Investigation of trace elements in agricultural soils by BCR sequential extraction method and its transfer to wheat plants

In this study, soil samples were collected from Edirne, Turkey in both summer and winter seasons and subjected to the modified Community Bureau of Reference (BCR) sequential extraction procedure in order to investigate the chemical partitioning of metals in soils and to predict heavy metals uptake by wheat grains which grown at the same soils. The samples were subjected to a three stage extraction procedure proposed by the BCR. The three phases that were separated out in the following order: (1) carbonate, exchangeable, (2) Fe?CMn oxides, and (3) organic matter. Metal concentrations of soil fractions and grain samples were determined by inductively coupled plasma atomic emission spectroscopy. The wheat samples were prepared to analysis using microwave acid digestion procedure. The pseudo-total concentrations of metals were determined after aqua regia digestion. The analytical accuracy of the method was evaluated by using the Standard Reference Materials (BCR 142R Light Sandy Soil, NIST 2711 Montana Soil, and NIST 2704 Buffalo River Sediment). The sum of the metal contents obtained from the modified BCR sequential extraction procedure and pseudo-total metal contents for soil samples were used to calculate recovery values. In order to evaluate the bioavailability of metals, the relationships between the wheat-metal and soil-extractable metal concentrations were compared.     

Phytoplankton distribution during two contrasted summers in a Mediterranean harbour: combining automated submersible flow cytometry with conventional techniques

Present study was conducted in rapidly growing city Islamabad, and surface soils were collected from three major land cover types viz., built-up, drain side, and green areas. A total of seven physicochemical parameters and 11 metals were determined in surface soils. Factor analysis based on principal component analysis explained total variance of 68.0%, 64.5%, and 60.2% of three land cover types and showed high loadings for major elements (Mg and K) in built-up and green area and Fe in drain side. Top soil pollution index was carried out by using geo-accumulation index and metal pollution index (MPI₆). Concentration of major elements (Ca, Mg, Na, K) in surface soils is derived by parent material, whereas concentration of Fe, Ni, Pb, and Zn were mainly related with anthropogenic sources. Geostatistical methods such as kirging identified hotspot areas of metal contamination by Pb, Ni, and Zn in built-up areas influenced mainly by vehicular emissions and waste disposal. The results stresses that land clearing should be avoided to reduce contamination and management of urban soils.     

Comparison of phytotoxic effects of bio-synthesised copper oxide nanoparticle and ionic copper on Elodea canadensis

This study aims to investigate the phytotoxic effects of both Punica granatum peel extract directed copper oxide nanoparticles (CuONPs) and copper nitrate on Elodea canadensis. The CuONPs were characterised by UV–visible spectroscopy (UV-Vis), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FT-IR) Spectroscopy. The ratio of photosynthetic pigments, total soluble protein, malondialdehyde (MDA), catalase (CAT), ascorbate peroxidase (APX), and copper accumulation in the E. canadensis was determined to evaluate the phytotoxicity of the CuONPs and copper nitrate on E. canadensis. The significant improvements were observed in the growth rate of E. canadensis, chlorophyll a and b, carotenoid contents, and total soluble protein in the E. canadensis when it was exposed to the CuONPs. Additionally, CAT and APX activities and MDA contents were enhanced by accumulation of the CuONPs into the E. canadensis. These results suggested that oxidative stress was alleviated, owing to the result of an increase in the antioxidants such as CAT and APX, with an increase in the concentration of the CuONPs. Finally, the findings of this study show that copper nitrate has many negative effects on E. canadensis compared bio-synthesised CuONPs.     

A chemical substitution study for a wet processing textile mill in Turkey

Wet processing textile industry has many different processing stages (dyeing, sizing, de-sizing, scouring, softening, etc.). Many chemicals currently used in the wet processing textile industry affect the amount and the type of waste produced and their influence on the aquatic life of the receiving stream. One of the critical steps in pollution prevention studies is auditing the use of chemicals and making the necessary chemical substitutions. This chemical substitution study was conducted on one of the major textile factories in Turkey with a capacity of 20,000 tons of denim fabric per year. During this study, chemical consumption level, receipts applied, environmentally problematic and alternative chemicals were examined. Integrated Pollution Prevention and Control (IPPC) Reference Document on Best Available Techniques (BAT) for the Textiles Industry was accepted as main reference document and also related case studies were examined. According to the study, over 70% reduction in sulphide, which is very toxic to aquatic life, was achieved by replacing sulphur dyestuff with low sulphide content. By replacing an alternative complexing agent, the mill not only prevented the 3100 kg/month COD load to the wastewater treatment plant (WWTP), but also obtained more biodegradable wastewater generated during production. On the other hand, some of the chemical substitution options were on progress or dropped.     

Preparation of Fe oxide nanoparticles for environmental applications: arsenic removal

The objective of this study is to examine the adsorption–desorption behavior of a magnetically active hybrid sorbent (MAHS) material, prepared by dispersing colloid-like hydrated iron oxide particles in the outer periphery of a macroporous ion-exchange resin (Amberlite XAD-2). The experimental results show that the new sorbent material can simultaneously remove arsenic (V) and a chlorinated organic compound (2,6-dichlorophenol [2,6-DCP]) from aqueous solutions at around neutral pH. The recovery of arsenic and 2,6-DCP from MAHS was conducted using a regenerant containing 50% (v/v) CH₃OH + 3% (w/v) NaOH. In less than 10 bed volumes of regenerant, more than 90% of As(V) and 2,6-DCP were recovered.     

Seasonal changes of metal accumulation and distribution in shining pondweed (Potamogeton lucens)

In this study, submerged aquatic plant Potamogeton lucens, corresponding sediment and water samples were seasonally collected from Lake Sapanca (Turkey) and analysed for their heavy metal contents (Pb, Cr, Cu, Mn, Ni, Zn and Cd). While heavy metals concentrations in the water samples were decreased as Zn > Cr > Ni > Pb > Mn > Cu > Cd, in sediment samples were Mn > Zn > Ni > Cu > Cr > Pb > Cd, respectively. Generally, heavy metals concentrations in the plant tissues were decreased in sequence of Mn > Zn > Cu > Ni > Cr > Pb > Cd. It was determined that Cu, Mn and Zn were actively transported to the root, where they were accumulated especially in autumn. Lower accumulation factor ratios were seen in spring than other seasons. Cd exhibited a relatively clear pattern of increasing accumulation in P. lucens with increasing sediment metal concentrations. Significant positive correlations were observed between Cr, Cu, Ni and Cd contents in sediment and Cd contents in root of P. lucens. The investigations suggested that Ni and Mn have a tendency to be accumulated in leaf especially in autumn and Cr and Cd to be accumulated in shoot especially in summer.     

Effect of feeding time on the performance of a sequencing batch reactor treating a mixture of 4-CP and 2,4-DCP

This paper investigated the biodegradation kinetics of 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) separately in batch reactors and mixed in sequencing batch reactors (SBRs). Batch reactor experiments showed that both 4-CP and 2,4-DCP began to inhibit their own degradation at 53 and 25 mg l(-1), respectively, and that the Haldane equation gave a good fit to the experimental data because r(2) values were higher than 0.98. The maximum specific degradation rates (q(m)) were 130.3 and 112.4 mg g(-1) h for 4-CP and 2,4-DCP, respectively. The values of the half saturation (K(s)) and self-inhibition constants (K(i)) were 34.98 and 79.74 mg l(-1) for 4-CP, and 13.77 and 44.46 mg l(-1) for 2,4-DCP, respectively. The SBR was fed with a mixture of 220 mg l(-1) of 4-CP, 110 mg l(-1) of 2,4-DCP, and 300 mg l(-1) of peptone as biogenic substrate at varying feeding periods (0-8h) to evaluate the effect of feeding time on the performance of the SBR. During SBR operation, in addition to self-inhibition, 4-CP degradation was strongly and competitively inhibited by 2,4-DCP. The inhibitory effects were particularly pronounced during short feeding periods because of higher chlorophenol peak concentrations in the reactor. The competitive inhibition constant (K(ii)) of 2,4-DCP on 4-CP degradation was 0.17 mg l(-1) when the reactor was fed instantaneously (0 h feeding). During longer feedings, increased removal/loading rates led to lower chlorophenol peak concentrations at the end of feeding. Therefore, in multi-substrate systems feeding time plus reaction time should be determined based on both degradation kinetics and substrate interaction. During degradation, the meta cleavage of 4-chlorocatechol resulted in accumulation of a yellowish color because of the formation of 5-chloro-2-hydroxymuconic semialdehyde (CHMS), which was further metabolized. Isolation and enrichment of the chlorophenols-degrading culture suggested Pseudomonas sp. and Pseudomonas stutzeri to be the dominant species.     

Evaluation of germination, root growth and cytological effects of wastewater of sugar factory (Afyonkarahisar) using Hordeum vulgare bioassays

In this study, the effect of Afyonkarahisar Sugar Factory's discharge water on germination percentage, root growth and mitotic divisions of the root tip cells of Hordeum vulgare L. were investigated. Six concentrations of wastewater and ranging from 10(0), 10(?-1), 10(?-2), 10(?-3), 10(?-4), 10(?-5), were applied for 6, 12, 18 and 24 h, respectively. It was observed that the treatments reduced the germination percentages of H. vulgare grains and inhibited the root growth as well as reduced mitotic index compared to the control group at all concentrations. It was also observed that the increase of the concentrations of wastewater decreased the cell division, and several mitotic anomalies such as c-mitosis, lagging chromosomes, multipolar anaphases and chromosome bridges increased.     

Genotoxic effects and molecular docking of 1,4-dioxane: combined protective effects of trans-resveratrol

Environmental Science and Pollution Research - In this study, the protective effects of trans-resveratrol (t-resv) against 1,4-dioxane-induced toxicity in meristematic cells were investigated. For...     

DNA damage effect of cyprodinil and thiacloprid in adult zebrafish gills

Cyprodinil and thiacloprid are two of the most commonly used pesticides in Turkey. It is more likely to reach humans or animals due to their widespread use. This study aims to investigate whether there is a DNA damage risk due to cyprodinil and thiacloprid exposure. Zebrafish, which is used as a model organism in health and environmental research, and comet assay were chosen to demonstrate this damage. Ten zebrafish per group were exposed to 2 different concentrations for each pesticides (0.31 and 0.155 mg/L for cyprodinil and 1.64 and 0.82 mg/L for thiacloprid) for 21 days. After, gills were excised and comet assay was performed. Photos of an average of 50 cells per slide were taken and were analyzed with visual evaluation program. DNA damage was found to be increased in the 0.31 mg/L cyprodinil, 0.82 mg/L thiacloprid, and 1.64 mg/L thiacloprid treatment groups when compared to the control group (p < 0.001). Average tail DNA percentage parameter values were 9.45 ± 0.51, 10.30 ± 0.34, 11.17 ± 0.33, and 2.47 ± 0.06 respectively. Cyprodinil and thiacloprid were identified as genotoxic agents that should be investigated further.