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Humic substances are mixtures of macromolecules with varied structures and chemical compositions that are affected by differences in parental biomaterials and environmental conditions. This study used elemental analysis, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and solid-state 13 C nuclear magnetic resonance spectroscopy (NMR) to identify the chemical and structural heterogeneity of 10 humic acids (HAs) and a humin. The HAs were obtained by progressively extracting solution from a soil in western Massachusetts, eight times with 0.1 M Na 4 P 2 O 7 and two times with 0.1 M NaOH. The humin was the residual fraction after 10 base extractions. As indicated by solid state NMR analysis, the aliphatic carbons (0 ϳ 108 ppm) of the HAs increased gradually from 50% in fraction 1 (F-1) to 62% in fraction 9 (F-9) and 70% for the humin, but the aromatic carbons (108 ϳ 162 ppm) were highest in F-1. The band assigned to aliphatic carbon (2930 cm ؊1 ) in the DRIFTS spectra gradually increased with further extractions, and the relative intensity of this peak was the highest in humin. The atomic C/H ratio declined from 1.1 for F-1 to 0.6 for F-10 and the humin, consistent with the spectroscopic analyses. In addition, both elemental and spectroscopic data reveal that the last extracted HA and humin contained relatively lower contents of polar functional groups such as carboxylic and phenolic groups. This study shows significant chemical, structural, and molecular differences among the 10 sequentially extracted HAs and humin, even from a single soil. (Soil Science 2003;Volume 168:880-887)

During the period 1900–1950, considerable amounts of Pb arsenate pesticides were used in apple orchards. Many of these orchards are not in fruit production any longer and are used for home gardening, pasture, or forage and vegetable cropping. This paper examines the spatial distribution of inorganic pesticide residues in an abandoned orchard in central Massachusetts.Maximum Pb and As concentration in surface soils sampled in a grid‐like pattern, were 870 µg g−1 and 120 µg g−1, respectively. Areas high in contaminants were either former tree sites or low spots where spray residues collected. A transect through the approximate location of a former tree site showed Pb and As concentrations under the dripline of 1400 µg g−1 and 330 µg g−1, respectively, and lower values of 170 µg g−1 and 50 µg g−1 outside the periphery of the crown. Lead, arsenic, and zinc concentrations decreased with increasing depth, with maximum concentrations in the upper 5 cm. No evidence of significant leaching of Pb, As, Zn, or Cu was observed below the 20‐cm depth. The rather insoluble Pb orthoarsenate appeared to be the predominant species for the Pb and As residues.

Reed beds are an alternative technology wastewater treatment system that mimic the biogeochemical processes inherent in natural wetlands. The purpose of this project was to determine the effectiveness of a reed bed sludge treatment system (RBSTS) in southern New England after a six-year period of operation by examining the concentrations of selected metals in the reed bed sludge biomass and by determining the fate of solids and selected nutrients. Parameters assessed in both the reed bed influent and effluent: total suspended solids, biochemical oxygen demand, nitrate-nitrogen and total phosphorus. In addition, the following metals were studied in the reed bed influent, effluent and Phragmites plant tissue and the sludge core biomass: boron, cadmium, chromium, copper, iron, lead, manganese, molybdenum, nickel, and zinc. The removal efficiencies for sludge dewatering, total suspended solids and biochemical oxygen demand were all over 90%. Nitrate and total phosphorus removal rates were 90% and 80% respectively. Overall metals removal efficient was 87%. Copper was the only metal in the sludge biomass that exceeded the standards set by the Massachusetts Department of Environmental Protection for land disposal of sludge. The highest metal concentrations, for the most part, tended to be in the lower tier of the sludge profile. The exception was boron, which was more concentrated in the middle tier of the sludge profile. The data and results presented in this paper support the notion that reed bed sludge treatment systems and the use of reed beds provide an efficient and cost effective alternative for municipal sludge treatment.

Moisture regimes and associated soil mottling patterns were investigated over a 2‐y period in a Paxton‐Rainbow‐Ridgebury‐Scarboro hydrosequence in central Massachusetts. Changes in physical conditions in these coarse‐loamy fragipan soils were monitored with well points, tensiometers, soil temperature probes, and redox potential electrodes. Well‐drained soils appeared uniformly brown, reflective of a generally strongly oxidized environment. They also showed the greatest seasonal fluctuations in soil temperature ranging from 0 to 23°C. Matrix colors of highest chromas (6 or higher) occurred in the moderately well‐drained (MWD) soils where reducing and oxidizing environments coexist within the profile at some time during the growing season. Prominent ferrans and albans in the 2Cx horizons of MWD soils were related to sustained groundwater levels, although higher water tables often occurred for periods too short or too cold for development of strongly reducing conditions. The characteristics grey streaking patterns of fragipans were best expressed in the 2Cx horizons of MWD soils and can be attributed to reducing environments during periods with soil temperature above biologic zero when conditions are wet but unsaturated. Significant translocation and leaching of iron occurred in the somewhat poorly drained soils, as evidenced by olive‐grey matrix colors. Channel neoferrans and some neoalbans indicated that a reducing environment may persist within the B2 horizon long after it has become unsaturated. Lowest chroma colors in this hydrosequence was found in the very poorly drained soils where perennial conditions of saturation or near saturation exists up to the soil surface resulting in the strongest reducing environment and least fluctuations in seasonal temperatures.