Separation and reuse of dispersed nanoparticles are major obstacles to the extensive application of nano-sized absorbents in wastewater treatment. Herein, we demonstrate the capability of directing acid-oxidized carbon nanotubes (CNTs) as the transfer vehicles of heavy metal ions from simulated wastewater. The heavy metal-loaded CNTs can be readily separated from the aqueous phase via the aggregation process at an oil/water (o/w) interface. The minimum surfactant amount to achieve 99 % transfer ratio (T ᵣ) of 100 mg/L CNTs from water phase to o/w interface was ∼0.01 mM. The adsorption experiments showed that the removal efficiency of the divalent lead ions increased with an increase in CNT mass, and the subsequent addition of cetyltrimethylammonium bromide (CTAB) surfactant did not negatively impact the removal of soluble divalent lead species (Pb(II)). In a wide region of pH and ionic strength, both the decontamination of Pb(II) and the transfer of CNTs from water phase to o/w interface can be accomplished successively. The method presented in this study may be developed as a generic one for collecting or recycling the pollutant-loaded nano-sized absorbents.

Spot sampling lacks representativeness for monitoring organic contaminants in most surface waters. Passive sampling has emerged as a cost-effective complementary sampling technique. We recently developed passive stir bar sorptive extraction (passive SBSE), with Twister from Gerstel, for monitoring moderately hydrophilic to hydrophobic pesticides (2.18 < log Kₒw < 5.11) in surface water. The aims of the present study were to assess this new passive sampler for the determination of representative average concentrations and to evaluate the contamination levels of two French rivers. Passive SBSE was evaluated for the monitoring of 16 pesticides in two rivers located in a small vineyard watershed during two 1-month field campaigns in spring 2010 and spring 2011. Passive SBSE was applied for periods of 1 or 2 weeks during the field campaigns and compared with spot sampling and weekly average automated sampling. The results showed that passive SBSE could achieve better time-representativeness than spot sampling and lower limits of quantification than automated sampling coupled with analytical SBSE for the pesticides studied. Finally, passive SBSE proved useful for revealing spatial and temporal variations in pesticide contamination of both rivers and the impact of rainfall and runoff on the river water quality.

The non-tanned proteinaceous tannery solid waste animal fleshing (ANFL), containing high nutritive value, was hydrolyzed using bacteria Selenomonas ruminantium HM000123 through submerged (SmF) and solid-state (SSF) fermentation processes. In addition, the effects of ANFL fermentative hydrolysate on growth, yield and biochemical properties of tomato plants were investigated. The treatments included T1 (SmF-ANFL), T2 (SSF-ANFL), T3 (recommended dose of NPK fertilizers) and a control without any amendment. Hydrolysates of both SmF-ANFL and SSF-ANFL treatments increased the biomass and yield as evidenced by plant height, stem girth, number of leaves and fruit yield when compared with both NPK and control plants. In this 90-day study, significant (p ≤ 0.05) changes were observed in SSF-ANFL treated plants compared to the other treatments. Protein profile analyzed through SDS-PAGE indicates the expression of a high molecular weight protein (205 kDa) and other proteins in the leaves of the SSF-ANFL treated plants. Overall results revealed that SSF-ANFL can be successfully utilized as a fertilizer particularly for cultivating tomato plants.

The purpose of this work was to examine solute release by the effect of leaching of a saline compost with two main objectives: (1) to identify the most efficient method for this purpose, in order to minimize the environmental impact of this process in terms of water consumption and (2) to study the composition of the leachates to manage them properly and avoid possible contamination. A laboratory method involving column leaching with distilled water (CL) and two field methods involving saturation leaching (SL) and drip leaching (DL) were compared to this end. In order to more accurately assess nutrient release and compare the three leaching techniques, the cumulative amounts of ions leached were processed by using an exponential growth model. All target ions fitted properly, and so did the curve for the ions as a whole. Salts were removed mainly by effect of the leaching of major ions in the substrate (Na⁺, Cl–, inorganic N, SO₄²–and K⁺). SL and CL proved similarly efficient and reduced the salt content of the substrate to an electrical conductivity below 2 dS m–¹in the saturation extract, which is the optimum level for nursery crops. By contrast, the DL method provided poor results: salt contents were reduced to an electrical conductivity of only 8 dS m–¹in the saturation extract, so the resulting substrate can only be useful to grow highly salt-tolerant crops.

In this study, the occurrence and concentrations of PAHs in dust samples, which were collected from the traffic police cabins/working spots, located on the main busy roads of Lahore (TP-L) and Rawalpindi (TP-R) cities (Punjab province, Pakistan) and from the public transport vehicles in the same cities (named as AM-L and AM-R, respectively) were determined. The mean and median concentrations of ∑PAHs were observed in the following descending order: AM-L (1340 and 774 ng g⁻¹ d.w., respectively), TP-L (866 and 854 ng g⁻¹ d.w.), TP-R (504 and 379 ng g⁻¹ d.w.), and AM-R (393 and 290 ng g⁻¹ d.w. Source apportionment of the soil/dust-bound PAHs was also performed. In all the sampling areas, the diagnostic ratios, principal component analysis (PCA) followed by multiple linear regression (MLR) analysis indicated signatures of mixed sources of PAHs (including vehicular exhaust emission, gasoline/diesel, and coal/wood combustion). Estimated results of incremental lifetime cancer risk (ILCR) indicated that the traffic policemen and drivers, especially those in the urban area of Lahore, were at high risk of cancer via routes of dust ingestion and dermal contact. The results of this research could be very useful for the local Government in order to control the exposure and promote actions to alleviate PAH contamination and to manage health both at work places in the big cities of Pakistan.

We tested the effects of solvent fractions (FA, FB, FC, and FD), which partitioned by liquid-liquid extraction from the methanol extract of Ulva pertusa, on the growth of red tide microalgae (Karenia mikimitoi, Skeletonema costatum, Alexandrium tamarense, Heterosigma akashiwo, Prorocentrum donghaiense), and FA, FB, and FC exhibited significantly antialgal activity. The chemical constituent analysis showed the existence of bioactive compounds such as phenols and alkaloids. Further, four solvent fractions were applied to silica gel column and repeated preparative TLC to produce 13 samples and their purity qualified as thin-layer chromatographic grade. Among these purified samples, FA₁₁₁, FB₄₁₁, FC₄₁₁, FD₁₁₁, and FD₂₁₁ exhibited stronger antialgal activity. Furthermore, their functional groups were analyzed by colorimetric methods and UV spectra data. FD₁₁₁ and FD₂₁₁ were temptatively identified as alkaloids; the others were initially identified as phenolic acids. This is a preliminary study and the structure identification of these purified samples requires further investigation. While concentration of these purified samples in this algae was very small, they showed excellent effects against red tide microalgae.

Tributyltin is listed as one of the priority substances in the European Water Framework Directive (WFD). Despite its decreasing input in the environment, it is still present and has to be monitored. In the European Metrology Research Programme project ENV08, a sensitive and reliable analytical method according to the WFD was developed to quantify this environmental pollutant at a very low limit of quantification. With the development of such a primary reference method for tributyltin, the project helped to improve the quality and comparability of monitoring data. An overview of project aims and potential analytical tools is given.

Comparative effects of long-term exposure to Polar Organic Chemical Integrative Sampler (POCIS) extracts (PE) and to a reconstituted mixture based on the major compounds quantified in the PE were evaluated on river biofilm communities. The study aimed to characterize the effects of long-term and low-dose exposure to pesticides on natural biofilm communities and to evaluate if the effects due to PE exposure could be explained solely by the major compounds identified in the extracts. Biofilms from an uncontaminated site were exposed in artificial channels to realistic environmental concentrations using diluted PE, with the 12 major compounds quantified in the extracts (Mix) or with water not containing pesticides (Ctr). Significant differences between biofilms exposed to pesticides or not were observed with regard to diatom density, biomass (dry weight and ash-free dry mass), photosynthetic efficiency (ΦpsII) and antioxidant enzyme activities. After 14 days of exposure to the different treatments, the observed trend towards a decrease of mean diatom cell biovolumes in samples exposed to pesticides was related to the control biofilms’ higher relative abundance of large species like Cocconeis placentula or Amphora copulata and lower relative abundance of small species like Eolimna minima compared to the contaminated ones. Principal component analyses clearly separated contaminated (PE and Mix) from non-contaminated (Ctr) biofilms; on the contrary, the analyses did not reveal separation between biofilms exposed to PE or to the 12 major compounds identified in the extract.

Incorporation of organic materials into soil improves the soil sorption capacity, while limiting the mobility of metals in soil and their availability to plants. These effects can be taken advantage for remediation of soils polluted with heavy metals. The objective of this study is to assess the remediatory potential of peat applied to soils with concomitant pollution with Cd, Pb, and Zn. Two 1-year experiments were run in microplots in which maize was grown as the test plant. The following treatments were compared on two soils (sandy soil and loess): (1) control, (2) heavy metals (HM), (3) HM + peat in a single dose, and (4) HM + peat in a double dose. Maize was harvested in the maturity stage; the biomass of roots and aerial parts, including grain and cobs, was measured. Besides, concentration of metals in all those plant parts and the net photosynthetic rate and transpiration rate were determined. The approach of using peat in soil remediation led to satisfactory results on sandy soil only. The application of peat to sandy soil caused significant changes in the accumulation of the metals and their translocation from roots to other parts of plants, which resulted in a higher intensity of photosynthesis and an increase in the maize biomass compared to the HM treatment.

Establishment of water quality criteria (WQC) is one procedure for protection of marine organisms and their ecosystems. This study, which integrated two separate approaches, quantitative ion character–activity relationships (QICARs) and species sensitivity distributions (SSDs), developed a novel QICAR-SSD model. The QICARs predict relative potencies of individual elements while SSDs integrate relative sensitivities among organisms. The QICAR-SSD approach was applied to derive saltwater WQC for 34 metals or metalloids. Relationships between physicochemical properties of metal ions and their corresponding potencies for acute toxicity to eight selected marine species were determined. The softness index (σp) exhibited the strongest correlation with the acute toxicity of metals (r² > 0.66, F > 5.88, P < 0.94 × 10⁻²). Predictive criteria maximum concentrations for the eight metals, derived by applying the SSD approach to values predicted by use of QICARs, were within the same order of magnitude as values recommended by the US EPA (2009). In general, the results support that the QICAR-SSD approach is a rapid method to estimate WQC for metals for which little or no information is available for marine organisms.