Drought stress is one of the major environmental factors responsible for reduction in crop productivity. In the present study, responses of two maize cultivars (Rung Nong 35 and Dong Dan 80) were examined to explicate the growth, yield, leaf gas exchange, leaf water contents, osmolyte accumulation, membrane lipid peroxidation, and antioxidant activity under progressive drought stress. Maize cultivars were subjected to varying field capacities (FC) viz., well-watered (80 % FC) and drought-stressed (35 % FC) at 45 days after sowing. The effects of drought stress were analyzed at 5, 10, 15, 20, ad 25 days after drought stress (DAS) imposition. Under prolonged drought stress, Rung Nong 35 exhibited higher reduction in growth and yield as compared to Dong Dan 80. Maize cultivar Dong Dan 80 showed higher leaf relative water content (RWC), free proline, and total carbohydrate accumulation than Run Nong 35. Malondialdehyde (MDA) and superoxide anion were increased with prolongation of drought stress, with higher rates in cultivar Run Nong 35 than cultivar Dong Dan 80. Higher production of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) and glutathione reductase (GR) resulted in improved growth and yield in Dong Dan 80. Overall, the cultivar Dong Dan 80 was better able to resist the detrimental effects of progressive drought stress as indicated by better growth and yield due to higher antioxidant enzymes, reduced lipid peroxidation, better accumulation of osmolytes, and maintenance of tissue water contents.

Sulfide, found in some wastewaters and industrial off-gases, is a toxic and highly corrosive pollutant, especially in wastewater applications. Sulfide removal was studied in a new sulfide-oxidizing reactor (External Silicone Membrane Reactor—ESMR) that employs a tubular silicone rubber membrane for micro-aeration. The chemical and biological sulfide oxidation at pH 8.0, 9.0, and 10.0 were investigated. The applied velocity (V ₛ) in the membrane was also investigated as a system control parameter. The local overall mass transfer coefficient (R) was estimated for the tubular silicone rubber membrane and had an average value of 0.153 m.h⁻¹. Oxygen mass transfer was found to not be influenced by the applied velocity. The sulfide oxidation to sulfate could be partially avoided and the biotic tests showed larger sulfur aggregates deposited in the silicone membrane, which could easily be washed away upon flushing. By contrast, colloidal sulfur formation observed in the chemical oxidation assays was harder to separate from the liquid phase. This study reveals that the ESMR is a suitable reactor design to promote partial sulfide oxidation because it provides an adequate oxygen supply with minimized aeration costs.

An experimental study was performed to determine the feasibility of using physically treated Candida tropicalis cells for sorption of Cu(II) and phenol, the role of competition between phenol molecules and Cu(II). The yeast cells were lyophilized (LC), heat-treated at 65 °C for 24 h (HT1), at 90 °C for 24 h (HT2), and 72 h (HT3), inactivated at 120 °C and 104 kPa for 20 min (PC). The adsorption isotherms were determined in batch system. Experimental equilibrium data were evaluated using Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models by linear and non-linear regression. The adsorbed Cu(II) and phenol amounts by yeast cells were decreased due to the physical treatments of cells. With the increase of biomass dosage from 1 to 10 g L⁻¹, the adsorption efficiency was increased. The Cu(II) adsorption capacity was also determined in the presence of phenol at various initial concentrations, and in these systems, phenol adsorption isotherms were determined. In the presence of phenol, the Cu(II) sorption capacity by lyophilized cells and carbon particles was decreased. The most commonly used sorbent in water treatment is activated carbon with large specific surface; therefore, the results were compared with the experimental data obtained by using activated carbon (AC).

In the current study, we report the utilization of the biogenic potential of Benincasa hispida (ash gourd) peel extract for the synthesis of Ag embedded AgCl nanoparticles nanoparticles (Ag/AgCl NPs) without the use of any external organic solvents. The appearance of dark brown color from the pale yellow color confirmed the formation of Ag/AgCl nanoparticles which was further validated by absorbance peak using UV–visible spectroscopy. The phytochemicals (flavones) present in the B. hispida peel extract acts as a reducing/stabilizing agents. The morphology and size of the synthesized NPs were characterized by transmission electron microscope (TEM), selected area electron microscope (SAED) and high resolution transmission electron microscope (HR-TEM). FT-IR spectra of the B. hispida peel extract and after the development of nanoparticles are determined to identify the functional groups responsible for the conversion of metal ions to metal nanoparticles. The synthesized nanoparticles showed an excellent photocatalytic property in the degradation of toxic dye like malachite green oxalate under sunlight irradiation. For the first time, malachite green oxalate dye was degraded by Ag/AgCl nanoparticles under sunlight irradiation.

High serum concentrations of polychlorinated biphenyls (PCBs) have been reported previously among residents of Anniston, Alabama, where a PCB production facility was located in the past. As the second of two cross-sectional studies of these Anniston residents, the Anniston Community Health Survey: Follow-Up and Dioxin Analyses (ACHS-II) will yield repeated measurements to be used to evaluate changes over time in ortho-PCB concentrations and selected health indicators in study participants. Dioxins, non-ortho PCBs, other chemicals, heavy metals, and a variety of additional clinical tests not previously measured in the original ACHS cohort will be examined in ACHS-II. The follow-up study also incorporates a questionnaire with extended sections on diet and occupational history for a more comprehensive assessment of possible exposure sources. Data collection for ACHS-II from 359 eligible participants took place in 2014, 7 to 9 years after ACHS.

The present work investigates the potential of two experimental field columns (FC-2 and FC-4) to reduce volatile organic compound (VOC) emissions from a municipal solid waste (MSW) landfill located in Quebec, Canada. The FC-2 and FC-4 were fed by raw biogas coming from the landfill site. The VOC were identified and quantified in emitted biogas and raw biogas. The emitted biogas was collected at the surface of FC-2 and FC-4, and the raw biogas was obtained directly from the well. The main groups of the VOC in the landfill biogas are BTEX (66 %), alkanes (19 %), cyclic compounds (10 %), and halogenated compounds (5 %). The concentration of VOC in the landfill raw biogas varies from below the limit of detection (BLD) to 22 ppmv, and that of the emitted biogas varies from BLD to 3.1 ppmv. The result of this study showed that the experimental field columns had a very high potential to reduce the VOC emissions from the investigated landfill. The effectiveness of the VOC emission removal for the FC-2 and FC-4 was shown to be practically 100 % for many compounds. The experimental field column elimination capacity of VOC emissions is in the range of 0.1 to 4.6 mg m⁻³ h⁻¹.

Various inorganic and organic pollutants in industrial soils may adversely affect soil microorganisms and terrestrial ecosystem functioning. The aim of the study was to explore the relationship between the microbial activity, microbial biomass, and functional diversity of soil bacteria and the metals and total petroleum hydrocarbons (TPHs) in the Upper Silesian Industrial Region (Poland). We collected soil samples in pine-dominated forest stands and analyzed them according to a range of soil physicochemical properties, including metal content (cadmium, lead, and zinc) and TPH content. Metal concentrations were normalized to their toxicity to soil microorganisms and integrated in a toxicity index (TI). Soil microbial activity measured as soil respiration rate, microbial biomass measured as substrate-induced respiration rate, and the bacterial catabolic activity (area under the curve, AUC) assessed using Biolog® ECO plates were negatively related to TPH pollution as shown in multiple regressions. The canonical correspondence analysis (CCA) showed that both TPH and TI affected the community-level physiological profiles (CLPPs) of soil bacteria and the pollutants’ effects were much stronger than the effects of other soil properties, including nutrient content.

Effects of low-temperature thermal desorption (LTTD) treatment on the ecological properties of soil contaminated by petroleum hydrocarbons were assessed. For this purpose, various ecological properties related to soil health and physicochemical properties of the oil-contaminated soil before and after LTTD treatment were investigated. Total petroleum hydrocarbon concentration, electrical conductivity, organic matter, and total nitrogen decreased while water-holding capacity and available P₂O₅ increased. The soil color was also changed but textural class was not changed after LTTD. The microbial number and dehydrogenase activity increased following LTTD, but there was no significant difference in the β-glucosidase and acid phosphatase activities. Seed germination succeeded after LTTD, but the germination rate was still lower than that in non-contaminated soil as the growth of plants and earthworms was. The results showed that overall soil health related to biological productivity and environmental functions was improved after LTTD and suggested that LTTD could be a better alternative to other harsh remediation methods. However, ecological indicators still show differences to the adjacent non-contaminated level. Therefore, to ensure safe soil reuse, the change in eco-physiochemical properties as well as contaminant removal efficiency during the remediation process should be considered.

The mass spectrometric analysis of the impact of sulfur dioxide and dust emission on carbon and oxygen stable isotopic compositions of glucose hydrolysed from α-cellulose samples extracted from Scots pine growing in the vicinity of “Huta Katowice” steelworks was the main aim of this study. The annual rings covered the time span from 1975 to 2012 AD. The relationships between climatic conditions, sulfur dioxide, and industrial dust emission and oxygen and carbon isotopic compositions were analyzed using correlation function methods. This study shows the first analysis of carbon and oxygen stable isotopes in glucose as the bio-indicators of CO₂, sulfur dioxide, and industrial dust emission. The anticoincidence trend of δ¹⁸O and δ¹³C and dust and sulfur dioxide confirms that the decreases of dust and sulfur dioxide industrial emission increase δ¹⁸O and δ¹³C values in glucose.

In the last 40 years of the twentieth century, as a result of the growth in the exploitation and industrial processing of sulphur, the northern part of the Sandomierz Basin was one of the most polluted areas of Poland. Forests growing in this region, predominantly the Scots pine, offered an opportunity to analyse the degradation of the environment during that period using the dendrochronological method. The study was based on 814 samples, taken from 53 research surfaces belonging to nine linear transects. The investigations demonstrated that the highest reduction in growth occurred during the years 1970–1990. After that period, a considerable improvement in the condition of the pine trees was observed in most of the research plots. The spatial schedule of the trees with reductions reveals a clear relationship with the distance from the emitter i.e. the reductions were significantly lower in more distant sites. A distinct weakening of the trees is also indicated by missing rings, recorded in the years: 1964, 1974, 1978, 1979, 1980, 1985, 1990, and 2002. A definite impact on the condition of the tree stands was also due to the cone of depression around the Jeziórko mine, the post-flotation landfills, as well as pollution on a regional scale.