Archives of Environmental Protection

The aims of the current study are the physicochemical characterization, spatial assessment and monitoring of hydrocarbon contamination in quagmire of three sites (Agreb, Gassi and Zotti) in the Hassi Messaoud region (Algerian Sahara), as a result of the presence of an important oil industry rejecting industrial wastewater. Samples were obtained from three different depths for each site. Total Hydrocarbons (THC) were determined by a gravimetric method, and the four (F1:C6-C10), (F2:C10-C16), (F3:C16-C34) and F4>C34) hydrocarbon fractions and BTEX (Benzene, Toluene, Ethyl-benzene and Xylene) were determined by using gas chromatography (FID). The results obtained show a high contamination with hydrocarbons in different sites and depths. The concentrations of THC, four hydrocarbon fraction and BTEX recorded on Agreb site in different depth were in this order: 51200–120000 mg/kg d.w.; <LOD – 59500 mg/kg d.w.; 2.4–90.8 mg/kg d.w. respectively; and for Gassi site, in this order: 59600–70300 mg/kg d.w.; < LOD – 43000 mg/kg d.w.; 8.5–112 mg/kg d.w. Finely they were in the following order: 18100–19200 mg/kg d.w.; <LOD – 9130 mg/kg d.w.; 2.75–65 mg/kg d.w. for Zotti site. Statistical analysis demonstrated an important site effect of THC and the three hydrocarbon fractions except for F4. However, there is no site and depth effect for BTEX. On the other hand the depth effect is significant just for THC, F1 and F2 of hydrocarbons. This variation can be attributed to the difference of physicochemical parameters between studied sites.

Since the implementation of the compulsory sorting of domestic waste policy in China, the participation rate of residents is low, which leads to the unsatisfactory result of terminal reduction of domestic waste. Therefore, the problem of domestic waste reduction still needs to rely on source reduction. Based on the panel data of 29 provincial capitals in China from 2009 to 2018, this study conducts a comprehensive threshold effect test on per capita GDP and other influencing factors of domestic waste production, conducts panel threshold regression for the factors with threshold value, and explores the nonlinear relationship between per capita GDP and domestic waste production under the influence of different threshold variables. The results show that when the urban population density is less than 272 people/km2, the increase of 1% of per capita GDP will lead to a decrease of 0.251% in the domestic waste production, otherwise, it will lead to an increase of 0.249%; when the per capita consumption expenditure is less than the threshold value of 10,260 yuan/year, the influence coefficient of per capita GDP is 0.155, which increases to 0.207 above the threshold. When the share of tertiary industry is taken as the threshold variable, the two threshold values are 61% and 71% respectively. Through the analysis of control variables, it has been found that population size and amount of courier per capita have significant positive effects on domestic waste production, while gas permeability and the number of non-governmental organizations have significant negative effects

Biochar has been extensively studied as a soil amendment to reduce nutrients losses. However, the comparative effectiveness of biochar adsorption capacity for ammonium (NH4-N), nitrate (NO3-N), and phosphate (PO4-P) remains unknown. In the present study, the effects of feedstock (banana stem and coconut shell) and temperature (300, 500, and 700°C) on biochar adsorption ability for NH ₄-N, NO ₃-N, and PO ₄-P were investigated and fitted by three adsorption models, viz Freundlich, Langmuir, and linear. Freundlich (R ² = 0.95–0.99) and Langmuir (R ² = 0.91–0.95) models were found suitable for adsorption of NH ₄-N. The maximum adsorption capacity (Q _m) for coconut shell biochar increased with pyrolysis temperature (Q _m = 12.8–15.5 mg g-1) and decreased for banana stem biochar (Q _m = 12.9–9.7 mg g-1). In the case of NO ₃-N adsorption, Freundlich (R ² = 0.82–0.99) and linear model (R ² = 1.00) were found suitable while Langmuir model showed much less contribution, similarly adsorption of PO ₄-P, was not supported by these three models. The minimum concentrations required for adsorption of phosphate were recorded as 36, 8, and 3 mg L ^-1 using pyrolyzed biochar at the temperatures of 300, 500, and 700°C, respectively. These results indicate that the feedstock and pyrolysis temperature, as well as aquatic nutrient concentration, were important factors for the adsorption of inorganic nitrogen and phosphorus.

Polymer mixed-matrix nanocomposite membranes were prepared by a wet-phase inversion method and used in ultrafiltration processes to treat wastewater treatment plant effluent spiked with organic micropollutants. The effects of halloysite (Hal), TiO2, and functionalized single-walled carbon nanotube (SWCNT-COOH) nanofillers on the treatment efficiency, permeability loss, and fouling behavior of polyethersulfone (PES) membranes were investigated and compared with those of a pristine PES membrane. The nanocomposite membranes exhibited lower porosity and stronger negative surface charge because of the added hydrophilic nanofillers. The PES-Hal membrane achieved the optimal balance of permeability and micropollutant removal owing to enhanced pollutant adsorption on the membrane surface and the creation of an easily removable cake layer (i.e., reversible fouling). The PES-SWCNT-COOH membrane demonstrated the highest treatment efficiency, but also the high permeability loss. In contrast, PES-TiO2 exhibited excellent antifouling properties, but poorer treatment capabilities.

The present study is focused on the evaluation of bioeffects of silver nanoparticles (AgNPs) synthesized by Bacillus subtilis strain I’-1a, the producer of iturin A lipopeptide biosurfactant. The following properties of biologically synthesized silver nanoparticles (bio-AgNPs) were evaluated: in vitro cytotoxicity, antioxidant properties, and metabolic activities of mammalian cells. As a control, chemically synthesized silver nanoparticles (chem-AgNPs) were used. In vitro, antioxidant activity of bio-AgNPs showed a significant effect on the scavenging of free radicals. Bio-AgNPs can be potent natural antioxidants and can be essential for health preservation against oxidative stress-related degenerative diseases, such as cancer. The cell viability of human skin fibroblasts NHDF was remarkably inhibited in the presence of both AgNPs. However, bio-AgNPs were more active than chem-AgNPs. In our experiment, microarrays PM-M1–PM-M4 were used to evaluate the growth of NHDF fibroblast cells in the presence of bio-AgNPs and chem-AgNPs. The NHDF fibroblast cells were more active in the presence of bio-AgNPs than in chem-AgNPs. Probably, the presence of biosurfactant produced by Bacillus subtilis I’-1a significantly increased the stability of biogenic AgNPs and enhanced their biological activities and specific interaction with human DNA. Furthermore, the evaluated biological activities were enhanced for the biosurfactant-based AgNPs.

Phosphogypsum (PG) – a waste material generated in enormous amounts, accumulates a wide range of pollutants and thus represents a major environmental problem. Among the proposed potential strategies for PG management, none has been implemented on a large scale up to date. At the same time, the rapid depletion of phosphorite resources, used to manufacture most commercial phosphorus (P) fertilizers, poses unprecedented challenges for future agriculture and environmental protection. The aim of this study was to assess the possibility of using PG as a source of P for fertilizing plants. The effect of PG fertilization on the dry mass accumulation, P and sulphur (S) contents in soil and in the above-ground parts of plants, as well as on the level of heavy metal contaminations, were studied in the experimental model consisted of 12 genotypes of three lupine species – Lupinus angustifolius, Lupinus albus and Lupinus luteus. The PG application increased the content of both the available and active P in the soil. The increased P bioavailability resulted in an elevated uptake and intracellular content of this nutrient in the studied plant species in a dose- and variety-dependent manner. The heavy metals present in the waste did not affect their accumulation in the plants. The results indicate the possibility of using P forms present in PG as an alternative source of this component in plant nutrition, at the same time allowing elimination of the waste deposited on huge areas, which will certainly contribute to improving the quality of the environment.

Regions with warm climate are poor in organic matter or have a deficit of soil. The purpose of the work was to select the optimal mix from biodegradable wastes such as cardboard (Cb), natural textiles (Tx) newspaper (Np), colored newspaper (Cp), and office paper (Op) for creating artificial soil by combining these materials with compost and sand. To select the optimum mix, 15 samples were taken (3 from each type of waste in the following proportions: 25%, 50% and 75% ). The optimum mix was analyzed for grass germination rate and root development. Tests were performed in the laboratory with conditions similar to those of regions with warm climate and soil deficiency in a specially designed testing spot (bioterm). The effects of particular mixes on plant germination rate and growth were measured. Out of all mixes, the textile compositions Tx50 and Tx25 supported best the plant propagation. During the whole experimental process, the grass showed various growth tendencies. The best results for grass height were observed for mixes with textiles and colored newspaper. Based on this data and subsequent laboratory research, the best substrate composition was selected. For the whole period of the tests, germination rate in the pot with the mix was higher than the germination rate in the control sample with compost. Considering the experimental conditions of this research, the tested substrates can be used to aid in plant propagation, especially in regions with warm climate and soil deficiencies, and for restoration of damaged land areas.

An attempt was made to determine the correlation between the granulometric structure of bottom sediments and the content of speciation forms of phosphorus and selected metals. Using the sedimentation method, the bottom sediments of a thermally contaminated dam reservoir were divided into fast and slow-draining fractions. Measurements of granulometric composition were made, determining the volume proportions of sediment particles in the range of 0.1 m to 650 m. Particle share sizes were determined in the size range: 0.1–50 m (F1), 50–100 m (F2), 100–200 m (F3), 200–400 m. (F4). The study showed that the content of speciation forms of phosphorus and selected metals remains related to the granulometric structure of bottom sediments. The content of organic matter in sediments is determined by the proportion of the smallest particles, from 0.1 to 50 μm, at the same time these particles most strongly aff ect the reduction conditions of sediments. According to Gilford›s correlation thresholds, there was no correlation between the proportion of sediment particles with dimensions of 0.1–50 μm and the concentration of speciation forms of phosphorus. For particles with dimensions of 50–100 μm, the strongest correlation was observed for the concentration of the EP fraction and for the WDP fraction (r2 = 0.4048, r2 = 0.3636). A strong correlation between the size of sediment particles and the concentration of speciated forms of phosphorus was noted for particles with dimensions of 100–200 μm and 200–400 μm. The coeffi cient of determination was for AAP, EP, WDP and RDP, respectively: 0.8292, 0.891, 0.7934, 0.47. The relationship between particles in the 0.1–50 m range and iron (Fe) concentration, R2 – 0.3792, aluminum (Al) R– 0.3208, and zinc (Zn) R2 – 0.4608, was classifi ed as medium. For particles in the 50–100 m range, a medium correlation with calcium (Ca) and magnesium (Mg) concentrations is apparent, R2 0.4443 and 0.3818, respectively. For particles 100–200 mm and 200–400 mm, an almost full correlation is noted for iron (Fe) R2 – 0.9835, aluminum (Al) R2 – 0.9878, calcium (Ca) R2 – 0. 824, very strong for manganese (Mn) R2 – 0.6817, and zinc (Zn) R2 – 0.7343. There is a very strong correlation between the concentration of the AAP fraction with the concentration of iron (Fe) R2 – 0.8694 and a strong correlation between the concentration of EP with the concentration of iron (Fe) R2 – 0.609. There is a strong correlation between the concentration of the AAP and EP fractions with the concentration of aluminum (Al) R2 – 0. 6253 and 0.8327. The concentration of AAP and EP fractions with the concentration of calcium (Ca) R2 – 0.5941 and 0.7576 remains in a strong relationship. The correlation between the concentration of RDP fractions and the concentration of magnesium (Mg) and manganese (Mn) remains in a medium relationship. The concentration of the EP fraction (Olsen-P) is in a strong relationship with the concentration of organic matter (R2 –.0.6763). No correlation was found between the concentration of the residuum form and the concentrations of organic matter, iron (Fe) and aluminum (Al). A medium correlation was found between the concentration of the residuum form and the concentration of calcium (Ca), magnesium (Mg), manganese (Mn) – R2 = 0.4206 and zinc (Zn).

To analyze the composition of norfloxacin-resistant bacteria and norfloxacin-degrading bacteria in pond water and sediment in subtropical China, the composition of antibiotic resistant bacteria in pond water and sediment enriched with norfloxacin-containing medium was analyzed by high-throughput sequencing. Sediment and water samples were collected from 3 fish ponds in subtropical China, and domesticated with norfloxacin, subsequently norfloxacin-resistant bacteria through high-throughput sequencing of 16S rDNA, and isolated norfloxacin- degrading bacteria. Our results showed that the pond sediment and water contain a variety of norfloxacin-resistant bacteria, mainly from Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, and Chloroflexi. Moreover, we isolated two norfloxacin-degrading bacteria (NorXu-2 and NorXu-3). The norfloxacin-degrading rate by NorXu-2 and NorXu-3 in the culture mediums with 200 μg/mL was the highest, which was up to 49.71% and 35.79%,respectively. When the norfloxacin concentration was 200 μg/mL, NorXu-2 and NorXu-3 had the best norfloxacin-degrading effect at pH of 6, and the degradation rates were 53.64% and 45.54%, respectively. Moreover, NorXu-3 exhibited a good tolerance to high NaCl concentration. These results not only provided basic data for the follow-up study of the molecular mechanism of antimicrobial microbial degradation, but also provided potential norfloxacin degrading bacteria for norfloxacin removal and bioremediation in aquaculture environment.

Many tons of micro- and nano-sized plastic particles enter the aquatic environment every year, due to increasing plastic production, with the consequent risk of microplastics contaminating our environment. Addressing this multifaceted threat requires innovative technologies that can efficiently remove microplastics from the environment. Therefore, there is an urgent need to study the efficiency of the removal of microplastics by different water and wastewater treatment technologies. After short overviewed the source, occurrence, and potential adverse impacts of microplastics to human health, we then identified promising technologies for microplastics removal, including physical, chemical, and biological approaches. A detailed analysis of the advantages and limitations of different techniques was provided. According to literature data, the performance of microplastics removal is as follows: membrane bioreactor (>99%) > activated sludge process (~98%) > rapid sand filtration (~97.1%) > dissolved air floatation (~95%) > electrocoagulation (>90%) > constructed wetlands (88%). Chemical treatment methods such as coagulation, magnetic separation, Fenton, photo-Fenton and photocatalytic degradation also show moderate to high efficiency of microplastics removal. Hybrid treatment such as the MBR-UF/RO system, coagulation followed by ozonation, adsorption, dissolved air flotation, filtration, and constructed wetlands based hybrid technologies have shown very promising results in the