Air pollution can generate changes in the morphology, physiology, and behavior of several animals, including birds, which, when responding to such environmental changes, can be used as biomonitors. Quantitative and qualitative analyses of erythrocyte nuclear anomalies comprise a useful tool for biomonitoring, with anucleated erythrocytes, called erythroplastids, being particularly significant. The objectives of the present study were to quantify the presence of erythroplastids in Antilophia galeata and relate their presence to distance from the nearest urban environment. Blood smears were analyzed for 80 individuals of A. galeata captured between June 2013 and October 2018 in five Cerrado forest fragments of different sizes and with different influences from urbanization. The quantity of erythroplastids differed among areas, with it being greater in fragments within a proximity with urban, and less in highly preserved areas far from an urban environment. Quantification of erythroplastids in A. galeata proved to be a useful tool for monitoring air quality.

Phytoremediation is an innovative, eco-friendly, and solar-driven technique, which becomes a well-known alternative solution for remediation of hazardous dyes from wastewater. In present research work, potential of a submerged fresh water macroalgae Chara vulgaris L. (C. vulgaris) examined for removal of acidic azo dye methyl red (MR) in its solution form. A series of experiments were done with C. vulgaris to predict the effects of different parameters viz. contact time, initial dye concentration, amount of macroalgae, and pH. The increase in initial dye concentration directly impacts on the potential of macroalgae. The decolorization percentage declined with increase in initial dye concentration. The equilibrium condition was found to achieve after contact time of approximately 48 h. The decolorization of MR dye was found to be favorable at pH 5. The macroalgae was successfully utilized repeatedly with MR for eight cycles in batch experiments. The kinetics of phytoremediation of MR dye was studied with help of pseudo-first-order, pseudo-second-order, and Elovich kinetic models and the results were well suited to pseudo-second-order kinetic model with the correlation value R² ≥ 0.99. In addition, the experimental data was also assessed by using Langmuir and Freundlich adsorption equilibrium isotherms. The results of phytoremediation data was found to be in favor of Freundlich equilibrium isotherm which having the correlation value R² ≥ 0.977. The intraparticle diffusion model also studied to interpret the macroalgae phytoremediation mechanism for phytoremediation of MR. The surface interactions of C. vulgaris were investigated before and after the removal of dye with Fourier transform-infrared spectroscopy (FTIR) technique. On the basis of these studies, a hypothetical mechanism has also been proposed to depict the phytoremediation of acidic azo dye by C. vulgaris.

Nitric oxide (NO) and nitrous oxide (N₂O) production in biological nutrient removal has been studied widely due to the strong negative effects on the environment. Nitrite-denitrifying phosphorus removal (N-DPR), as a significant source of NO and N₂O production, has received great attention. However, the mechanism of NO and N₂O production at different phosphorus concentrations is not well understood. Therefore, this study was conducted to investigate the effect of phosphorus concentration on pollutant removal, as well as NO and N₂O production during the N-DPR process. The results showed that the phosphorus removal efficiency was improved with the increase of phosphorus concentration, which is caused by the enrichment of denitrifying phosphorus accumulating organisms (DPAOs) at high phosphorus concentration. High NO production was observed at phosphorus concentration of 0.5 mg L⁻¹, which is mainly attributed to the slow recovery of reductase activity and low abundance of DPAOs. The maximal N₂O accumulation of 31.45 mg L⁻¹ was also achieved at phosphorus concentration of 0.5 mg L⁻¹. The possible reason is that fewer poly-β-hydroxyalkanoates (PHAs) were synthesized by glycogen accumulating organisms (GAOs) at low phosphorus concentration, which could intensify the electron competition among different reductases. In addition, free nitrous acid (FNA) inhibition was another significant reason for high N₂O production.

Citrus fruits are cultivated in more than 100 countries around the world. The main citrus fruit–producing counties are Brazil, China, and the USA although the whole Mediterranean region ranks first worldwide. In Greece, citrus occupy an area of about 40.000 ha, representing 43% of total fruit crops. Soil quality is affected by long-term citrus cultivation. Soil organic matter is depleted in long-term citrus cultivation, in contrast to nutrients that seemed to increase in the following descending order: POₗₛₑₙ > Naₑcₓₕ > NO₃-N > Kₑcₓₕ > Caₑcₓₕ > Mgₑcₓₕ due to usual management practices. To evaluate the environmental impact due to broad use of Cu fungicides in long-term citrus cultivation, Cu total fraction and DTPA-extractable in agricultural soil were determined. Soil contamination rate was evaluated via proper indices of different sensitivities on their calculations. In particular, 22% of samples in older orchards were highly polluted based on the single-factor pollution index (PI). The index geo-accumulation index (Igeo) presented hysteresis in comparison with PI, which was more sensitive, comprehensive, and reliable, able to describe better the pollution classification of citrus soils. The calculation of monomial potential ecological risk for Cu showed that in older citrus groves, the average value was 11.8, while the max value was 49.8 indicating moderate ecological risk suggesting the negative environmental impact of intensive citrus cultivation. These results denote the need to preserve soil fertility and prevent potential toxic element accumulation due to long-term cultivation management practices, aiming to achieve soil sustainability and food security in National or Euro-Mediterranean scale.

This paper describes prototypes of an on-site early warning water quality monitoring system (EWWQMS) for pesticide quantification in natural waters by fluorescence and absorbance. As many pesticides are not naturally fluorescent, this EWWQMS uses UV irradiation to transform these compounds into highly fluorescent photoproducts and obtain sufficient sensitivity. To obtain a better specificity, the system uses four UV LEDs at different wavelengths to excite the fluorescent photoproducts. For pesticides that are not sensitive to photoconversion, the EWWQMS prototypes also use UV absorption for their quantification, thus offering a wider application range. A first system uses a diode array spectrometer for detection. A second system uses a higher resolution spectrometer and an intensified CCD camera detection to increase sensitivity. Analytical applications were conducted for the determination of fipronil, acetamipride, cyprodinil, trifluraline and pendimethaline in water using both the EWWQMS prototypes. The analytical performances of these new systems are good compared with other photo-induced fluorescence methods already published. Limits of detection without pre-concentration are in the range of 0.2 to 3 ng mL⁻¹ and the recovery values range from 95 to 108%. These results show that the EWWQMS prototypes can be used as an alert system to protect industrial plants from pesticide contaminations that exceed the capabilities of their cleaning processes.

Wastewater reuse coupled to managed aquifer recharge (MAR) provides a means to store and reuse treated wastewater (TWW) year-round. Determining the fate of nutrients in the subsurface during MAR remains challenging for environmental regulation due to the interaction of the MAR source water with site specific aquifer conditions. To facilitate the understanding of natural treatment processes, this study uses operational monitoring data from a full-scale aquifer storage and recovery (ASR) scheme using TWW to assess nutrient (N and P) transformation and fate. Analysis of median water quality injected into and recovered from the ASR wells for two complete ASR cycles (June 2014 to March 2016) was used to describe the removal of nutrients in an anoxic carbonate aquifer. Total nitrogen (TN) removal was dominated by redox processes, with median removal of 40 to 60% for TN and nitrate (the dominant N species) and higher removal of ammonia (95%) and total Kjeldahl nitrogen (TKN) (70%). Total phosphorous (TP) removal was also observed (~ 90%) due to sorption (filterable reactive phosphorous median removal of ~ 80%). A 40% increase in median salinity was evident within each ASR cycle due to recovery of the entire volume of injected water each year (ambient groundwater is 200% higher in TDS, on average). A reduction in salinity of the recovered water could be achieved by leaving a residual of source water in the aquifer to create a buffer zone between the ambient groundwater and the fresher source water.

A composite flocculant (PSAS-CS) consisted of cationic starch (CS) and polyaluminum silicate (PSAS) was prepared and used for the flocculation of simulated water samples. The morphology and structure of PSAS-CS were characterized by X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. The effect of flocculation conditions such as the flocculant dosage and the simulated water pH were investigated. The turbidity and color removal rates could reach 97.79% and 98.07% at PSAS-CS dosage of 1.5 mL/L and the simulated water pH of 5–9. Furthermore, the flocculation efficiency of PSAS-CS was compared with PSAS, CS and the starch modified polyaluminum silicate at different dosage. The results indicated that PSAS-CS showed the highest flocculation efficiency due to its plentiful of positive charges and extended molecular chain. Moreover, the removal rate of PSAS-CS could remain 85% at a low dosage of 0.2 mL/L.

Being known with its agricultural fertility, the soil of the Nile Valley of Egypt was subjected to degradation due to fast urbanization and increased industrial activities in recent years. The quality of the agricultural soil and associated radiological health hazards to farm workers in the Northeastern Nile Valley was assessed based on the trace metal analyses (Hg, Cd, Zn, Pb, Cu, Mn, and Fe) and natural radionuclide measurements (²³⁸U, ²²⁶Ra, ²³²Th, ⁴⁰K, and ²¹⁰Pb) of twenty soil samples. Results indicated that the agricultural soil has concentrations of trace elements below the soil world average. However, a significant enrichment in Cd and Cu content was observed in some soil sites. The enrichment in some trace elements contents, especially the Cd metal, was attributed to the effects of the natural and human factors, including the occurrence and distribution of silt and clay deposits, the extensive use of municipal wastewater and pesticide, the incineration of agricultural wastes, and the emission from bricks factories and mazut-fired thermal power plants around the area. The estimated contamination and ecologic risk indices revealed that some soils in the area are uncontaminated with trace elements; others are “moderately contaminated” soil to “contaminated.” Results from the radiological measurements revealed that the activity concentrations of the investigated radionuclides were also below the world median activities of soil. The total annual effective dose rates from the different exposure pathways were calculated. The estimated excess lifetime cancer risk values for farm workers were greatly higher than that of the soil world average. This implies a high probability of introducing cancer over the lifetime of farmers in the study area.

Among all female sex hormones, 17β-estradiol (E2) has been most often detected in discharge water from animal farms. The objectives of this study were to evaluate the performance of UV/heat-activated persulfate to degrade E2 and the technical feasibility to use this system for treating real wastewater. As an individual persulfate (PS) homogeneous activator, UV-activated PS removed E2 better than using low heat (40 °C) and solar irradiation to activate PS. When both UV and heat (25–65 °C) were used to activate PS, the Arrhenius equation represented well the observed rate constant, with activation energy of 118.07 kJ mol⁻¹. Inorganic ion concentrations increased the degradation rate. These ions included Cl⁻ (3500 mg L⁻¹), which increased rates by 18.1%, HCO₃⁻ (250 mg L⁻¹) by 4.6%, and NO₃⁻ (5 mg L⁻¹) by 7.9%. However, lesser impacts on degradation kinetics were observed at higher concentrations for all constituents due to SO₄·⁻ scavenging by the formed radicals such as Cl₂·⁻, Cl·, HCO₃·, CO₃·⁻, and NO₃·. The E2 degradation observed rate constant (kₒbₛ) was highest at pH 3. Although both synthetic wastewater and real wastewater showed inhibitory effects due to UV blocking from turbidity and the existence of the –COOH and –OH functional groups that acted as radical scavengers, E2 degradation was still observed. The overall results provided proof-of-concept that UV/heat-activated PS can be applied to treat E2 in wastewater containing a high organic content and can minimize the chemical and operating costs, as solar irradiation provides the heating source.

Shale reservoirs are one of the unconventional reservoirs that a large volume of hydrocarbon reserves have remained in these reservoirs. Thereby, proper measurement of reservoir characteristics will help to provide an economical and efficient required water as water scarcity has always been a significant challenge throughout recent decades. In this study, eight different production wells in the same formation were selected to consider the required freshwater and reused water for each well as a comparative analysis. According to the results of this study, the percentage of saved water from hydraulic fracturing flow-back water is approximately 85%. Therefore, it only needs 15% of freshwater to continue fracturing process each day, and photo-Fenton and floatation would be an excellent method to remove solids and chemicals from flow-back water. Furthermore, the percentage of saved water from water flooding processes and chemical enhanced oil recovery methods is approximately 70% and 75%, respectively. Therefore, it only needs 30% and 25% of freshwater to continue water flooding processes and chemical enhanced oil recovery methods each day. The approximate total volume of annual saved water is 104 MM m³ in which 1000 inhabitants could be still alive, and it will not be necessary to use the extreme volume of sweet water for hydrocarbon production.