Transport and fate of organic wastes in groundwater at the Stringfellow hazardous waste disposal site, southern California

In January 1999, wastewater influent and effluent from the pretreatment plant at the Stringfellow hazardous waste disposal site were sampled along with groundwater at six locations along the groundwater contaminant plume. The objectives of this sampling and study were to identify at the compound class level the unidentified 40-60% of wastewater organic contaminants, and to determine what organic compound classes were being removed by the wastewater pretreatment plant, and what organic compound classes persisted during subsurface waste migration. The unidentified organic wastes are primarily chlorinated aromatic sulfonic acids derived from wastes from DDT manufacture. Trace amounts of EDTA and NTA organic complexing agents were discovered along with carboxylate metabolites of the common alkylphenolpolyethoxylate plasticizers and nonionic surfactants. The wastewater pretreatment plant removed most of the aromatic chlorinated sulfonic acids that have hydrophobic neutral properties, but the p-chlorobenzene-sulfonic acid which is the primary waste constituent passed through the pretreatment plant and was discharged in the treated wastewaters transported to an industrial sewer. During migration in groundwater, p-chlorobenzenesulfonic acid is removed by natural remediation processes. Wastewater organic contaminants have decreased 3- to 45-fold in the groundwater from 1985 to 1999 as a result of site remediation and natural remediation processes. The chlorinated aromatic sulfonic acids with hydrophobic neutral properties persist and have migrated into groundwater that underlies the adjacent residential community.     

富营养化水体中底泥释磷的影响因素及其释放机理

磷是湖泊富营养化的主要限制因子,本文综述了沉积物中磷的赋存形态,释放机理及其影响因素.内源磷的赋存形态主要分为铝磷、铁磷、钙磷及有机磷.磷释放受pH值、溶解氧、生物、温度、扰动5种因素影响.对富营养水体内源磷释放的影响因素及其机理进行研究可为富营养化水体的治理提供理论依据.     

PRESENCE AND DISTRIBUTION OF CHLORINATED ORGANIC COMPOUNDS IN STREAMBED SEDIMENTS,NEW JERSEY1

ABSTRACT: Concentrations of 18 hydrophobic chlorinated organic compounds in streambed sediments from 100 sites throughout New Jersey were examined to determine (1) which compounds were detected most frequently, (2) whether detection frequencies differed among selected drainage basins, and (3) whether concentrations differed significantly among selected drainage basins. Twelve drainage basins across New Jersey that contain a range of land-use patterns and population densities were selected to represent various types and degrees of development. To ensure an adequate number of samples for statistical comparison among drainage basins, the 12 selected basins were consolidated into seven drainage areas on the basis of similarities in land-use patterns and population densities. Additionally, data for three classes of chlorinated organic compounds in streambed sediments from 255 sites throughout New Jersey were examined to determine whether the presence of these compounds in streambed sediments is related to the type and degree of development within the drainage area of each sampling site. Chlorinated organic compounds detected most frequently within the seven representative drainage areas were DDT, DDE, DDD, chlordane, dieldrin, and PCBs. DDT, DDE, and DDD, which were the most widely distributed organic compounds, were detected in about 60 to 100 percent of the samples from all drainage areas but one (where the detection rate for these compounds was about 20 to 40 percent). Chiordane and dieldrin were detected in about 80 to 100 percent of samples from highly urbanized and populated drainage areas; detection frequencies for these compounds tended to be smaller in less developed and populated areas. PCBs were detected in about 40 to 85 percent of samples from all drainage areas; detection frequencies were highest in the most heavily developed and populated areas. Analysis of variance on rank-transformed organic compound concentrations normalized to sediment organic carbon content was used to evaluate differences in concentrations among the seven representative drainage areas. Chlordane and PCBs were the chlorinated organic compounds with the most highly elevated concentrations in streambed sediments across the State. Median normalized concentrations of all six of the most frequently detected chlorinated organic compounds were highest in the most heavily urbanized and populated drainage area and lowest in the less populated, predominantly agricultural or forested areas. Concentrations of DDT and DDE, however, did not differ significantly among most of the drainage areas. Concentrations of DDD, chlordane, dieldrin, and PCBs differed significantly among drainage areas. The highest median normalized concentrations were found in samples from the most heavily urbanized and populated areas, and the lowest were in samples from the least developed, most heavily forested area. Logistic regression was used to examine relations between the presence of hydrophobic chlorinated organic compounds in streambed sediments at specified concentrations and variables that characterize the type and degree of development within the drainage areas of 255 sites across New Jersey. The explanatory variables found most useful for predicting the presence of chlorinated organic compounds in streambed sediments include total population and amounts (in square kilometers) of various land-use categories. Logistic regression equations were developed to identify significant relations between population and amounts of specific land-use categories within drainage areas and the probability of detecting chlorinated organic contaminants in streambed sediments. These relations can be used to assist in the identification of geographic regions of primary concern for contamination of bed sediments by chlorinated organic compounds across the State.     

Organic matter characteristics and nutrient content in eroded soils

Twenty-one severely eroded soils of SE Spain (Torriorthent xeric soils) were studied. These soils form a fragile system characterized by soils with a low density of plant cover (<5%), are loamy and occur in a semiarid climate. The soils formerly were used for agricultural purposes but were abandoned at least 15 years ago. These eroded soils had a low total organic carbon content, and their humic substances, humic acid carbon, and carbohydrates were lower compared with soils that had never been cultivated (natural soils). The variables in which the effects of erosion were particularly noted were those related with the active organic matter (respiration and water-soluble organic matter). Those eroded soils with higher salt content showed lower organic matter and carbohydrate contents. Only total nitrogen was correlated with the carbon fractions in the eroded soils.     

Changes in carbon fractions during composting and maturation of organic wastes

Seven mixtures from four organic residues—an aerobic sewage sludge, a city refuse, a peat residue, and a grape debris—were composted, and the changes undergone by their different carbon fractions during their composting and maturation were studied. In most cases a decrease in carbon fractions during the composting and maturation processes was observed. The extractable carbon, however, increased during maturation. Organic matter mineralization was greater in the composts with city refuse than in those with sewage sludge. The samples with peat residue showed the lowest decreases in carbon fractions. During maturation, an increase of humiclike fraction was observed, which was reflected by a decrease in the soluble carbon-precipitated carbon ratio at pH 2. Water-soluble carbon was the carbon fraction most easily degradable by microorganisms, and its amount correlated significantly with composting time in all the samples.     

RIVER PHOSPHORUS DYNAMICS AND RESERVOIR EUTROPHICATION POTENTIAL1

ABSTRACT: Sediments from the Pompton and Passaic Rivers at Two Bridges were analyzed for potentially available phosphorus fractions and total phosphorus (TP). Water samples from the same sites were analyzed for dissolved phosphorus, TP, suspended solids (SS), and volatile SS. Significant negative correlations between river TP concentrations and flow were observed. However, storm flows resulted in increases in TP and SS concentrations and flux (loadings). Most of the increase in river P loading at high flow was in the dissolved fraction, suggesting that the sediments may be a large source of dissolved P. Concentrations of potentially available P in the sediments ranged from 140 to 1310 times the TP concentration in the overlying water. According to a modified Vollenweider model, current P concentrations in the Pompton and Passaic Rivers will result in excessive P loading in the Wanaque Reservoir if even small volumes of river water are pumped to the reservoir through the recently completed Wanaque South pipeline. Reductions in sewage treatment plant effluent P concentrations alone will not produce sufficient decreases in river phosphorus concentrations to avoid this predicted overloading and eutrophication.     

RATES OF RECENT SEDIMENTATION IN LAKE PEPIN1

ABSTRACT: Sedimentation rates since 1954 in Lake Pepin, as determined from the content of fallout cesium-137 in the sediment profile, have exceeded 2.5 cm/yr in the upper part of the lake. These rates, although somewhat less than those of the previous half century (1895–1954), are sufficiently large that the upstream portion of Lake Pepin is threatened with conversion to a marsh within a century. The density of the sediments measured increased with depth in the sampled profile from 1.1 to 1.2 g/ml at the sediment surface to 1.4 to 1.5 g/ml at 2- or 3-m depth. There was little or no change in the patterns of textural composition or density of the sediment profile with depth and age over the past 80 to 150 years.     

Water treatment by aquatic ecosystem: Nutrient removal by reservoirs and flooded fields

Potential use of reservoirs and flooded fields stocked with aquatic plants for reduction of the nutrient levels of organic soil drainage water was evaluated. The treatment systems include 1) a large single reservoir (R1) stocked with waterhyacinth (Eichhornia crassipes), elodea (Egeria densa), and cattails (Typha sp.) in series; 2) three small reservoirs in series with waterhyacinth (R2), elodea (R3), and cattails (R4), grown in independent reservoirs; 3) a control reservoir (R5) with no cultivated plants; 4) a large single flooded field planted to cattails; 5) three small flooded fields in a series planted to cattails; and 6) a flooded field with no cultivated plants. Drainage water was pumped daily (6 hours a day, and 6 days a week) into these systems for a period of 27 months at predetermined constant flow rates. Water samples were collected at the inlet and outlet of each treatment system and analyzed for N and P forms.The series of reservoirs stocked with aquatic plants functioned effectively in the removal of N and P from agricultural drainage water, compared to a single large reservoir. Allowing the water to flow through the reservoir stocked with waterhyacinth plants with a residence time of 3.6 days was adequate to remove about 50% of the incoming inorganic N. Allowing the water to flow through a series of two small reservoirs, R2 and R3, with a residence time of 7.3 days was necessary to remove about 60% of the incoming ortho-P. Flooded fields were effective in the removal of inorganic N, but showed poor efficiency in the removal of ortho-P.Florida Agricultural Experiment Stations Journal Series No. 2320.     

REVIEW OF LAKE RESTORATION PROCEDURES1

ABSTRACT Relevant information on the restoration of lakes is presented. The restoration procedures considered are applicable to the water, the bottom sediments, and aquatic plant improvement. A summary of thirteen (13) suggested methods of restoration are reviewed.     

Applications of Numerical Sediment Quality Targets for Assessing Sediment Quality Conditions in a US Great Lakes Area of Concern

Contaminated sediments are receiving increasing recognition around the world, leading to the development of various sediment quality indicators for assessment, management, remediation, and restoration efforts. Sediment chemistry represents an important indicator of ecosystem health, with the concentrations of contaminants of potential concern (COPCs) providing measurable characteristics for this indicator. The St. Louis River Area of Concern (AOC), located in the western arm of Lake Superior, provides a case study for how numerical sediment quality targets (SQTs) for the protection of sediment-dwelling organisms can be used to support the interpretation of sediment chemistry data. Two types of SQTs have been established for 33 COPCs in the St. Louis River AOC. The Level I SQTs define the concentrations of contaminants below which sediment toxicity is unlikely to occur, whereas the Level II SQTs represent the concentrations that, if exceeded, are likely to be associated with sediment toxicity. The numerical SQTs provide useful tools for making sediment management decisions, especially when considered as part of a weight-of-evidence approach that includes other sediment quality indicators, such as sediment contaminant chemistry and geochemical characteristics, sediment toxicity, and benthic macroinvertebrate community structure. The recommended applications of using the numerical SQTs in the St. Louis River AOC include: designing monitoring programs, interpreting sediment chemistry data, conducting ecological risk assessments, and developing site-specific sediment quality remediation targets for small, simple sites where adverse biological effects are likely. Other jurisdictions may benefit from using these recommended applications in their own sediment quality programs.