Quinoline, which belongs to N-heterocyclic compounds, occurs naturally in the environment and is used in numerous industrial processes. The structures of various chemicals, such as dyes and medicines, are based on this compound. Due to that fact, quinoline and its derivatives are widely distributed in environment and can exert toxic effects on organisms from different trophic levels. The ability of the filamentous fungus Cunninghamella elegans IM 1785/21Gp to degrade quinoline and modulate the membrane composition in response to the pollutant was studied. C. elegans IM 1785/21Gp removes quinoline with high efficiency and transforms the pollutant into two novel hydroxylated derivatives, 2-hydroxyquinoline and 3-hydroxyquinoline. Moreover, due to the disruption in the membrane stability by quinoline, C. elegans IM 1785/21Gp modulates the fatty acid composition and phospholipid profile.

In the present study, the biotechnological potential of the marine-derived fungus Peniophora sp. CBMAI 1063 was investigated in relation to Reactive Black 5 (RB5) dye decolorization and degradation using an integrated statistical design composed of Plackett-Burman design (P&B), central composite design (CCD), and response surface methodology (RSM). RB5 dye was effectively decolorized (94 %) in saline conditions, without any detection of mutagenic compounds, and simultaneously, 57 % of total organic carbon (TOC) was removed in 7 days. The activity of lignin peroxidase (LiP) was not detected during the process. The gene expression of laccase (Lac) and manganese peroxidase (MnP) enzymes produced during the process was evaluated, and results from this experiment coupled with LC-MS analyses revealed that in the early stage of dye decolorization, a higher MnP gene expression and significant enzymatic activity was detected in Peniophora sp. CBMAI 1063 with the formation of p-Base and TAHNDS compounds. This paper reports innovative data related to the textile dye decolorization by the marine-derived basidiomycete Peniophora sp. CBMAI 1063, showing the metabolites formed and enzymatic action throughout the process in saline condition. The strategy used showed to be an efficient statistical approach that provides an attractive solution for the screening and simultaneous optimization of the degradation process.

ToxTrak™ method is an analytical tool for the measurement of toxicity of drinking water, wastewater and natural water. It is based upon the estimation of the inhibitive effect on bacterial respiration processes. The main aim of this work was to test the applicability of ToxTrak™ method in the assessment of wastewater toxicity in a full-scale WWTP in Poland. In order to achieve it, the study was divided into two parts. First, the validation of ToxTrak™ method was performed. Second, wastewater toxicity was monitored in the long- and short-term campaigns. Validation of ToxTrak™ method revealed that the indigenous biomass (mixed cultures of activated sludge microorganisms) was more sensitive than Escherichia coli for both materials (wastewater and phenol) tested. The values of degree of inhibition determined for phenol towards indigenous biomass and E. coli were close to each other, and no statistically significant difference between them was found. It confirmed the reliability of the results obtained with the help of ToxTrak™ test. The toxicity of the effluent was always lower than that of the influent and the linear correlation between them was found. Despite, the decrease of wastewater toxicity in the WWTP, the effluents were ranked as toxic or highly toxic according to the classification of wastewater based upon the acute toxicity.

Nitrate contamination in aquifers has posed human health under high risk because people still rely on groundwater withdrawn from aquifers as drinking water and running water sources. These days, bioelectrochemical technologies have shown a great number of benefits for nitrate remediation via autotrophic denitrification in groundwater. This study tested the working possibility of a denitrifying biocathode when installed into a simulated aquifer. The reactors were filled with sand and synthetic groundwater at various ratios (10, 50, and 100 %) to clarify the effect of various biocathode states (not-buried, half-buried, and fully buried) on nitrate reduction rate and microbial communities. Decreases in specific nitrate reduction rates were found to be correlated with increases in sand/medium ratios. A specific nitrate reduction rate of 322.6 mg m⁻² day⁻¹ was obtained when the biocathode was fully buried in an aquifer. Microbial community analysis revealed slight differences in the microbial communities of biocathodes at various sand/medium ratios. Various coccus- and rod-shaped bacteria were found to contribute to bioelectrochemical denitrification including Thiobacillus spp. and Paracoccus spp. This study demonstrated that the denitrifying biocathode could work effectively in a saturated aquifer and confirmed the feasibility of in situ application of microbial electrochemical denitrification technology.

Pb/Zn smelting, an important economic activity in China, has led to heavy environmental pollution. This research reviewed studies on soil Pb contamination at Pb/Zn smelting sites in China published during the period of 2000 to 2015 to clarify the total levels, spatial changes, and health risks for Pb contamination in soils at local and national scales. The results show that Pb contents in surface soils at 58 Pb/Zn smelting sites in China ranged from 7 to 312,452 mg kg⁻¹ with an arithmetic average, geometric average, and median of 1982, 404, and 428 mg kg⁻¹, respectively (n = 1011). Surface soil Pb content at these smelting sites decreased from an average of 2466 to 659 mg kg⁻¹, then to 463 mg kg⁻¹ as the distance from the smelters increased from <1000 to 1000∼2000 m, and then to >2000 m. With respect to variation with depth, the average soil Pb content at these sites gradually decreased from 986 mg kg⁻¹ at 0- to 20-cm depth to 144 mg kg⁻¹ at 80- to 100-cm depth. Approximately 78 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites were classified as having high Pb pollution levels. Approximately 34.2 and 7.7 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites might pose adverse health effects and high chronic risks to children, respectively. The Pb/Zn smelting sites in the southwest and southeast provinces of China, as well as Liaoning province, were most contaminated and thus should receive priority for remediation.

Due to high durability, cheap cost, and ease of manufacture, 311 million tons of plastic-based products are manufactured around the globe per annum. The slow/least rate of plastic degradation leads to generation of million tons of plastic waste per annum, which is of great environmental concern. Of the total plastic waste generated, polythene shared about 64 %. Various methods are available in the literature to tackle with the plastic waste, and biodegradation is considered as the most accepted, eco-friendly, and cost-effective method of polythene waste disposal. In the present study, an attempt has been made to isolate, screen, and characterize the most efficient polythene degrading bacteria by using rhizosphere soil of Avicennia marina as a landmark. From 12 localities along the west coast of India, a total of 123 bacterial isolates were recorded. Maximum percent weight loss (% WL; 21.87 ± 6.37 %) was recorded with VASB14 at pH 3.5 after 2 months of shaking at room temperature. Maximum percent weight gain (13.87 ± 3.6 %) was reported with MANGB5 at pH 7. Maximum percent loss in tensile strength (% loss in TS; 87.50 ± 4.8 %) was documented with VASB1 at pH 9.5. The results based on the % loss in TS were only reproducible. Further, the level of degradation was confirmed by scanning electron microscopic (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. In SEM analysis, scions/crakes were found on the surface of the degraded polythene, and mass of bacterial cell was also recorded on the weight-gained polythene strips. Maximum reduction in carbonyl index (4.14 %) was recorded in untreated polythene strip with Lysinibacillus fusiformis strain VASB14/WL. Based on 16S ribosomal RNA (rRNA) gene sequence homology, the most efficient polythene degrading bacteria were identified as L. fusiformis strainVASB14/WL and Bacillus cereus strain VASB1/TS.

Interior air environment and health problems of vehicles have attracted increasing attention, and benzene homologues (BHs) including benzene, toluene, ethylbenzene, xylenes, and styrene are primary hazardous gases in vehicular cabins. The BHs impact on the health of passengers and drivers in 38 taxis is assessed, and health risk equations of in-car BHs to different drivers and passengers are induced. The health risk of in-car BHs for male drivers is the highest among all different receptors and is 1.04, 6.67, and 6.94 times more than ones for female drivers, male passengers, and female passengers, respectively. In-car BHs could not lead to the non-cancer health risk to all passengers and drivers as for the maximal value of non-cancer indices is 0.41 and is less than the unacceptable value (1.00) of non-cancer health risk from USEPA. However, in-car BHs lead to cancer health risk to drivers as for the average value of cancer indices is 1.21E-04 which is 1.21 times more than the unacceptable value (1.00E-04) of cancer health risk from USEPA. Finally, for in-car airborne benzene concentration (X, μg/m³) to male drivers, female drivers, male passengers, and female passengers, the cancer health risk equations are Y = 1.48E-06X, Y = 1.42E-06X, Y = 2.22E-07X, and Y = 2.13E-07X, respectively, and the non-cancer health risk equations are Y = 1.70E-03X, Y = 1.63E-03X, Y = 2.55E-04X, and Y = 2.45E-04X, respectively.

Heavy oil-produced water (HOPW) is a by-product during heavy oil exploitation and can cause serious environmental pollution if discharged without adequate treatment. Commercial biochemical treatment units are important parts of HOPW treatment processes, but many are not in stable operation because of the toxic and refractory substances, salt, present. Therefore, pilot-scale experiments were conducted to evaluate the performance of hydrolytic acidification-biological filter with airlift aeration (HA-BFAA), a novel HOPW treatment system. Four strains isolated from oily sludge were used for bioaugmentation to enhance the biodegradation of organic pollutants. The isolated bacteria were evaluated using 3-day biochemical oxygen demand, oil, dodecyl benzene sulfonic acid, and chemical oxygen demand (COD) removals as evaluation indices. Bioaugmentation enhanced the COD removal by 43.5 mg/L under a volume load of 0.249 kg COD/m³ day and hydraulic retention time of 33.6 h. The effluent COD was 70.9 mg/L and the corresponding COD removal was 75.0 %. The optimum volumetric air-to-water ratio was below 10. The removal ratios of the total extractable organic pollutants, alkanes, and poly-aromatic hydrocarbons were 71.1, 94.4, and 94.0 %, respectively. Results demonstrated that HA-BFAA was an excellent HOPW treatment system.

This study aimed to identify the most commonly used agricultural pesticides around Ichkeul Lake–Bizerta Lagoon watershed. First survey of pesticide use on agricultural watershed was performed with farmers, Regional Commissioner for Agricultural Development, and pesticide dealers. Then, sediment contamination by pesticides and response of benthic communities (bacteria and free-living marine nematode) were investigated. The analysis of 22 active organochlorine pesticides in sediments was performed according to quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, biodiversity of indigenous bacterial community sediment was determined by terminal restriction fragment length polymorphism (T-RFLP), and free-living marine nematodes were counted. The results of the field survey showed that iodosulfuron, mesosulfuron, 2,4-dichlorophenoxyacetic acid (2,4 D), glyphosate, and fenoxaprops were the most used herbicides, tebuconazole and epoxiconazole the most used fungicides, and deltamethrin the most used insecticide. Sixteen organochlorine pesticide compounds among the 22 examined were detected in sediments up to 2 ppm in Ichkeul Lake, endrin, dieldrin, and hexachlorocyclohexane being the most detected molecules. The most pesticide-contaminated site in the lake presented the higher density of nematode, but when considering all sites, no clear correlation with organochlorine pesticide (OCP) content could be established. The bacterial community structure in the most contaminated site in the lake was characterized by the terminal restriction fragments (T-RFs) 97, 146, 258, 285, and 335 while the most contaminated site in the lagoon was characterized by the T-RFs 54, 263, 315, 403, and 428. Interestingly, T-RFs 38 and 143 were found in the most contaminated sites of both lake and lagoon ecosystems, indicating that they were resistant to OCPs and able to cope with environmental fluctuation of salinity. In contrast, the T-RFs 63, 100, 118, and 381 in the lake and the T-RFs 40, 60, 80, 158, 300, 321, and 357 in the lagoon were sensitive to OCPs. This study highlighted that the intensive use of pesticides in agriculture, through transfer to aquatic ecosystem, may disturb the benthic ecosystem functioning of the protected area. The free-living marine nematodes and bacterial communities represent useful proxy to follow the ecosystem health and its capacity of resilience.

The catalysts such as Fe, Bi₂O₃, and Fe-doped Bi₂O₃ were synthesized for the sonophotocatalytic treatment of synthetic dye and real textile wastewater. The resultant catalysts were characterized for its size and uniform shape using x-ray diffractogram (XRD) and scanning electron microscopy (SEM) which signified the nanorod shape formed Bi₂O₃. The higher ultraviolet light absorbance capacity of the catalysts was also evident using diffuse reflectance spectroscopy (DRS). Initially, the effect of conventional parameters such as initial pH, gas bubbling (argon, oxygen, air and nitrogen) and oxidant addition (H₂O₂ and peroxymonosulfate) in the presence of sonolysis (22 and 37 kHz frequency) and photolysis (UV-C light) on 10 ppm Basic Brown 1 dye was studied. The results showed that highest decolorization of 62 % was attained for 3 g/L peroxymonosulfate under 37 kHz frequency sonolysis treatment. Secondly, with the catalyst study, highest of 46 % dye color removal was obtained with 4 g/L Fe under 37 kHz frequency sonolysis treatment. The sonophotocatalytic treatment of dye with Fe-doped Bi₂O₃ catalyst in combination with peroxymonosulfate showed highest color removal of 99 %. Finally, the sonophotocatalytic treatment of real textile wastewater in the presence of 3 g/L Fe-doped Bi₂O₃ and 6 g/L peroxymonosulfate reduced the total organic carbon (TOC) and chemical oxygen demand (COD) level to 77 and 91 %, respectively, in 180 min. The reported treatment process was found to treat the synthetic dye and real textile wastewater effectively.