduce overreliance on pharmaceuticals are considered. Perhaps the obvious solution, cessation by law that has proven effective in other nations, is not a likely option in the US.

Formation of chromium(III) complexes with 8-hydroxyquinoline derivatives in nonionic micellar solutions

Abstract Due to the inertness of hydrated chromium ion, chromium(III) complexes are formed very slowly in aqueous solutions but not in surfactant solutions. Micelle effects were observed in the reaction of chromium(III) ion with 8‐hydroxyquinoline or its derivatives. In nonionic surfactant solutions, reactions between chromium(III) ion and 8‐hydroxyquinoline at 23 EC and 40 EC followed first‐order kinetics. The reaction between chromium(III) ion and Kelex 100, 7‐(4‐ethyl‐l‐methyloctyl)‐8‐hydroxyquinoline, was zero order, and was much slower than the unsubstituted chelating agent. The rate of formation of the chromium(III)‐Kelex 100 complex was dependent upon the surfactant concentration.