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.

A low-cost carbon black has been used as an adsorbent for the removal of trimethoprim (TMP) from aqueous solution. The kinetic and equilibrium aspects of the adsorption of TMP by this adsorbent were studied. The influence of different operation conditions, namely temperature (20–40 °C), pH (4–8), and ionic strength (0.001–0.1 M) on the removal efficiency of TMP by the adsorbent has been analyzed by applying a statistical design of experiments. Response surface methodology technique was used to optimize TMP removal. Temperature resulted to be the main variable influencing TMP removal, followed by pH. Analysis of variance test reported significance for three of the nine involved variables. An optimum TMP removal was found at pH 9.2, at a temperature of 47 °C and with a value of ionic strength equal to 0.48 M. Under these conditions, a maximum value of removal efficiency equal to 156.2 mg of TMP per gram of adsorbent was attained.

Three different solventless sample preparation techniques based on microextraction, membrane extraction, and headspace extraction have been developed and optimized for determination of trihalomethanes in drinking water by gas chromatography electron capture detector and mass spectrometry detection. The techniques employed were headspace (HS) solid-phase microextraction, hollow fiber liquid-phase microextraction (HFLPME) and HS extraction. All techniques used were optimized with different experimental designs in order to select the most relevant variables which significantly affect the different processes. The different analytical figures of merit such as limit of detection (LOD), limit of quantification, reproducibility, accuracy, and linear dynamic range were obtained. The new HFLPME method applied used a hollow fiber membrane of polypropylene and the optimized variables were extraction time, extraction temperature, and salting-out effect. The software MODDE 6.0 was used and its design was one central composite on face with a total of 17 runs. The best conditions for the HFLPME were 20 min, 40°C, and 10% NaCl, respectively. The LODs ranged from 0.018 μg·L−1 (for CHClBr2) to 0.049 μg·L−1 (for CHBr3), being this technique the most sensitive one among those studied. Finally, after having optimized the sample preparation techniques and chromatographic conditions, several water samples were taken in two different water treatment plants in Spain (Zaragoza) and Colombia (Viterbo, Caldas). The results obtained are shown and discussed.

The present work describes a detailed study about the adsorption of malachite green (MG) by a polyether-type polyurethane foam (PUF) using sodium dodecylsulfate (SDS) as a carrier. The adsorption process was based on the formation of a hydrophobic ionic-pair between the MG cationic dye and the dodecylsulfate anion, which presented high affinity for the PUF. The manifold employed in the study was built up by adjusting a cylinder of PUF with 200 mg in the arm of an overhead stirrer, which was soaked (and stirred) in the solution containing the dye and SDS. The adsorption process was characterized in relation to equilibrium and kinetic aspects. Langmuir (r 2 = 0.842) and Freundlich (r 2 = 0.996) isotherms were also employed for modeling the system as well as the Nernst partition law (r 2 = 0.999). A study about the recovery of MG and the PUF regeneration was conducted, and the acetonitrile was the most efficient solvent for the desorption of the adsorbed ionic pair. The obtained results showed that the concentration of SDS added to the medium plays an important role on the adsorption process, which can be better described by employing a second-order kinetic model.

In the present study, the preparation of sorbent from waste-derived siliceous materials has been investigated for the removal of nickel ion (Ni) from aqueous solutions. Three types of ashes, i.e., rice husk ash (RHA), palm oil fuel ash (PFA), and coal fly ash (CFA), were used in the preparation of sorbent. Batch studies were carried out to examine the effect of various experimental parameters, i.e., RHA/CFA/PFA ratio in the sorbent preparation, contact time, initial concentration of Ni, agitation rate, and pH. Among all the ratios of the prepared sorbent, it was found that sorbent containing RHA and PFA gave the highest Ni removal efficiency. The optimum conditions for Ni removal using RHA/PFA sorbent were obtained at contact time of 30 min, Ni concentration of 100 mg/L, agitation rate of 130 rpm, and pH 4. During the optimum condition, more than 90% of Ni could be removed in all experiment studies. It was also found that the spent RHA/PFA sorbents had a narrow range of particle size distributions as compared to prepared RHA/PFA sorbent. In addition, the surface morphology of the spent RHA/PFA sorbents had more compact structures.

A Cd-, Pb-, Zn-, Cu-resistant endophytic yeast CBSB78 was isolated from surface-sterilized rape roots. The isolate was identified as Cryptococcus sp. based on the ITS1–5.8S–ITS2 sequence analysis. The strain was resistant to 20 mM Cd²⁺, 20 mM Pb²⁺, 10 mM Zn²⁺, and 7 mM Cu²⁺. The yeast CBSB78 was a low indole-3-acetic acid (IAA) producer and possessed low 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Overall, 29.4–244 % of survival rates increased and the dry weight of Brassica alboglabra showed a 41.1 % increase when it was inoculated into the seedlings. The inoculation of CBSB78 could also increase the extraction amounts of Cd, Pb, and Zn by B. alboglabra simultaneously in the multi-metal contaminated soils, which showed the potential to improve extraction efficacy of Cd, Pb, Zn by B. alboglabra seedlings in the field.

Sulfuric acid leaching is a promising technique to extract toxic metals from polluted soils. The objective of this study was to define the optimum sulfuric acid leaching conditions for decontamination of the fine particle fraction (<125 μm) of an industrial soil polluted by Cd (16.8 mg kg⁻¹), Cu (3,350 mg kg⁻¹), Pb (631 mg kg⁻¹) and Zn (3,010 mg kg⁻¹). Batch leaching tests in Erlenmeyer shake flasks showed that a soil pulp pH between 1.5 and 2.0 using a solid concentration (SC) ranging from 5 to 20 % is adequate to efficiently solubilize toxic metals. Leaching tests performed at different temperatures (20, 40, 60 and 80 °C) also revealed that it is not beneficial to heat the soil suspension during the leaching treatment. The application in a 1-L stirred tank reactor of five consecutive 1-h leaching steps at 10 % SC and ambient temperature, followed by three water washings steps resulted in the following metal extraction yields: 30 % As, 90 % Cd, 43 % Co, 7 % Cr, 88 % Cu, 75 % Mn, 26 % Ni, 18 % Pb and 86 % Zn. The decontaminated soil conformed to Quebec norms for commercial and industrial use of soil.

The performance of a solar system designed to heat a packed bed reactor for anaerobic treatment of municipal wastewater was evaluated, and the feasibility of employing low-scale solar reactors in small settlements or enterprises was investigated. An energy balance was performed using a simple reactor model previously proposed by Yiannopoulos et al. (Bioresource Technology 99:7742–7749, 2008) to estimate the size of a solar system in Patras, Greece. The main objective is to feed the reactor with warm water produced by solar energy and achieve an increase of temperature close to 35°C for the majority of the year. Model simulations indicated that the heat demand of the reactor could be balanced practically by a number of flat plate solar collectors supplying warm water at above 20°C for over 95% of the year. Therefore, the proposed system can offer a viable alternative to enhancing anaerobic treatment in wastewater facilities.

This work was undertaken to study the influence of soil type and its physical and chemical properties on uranium sorption and bioavailability, in order to reduce the uncertainty associated with this parameter in risk assessment models and safe food production. The tests were conducted on three types of Serbian soils: alluvium, chernozem, and gajnjaca, from which 67 samples were taken. Dominant factors of uranium mobilisation: the specific content of total/available form of uranium and phosphorus, the degree of acidity (pHKCl), and humus content and their correlation, were analysed. Content of available uranium form, according to the type of soil decreases in the following order: gajnjaca > alluvium > chernozem. It was found the medium correlation between pH values and available content of uranium in chernozem and gajnjaca, statistically significant at the level of significance of 99% and the alluvium at the level of significance of 95%. Correlation coefficients in all cases were negative, indicating that the reduction in pH increases the mobility of uranium and thus its availability for the adoption of the plants. Soil pH was the only dominant factor that significantly controlled the uranium value with no further significant contribution of other soil parameters.

In Southern Spain, as in other semi-arid zones, plants used for the phytoremediation of heavy metal-contaminated sites must be able to withstand not only the challenging soil conditions but also seasonal drought and high temperatures. A pot assay was carried out to determine the ability of soil amendments to promote the survival and growth of the seedlings of two native species, Atriplex halimus L. (Amaranthaceae) and Bituminaria bituminosa (L.) C.H. Stirton (Fabaceae), in two heavy metal-contaminated soils, one of which also had a high level of arsenic (As). Restriction of A. halimus shoot growth in the non-amended soils appeared to be due to deficiency of nitrogen, phosphorus (P) and potassium (K) and in the more highly contaminated soil to lead (Pb) toxicity. Shoot biomass of A. halimus in the more highly contaminated soil was increased significantly by compost addition, due to increased uptake of K and P and decreased tissue Pb. The lack of effect of compost on B. bituminosa growth in this soil, despite a large increase in tissue K, may have been due to elevated tissue levels of As and Pb and the high soil salinity. The combination of A. halimus and compost addition seems appropriate for the phytostabilisation of contaminated semi-arid sites.