In this study, the oxidation of the dye rhodamine B (RhB), present in a synthetic effluent, and the degradation of organic matter present in a textile effluent, were assessed by photolysis (H₂O₂, UV), homogeneous Fenton (Fe²⁺, H₂O₂), and photocatalysis (TiO₂, UV). The results showed that photolysis and Fenton had an efficiency of 100 % and photocatalysis, 96 %, to discoloration 10 mg L⁻¹ RhB, present in the synthetic effluent. The best experimental conditions determined for these reactions showed that the one performed with 51 mg L⁻¹ H₂O₂ and UV light had the best results, where 100 % of RhB was discolored in only 6 min of reaction. The optimum conditions determined in the first part of this study for the RhB oxidation did not show satisfactory results for the degradation of organic matter present in the textile effluent sample, and it was necessary to increase the amount of reagents in the three processes. After resizing the concentration of the reagents for the reactions with the textile effluent, the following reductions of color, total organic carbon (TOC), and total soluble solids (SS) were obtained: photocatalysis 29, 25, and 32 %; photolysis 85, 69, and 35 %; Fenton 98, 90, and 23 %; and biological (followed by physicochemical) treatment carried out by the textile industry 96, 48, and 9 %. It is observed that the Fenton reaction showed the best result, followed by photolysis reaction, a treatment carried out by industry and, at last, photocatalysis.

Slope failure has become a major concern in Malaysia due to the rapid development and urbanisation in the country. It poses severe threats to any highway construction industry, residential areas, natural resources and tourism activities. The extent of damages that resulted from this catastrophe can be lessened if a long-term early warning system to predict landslide prone areas is implemented. Thus, this study aims to characterise the relationship between Oxisols properties and soil colour variables to be manipulated as key indicators to forecast shallow slope failure. The concentration of each soil property in slope soil was evaluated from two different localities that consist of 120 soil samples from stable and unstable slopes located along the North-South Highway (PLUS) and East-West Highway (LPT). Analysis of variance established highly significant difference (P < 0.0001) between the locations, the total organic carbon (TOC), soil pH, cation exchange capacity (CEC), soil texture, soil chromaticity and all combinations of interactions. The overall CIELAB analysis leads to the conclusion that the CIELAB variables lightness L*, c* (Chroma) and h* (Hue) provide the most information about soil colour and other related soil properties. With regard to the relationship between colour variables and soil properties, the analysis detected that soil texture, organic carbon, iron oxide and aluminium concentration were the key factors that strongly correlate with soil colour variables at the studied area. Indicators that could be used to predict shallow slope failure were high value of L*(62), low values of c* (20) and h* (66), low concentration of iron (53 mg kg⁻¹) and aluminium oxide (37 mg kg⁻¹), low soil TOC (0.5%), low CEC (3.6 cmol/kg), slightly acidic soil pH (4.9), high amount of sand fraction (68%) and low amount of clay fraction (20%).

The authors dealt with some hazardous elements, i.e. As, Cd, Co, Cr, Cu, Ni, Pb and Zn, contained in sands of the sandboxes localized in playgrounds of seven spas in southern Poland (CEE). The following determinations were made: the total contents of metals, the most mobile metals (water-leachable fraction) and the metals available to plants and organisms (CaCl₂- and EDTA-extractable fractions). The totals of the metals are below the upper limits of the values recommended for soils of the protected areas (type A). The mobility of the metals is low: the forms leachable with water range from 0.7% of the total content (TC) of Pb to 13.4% TC of Cd. The forms available to living organisms contain considerably higher quantities of the metals: from 2.3% TC of Ni to 22.6% TC of As in CaCl₂-extractable fractions and from 0.7% TC of Cr to 82% TC of As in EDTA-extractable fractions. An assessment of the health risk indicates that children are exposed to the metals present in the sandboxes mostly due to inadvertent swallowing of “dirt” from their hands. The highest are the HQᵢₙgₑₛₜᵢₒₙ indexes of As and Cr, both for the 3-year-old permanent spa residents (5.74E−02 and 1.71E−02, respectively) and the spa visitors of the same age (7.47E−03 and 2.22E−03, respectively) and the 6-year-old residents (4.31E−02 and 1.28E−02, respectively) and visitors (5.60E−03 and 1.66E−03, respectively). The health risk indexes HI in the case of non-cancerogenic substances for children 3 and 6 years old are for spa residents, 9.59E−02 and 7.19E−02, respectively, and for children visitors, who are exposed to environmental factors for a much shorter time than the residents, 1.25E−02 and 9.35E−03, respectively. All the risk indexes have their values significantly below 1, which proves the lack of deleterious effects resulting from the exposition of children to the elements considered. The children of both age groups, exposed to the cancerogenic substances, are endangered mainly by As. The risk values of the cancerogenic As for 3- and 6-year-old children residents are 1.27E−06 and 1.90E−06, respectively, and for children visitors of the same ages 1.65E−07 and 2.47E−07, respectively. These values are significantly lower than a permissible level of "1∙10E-05" and means that also in this case, the health risk is minimal. The risk values calculated for the remaining metals are much lower and follow the sequence Cr > Co > Cd. However, an adverse impact of some sand-contained pollutants that are attributed to the motor traffic (Cu, Zn, Ni, Cr, Co and Pb) and low emissions (mainly As and Cd) has been established in the spa resorts in question.

The Songhua River represents one of the seven major river systems in China. It flows through Harbin city with 66 km long, locating in the northern China with a longer winter time. This paper aimed to study concentration distributions, stability, risk assessment, and source apportionment of heavy metals including chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), copper (Cu), zinc (Zn), and nickel (Ni) in 11 selected sections of the Songhua River Harbin region. Results showed that Cr, Cd, Pb, Hg, and As exceeded their respective geochemical background values in sediments of most monitoring sections. Compared with other important rivers and lakes in China, Cr, Hg, Cd, and As pollutions in surface sediments were above medium level. Further analysis of chemical speciation indicated that Cr and As in surface sediments were relatively stable while Pb and Cd were easily bioavailable. Correlation analysis revealed sources of these metals except As might be identical. Pollution levels and ecological risks of heavy metals in surface sediments presented higher in the mainstream region (45° 47.0′ N ~ 45° 53.3′ N, 126° 37.0′ E ~ 126° 42.1′ E). Source apportionment found Hejiagou and Ashi River were the main contributors to metal pollution of this region. Thus, anthropogenic activities along the Hejiagou and Ashi River should be restricted in order to protect the Songhua River Harbin region from metal contamination.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the two best-known perfluorinated chemicals and have received much attention due to their ubiquity in the environment. In the present study, we evaluated the effects of PFOS and PFOA on acute toxicity, superoxide dismutase (SOD), and cellulase activities in Eisenia fetida. The results of acute toxicity testing using a filter paper contact test and a natural field soil test showed that PFOA and PFOS exhibited acute toxicity in earthworms, and the toxic effect of PFOS was greater than that of PFOA. The results also showed that avoidance behavior is a more sensitive and easy operation biomarker than acute toxicity and will give us information for early diagnosis of soil pollution, well before the lethal effect becomes apparent. Subchronic exposure to PFOA or PFOS resulted in changes in SOD and cellulase activities in E. fetida, and SOD activity was more sensitive than cellulase activity during early exposure. Based on these findings, we suggest that avoidance behavior and SOD activity in earthworms are suitable biomarkers for evaluating the toxicity of PFOA- and PFOS-contaminated soils. These results indicate that exposure to PFOA and PFOS has a potential impact on soil animals and their environment.

In order to investigate the distribution, transfer, and human health risks of polycyclic aromatic hydrocarbons (PAHs) in the soil-wheat systems, soil samples from 20 farmlands and corresponding wheat tissues were collected from selected regions of Henan Province in June 2013 and were analyzed to estimate the concentration of PAHs. The total concentrations of 15 PAHs (∑₁₅ PAHs) in soils from Henan Province varied from 6.91 to 72.4 ng/g. Moreover, two-ring to three-ring PAHs (1.59–29.1 ng/g) were the major species in soils, occupying 56.2% of total PAHs. Principal component analysis (PCA)-multiple linear regression (MLR) revealed that fossil fuel burning dominated the input of PAHs in agricultural soils of Henan Province. The range of ∑₁₅ PAHs concentrations in wheat tissues was 13.9–50.9 ng/g, which decreased along the root-straw-grain. Positive correlation among PAHs of soil and wheat tissues showed that PAHs in wheat mainly came from soil and then migrated along root-straw-grain. Moreover, PAHs were accumulated highest in root and lowest in grain. Two-ring to three-ring PAHs were easier to transfer from soil to wheat than five-ring to six-ring PAHs. Consumption of wheat grain created potential risk of cancer in Henan Province.

This paper deals with the methylene blue molecule (MB) removal from synthetic and real textile wastewaters by alkali-treated orange tree sawdust (ATOS) under different dynamic conditions. Experimental results showed that MB removal efficiencies by ATOS increased when increasing initial dye concentrations and bed depths but decreased with the increase of the applied flow rates with a maximum adsorption capacity of about 110 mg g⁻¹. Moreover, various empirical models were applied to predict the experimental breakthrough curves (BTCs) and to determine the characteristic adsorption parameters. The applied models successfully fitted data in the following order: Thomas ([Formula: see text] = 0.969), dose response ([Formula: see text] = 0.949), and Clark ([Formula: see text] = 0.874). ATOS was also found to efficiently remove dyes and other mineral pollutants such as chlorides, nitrates, and phosphates from real wastewaters. MB removal by ATOS involved not only cationic exchange but also complexation with acidic and basic functional groups. Moreover, important MB desorption yields from ATOS (more than 93%) were obtained when using saline solutions. All these results confirmed that NaOH-treated orange tree sawdust can be considered as a promising material for the removal of cationic dyes from industrial wastewaters.

Technical dichlorodiphenyltrichloroethane (DDT) has been used worldwide as a pesticide since the beginning of the 1940s. Due to its persistence, DDT residues are still ubiquitously distributed in the environment. Photochemical UV degradation has been shown to be a potent degradation path for DDT and most of the resulting photoproducts have been identified up to now. Nevertheless, in 2012, a new DDT metabolite, most likely formed photochemically from DDE, was detected in ray liver samples from Brazil, an area which is highly contaminated with DDT. This study includes photochemical generation, chemical synthesis and isolation of this compound which was verified to consist of both cis- and trans-2,4-dichloro-1-[2-chloro-1-(4-chlorophenyl)ethenyl]benzene. Both stereoisomers were resolved by gas chromatography on a polar capillary column and detected in more than 60 biotic (e.g. marine mammals, birds, human milk) and abiotic samples (fat deposits in kitchen hoods) from different areas all over the world. The stereoisomer distribution and concentrations (0.3–3.9% relative to corresponding 1,1-dichloro-2,2-bis(p-chlorophenyl) ethane (p,p′-DDE) levels) were determined by means of the synthesized analytical standard, indicating the widespread occurrence of this compound as an additional minor metabolite of DDT.

Iron deficiency is an important abiotic stress that limits productivity of crops all over the world. We selected a hybrid rice (Oryza sativa L.), LYPJ, which is super high-yield and widely cultured in China, to investigate changes in the components and structure of thylakoid membranes and photosynthetic performance in response to iron deficiency. Our results demonstrated that photosystem I (PSI) is the primary target for iron deficiency, while the changes in photosystem II (PSII) are important for rebuilding a balance in disrupted energy utilization and dissipation caused by differential degradation of photosynthetic components. The result of immunoblot analysis suggested that the core subunit PsaA declined drastically, while PsbA remained relatively stable. Furthermore, several organizational changes of the photosynthetic apparatus were found by BN-PAGE, including a marked decrease in the PSI core complexes, the Cytb ₆ /f complex, and the trimeric form of the LHCII antenna, consistent with the observed unstacking grana. The fluorescence induction analysis indicated a descending PSII activity with energy dissipation enhanced markedly. In addition, we proposed that the crippled CO₂ assimilation could be compensated by the enhanced of phosphoenolpyruvate carboxylase (PEPC), which is suggested by the decreased ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and photosynthetic efficiency.

Plant-based bioassays have gained wide use among the toxicological and/or ecotoxicological assessment procedures because of their simplicity, sensitivity, low cost, and reliability. The present study describes the use of Vicia faba (V. faba) micronucleus (MN) test and V. faba comet assay in the evaluation of the genotoxic potential of disinfection by-products (DBPs) commonly found in chlorine-disinfected drinking water. Five haloacetic acids and three halogenated acetonitriles were chosen as representatives of DBPs in this study because they are of potentially great public health risk. Results of the MN test indicated that monochloroacetic acid (MCA), monobromoacetic acid (MBA), dichloroacetic acid (DCA), dibromoacetic acid (DBA), trichloroacetic acid (TCA), and trichloroacetonitrile (TCAN) caused a statistically significant increase in MN frequency in V. faba root tip cells. However, no genotoxic response was observed for dichloroacetonitrile (DCAN) and dibromoacetonitrile (DBAN). Results of the comet assay showed that all tested DBPs induced a statistically significant increase in genomic DNA damage to V. faba root tip cells. On considering the capacity to detect genomic damage of a different nature, we suggest that a combination of V. faba MN test and V. faba comet assay is a useful tool for the detection of genotoxic effects of DBPs. It is worthy of assessing the feasibility of using V. faba comet assay combined with V. faba MN test to screen for the genotoxic activity of chlorinated drinking water in future work.