A simulation-based interval-fuzzy nonlinear programming (SIFNP) approach was developed for seasonal planning of stream water quality management. The techniques of inexact modeling, nonlinear programming, and interval-fuzzy optimization were incorporated within a general framework. Based on a multi-segment stream water quality simulation model, dynamic waste assimilative capacity of a river system within a multi-season context was considered in the optimization process. The method could not only address complexities of various system uncertainties but also tackle nonlinear environmental–economic interrelationships in water quality management problems. In addition, interval-fuzzy numbers were introduced to reflect the dual uncertainties, i.e., imprecision associated with fixing the lower and upper bounds of membership functions. The proposed method was applied to a case of water quality management in the Guoyang section of the Guo River in China. Interval solutions reflecting the inherent uncertainties were generated, and a spectrum of cost-effective schemes for seasonal water quality management could thus be obtained by adjusting different combinations of the decision variables within their solution intervals. The results indicated that SIFNP could effectively communicate dual uncertainties into the optimization process and help decision makers to identify desired options under various complexities of system components.

The decolorization of the recalcitrant dye Remazol Brilliant Blue R (RBBR) by the culture filtrate of Polyporus sp. S133 and the effect of various environmental factors were investigated. Both biodegradation and biosorption were playing an important role in bioremoval mechanisms. The highest biosorption of RBBR in Polyporus sp. S133 was shown by all carbon sources such as sucrose, glucose, fructose, and starch. No biosorption was shown by the addition of aromatic compounds and metal ions; 97.1 % RBBR decolorization was achieved in 120-rpm culture for 96 h, as compared to 49.5 % decolorization in stationary culture. Increasing the shaking rotation of the culture to more than 120 rpm was proven to give a negative effect on decolorization. The highest production of laccase was shown at pH 4 and constantly decreases when the pH level increases. The addition of glucose, ammonium tartrate, Cu²⁺, and protocatechuic acid was the suitable environmental condition for RBBR decolorization. There was a positive relationship between all environmental conditions and laccase production in the decolorization of RBBR.

In order to quickly assess the transfer of radioactive cesium after a nuclear incident, it is useful to know the main biospheric parameters influencing this transfer. A suitably simplified heuristic formula for the Cs transfer is helpful for further application in a Geographic Information System (GIS). In order to determine the most relevant parameters given their huge variability in nature, samples of 150 aquatic plants and the corresponding sediments of 26 diverse aquatic locations such as lakes, ponds, and disconnected parts of rivers were measured for 137Cs, 134Cs, and 40K radioactivity one year after the nuclear disaster of Chernobyl. Sediments were characterized by determination of weight loss after heating, extractable Cs and K, pH(KCl), particle size distribution, content of clay minerals, and similar biospheric, chemical, and physical parameters. As a general concept, the procedure of uptake of radioactive cesium was subdivided into the two following steps: “resorption of cesium fallout by soil” and “uptake of soil cesium by plants”. Results for the resorption by soil show strong dependence on the percentage of dry matter and on the content of muscovite (mica) in the sediment. The uptake in plants, however, depends mostly on the content of 137Cs in the sediment itself, on the content of montmorillonite (weathered mica) and on the transfer factor of 40K which indicates the potassium affinity of the 30 different collected plant species. These findings can serve to quickly and practically assess the transfer factor across larger geographic regions in an evidence-based manner. Suitable IT tools for such space-related estimations are Geographic Information Systems or Virtual Globes such as Google Earth.

Nanocomposite of CeO₂–SnO₂ containing different CeO₂ contents was prepared by coprecipitation process. The material obtained was characterized by X-ray diffraction and N₂ adsorption–desorption isotherms. Its photocatalytic activity was tested in the degradation of azo dye of leather, Direct Black 38, in aqueous solution under sunlight. The photocatalytic activity of the coupled CeO₂–SnO₂ oxide ranged depending on the CeO₂ contents. The optimum amount of CeO₂ for the synthesis of CeO₂–SnO₂ was 7 wt.% since the nanoparticles showed high photocatalytic activity in the degradation of the dye, similar to that of the TiO₂–P25 photocatalyst. The kinetics of photocatalytic degradation and total organic carbon removal under sunlight were found to follow a first-order rate law. The results indicated that CeO₂–SnO₂ can be used for the removal of dyes from wastewater.

Four devices developed for measuring settling velocity distributions of combined sewer overflow (CSO) solids were applied to dry and wet weather flow samples from an urban area serviced by combined sewers (Welland, ON, Canada). The settling column-based methods (the Aston, Brombach and US Environmental Protection Agency columns) produced comparable results indicating minimal differences in settleability of dry and wet weather samples. The elutriation apparatus, which assessed settling velocities in a flowing medium, indicated higher settleabilities than the column methods. This was attributed to enhanced opportunities for particle coalescence in the flowing medium, which should better approximate actual sedimentation conditions. While the elutriation apparatus also indicated larger differences in settleabilities between dry and wet weather samples than the column methods, this difference was not statistically significant. Experimental distributions of particle settling velocities were approximated by a mathematical function, which was then used to estimate partial settling of total suspended solids (TSS) with settling velocities smaller than the clarifier overflow rate. The TSS removal target of 50%, which is applicable to CSOs in Ontario, could be met for overflow rates ranging from 4.7 to 6.8 m/h, for dry and wet weather flows, respectively, based on the average settling velocities measured. Experimental data collected in the study indicate that the design of CSO storage and settling facilities is affected, among other factors, by both the apparatus used to assess CSO settleability and the inter-event variability of CSO settling characteristics.

This work aims to identify and characterize heavy metal contamination in a fluvial system from Cartagena–La Unión mining district (SE Spain). In order to assess the dynamics of transport and the accumulation of heavy metals, sediments, surface water and vegetation, samples along “El Avenque” stream were collected. The former direct dumps of wastes and the presence of tailing ponds adjacent to the watercourse have contributed to the total contamination of the stream. Total Cd (103 mg kg−1), Cu (259 mg kg−1), Pb (26,786 mg kg−1) and Zn (9,312 mg kg−1) in sediments were above the limits of European legislation, being highest where tailing ponds are located. Bioavailable metals were high (3.55 mg Cd kg−1, 6.45 mg Cu kg−1, 4,200 mg Pb kg−1 and 343 mg Zn kg−1) and followed the same trend than total contents. Metals in water were higher in sampling points close to ponds, exceeding World Health Organization guidelines for water quality. There is a direct effect of solubilisation of sediment metals in water with high contents of SO 4 2− , product of the oxidation of original sulphides. The mobility of metals varied significantly with shifts in pH. Downstream, available and soluble metals concentrations decreased mainly due to precipitation by increments in pH. As a general pattern, no metal was bioaccumulated by any tested plant. Thus, native vegetation has adopted physiological mechanisms not to accumulate metals. This information allows the understanding of the effect of mining activities on stream contamination, enforcing the immediate intervention to reduce risks related to metals’ mobility.

Characterization of spatial variation of heavy metals in urban soils is essential to identify pollution sources and potential risks to humans and the environment. While heavy metals concentration in soils depends also on the nature of bedrock and on abiotic and biotic factors, it can be argued that nowadays, due to increasing human activities, it is determined mainly by anthropogenic sources. We determined concentrations and spatial distribution of heavy metals, with particular focus on those potentially toxic (As, Cr, Pb, V, and Zn), in urban and peri-urban soils of Cosenza-Rende (southern Italy). One hundred forty-nine samples of topsoil (0–10 cm) were collected and analyzed for 36 elements by X-ray fluorescence spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). In addition, 18 samples of rocks were collected on outcrops of whole area and analyzed by ICP-ES and ICP-MS. Geostatistical methods were used to map the concentrations of major oxides and several minor elements. Heavy metals in the analyzed samples showed a wide range of concentrations, primarily controlled by the geochemical composition of bedrock, with the notable exceptions of Cu, Pb, and Zn, whose concentrations are heavily affected by land use and anthropogenic pollution in urban areas. Geochemical analysis and spatial distribution showed that high concentrations of potentially toxic elements are found in soils near major roads, indicating that anthropogenic factors determine the anomalies in these areas.

Air pollutants emissions from traffic are very closely connected to urban air quality, in a local scale, as well as to global problems like climate change, in a large scale. Road transport air pollutants emissions represent, in most cases, a critical parameter for a comprehensive and successful understanding of the mechanisms governing the air pollutants concentrations. Hence, reliable estimations and comprehension of road transport emissions are indispensable in order to set reliable strategies in the direction of air pollution abatement and management of air pollutants and greenhouse gases emissions. In this framework, in the present work, the emissions of air pollutants from road transport in Greece will be presented for the whole period 1990–2009 as it was found that a detailed, accurate and reliable emissions inventory was missing. The whole period emissions variation has clarified the impact of the change in the vehicle fleet, the engine technologies and the fuel quality. The calculated results have revealed that the age of the vehicles and the corresponding engine technology are the critical parameters determining the amount of the pollutants emitted. This was mainly observed in both passenger cars and heavy duty vehicles demonstrating the importance of a renewal programme of the old circulating vehicles in order to set an effective air pollution abatement strategy. Passenger cars were found to be responsible for the major part of most air pollutants emissions except from nitrogen oxides and particulates emissions. Heavy duty vehicles contribute more than 66% to nitrogen oxides and particulates emissions. For the whole time period, all calculated pollutants present a decreasing trend, with the exception of carbon dioxide and nitrous oxide which increase constantly, ranging from −96% for sulphur dioxide to −1% for PM10.

Batch sorption experiments were carried out to investigate the potentiality of papaya leaf powder (PLP) for the removal of methylene blue (MB) from aqueous solution. The effects of various experimental parameters, such as adsorbent dose, initial solution concentration, contact time, and solution pH were also studied. The amount of dye adsorbed was found to increase with increase in initial dye concentrations. Papaya leaf adsorbs MB better in basic medium. The adsorption equilibrium data fitted well in the Langmuir isotherm equation with a monolayer sorption capacity of 512.55 mg g⁻¹. The kinetics of MB adsorption onto papaya leaf was examined using the pseudo-first and pseudo-second order and unified approach kinetic models. The adsorption kinetics followed the pseudo-second order kinetic model, but the rate constant was found to depend on initial dye concentration. The unified approach model described the equilibrium and kinetics well. The forward and backward rate constants were determined from the unified approach model.

Single and joint ectomycorrhizal (+ Hebeloma mesophaeum) and bacterial (+ Bacillus cereus) inoculations of willows (Salix viminalis) were investigated for their potential and mode of action in the promotion of cadmium (Cd) and zinc (Zn) phytoextraction. Dual fungal and bacterial inoculations promoted the biomass production of willows in contaminated soil. Single inoculations either had no effect on the plant growth or inhibited it. All inoculated willows showed increased concentrations of nutritional elements (N, P, K and Zn) and decreased concentrations of Cd in the shoots. The lowest biomass production and concentration of Cd in the willows (+ B. cereus) were combined with the strongest expression of metallothioneins. It seems that biotic stress from bacterial invasion increased the synthesis of these stress proteins, which responded in decreased Cd concentrations. Contents of Cd and Zn in the stems of willows were combination-specific, but were always increased in dual inoculated plants. In conclusion, single inoculations with former mycorrhiza-associated B. cereus strains decreased the phytoextraction efficiency of willows by causing biotic stress. However, their joint inoculation with an ectomycorrhizal fungus is a very promising method for promoting the phytoextraction of Cd and Zn through combined physiological effects on the plant.