Copper distribution in surface and subsurface soil horizons

The horizons of four natural soils were treated with Cu²⁺ in an acid medium to study the retention capacity of Cu. The possible mineralogical changes arising because of the treatment were also studied. The soil properties and characteristics with the greatest influence on the metal retention and its distribution among the different soil fractions were determined. Crystalline phases of each horizon were determined by X-ray diffraction (XDR). The morphology, structural distribution and particle chemical composition of soil samples were investigated using field emission scanning electron microscopy. Cu distribution in the different geochemical phases of the soil was studied using a sequential extraction. The treatment led to an increase in the amorphous phases and the formation of new crystalline phases, such as rouaite (Cu₂(NO₃)(OH)₃) and nitratine (NaNO₃). Cu was also found superficially sorbed on amorphous hydroxy compounds of Fe that interact with albite, muscovite and gibbsite, and also on spherical and curved particles of aluminium clays. The largest amount of Cu retained was in an exchangeable form, and the smallest amount associated with the crystalline Fe oxides and residual fraction. In the surface horizons, the predominant Cu retention process is complexation in organomineral associations, while in the subsurface horizons it is adsorption.     

Geogenic Distribution of Arsenic (As) and Antimony (Sb) in Soils of the Murcia Region in Spain

The objective of this study was to determine the As and Sb contents in soils from the Murcia Region of Spain and the possible relationship between the mineralogical composition, soil properties, and As and Sb concentrations. In this study, 490 samples were selected from areas with different characteristics in order to study As and Sb variability. Results show that As and Sb concentrations are positively correlated with the phyllosilicate and quartz content but negatively correlated with the calcite content. The generic reference level (GRL) for these elements was determined according to the Spanish legislation. Established GRL values vary according to the established mineralogical groups, suggesting that GRL has to be determined considering the lithological characteristics of the study area.     

Reduction of Baltic Sea Nutrient Inputs and Allocation of Abatement Costs Within the Baltic Sea Catchment

The Baltic Sea Action Plan (BSAP) requires tools to simulate effects and costs of various nutrient abatement strategies. Hierarchically connected databases and models of the entire catchment have been created to allow decision makers to view scenarios via the decision support system NEST. Increased intensity in agriculture in transient countries would result in increased nutrient loads to the Baltic Sea, particularly from Poland, the Baltic States, and Russia. Nutrient retentions are high, which means that the nutrient reduction goals of 135 000 tons N and 15 000 tons P, as formulated in the BSAP from 2007, correspond to a reduction in nutrient loadings to watersheds by 675 000 tons N and 158 000 tons P. A cost-minimization model was used to allocate nutrient reductions to measures and countries where the costs for reducing loads are low. The minimum annual cost to meet BSAP basin targets is estimated to 4.7 billion €.     

Use of hairy roots extracts for 2,4-DCP removal and toxicity evaluation by Lactuca sativa test

2,4-Dichlorophenol (2,4-DCP) is widely distributed in wastewaters discharged from several industries, and it is considered as a priority pollutant due to its high toxicity. In this study, the use of different peroxidase extracts for 2,4-DCP removal from aqueous solutions was investigated. Tobacco hairy roots (HRs), wild-type (WT), and double-transgenic (DT) for tomato basic peroxidases (TPX1 and TPX2) were used to obtain different peroxidase extracts: total peroxidases (TPx), soluble peroxidases (SPx), and peroxidases ionically bound to the cell wall (IBPx). All extracts derived from DT HRs exhibited higher peroxidase activity than those obtained from WT HRs. TPx and IBPx DT extracts showed the highest catalytic efficiency values. The optimal conditions for 2,4-DCP oxidation were pH 6.5, H₂O₂ 0.5 mM, and 200 U mL^?1 of enzyme, for all extracts analyzed. Although both TPx extracts were able to oxidize different 2,4-DCP concentrations, the removal efficiency was higher for TPx DT. Polyethylene glycol addition slightly improved 2,4-DCP removal efficiency, and it showed some protective effect on TPx WT after 2,4-DCP oxidation. In addition, using Lactuca sativa test, a reduction of the toxicity of post removal solutions was observed, for both TPx extracts. The results demonstrate that TPx extracts from both tobacco HRs appear to be promising candidate for future applications in removing 2,4-DCP from wastewaters. This is particularly true considering that these peroxidase sources are associated with low costs and are readily available. However, TPx DT has increased peroxidase activity, catalytic efficiency, and higher removal efficiency than TPx WT, probably due to the expression of TPX1 and TPX2 isoenzymes.     

Spatial distribution and reduction of PCDD/PCDF Toxic Equivalents along three shallow lowland reservoirs

Reservoirs situated along a river continuum are ecosystems where rates of transfer of suspended matter and associated micropollutants are reduced due to sedimentation, accumulation, and biological and physical transformation processes. Among the micropollutants, PCDDs and PCDFs are substances that are highly toxic and carcinogenic for humans and animals. They are emitted and dispersed in the environment throughout the whole catchment area and may accumulate in aquatic and terrestrial food chains, creating a risk for human health. A wealth of data exists indicating the increase in the concentrations of pollutants along a river continuum. A comparative analysis of total, individual, and TEQ PCDD/PCDF concentrations in large lowland, shallow reservoirs located in different catchments (“I”—industrial/urban/agricultural, “U”—urban/agricultural, and “A”—agricultural/rural) showed decreases of the TEQ concentrations in bottom sediments along a gradient from the middle sections to the dam walls. Moreover, penta-, hexa-, and heptachlorinated CDD/CDF congeners were reduced from 28.8 up to 93.6 % in all three types of reservoirs. A further analysis of water samples from the inlets and outlets of the “A” reservoir confirmed this tendency.     

Effect of ibuprofen exposure on blood,gill, liver,and brain on common carp (Cyprinus carpio) using oxidative stress biomarkers

Although trace concentrations of ibuprofen (IBP) have been detected in diverse water bodies, there is currently insufficient information on the potentially deleterious effects of this xenobiotic. The present study aimed to determine whether IBP induces oxidative stress in brain, liver, gill, and blood of the common carp Cyprinus carpio. To this end, the median lethal concentration at 96 h (96-h LC₅₀) was determined and the lowest observed adverse effect level was established. Carp were exposed to the latter concentration (17.6 mg L^?1) for 12, 24, 48, 72, and 96 h, and the following biomarkers were evaluated: lipid peroxidation (LPX) and activity of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase. Results indicated that LPX and antioxidant enzymes’ activity increased significantly (p?<?0.05) with respect to the control group in liver, gill, and blood, while no significant differences occurred in brain. In conclusion, IBP induced oxidative stress on C. carpio, the liver being the organ most affected by this damage.     

Investigation of pharmaceutical metabolites in environmental waters by LC-MS/MS

Pharmaceuticals, once ingested, are commonly metabolized in the body into more polar and soluble forms. These compounds might not be completely removed in the wastewater treatment plants and consequently being discharged into the aquatic ecosystem. In this work, a multi-class sensitive method for the analysis of 21 compounds, including 7 widely consumed pharmaceuticals and 14 relevant metabolites, has been developed based on the use of UHPLC-MS/MS in selected reaction monitoring (SRM) mode. The method was validated in six surface waters (SW) and six effluent wastewaters (EWW) at realistic concentration levels that can be found in waters. The optimized method was applied to the analysis of different types of water samples (rivers, lakes and effluent wastewater), detecting nearly all the parent compounds and metabolites investigated in this work. This fact illustrates that not only pharmaceuticals but also their metabolites are commonly present in these types of waters. Analytical research and monitoring programs should be directed not only towards parent pharmaceuticals but also towards relevant metabolites to have a realistic overview of the impact of pharmaceuticals in the aquatic environment.     

A new bioseed for determination of wastewater biodegradability: analysis of the experimental procedure

A new bioassay proposed in the patent P201300029 was applied to a pre-treated wastewater containing a mixture of commercial pesticides to simulate a recalcitrant industrial wastewater in order to determine its biodegradability. The test uses a mixture of standardized inoculum of the lyophilized bacteria Pseudomonas putida with the proper proportion of salts and minerals. The results highlight that biodegradation efficiency can be calculated using a gross parameter (chemical oxygen demand (COD)) which facilitates the biodegradability determination for routine water biodegradability analysis. The same trend was observed throughout the assay with the dehydrated and fresh inoculums, and only a difference of 5 % in biodegradation efficiency (E _f) was observed. The obtained results showed that the P. putida biodegradability assay can be used as a commercial test with a lyophilized inoculum in order to monitor the ready biodegradability of an organic pollutant or a WWTP influent. Moreover, a combination of the BOD₅/COD ratio and the P. putida biodegradability test is an attractive alternative in order to evaluate the biodegradability enhancement in water pre-treated with advanced oxidation processes (AOPs).     

Combined effect of diuron and simazine on photosystem II photochemistry in a sandy soil and soil amended with solid olive-mill waste

Diuron (3-(3,4-dichlorophenyl)- = 1,1-dimethylurea) and simazine (6-chloro-N ², N ⁴-diethyl-1,3,5-triazine-2,4-diamine) are soil-applied herbicides used in olive crops. The objective of this study is to investigate the effect of these herbicides on Photosystem II photochemistry of Olea europaea L., and whether the amendment of soil with an organic waste (OW) from olive oil production industry modifies this effect. For this purpose, herbicide soil adsorption studies, with unamended and OW-amended soil, and chlorophyll fluorescence measurements in adult olive leaves, after one, two and three weeks of soil herbicide treatment and/or OW amendment, were performed. Soil application of these herbicides reduced the efficiency of Photosystem II photochemistry of olive trees due to chronic photoinhibition, and this effect is counterbalanced by the addition of OW to the soil. OW reduces herbicide uptake by the plant due to an increase in herbicide adsorption.     

Bacterial diversity in paclobutrazol applied agricultural soils

The aim of this study was to investigate the bacterial communities on paclobutrazol [(2RS, 3RS)-1-(4-Chlorophenyl)-4, 4-dimethyl-2-(1H-1,2,4-triazol-1-yl) pentan-3-ol]–applied agricultural soils by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR) amplified 16S rDNA gene fragments. Three different agricultural soil samples were collected from paclobutrazol applied mango and waxapple orchards, peanut fields and untreated rice fields as a control for DGGE analysis. The DGGE pattern of PCR- generated 16S rDNA gene fragments indicated that the bacterial populations from four paclobutrazol–applied soils of peanut fields were closely related to each other and two paclobutrazol–applied soils of mango and waxapple orchards harbored closely related bacterial communities. But, paclobutrazol–free agricultural soils comprised relatively a different bacterial group. However, the bacterial populations of mango and waxapple orchard are completely different from the bacterial communities of peanut field. Further purification and sequence analysis of 40 DGGE bands followed by phylogenetic tree assay showed similar results that soil bacteria from paclobutrazol applied mango and waxapple orchard are phylogenetically related. Based on the phylogenetic analysis, the clone M-4 was clad 100 % (bootstrap value) with Mycobacterium sp. The Mycobacterium sp. has been proved to degrade the phenolic compounds such as phenol, 4-chlorphenol, 2,4-dichlorophenol and paclobutrazol molecule containing chlorobenzene ring.