The present study developed epidemic models to predict the diffusion of remediation technology. Hypotheses were derived from the models and then tested using data collected from a questionnaire survey (n = 223) and a qualitative interview (n = 28) mainly conducted in the USA, UK, and China, as well as data from the US Superfund program. Hypothesis testing results indicate that: (1) tacit knowledge in innovative remedial technologies leads to logistic rather than exponential growth in their adoption, and (2) social-economic and regulatory factors affect the adoption of remediation technologies. For specific remedial technologies adopted in the US Superfund program, it was found that in-situ bioremediation (ISB) has a higher maximum adoption rate than in-situ chemical treatment (ISC), likely due to lower cost and higher social acceptance associated with ISB. The diffusion of ISC was found to be more rapid than that of ISB due to a greater degree of tacit knowledge associated with ISB.

Surface water quality monitoring is one of the responsibilities of a number of provincial and federal environmental departments in Canada. In Saskatchewan, the Ministry of Environment is responsible for the province water quality monitoring network. The sampling effort was initiated 40 years ago and has been ongoing since, with varying degrees of spatial and temporal coverage. The main objective of the Saskatchewan monitoring network is the assessment of ambient water quality status. In addition, one of the main uses of the generated water quality data is the calculation of a Water Quality Index. The adequacy of the monitoring network to perform these tasks needs to be validated. The objective of this study is to provide a statistical assessment of two of the monitoring network main aspects, the water quality variables and their sampling frequency. A new rationalization approach is applied for the assessment and reselection of water quality variables. The proposed approach provides, in a systematic way, the optimal combinations of variables to continue measuring, variables that may be redundant and could be considered for discontinuance, and variables that may need to be added to the list of variables being measured. The confidence interval around the mean is used as the main criterion for the sampling frequency assessment. A design chart is provided for the sampling frequency assessment, which is easy to use, and provides an initial assessment of the number of samples required to provide a mean value with a predefined error percentage.

The growth behavior of canary grass (Phalaris canariensis L) when cultivated in presence of farming fuels is reported in this work. P. canariensis L. is relevant in several countries. It is an emergent plant for phytoremediation and biofuel activities. The following variables: root length, stem length, total plant weight, green tissue weight (tiller, leaf), and total chlorophyll and chlorophyll a/b ratio, were monitored during the growth in presence of commercial fuels (premium grade, regular grade, diesel, and kerosene) at different concentrations. We applied a comprehensive statistical analysis to understand the results: Univariate analysis, factorial analysis of variance, and subsequent Tukey test were applied to the variables to assess the significance of the differences found. The normality of these variables was analyzed with the Shapiro Wilk test. All parameters were affected by all type and concentrations of fuels and its interaction. This is one of the first reported cases which describe the growth parameters responses from canary grass when cultivated in presence of an essentially constant concentration of farming fuels.

US National Ambient Air Quality Standards (NAAQS) are based on quantitative linkages between ambient air concentrations and an effects indicator. Critical loads (CLs) can provide quantitative information on safe levels of atmospheric deposition to aquatic systems, but CLs cannot be directly used in the NAAQS context because they are not expressed in terms of atmospheric concentrations. Here, we describe the aquatic acidification index (AAI) model that incorporates CL concepts and relates atmospheric nitrogen and sulfur concentrations to an acid neutralizing capacity (ANC) effects indicator (Fig. 1). The AAI estimates the potential surface water ANC associated with a set of atmospheric concentrations of nitrogen and sulfur and a region's biogeochemical and hydrological attributes by combining steady-state CL modeling with air quality modeling outputs. Initial applications of the AAI model yielded results consistent with well-recognized spatial patterns of acid-sensitive aquatic systems. Furthermore, the response of AAI predictions to future year changes in NO ₓ and SO ₓ emissions suggest that planned national emission reduction strategies designed to reduce ozone and particulate matter air pollution will produce increases in surface water ANC.

In this study, the magnetic cellulose nanomaterials, containing magnetic nanoscale zerovalent iron (nZVI) and cellulose, were prepared by a novel reduction method and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM). The XRD and XPS results demonstrated the formation of zerovalent iron nanoparticles in the nanocomposite materials. With a saturation magnetization of 57.2 emu g⁻¹, the cellulose@nZVI composites could be easily separated from solutions in 30 s through the external magnetic field. We investigated the adsorption performance of the magnetic cellulose nanomaterials for As(III) removal from aqueous solutions. The experimental results showed that arsenite adsorption followed the pseudo-second-order kinetic model and Langmuir isotherm model. A maximum removal of 99.27 % was observed for an initial concentration 10 mg L⁻¹, at pH 8.0, and an adsorbent dose of 1.0 g L⁻¹. Considering the high adsorption capacity, fast adsorption rate, and quick magnetic separation from treated water, the cellulose@nZVI composites were expected to be an efficient magnetic adsorbent for arsenic removal from aqueous solutions.

This study investigated lead (Pb) sorption by inorganic and acid-non-soluble organic fractions, which were physicochemically fractionated from cattle, swine, and poultry composts, to understand how Pb is immobilized by animal manure compost and to evaluate the contribution of each fraction in Pb immobilization. Pb was predominantly sorbed on humic acid in the acid-non-soluble organic fraction; on the other hand, Pb sorption by the inorganic fraction could be attributed to the precipitation of Pb compound minerals such as lead phosphate and lead sulfate. The amounts of Pb sorbed on the inorganic fraction were 4.1–8.1 times higher than that sorbed on the acid-non-soluble organic fraction. The amount of Pb sorbed on the inorganic fraction and acid-non-soluble organic fractions was 37–60 and 19–43 %, respectively, of the total Pb sorbed. The results of this study clearly show that the inorganic fraction in the composts effectively immobilizes Pb. Furthermore, the high content of the inorganic components, particularly phosphorus, is important in Pb immobilization.

An on-line preconcentration system using solid-phase extraction with polytetrafluoroethylene was used for the determination of mercury by cold vapor atomic absorption spectrometry. The system uses electronically controlled valves and operates in two simple steps using sorption and elution. The Hg(II) ammonium pyrrolidinedithiocarbamate complexes are retained in a minicolumn packed with the sorbent. The elution, transportation, and reduction of the analyte ions are promoted by a solution of sodium tetrahydroborate(III). After optimization, the developed method showed the following analytical characteristics: a limit of detection of 0.02 μg L⁻¹, linearity of 0.07 to 2.00 μg L⁻¹, enrichment factor of 35, and sampling frequency of 27 h⁻¹. The accuracy of the method was tested by analyzing the certified reference material BCR-060 Lagarosiphon major (aquatic plant). The proposed method was applied to the determination of mercury in water samples.

The Lea Navigation in the north-east of London, a canalized reach of the River Lea, is affected by episodes of very low levels of dissolved oxygen. The problem was detected by the Environment Agency from the confluence with Pymmes Brook (which receives the final effluent of Deephams sewage treatment works) to the Olympic site (Marshgate Lane, Stratford). In this study, possible causes and sources of the poor water quality in the Lea Navigation were investigated using algal bioassays and detailed spatial seasonal mapping of the physico-chemical parameters collected in situ. Results showed chronic pollution and identified polar compounds in the river water and high bacterial concentrations as possible causes of low dissolved oxygen levels. This study confirmed the negative impact of Deephams sewage treatment works (via Pymmes Brook) on the water quality of the Lea. However, whilst the Environment Agency had previously focused on the pollution created by the sewage treatment works, results showed evidence of other sources of pollution; in particular, Stonebridge Brook was identified as an uncontrolled source of pollution and untreated wastewater. This study demonstrates the value of conducting combined methodologies and detailed monitoring. Other possible sources include Old Moselle Brook, diffuse pollution from surface run-off, boat discharges and other undetected drainage misconnections.

The aim of this work was to study the short-term effect of clear-cut harvest on concentrations of dissolved organic carbon (DOC), B, Al, Zn, Cu, Ni, Cr, Cd and Pb in drainage water from northern peatland catchments in Finland underlain by granitic or black shale bedrock, the latter having higher concentrations of several trace elements, such as Ni and Zn. Stem-only harvest (SOH) or whole-tree harvest (WTH) with stump removal were carried out at coniferous sites. Controls were left unharvested. DOC and trace element concentrations were monitored during one pre-treatment and two post-treatment years. There was no constant increase in the element concentrations. However, there were signs that both SOH and WTH clear-cut harvest on northern peatland catchments increases the concentrations of DOC, B, Al, Zn and Ni in ditchwater in some sites irrespective of the bedrock type. The greatest increases were observed in WTH sites but the study does not allow us to assess the statistical significance of the magnitude of the difference between SOH and WTH. We conclude that the element concentrations in ditchwater depend largely on site characteristics masking the possible effect of harvest.

In this study, dissolved air flotation (DAF) was examined as a possible treatment method for the removal of chromium from aqueous solution and plating wastewater. Two coagulants, ferric chloride and poly aluminum chloride (PAC), were used for pretreatment of wastewater. Maximum removal of chromium was achieved for poly aluminum chloride (98 %). Artificial neural network was used for the prediction of the DAF system. The best neuron used for the prediction of chromium removal percentage of interpolated wastewater was 6 %. The mean score error and the coefficient correlation were 0.0007542 and 0.997, respectively.