BACKGROUND Research on drinking water in the United States has rarely examined disproportionate exposures to contaminants faced by low-income and minority communities. This study analyzes the relationship between nitrate concentrations in community water systems (CWSs) and the racial/ethnic and socioeconomic characteristics of customers. OBJECTIVES We hypothesized that CWSs in California's Sa...

An integrated enzyme-functionalized field-effect transistor (ENFET) device for the sensing of nitrate ions is described. An aminosiloxane-functionalized gate interface is modified with N-methyl-N'-(carboxyalkyl)-4,4'-bipyridinium relay units. The complex formed between nitrate reductase and the bipyridinium units on the gate surface is crosslinked with glutaric dialdehyde to yield a stable rela...

Globally, the presence of nitrate anions in water beyond the threshold limit can be deleterious to both flora and fauna life. Guyana‟s waste and domestic water needs monitoring to assess the concentration of toxic anions and cations. High levels of nitrate anion beyond the threshold limit can induce the “blue baby” syndrome amongst other effects. This paper focuses on the determination of nitra...

Denitrifying polyphosphate accumulating organisms (DNPAOs) are very promising for simultaneous nitrogen and phosphorus removal. While during denitrification, emission of a greenhouse gas, nitrous oxide (N2O), may occur. In this study, DNPAOs were enriched in a lab-scale reactor, and N2O emission was examined under different electron acceptor conditions. During the anoxic phase, with the uptake ...

Ecologists have found a close relationship between the concentrations of nitrate (NO3-) and dissolved organic carbon (DOC) in ecosystems. However, it is difficult to determine the NO3- fate exactly because of the low coefficient in the constructed relationship. In the present paper, a negative power-function equation (r(2) = 0.87) was developed by using 411 NO3- data points and DOC:NO3- ratios ...

The 204- and 229-nm excited UV resonance Raman spectra of wastewater solutions containing sodium nitrite and nitrate were measured in the concentration range 7 microM to 3.5 mM (0.1-50 ppm nitrogen). The other chemical species present in wastewater do not interfere with Raman measurements of NO2-/NO3- bands. We observe detection limits of < 14 microM (< 200 ppb) for both NO2- and NO3-. UV reson...

Quantifying and simulating the relationships between crop growth, total-nitrogen (total-N) and nitrate-N (NO3--N) concentration can improve crop nutritional husbandry. In this study, the relationship between shoot relative growth rate (RGR) and shoot total-N, organic-N and NO3--N concentration of hydroponically-grown lettuce (Lactuca sativa var. capitata L. cv. Kennedy) was described and simula...

A rare variety of coordination rings having the M3L6 composition are prepared by the combination of Pd(NO3)2 with an imidazolyl or benzimidazolyl appended bidentate non-chelating ligand (i.e.L1 or L2). The variable concentration 1H NMR spectra of the trinuclear complexes [Pd3(L1)6](NO3)6, 1a and [Pd3(L2)6](NO3)6, 2a in DMSO-d6 provided valuable information on the self-assembly phenomenon of the...