Climate change may result in increased variability in rainfall intensity in the future, leading to more frequent flooding and a substantial loss of lives and properties. To mitigate the impact from flooding events, flood control facilities need to be designed and operated more efficiently, which requires a better understanding of the relationship between climate change and flood events. This study proposed a framework combining the Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) and the Coupled Model Intercomparison Project Phase 5 (CMIP5) general circulation models to assess the impact of climate change on flood events. HEC-HMS is one of the most commonly used hydrologic models in the USA, and CMIP5 provides the latest climate data for potential future climate scenarios. The proposed approach is applied to the Nippersink Creek watershed, which shows that 10-, 25-, 50-, and 100-year precipitations for the low, medium, and high emission scenarios are all greater than the historic observations. The corresponding 10-, 25-, 50-, and 100-year floods are remarkably higher than in the historic observations for the three climate scenarios. The high emission scenario results in dramatically increased flood risks in the future. The case study demonstrates that the framework combining HEC-HMS and CMIP5 is easy to use and efficient for assessing climate change impacts on flood events. It is a valuable tool when complicated and distributed hydrologic modeling is not an option because of time or monetary constraints.

The development of powdery photocatalyst has long been studied, yet the low recovery in water is still its bottleneck. In this work, magnetic recyclable lanthanum-doped TiO₂/copper ferrite/diatomite (La-TCD) ternary composite was synthesized via sol-gel method. The physicochemical properties of various hybrid catalysts were characterized and studied, and their photocatalytic properties were evaluated via the decomposition of antibiotic oxytetracycline and disinfection of bacteria Escherichia coli under visible light. The formation of heterojunction between La-doped TiO₂ and copper ferrite hindered the recombination of photo-induced charge carriers and improved the photocatalytic activity. The photodecomposition rate of OTC was accelerated by the high adsorption ability of diatomite, due to the adsorption and decomposition synergistic effect between catalysts and substrate diatomite. The optimal La dopant amount as well as optimal catalyst dosage was determined. The composite could simply be recovered from waterbody via an external magnet, and the repetition tests indicated no obvious decrease of photoactivity. This nanocomposite presented good potential to be applied in environmental remediation process, due to its high photocatalytic efficiency under visible light, as well as its good reusability and stability.

The entire Laguna Madre of Tamaulipas is a natural protected area and a Priority Marine Region of Mexico. However, its important biodiversity and high levels of endemism are threatened by the discharge of different pollutants and activities related to the ocean oil and gas industry. Therefore, the assessment of these effects on this marine ecosystem is of paramount importance. At present, the joint approach of monitoring chemical contaminant levels, alongside the use of pollution biomarkers as surrogate measures of biological impact within the environment, provides the better evaluation of the environmental hazard. Within this context, a biomonitoring study using native Chione elevata mussels sampled from four locations along the Mexican Laguna Madre coasts evaluated whether a battery of select biomarkers was suitable for identifying and quantifying pollution-induced stress in mussels. The levels of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carboxylesterase (CaE), alkaline phosphatase (ALP), glutathione s-transferase (GST), and the oxygen radical absorbance capacity (ORAC) were measured in soft tissues samples. Different metals (Cd, Pb, Cu, Zn, and Fe) as well as total heavy hydrocarbons were also determined in sediments. Higher concentrations of metals were observed in sampling localities with marine influence possibly related to the presence of marine grass. The concentration of total heavy hydrocarbons, as expected, was higher in sites with intensive fishing activity. The integrated biomarker response (IBR) and the condition index of mussels allowed discriminating between localities of continental and marine influence, revealing that the sampling stations with continental influence were subjected to a greater stress as a result of anthropogenic effects.

Erroneous information considering Chironomidae and Chaoboridae accumulation was given in Figure 4 published in Luoto et al. (2017).

Polysilicon production wastewater (PPW) is characterized by complex composition, high chemical oxygen demand (COD) concentration and poor biodegradability. An integrated process comprising of ferrate(VI) oxidation and biological aerated biofilter (BAF) was developed at lab scale for treating PPW with an initial COD of 3630 mg/L, biochemical oxygen demand (BOD₅) of 350 mg/L, suspended solids (SS) of 440 mg/L, and turbidity of 430 nephelometric turbidity units (NTU). Firstly, the potassium ferrate(VI) (K₂FeO₄) microcapsules were synthesized by using the phase separation method in cyclohexane, and ethylcellulose was used as the microcapsule wall materials (WM). The stability could be enhanced greatly when ferrate(VI) was encapsulated in the microcapsules with a mass ratio of K₂FeO₄:WM of 1:4 in the air compared with pure K₂FeO₄. The microcapsules exhibited sustained release behaviour and higher oxidation efficiency than pure K₂FeO₄. The microcapsules were used to pretreat PPW. Under the oxidation conditions of pH 6.0, microcapsule dosage 5.0 g/L and reaction time 70 min, the removal efficiency of COD, suspended solids (SS) and turbidity reached 55.1%, 61.3% and 74.2%, respectively. Subsequently, the oxidation effluent was subjected to BAF treatment. Under a hydraulic residence time of 48 h and a gas:water ratio of 6:1, the final effluent values of COD, SS and turbidity were 308 mg/L, 35 mg/L and 28 NTU, respectively, corresponding to total removal of 91.5%, 92.0% and 93.5%, respectively. Thus, this work demonstrates the feasible and potential application of encapsulated ferrate(VI) samples in the degradation of various toxic effluents.

In degradation of total petroleum hydrocarbon, 35 isolates belonging to 11 genera were sanitized and 3 isolates as well as their consortium were initiated to be able to raise in association with petroleum hydrocarbon as sole source of carbon under in vitro circumstances. The isolated strains were grounded on internal transcribed spacer (ITS) rDNA sequence analysis. The fungal strains with the utmost potentiality to reduce petroleum hydrocarbon without emerging antagonistic activities were Aspergillus niger, Penicillium ochrochloron, and Trichodema viride. For fungal growth on petroleum hydrocarbon, P. ochrocholon gained weight of 44%, A. niger 49%, and T. viride 39% within the first 30–40 days. As compared to the controls, these fungi accumulated significantly higher biomass, produced extracellular enzymes, and degraded total petroleum hydrocarbon and A. niger strongly degraded total petroleum hydrocarbon with a degradation of about 71.19%. These observations with GC-MS data confirm that these isolates displayed rapid total petroleum hydrocarbon biodegradation within a period of 60 days and the half-life showed that A. niger was the shortest with t1/2 = 21.280 day⁻¹ corresponding to the highest percent degradation of 71.19% and first-order kinetic fitted into the present study. By multivariate analysis, five main factors were identified by factor analysis (FA). The first factor (F1) of the fungi species accounts for 20.0% which signifies that fungi species controls the degradation of petroleum variability and hierarchical cluster analysis (HCA) as a dendrogram with five observations and three variables shows two predominant clusters order cluster 1 > 2.

Raw coal fly ash (RCFA) was recycled as three kinds of adsorbents by hydroxyl anion (OH⁻), hydrogen ion (H⁺), and thermal activation, respectively, for the adsorption of Cr(VI) from water. The H⁺ activation can explore the adsorptive potential of RCFA more effectively than the other two methods. The specific surface areas of the adsorbents are 12.33, 16.32, and 13.89 m² g⁻¹ for OH⁻, H⁺, and thermal activation, respectively. The adsorption process follows the pseudo-second-order kinetic model and the Langmuir model better and exhibits exothermic property. The activation energy (20.65–31.88 kJ mol⁻¹) and the negative Gibbs free energy reveal that the adsorption is a physical and spontaneous process. The adsorbents derived from OH⁻, H⁺, and thermal activation can be used at least 5, 7, and 4 times, respectively, while the one from H⁺ activation has the best adsorption capacity (6.41 μg g⁻¹ for the first run). The adsorption process can introduce other metallic/toxic elements, but within the Chinese standard. The preparation cost of the H⁺ activation is $1103 ton⁻¹ adsorbent, while the treatment cost is $1.6 ton⁻¹ water. The more accurate parameters in the pseudo-second-order kinetic model and Langmuir model can be calculated by nonlinear method and provided by the error function of the sum of the squares of the errors.

High specific surface area activated carbon prepared from endocarp of Jerivá (Syagrus romanzoffiana) (ACJ) was used for ciprofloxacin (CIP) antibiotic removal from aqueous effluents. The activated carbon (AC) was characterized via scanning electron microscope, Fourier transform infrared spectroscopy, N₂ adsorption/desorption, and pH value at the zero-charge point. Avrami kinetic model was the one that best fit the experimental results in comparison to the pseudo-first-order and pseudo-second-order kinetic models. The equilibrium data obeyed the Liu isotherm equation, showing a maximum adsorption capacity of 335.8 mg g⁻¹ at 40 °C. The calculated thermodynamic parameters indicate that the adsorption of CIP was spontaneous and endothermic at all studied temperatures. Also, the free enthalpy changes (∆H° = 3.34 kJ mol⁻¹) suggested physical adsorption between CIP and ACJ. Simulated effluents were utilized to check the potential of the ACJ for wastewater purification. The highly efficient features enable the activated carbon prepared from endocarp of Jerivá, an attractive carbon adsorbent, to remove ciprofloxacin from wastewaters.

The removal of greenhouse gas (GHG) emission from bitumen used in the construction of flexible pavement by iron-polyphenol complex nanoparticles (Fe-PNPₛ) has been examined in the study. Laboratory studies indicated the removal of carbon dioxide (CO₂) with Fe-PNPₛ is a function of the amount of additive (Fe-PNPₛ). From the experimental data, it was found that the reduction of CO₂ increases with increasing amount of additive up to a dosage of 4% (by weight of bitumen) without severely changing the basic engineering properties of the bitumen. The reduction of GHG is due to the conversion of the CO₂ to a mixture of hydrocarbon in the presence of Fe-PNPₛ. The characterization of the additive by SEM, FTIR, UV, and XRD indicated the formation of the Fe-PNPₛ. The analysis of the basic engineering properties of bitumen such as penetration value, softening point of the bitumen, flash point, fire point, and ductility in the presence of additive as well as without the additive were studied and reflected a noticeable effect in the reduction of the CO₂. The reduction of GHG by Fe-PNPₛ minimizes the environmental impact and saving energy by increasing the yield of hydrocarbons.

The goal of the study was to assess the sorption properties of calcined eggshells (CEs) as a P reactive media filter. The CEs were calcined in a temperature of 900 °C. A double stage test was performed: batch studies (kinetic and equilibrium) and small-scale column experiment. The estimation of optimal mass ratio of CEs for perspective usage was the additional benefit of column experiment. The short kinetic tests showed that 5 min of contact time with solution of initial concentration of 6.020 mgP-PO₄ L⁻¹ is enough to reduce the P-PO₄ in 100%. The equilibrium studies were conducted with P-PO₄ solution of 6.020 to 977.7 mg L⁻¹ with contact time of 30 min. The obtained data was compensated by non-linear regression using the Marquardt algorithm in the Statgraphics Centurion XVI. The eggshell calcined characterized by high sorption capacity (Sₘₐₓ = 72.87 mg g⁻¹) obtained from the Langmuir isotherm model with a good fit (96.77%). To choose the appropriate ratio of a sand filter to eggshells amendment, four small columns were constructed and fed with P-PO₄ solution (Cᵢₙ ≈ 5 mg L⁻¹). The percentage mass (m/m) of CEs in the columns was 0.0 (the reference one); 1.0; 2.5; and 5.0. The unit sorption obtained during 95 days of column experiment was 10.668, 4.277, and 2.286 mg P-PO₄ g⁻¹ for 1.0, 2.5, and 5.0%, respectively. For practical implementation, the most recommended addition seems to be 1% of CEs. It corresponds, e.g., to the mass of 49 kg CEs for septic tank system.