This research is aimed at predicting erosion and sedimentation in the Ghareh Aghach Basin in the central part of Iran using Erosion Potential Model (EPM) models incorporated into Geographic Information System (GIS) software. This basin has an area of about 8955 hectares. The region has a range of vegetation, geological, soil texture and land use types. The basin was subdivided into 5 sub-basins. Data required for this study were collected in part through published reports, whilst the remaining was derived by field surveys. Necessary maps in EPM models were prepared in Autocad-2006 medium and were transported to IILWIS, after some revision. After constructing topologies for all polygons, we entered weightings for all layers within the Arc-View software. Combinations of all layers were managed thereafter. Coefficient of each factor was determined, and erosion intensity coefficient (Z) was calculated. Four layers for EPM model were combined to develop the final layer of erosion and sedimentation. The results of the EPM model for homogenous and uniform sampling units showed that 0.19% (16.7 ha) of the total watershed area were classified as class I of erosion category with very low sedimentation and 15.1% (1352 ha) were classified as class II of erosion category with low sedimentation and 41.3% (3699 ha) were classified as class III of erosion category with medium sedimentation and 13.2% (1175 ha) were classified as class IV of erosion category with high sedimentation and finally 30.2% (2711 ha) were classified at class V of erosion category with very high sedimentation, respectively. The result of comparing erosion and sediment values using an EPM model with measured values showed that no significant difference was observed between the estimated and measured values (P < 0.05).

In this work, the treatment of synthetic wastewaters containing methylene blue (MB) and rhodamine B (RB) and actual textile wastewaters (ATW) using boron doped diamond (BDD) anodic oxidation was investigated. Voltammetric study has shown that both MB and RB can be oxidized directly at the anode surface in the potential region where the electrolyte salt is stable. Galvanostatic electrolyses of synthetic and actual industrial wastewaters have led to total abatement of COD and TOC at different operating conditions (electrolyte salt and initial pollutant concentration and current density) and the efficiency of the electrochemical process was governed only by mass-transfer limitations. The nature of the supporting electrolyte has a great influence on the rate and the efficiency of the electrochemical oxidation of dyes. The treatment in the presence of NaCl appears to be more efficient in the COD removal, while in the presence of Na₂SO₄ improves the TOC removal. From the experimental results it seems that the primary mechanisms in the oxidation of dyes are the mediated electro-oxidation by hydroxyl radicals and other oxidants electro-generated from supporting electrolyte oxidation.

Excess sediment and nutrients in surface waters can threaten aquatic life. To determine the relative importance of subsurface drainage as a pathway for movement of sediment and nutrients to surface waters, loading from various tile systems was compared to that from sewage treatment plants (STP) within the same watershed. Movement through tiles comprised 1 to 8% of estimated total (overland plus tile) annual sediment loading from the respective areas drained by the tile. Load during the growing season from five closed drainage systems without surface inlets averaged 5 kg sediment/ha, 0.005 kg dissolved reactive P (DRP)/ha, 0.003 kg NH₄-N/ha, and 3.8 kg NO₃-N/ha; and from two open drainage systems with surface inlets averaged 14 kg sediment/ha, 0.03 kg DRP/ha, 0.04 kg NH₄-N/ha, and 3.1 kg NO₃-N/ha. The eight STP contributed about 44 530 kg suspended sediments, 3380 kg total P, 1340 kg NH₄-N, and 116 900 kg NO₃-N to the watershed annually. Drainage systems added less NH₄-N and P, but more NO₃-N and suspended solids to surface waters than STP. Tile drainage pathways for NO₃-N, STP in the case of P, and overland pathways for sediment are indicated as targets to control loading in artificially drained agricultural watersheds.

The passive flux meter (PFM) developed at the University of Florida is an innovative device that is inserted into a well in order to measure groundwater and contaminant flux. The in-situ device consists of an activated carbon matrix impregnated with known amounts of alcohols that are desorbed at rates proportional to the groundwater flux through the device. After exposure the sorbent is extracted to quantify the contaminant mass intercepted and the resident alcohol mass remaining. Since the alcohols employed in bioactive sites are degradable, studies were conducted to investigate biodegradation issues and microbial acclimation times in field application. Also, silver-impregnated activated carbon was compared to unamended activated carbon in batch and column studies to determine silver ion effects on degradation. The studies confirm degradation and microbial acclimation occurrence, and demonstrate that silver impregnated activated carbon does inhibit degradation. Issues remain with biofilm/biofouling observed in the field as well as column studies.

The sources of microbial and chemical contamination of groundwater are numerous and have severe implications for public health. The objective was to determine the microbiological and physicochemical quality of wells in the west and east of the Cuautla-Yautepec aquifer in Mexico. Wells showed bacteriological contamination in at least one sampling. Coliform values were lower than the maximum permissible limit indicated in the Mexican Ecological Criteria of Water Quality (1000 colony forming unit (CFU)/100 ml of fecal coliforms) for supply sources. The number of isolated amoebae was low, but these were present all year round. Amoebae were found in 71.7% of the samples and belonged to 13 genera. The most frequent amoeba, Hartmannella, occurring in 44% of the samples, has been associated with eye and brain infection, but its role as a cause of infection has not been confirmed. A gradient was observed for dissolved solids according to altitude; the concentrations of dissolved solids increased in wells with lower altitudes. Total hardness values were above 180 mg/L CaCO₃, therefore the water is considered very hard, and both carbonate and non-carbonate hardness was detected. The average values of physicochemical parameters were below the maximum permissible limits indicated in the Mexican official norm.

Metal distributions in lakes surrounding Kostomuksha iron mine and ore dressing mill were explored to study the effects of the mill on the state of the lakes. Both surface water and 10 cm sediment core samples were taken from six lakes in the Russian side and another two in the Finnish side at a maximum distance of 70 kilometres from the plant. Concentrations of thirteen metals, phosphorus and sulphur were determined in waters and sediments by ICP-MS after filtration of the water samples and acid digestion of the sediment samples. No increase of these elements was observed in lakes in southwestern direction towards Finland where air transport was the only pathway. In the northwestern direction where there are also water releases from a waste pond of the plant increasing concentrations of Ca, Mn, S, Fe and As towards the plant were seen both in water and sediments phases. This was also the trend for Na, K and Mg in water and for Zn, Pb, Cd and Hg in the sediment. No systematic change was seen in case of Al, P and Ni. It is likely that elevated water concentrations of at least K, S and As are due to water releases from the waste pond but for other elements the source is not quite evident.

Seven solid sorbents including Amberlite^® XAD-2 and XAD-4, Tenax-TA^®, Anasorb-747, Chromosorb 102, 108, and 750 were evaluated for the collection of the gas phase fraction of pesticides under field conditions at an agricultural site, Bratt's Lake, SK, located in the Canadian prairies. The polyurethane foam (PUF)/sorbent cartridge consists of two PUF layers which sandwich the solid sorbent and each layer was analyzed separately to determine which portion of the PUF/solid sorbent retained the pesticides and the extent of breakthrough. The pesticides that had high detection frequency throughout the study and ambient air concentrations well above MDL were triallate, trifluralin, ethalfluralin, and chlorpyrifos. All sorbents had improved collection efficiency as compared to a standard 7.6 cm PUF and the improvement varied with each pesticide. The most effective sorbents for trapping gas phase fraction of pesticides were XAD-2, XAD-4, Tenax-TA, and Chromosorb 108. The only sorbent not recommended for use is Chromosorb 750. For selected sampling periods when ambient concentrations were above detection limits a number of other organochlorine and organophosphorus pesticides also showed more efficient collection with PUF/solid sorbent cartridges as compared to PUF cartridge. Shorter sample collection periods of 4-days improved detection frequency of pesticides.

This paper discusses the interpretation of surface features that can assist in the evaluation of groundwater resources in semi-arid and arid developing regions. The lack of infrastructure in these areas places serious constraints on borehole drilling, which in turn limits the data which can be obtained directly from the subsurface. Under these conditions, surface indicators may be used to infer useful information about the subsurface, which includes shallow aquifers. This article summarizes those surface indicators which provide useful data in arid and semi-arid regions and provides a review of the literature to assist in their interpretation. Patterns of surface indicators covering a large area may be more effective and less costly for interpreting basic regional hydrogeological conditions than detailed data obtained from a limited number of boreholes. The hydrogeological information which can be obtained by using the methods discussed in this article include the regional flow patterns, an estimate of the depth to groundwater, aquifer geology and estimates of the regional recharge and discharge zones. This data may in turn provide support for subsequent well drilling campaigns, limited environmental assessments, and potable water assessments for humanitarian base camps in developing regions.

Aerobic and facultative bacteria belonging to the Enterobacteriaceae, Pseudomonadaceae, Bacillaceae, Corynebacteriaceae and Streptococcaceae families have been isolated from corroded metallic structures of a hydroelectric power unit in the Amazon region of Brazil. In addition to anamorphic dematiaceous and moniliaceous fungi, members of the archeobacteria kingdom were also detected in the same samples. Scanning electron micrographs of metal bars cultivated with consortia of the isolated microorganisms depicted suggestive images of biofilm formation and corroded metallic structures questioning the possible role of these microorganisms in the corrosion activity. We also found Amazonian medicinal plants exhibiting inhibitory activity against some of the isolated microorganisms. Our new findings need additional studies to confirm the participation of some isolated microorganisms in the process of metallic degradation despite our main question if are there particular microorganisms involved in the corrosion process? or if physicochemical conditions would favor the development of a particular microbiota and consequently the corrosion process would result from its metabolism? Therefore we hypothesize that any microorganism could be potentially involved in the genesis of corrosion process. This is the first report in the literature dealing with microbiologically induced corrosion in the Amazon region which is especially characterized by its high humidity and elevated temperature all year round.

Knowledge of the partitioning between the dissolved and particulate phases of nutrient elements is a key factor in aquatic ecosystem modeling since partitioning regulates the availability to demand ratio of the nutrient in question. This is seldom taken into account in environmental monitoring programs. In this paper, the occurrence and variability of particulate and dissolved phosphorus were studied in the coastal zone of the Baltic Sea. The particulate fraction (PF) of total phosphorus (TP) concentration in coastal waters from some forty stations along the east coast of Sweden was, on average, 0.33. Dissolved inorganic phosphorus (DIP) was a poor predictor of total dissolved phosphorus (DP) representing only 20%-30% of this fraction. Sensitivity analyses showed that the value of PF had a significant impact on modeled predictions of TP concentration in the water on a Baltic sub-basin scale, whereas an applied coastal model was insensitive to variations in PF. Hence, this study encourages further sampling efforts on the partitioning of phosphorus in the open waters of the Baltic Sea.