The biodegradation of different peat types was studied with a manometric respirometric test. Compaction peat and sphagnum peat samples were analysed, and the effect of peat pH on biodegradation behaviour was evaluated. Only minor (BOD/ThOD < 0.4%) biodegradation was observed with compaction peat samples, and the stable state, in which biodegradation stopped, was achieved during a two month period. As expected, sphagnum peat samples with a lower decomposition rate degraded more than compaction peat samples. Alkalinity (pH between ca. 4-9) of the peat was noticed to reduce the degree of biodegradation and accelerate the achievement of the stable state.

The development of a monitoring tool for predicting water quality and tracing pollution sources are important for the management of sustainable aquatic ecosystems in urban areas. In this study, synchronous fluorescence technique was applied to 18 sampling sites of a typical urban watershed in Korea, some of which are directly affected by the effluent from a wastewater treatment plant (WWTP), to investigate the capability of the technique for biochemical oxygen demand (BOD) prediction and source discrimination. Sampling was conducted three times at the same sites during the low flow period between October and November, 2005. Protein-like fluorescence intensities of the samples showed a positive linear relationship with the BOD values (Spearman’s rho = 0.90, p < 0.0001). The BOD prediction capability was superior to other monitoring tools such as UV absorption and conductivity measurements particularly for the upstream sites from the WWTP, which ranged from 0.0 to 5.0 mg/l as BOD. The protein-like fluorescence and a ratio of protein-like/fulvic-like fluorescence were suggested as good fluorescence signatures to discriminate different sources of dissolved organic matter (DOM). The samples collected from four different DOM source regions including upstream sites from the WWTP, downstream sites, discharge from a reservoir, and headwater were distinguished from one another by varying ranges of the two selected fluorescence signatures. Our results suggest that the synchronous fluorescence technique has the potential to be developed into a real-time water quality management tool for the comprehensive monitoring of urban rivers.

Sandstorms which distribute a great number of particles are a special atmospheric occurrence and are uncommon in northern China. This study was conducted to determine, for the first time, the concentration of organochlorine pesticides (OCPs) in sandstorm depositions. Samples were collected from urban areas of Beijing and a total of eight OCPs were measured. All samples contained OCP residues. The total hexachlorocyclohexane (HCHs) concentration ranged from 20.6 to 59.8ng g⁻¹ and the total dichlorodiphenyltrichloroethane (DDTs) concentration ranged from 12.0 to 14.3ng g⁻¹. Furthermore, increasing HCH contamination was observed from the northwest to the southeast and a uniform distribution of DDT contamination was discovered in Beijing. Analysis of the sources of contamination showed that HCHs in the sandstorm depositions were derived from a relatively old source of lindane, and DDTs mainly originated from an old source of dicofol in Beijing. The preliminary pollution assessment of the samples indicated that HCH levels might be categorized as low pollution and DDT levels might be categorized as no pollution. The present study suggests that sandstorm depositions may not produce the special risk of adverse health effect from OCPs for the residents of Beijing, China.

Agrichemical spills and discharges to soil can cause point-source contamination of surface and ground waters. When high contaminant concentrations inhibit natural attenuation in soils, chemical treatments can be used to promote degradation and allow application of treated soils to agricultural lands. This approach was used to remediate soil containing >650 mg atrazine, >170 mg metolachlor and >18,000 mg nitrate kg⁻¹. Results indicated a decrease in metolachlor concentration to <1 mg kg⁻¹ within 95 days of chemical treatment with zerovalent iron (Fe⁰, 5% w/w) and aluminum sulfate (Al₂(SO₄)₃, 2% w/w) but after one year >150 mg atrazine and >7000 mg nitrate kg⁻¹ remained. Laboratory experiments confirmed that subsequent additions of sucrose (table sugar) to the chemically pretreated soil promoted further reductions in atrazine and nitrate concentrations. Field-scale results showed that adding 5% (w/w) sucrose to windrowed and pretreated soil significantly reduced atrazine (<38 mg kg⁻¹) and nitrate (<2,100 mg kg⁻¹) concentrations and allowed for land application of the treated soil. These results provide evidence that zerovalent iron in combination with Al₂(SO₄)₃ and sucrose can be used for on-site, field-scale treatment of pesticide- and nitrate-contaminated soil.

This study presents the analysis of two series of concentrations of airborne particulate matter (APM) collected in two exploratory campaigns aimed at elucidating the source-receptor problem (SRP) in the metropolitan area of Buenos Aires. Although several techniques have been previously applied to interpret these measurements, we have almost exclusively used here the method of angular distances among objects (ADO) to discuss its advantages as a tool in understanding environmental questions within the source-receptor framework. We present a simple method of calculating the ADO, explain its chemical interpretation and the information that is possible to get by classifying the angular distances. A comparison among ADO with principal component analysis and Kohonen artificial neural networks is also discussed.

The major objective of this paper is to provide insights to sources and sinks of nitrous acid in urban areas, and their seasonal dependency on meteorology, photochemistry and long range transport. With this aim, nitrous acid (HONO) mixing ratios and other compounds were measured in Ashdod (south of Tel Aviv, Israel), a typical Mediterranean urban area. Statistical data analysis revealed the expected correlation between HONO and nitrogen oxides during the autumn campaign when HONO sources appeared to be traffic-, harbor-, and industry-related. Conversely, during summer HONO and NO₂ were no longer correlated: NO₂ at nighttime was probably deposited onto surfaces, soil and plants, whereas HONO at daytime was likely destroyed photolytically contributing to the OH concentration. Photolysis was expected to be the dominant HONO sink at daytime, especially during the summer period. Using modeled photolytical HONO lifetimes we estimate the magnitude of heterogeneous and/or organic electron transfer source reactions of HONO as 6-8 ppbv/h.

A mesocosm system was designed to study evaporation kinetics and transport of TCE in flowing surface water. The airtight unit, with a total internal volume of 52.01 x 10⁻² m³, was fabricated with glass and Teflon material, and was provided with 8.53 m long channel to simulate water flow in an open channel. The peristaltic pumps, connected to the inlet and the outlet of the mesocosm, provided a constant water flow through the channels. The experimental studies were conducted at two different velocities, 9.42 x 10⁻³ and 4.71 x 10⁻³ m/s, respectively. For both the velocities, a tracer (NaBr) test confirmed uniform water flow in the channels. The total length and the length between the sampling ports were found sufficient to record gradual decrease in TCE concentrations along the direction of the flow in the channels. The volatilization coefficient for TCE was found to be 0.49 and 1.07 h⁻¹ for the experiments conducted at lower and higher water velocities, respectively. The TCE evaporation half life (t 1/2) and the corresponding evaporation half distance (d 1/2) were 1.41 h and 23.98 m for lower velocity, and 0.65 h and 21.96 m for higher velocity, respectively.

Advances in computing processing power and in availability of environmental and biological data have allowed the development and application of comprehensive modeling systems that utilize a holistic, integrated, approach for assessing the interactions of environmental and biological systems across multiple scales of spatiotemporal extent and biological organization. This approach allows mechanism-based environmental health risk assessments in a person-oriented framework, which accounts for simultaneous exposures to contaminants from multiple media, routes, and pathways. The conceptual basis and example applications of the Modeling ENvironment for TOtal Risk (MENTOR), and the DOse-Response Information ANalysis system (DORIAN) are presented.

Although the area of urban river sediment quality has received increasing attention over the last 10 years, the presence of contaminated sediments in urban rivers and the potential risk to public health it poses has yet to be rigorously addressed within the urban river restoration context. This is an issue of particular concern at the current time, as the opening-up of urban rivers is being strongly promoted by many legislative and non-legislative bodies as a multi-benefit approach to tackling a range of urban challenges; from decreasing the risk of flooding to increasing the quality-of-life in urbanised areas. This paper brings together these two contrasting concepts; urban rivers as pollutant sinks and sources (presentation of data on urban river sediment quality) and urban rivers as sites of flood alleviation, amenity, recreation and wildlife value (review of the drivers and initiatives behind the increasing implementation of urban river rehabilitation schemes). In light of this combined assessment, the urgent need for a risk assessment of restored urban river sites to establish whether the presence of contaminated sediments poses a risk to public health is strongly recommended. Should such a risk be demonstrated, a tiered approach to supporting the identification and pro-active management of these risks is proposed as a way to inform and enable, rather than to prevent, the safe and appropriate use of the increasing number of urban river restoration schemes being implemented.

This is a study of the sources of alkylphenol and alkylphenol ethoxylates in wastewater, including the new observation that the main contribution is from textiles. Alkylphenols and alkylphenol ethoxylates are widely used chemicals in various applications that are partly under environmental restrictions within Europe. The study sets out to analyze the most important sources of this large group of organic compounds in an urban wastewater system. A substance flow analysis (SFA) of the technosphere in Stockholm, Sweden in 2004 was conducted, allowing a comparison of 13 groups of goods' emissions to wastewater. It was found that the groups of textiles and cleaning agents were the major sources to wastewater, while the group's personal care products and paint and lacquers give smaller contributions. The content of alkylphenol ethoxylates in goods, especially in textiles, is a most significant source and is probably valid for other urban areas as well.