Albendazole (ALB) belongs to a group of benzimidazoles - classified as antiparasitic pharmaceuticals. Its widespread application results in the presence of this pharmaceutical in natural environment (water and soil). In this paper a suitable pretreatment method was established including sampling, freeze-drying and extraction. Vicia faba was used as model organism. ALB accumulation by plant tissues was observed in hydroponic culture as well as in soil. The range of pharmaceutical concentrations was 1.7 × 10-5 mol/L (in hydroponic culture) and 1.7 × 10-5 to 1.7 × 10-4 mol/kg air dry soil (in soil). Observations were conducted for 14 days. After this time biological material was freeze-dried and after homogenization, dimethyl sulfoxide (DMSO) extraction was performed. The recovery of ALB for the roots was 93 % while for the shoots 86 %. After cleaning, the samples were subjected to further analysis by HPLC system. Phosphate buffer and acetonitrile (50:50) were used as a mobile phase. Drug retention time was 6.3 min. Results obtained in this experiment indicate higher drug accumulation in roots rather than in the hypocotyl part of the plant, cultivated both in soil and in hydroponic culture. © 2013 The Author(s).

Rapid expansion of natural gas drilling in Sublette County, WY (1999-present), has raised concerns about the potential ecological effects of enhanced atmospheric nitrogen (N) deposition to the Wind River Range (WRR) including the Class I Bridger Wilderness. We sampled annual throughfall (TF) N deposition and lichen thalli N concentrations under forest canopies in four different drainages of the WRR. Measurements of TF N deposition and N concentrations in lichen thalli were highest at plots closest to drilling operations (<30 km). N concentrations in lichens decreased exponentially with distance from drilling activity. Highest TF N deposition, 4.1 kg ha -1 year-1, coincided with clear evidence of damage to lichen thalli. This deposition value is above estimated preindustrial deposition conditions (0.9 kg N ha-1 year-1) and regional critical loads (a deposition value below which ecosystem harm is prevented) of N deposition for sensitive ecosystem components. N concentrations in Usnea lapponica were strongly correlated (r = 0.96) with TF N deposition, demonstrating that elemental analysis of lichen material can be used to estimate TF N deposition. N concentrations below 1.35 % in U. lapponica and 1.12 % in Letharia vulpina were associated with estimated background conditions of 0.9 kg N ha-1 year-1. Additional lichen sampling in the Bridger Wilderness is recommended to further quantify and monitor spatial patterns of N deposition and to define areas of elevated N deposition. © 2013 Springer Science+Business Media Dordrecht (outside the USA).

A laboratory-scale study was conducted to determine the removal efficiencies of nine contaminants from a tannery wastewater using a number of physicochemical processes. Coagulation–flocculation using bittern as coagulant, oxidation-utilizing ozone, and adsorption using activated carbon were applied separately and in different sequences. Jar tests were utilized to conduct the experimental work. Except for arsenic, the highest removal efficiencies were recorded when coagulation/flocculation was conducted on the alkalized samples using a bittern dose of 5 mL/L. Activated carbon adsorption improved removal efficiencies of several contaminants. The coagulation/flocculation–adsorption sequence using the optimum dose of 5 mL/L of bittern resulted in high removal efficiencies for total suspended solids (TSS) (97 % ± 1), apparent color (100 % ± 0), turbidity (97 % ± 1), total nitrogen (86 % ± 1), and chromium (100 % ± 0). On the other hand, the same sequence resulted in moderate removal efficiencies for chemical oxygen demand (COD) (72 % ± 7) and total phosphorus (74 % ± 5) and relatively low removals for biochemical oxygen demand (BOD) (55 % ± 10) and arsenic (42 % ± 14). The removal efficiencies for the different tested sequences demonstrated that each sequence did improve the removal efficiencies for most of the parameters tested and consequently, the quality of tannery effluent. However, no single optimum sequence was capable of attaining high removal efficiencies for all nine parameters.

The use of reclaimed wastewater in agriculture can be a solution for regions with water shortages or low rainfall periods; besides fulfilling the crop's water needs, it would also promote the recycle of nutrients. However, care should be taken regarding soil salinization, especially in closed environments such as greenhouses for the cultivation of ornamental plants. The domestic effluents are rich in sodium which can accumulate on soil and cause soil sealing. This study evaluated the use of effluents from anaerobic filters and intermittent sand filters in the production of rosebushes (Rosa hybrida "Ambiance"). The crop yield of the rosebushes irrigated with reclaimed wastewater exceeded the one obtained with traditional cultivation, reaching a value 31.8 % higher when employing nitrified effluent originated from intermittent sand filters, with no difference in the product quality. The salinity levels are below the critical limits found in the literature; however, there was a significant increase compared to the irrigation with drinking water. © 2013 The Author(s).

Low-grade weirs are innovative management strategies that control surface drainage, slow water velocities, and encourage sedimentation in agricultural drainage ditches. There is little information on how low-grade weirs perform in terms of short-term (0–12 months) sediment retention and associated phosphorus (P) dynamics. This study documents initial results of sediment and P dynamics of low-grade weirs in a drainage system that was built in a two-stage ditch design. Average sediment deposition did not differ significantly among sites (χ ² = 2.42; P = 0.49); however, average water depths behind weir sites were significantly greater (28 ± 10 cm) than the comparison inflow site (6 ± 8 cm; χ ² = 7.67; P = 0.05). Total P concentrations were not significantly different through time, or between sites, but there was a general trend of progressively higher total P retention moving downstream. Bioavailability ratios of P (i.e., the ratio of potentially bioavailable to non-bioavailable P fractions) were similar between all sites through time (χ ² = 2.09; P = 0.55). The only variables correlated significantly with time were found at the inflow site, where water depth significantly decreased with corresponding increases in sediment/water column pH and bioavailability ratios. From best management practice installation to 12 months after construction, there was a lack of significant correlations with any measured variables behind weirs. However, the lack of correlation between variables suggests increasing the hydroperiod, reducing the ephemeral nature of the drainage ditch system, and prolonging inundation, improves conditions for P retention.

A pilot-scale anaerobic bioreactor with high levels of microbial sulfate reduction, known to be capable of removing cationic metals from a metal- and acid-contaminated waste stream, was utilized to determine if the system would be effective in removing metals in the form of oxyanions such as arsenate and chromate. The system removed 90 % to >99 % of the arsenic and between 86 % and 94 % of the chromium from a waste stream containing 5 mg/L of each. Cadmium, copper, iron, lead, and zinc also were removed. An equilibrium geochemistry computer modeling code, MINTEQAK, modified from MINTEQA2, was used for the chemical modeling of processes in the bioreactor. Experimental evidence on the chemical and biological reduction of arsenic and chromium and fluorescent diffraction analysis of precipitates support the following hypotheses: the primary removal process for chromium was the reduction of Cr(VI) to Cr(III) by sulfides, followed by precipitation of chromium hydroxide [Cr(OH) 3(s)]; removal of arsenic was by direct microbial enzymatic reduction of As(V) to As(III) followed by precipitation of arsenic sulfides (As 2S3 or AsS). Experimental evidence and modeling with MINTEQAK confirmed that 90 % to 95 % of the removal of arsenic and chromium occurred in the first quarter volume of the bioreactor. Additional removal of arsenic and chromium occurred in the remaining volume of the bioreactor. The use of a sulfate reduction-based anaerobic treatment system was effective for metal-laden wastewater with elevated concentrations of arsenic and chromium. © 2013 Springer Science+Business Media Dordrecht.

Bioclogging extensively exists in porous media, such as permeable reactive barrier (PRB), constructed wetland, reverse osmosis, and biofilter systems and affects efficiency of sewage treatment. In this paper, variation in biochemical and hydraulic parameters under discontinuous flow condition during the clogging process was obtained. Hydraulic conductivity (K) first decreased sharply to 34.22 % of the original value during the initial 12th day and, finally, decreased to 13.70 %. Hydrodynamic dispersion (D) went through slow increase, fast increase, fast decrease, slow increase, and ultimately decreased to 44.25 %. Porosity (n) decreased obviously, especially during the initial 12 days, and total bacterial counts in the inlet of the column had more than one order of magnitude increase. The bioclogging process can be divided into four stages: (1) severe bioclogging occurred and aerobic microorganisms reproduced rapidly in the inlet, (2) bioclogging existed in the entire sand column and the hydrodynamic dispersion increased drastically as anaerobic microorganisms generated some gas, (3) aerobic and anaerobic microorganisms reproduced and hydrodynamic dispersion decreased rapidly, and (4) microorganisms multiplied continuously and the hydraulic parameters (hydrodynamic dispersion, hydraulic conductivity, and porosity) decreased steadily. Bioclogging then transformed into steady stage. Based on analysis of experimental data, hydraulic conductivity (K) follows the rule of negative exponent relationship, porosity (n) accords with power exponent relationship, and hydrodynamic dispersion (D) is polynomial equation under bioclogging process.

A low-cost microbial fuel cell (MFC) with a brush-shaped anode was constructed with low-cost materials and operated in a fed-batch mode using wastewater as a substrate. The operational performance of the MFC was evaluated considering the organic matter removal, coulombic efficiencies, and current and power densities. Its relative performance to cost was evaluated considering a MFC with platinum/carbon cathode. It was observed that the organic matter removal efficiency was up to 80 % and the coulombic efficiencies varied from 3.5 to 5.7 %. Maximum average voltages and power and current densities of 207 ± 30 mV, 9.2 ± 2.4 mW m-2, and 56.8 ± 14.9 mA m-2 were obtained, respectively. It was observed that the low-cost MFC produced higher power and current densities per dollar when compared to a MFC using platinum-catalyzed electrode. © 2013 Springer Science+Business Media Dordrecht.

Centrifugal mother liquid (CML) is one of the main sources of wastewater produced during the production of polyvinyl chloride in chlor-alkali industry. CML is a typical poorly biodegradable organic wastewater, containing many kinds of refractory pollutants. Specifically, it contains dissolved refractory polymers, especially polyvinyl alcohol (PVA), which can pass though the biotreatment processes and clog the membranes used for further treatment. In this study, to ensure the CML applicable to biotreatment and membrane treatment, a novel efficient and mild technique, air-Fenton treatment, was employed as a pretreatment technique to improve biodegradability of the CML and to break down the polymers in the CML. Firstly, the technique was optimized for the CML treatment by optimizing the main parameters, including the dosage of ferrous sulfate, initial pH of the wastewater, [H2O2]/[Fe(2+)], aeration rate, reaction time, and temperature, based on removal efficiency of COD and PVA from the CML. Then, the optimized technique was tested and evaluated. The results indicated that under the optimized conditions, the air-Fenton treatment could remove 66, 98, and 55 % of the COD, PVA, and TOC, respectively, from the CML. After the treatment, biodegradability of the wastewater increased significantly (BOD/COD increased from 0.31 to 0.68), and almost all of the PVA polymers were removed or broken down. Meanwhile, concentration of the remaining iron ions, which were added during the treatment, was also quite low (only 2.9 mg/L). Furthermore, most of the suspended materials and ammonia nitrogen, and some of the phosphorus in the wastewater were removed simultaneously.

A post-harvest experiment was conducted further to our previous greenhouse pot study on upland kangkong (Ipomoea aquatica Forsk.) and Alfred stonecrop (Sedum alfredii Hance) intercropping system in Cd-contaminated soil inoculated with arbuscular mycorrhizal (AM) fungi. Previously, four treatments were established in the intercropping experiment, including monoculture of kangkong (control), intercropping with stonecrop (IS), and IS plus inoculation with Glomus caledonium (IS+Gc) or Glomus versiforme (IS+Gv). Both kangkong and stonecrop plants were harvested after growing for 8 weeks. Then, the tested soils were reclaimed for growing post-harvest kangkong for 6 weeks. In the post-harvest experiment, there were no significant differences between the IS and control treatments, except for a significantly decreased (p<0.05) soil available P concentration with IS treatment. Compared with IS, both IS+Gc and IS+Gv significantly decreased (p<0.05) soil DTPA-extractable (phytoavailable) Cd concentrations, but not total Cd, by elevating soil pH, causing significantly lower (p<0.05) Cd concentrations in both the root and shoot of kangkong. In addition, both Gc and Gv significantly increased (p<0.05) soil acid phosphatase activities and available P concentrations and hence resulted in significantly higher (p<0.05) plant P acquisitions. However, only Gv significantly increased (p<0.05) kangkong yield, while Gc only significantly elevated (p<0.05) the shoot P concentration. It suggested that AM fungi have played key roles in Cd stabilization and P mobilization in the intercropping system, and such positive responses seemed to be sustainable and valuable in post-harvest soils.