Metals are indicators of contamination by anthropic activities, such as road traffic. To assess the extent of the metal contamination, more comprehensive studies analyzing different environmental matrices, such as soils, dust, and plants, collected in different sites that are potential sources of these pollutants along the highways, must be prioritized. Samples of soils, dust, and plants were collected alongside the highways of Brazil at 20 sites selected in strategic locations of metal accumulation (Cr, Pb, Zn, As, and Sb) or different situations of the high ways during two rain conditions (wet and dry weeks of sampling): nearby gutters and water supplies, tolls, petrol stations, a federal road police station, and areas associated with agriculture (yearly culture planting upstream of the highway). The geoaccumulation index (metal concentration in the sample of interest/background) varied from 0 to 6, and the decreasing order of contamination by metals during the wet and dry periods were, respectively: Zn > As > Pb = Sb > Cr and Zn > As > Pb > Cr > Sb. In the soils near the highways, the highest concentrations of metals were as follows (mg kg⁻¹): As = 15.6, Cr = 81.9, Pb = 39.7, Sb = 5.0, and Zn = 379.3. The highest amounts of these elements in the most superficial layer in soils indicated their addition through atmospheric emissions. The most prominent metal was Sb, whose concentration was greater than the quality limits for soils. The concentration of Sb in soils was higher in the wet week than in the dry week. The emissions from road traffic promoted the increase in metals in the dust on the track, especially Zn and Pb. The highest metal concentrations in grasses (Brachiaria) were found in the roots, except for Sb and Zn, which suggests leaf absorption of atmospheric deposition. Metal contamination was widespread in all studied matrices along the highways.

This study uses the tropospheric ozone data derived from combined observations of Ozone Monitoring Instrument/Microwave Limb Sounder instruments by using the tropospheric ozone residual method. The main objective was to study the spatial distribution and temporal evolution in the troposphere ozone columns over Pakistan during the time period of 2004 to 2014. Results showed an overall increase of 3.2 ± 1.1 DU in tropospheric ozone columns over Pakistan. Spatial distribution showed enhanced ozone columns in the Punjab and southern Sindh consistent to high population, urbanization, and extensive anthropogenic activities, and exhibited statistically significant temporal increase. Seasonal variations in tropospheric ozone columns are driven by various factors such as seasonality in UV-B fluxes, seasonality in ozone precursor gases such as NOₓ and volatile organic compounds (caused by temperature dependent biogenic emission) and agricultural fire activities in Pakistan. A strong correlation of 96% (r = 0.96) was found between fire events and tropospheric ozone columns in Pakistan.

Trees in urban areas are important for their ecological functions in addition to their esthetic characteristics. Trees provide positive effects on urban microclimate by canopy, reflection, and transpiration activities; therefore, they help to decline formation of heat island. The objective of this study was to determine thermal effects of 15 different tree types: 4 coniferous and 11 deciduous species commonly found in the city of Erzurum located at the northeastern part of Turkey. The relationships between sky view factor and surface temperature regarding the differences in leaf density and tree species. In August 2016, the surface temperature of trees was measured using a thermal camera at 10:00 am and 4:00 pm hours. Sky view factor (SVF) was obtained by fisheye photos and physiologically characteristics of trees were determined. In all trees while the surface temperature was 20.1 °C at 10:00 am, it was 23.4 °C at 4:00 pm. Among the deciduous tree species, Betula verrucosa Ehrh. and Robinia pseudoacacia “Umbracuifera” had the lowest surface temperature; however, Abies concolor (Gord. & Glen.) had the lowest surface temperature among the coniferous tree species. The results indicated that the surface temperatures of different tree species varied considerably, and the SVF value had a significant effect on tree surface temperatures. However, it was obtained that the leaf types had no statistically significant effect on tree surface temperature.

All locust epiphytic bacteria were screened and a total of 62 epiphytic bacteria were obtained from samples of Acrida cinerea. Via phylogenetic analysis, the 62 epiphytic bacteria were allocated to 27 genera, 18 families, 13 orders, six classes, and four phylums. Then, cyhalothrin degradation experiments were conducted, and the 10 strains that degraded more than 30% cyhalothrin and Paracoccus acridae SCU-M53 showed the highest cyhalothrin degradation rate of 70.5%. Furthermore, Paracoccus acridae SCU-M53 was selected for optimal cyhalothrin biodegradation conditions via the response surface method (Design-Expert). Under the optimum conditions (28 °C, 75 mg/L, and 180 rpm), the cyhalothrin degradation rate reached 79.84% after 2 days. This suggests the possibility that isolating biodegradation cyhalothrin strains from Acrida cinerea is feasible.

This study quantified the complex stability constants of sulfamethazine (SMT) with cadmium (Cd²⁺) and lead (Pb²⁺) under different pH conditions. The UV-Vis spectrophotometer was used for acquiring the complexation data. Results showed that the complex stability constants of SMT with cadmium (Cd²⁺) and lead (Pb²⁺) increased as a function of the solution pH. In the investigated pH range, Cd²⁺ showed stronger complex affinity with SMT than Pb²⁺. It appeared that cation-π interactions might dominate the complex between SMT with Pb²⁺ and Cd²⁺ at acid environment, and the covalent bonding might play a major role at neutral environment. Batch adsorption equilibrium experiment showed that the sorption capacity of Cd²⁺ on goethite increased from 3.83 to 7.64 mg/g along with the addition of 1 mg/L SMT, indicating SMT can impede the transportation of Cd. In general, this study worked out the complexation constants and clarified the complexation mechanism between SMT with lead and cadmium, while sorption experiment indicated that sorption of Cd onto goethite was enhanced with SMT.

Seawater intrusion promotes the salinity of groundwater, and it poses a great environmental impact on a global scale. The present study was carried out to determine the hydrogeochemical processes and influence of seawater intrusion in the coastal aquifers using geophysical, geochemical, and stable isotope techniques. The true resistivity value ranges from 0.5 to 8008.5 Ω-m which has been measured using vertical electrical sounding (VES) based on the Schlumberger method. About 33 groundwater samples were collected during post-monsoon (POM) (January 2012) and pre-monsoon (PRM) (June 2012) seasons from open and bore wells and were analyzed for major ions and stable isotopes. EC, Na⁺, and Cl⁻ were high in groundwater of wells near salt pan, the Buckingham Canal, and backwater regions. Around 45% of the groundwater of this study area is of Na⁺-Cl⁻ type due to salinisation. Reverse ion exchange and silicate weathering are the dominant processes controlling the geochemistry of groundwater. Saturation indexes (SI) of halite (SIₕₐₗᵢₜₑ) and gypsum (SIgyₚₛᵤₘ) versus sulfate show an increasing trend line from > 0 to < 0, which implies higher dissolution of minerals and hints increasing salinization during both seasons. The value of Na⁺/Cl⁻ ranges between 0.7 and 2.4 (POM) and from 0.6 to 2.8 (PRM). The molar ratio suggested that around 25% of the groundwater samples are with values similar to those of seawater. Further, the groundwater is also affected by saline backwater, salt pan activities, and Buckingham Canal. Some locations are also are affected by anthropogenic, agricultural activities and geochemical processes. Heavy stable isotopes were found to be dominant in the coastal region due to seawater intrusion. Stable isotopes of δ¹⁸O range from − 5.6 to − 2.9‰ during both periods. About 201 km² of this area is affected by salinization. It is necessary to reduce pumping and plan for physical barriers to create freshwater ridges for controling the seawater intrusion.

Acidic herbicides are used to control broad-leaved weeds. They are stable, water-soluble, and with low binding to soil are found frequently in surface waters, often at concentrations above the EU Drinking Water Directive limit of 0.10 μg L⁻¹. This presents a problem when such waters are abstracted for potable supplies. Understanding their sources, transport and fate in river catchments is important. We developed a new Chemcatcher® passive sampler, comprising a 3M Empore™ anion-exchange disk overlaid with a polyethersulphone membrane, for monitoring acidic herbicides (2,4-D, dicamba, dichlorprop, fluroxypyr, MCPA, MCPB, mecoprop, tricolpyr). Sampler uptake rates (Rₛ = 0.044–0.113 L day⁻¹) were measured in the laboratory. Two field trials using the Chemcatcher® were undertaken in the River Exe catchment, UK. Time-weighted average (TWA) concentrations of the herbicides obtained using the Chemcatcher® were compared with concentrations measured in spot samples of water. The two techniques gave complimentary monitoring data, with the samplers being able to measure stochastic inputs of MCPA and mecoprop occurring in field trial 1. Chemcatcher® detected a large input of MCPA not found by spot sampling during field trial 2. Devices also detected other pesticides and pharmaceuticals with acidic properties. Information obtained using the Chemcatcher® can be used to develop improved risk assessments and catchment management plans and to assess the effectiveness of any mitigation and remediation strategies.

Organochlorine (OCs) concentrations were measured in two fish species, Mullus barbatus and Diplodus annularis, collected from Izmir Gulf during 2009–2012 in order to explain the status of these contaminants in edible fish. No data is available on the levels of organochlorines in marine organism from Izmir Gulf. In both fish species from the study area, Aroclors were determined in higher concentrations than organochlorine pesticides (OCPs). Maximum concentrations of OCPs and PCBs measured in the edible part of D. annularis were 45–165 and 530–1591 ng g⁻¹ lipid weight (lw), respectively. DDTs (sum of DDT and metabolites) and cyclodienes ranged from 4–56 to 16–110 ng g⁻¹ lw, respectively. The levels of DDTs measured in the present study were generally comparable or lower than those found in studies from other Mediterranean and non-Mediterranean regions. The potential risks for fish consumers were assessed. Although the estimated daily intake (EDI) for DDTs, heptachlor, and drins through the sampled fish species by Izmir inhabitants was quite lower than the ADI (acceptable daily intake) established by the FAO/WHO, EDI for Aroclor 1254 was close to the ADI value of 20 ng g⁻¹ recommended by the IPCS (2000).

Eutrophication in lakes and rivers caused by the nitrogen (N) and phosphorus (P) is urgent since the accumulation of N and P can possibly cause the algal blooms and devastation to the water ecological system. The removal of N and P in the landscape water would be an efficient way to reduce the enrichment of nutrition before they reach the large water system. The N and P removal efficiency of PFS as well as the synergistic effect of natural rocks (four types of purple parent rock (J₃p, J₂s, T₁f, and J₃s)) as promoter was examined under laboratory conditions. The results indicated that TN and TP removal efficiency of the composite coagulant was significantly better than that of PFS or purple parent rock alone and J₃p + PFS (combination of PFS and J₃p purple parent rock) showed the best TN and TP removal efficiency. TN and TP removal efficiency of 53.53 and 86.48%, respectively, were achieved with coagulant dosage of 6 g L⁻¹ J₃p and 30 mg L⁻¹ PFS, water temperature of 30 °C, and wastewater initial pH of 9. In addition, Fourier transformed infrared (FTIR) spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis (EDX), and the water quality index analysis revealed that the treatment of TN and TP by using J₃p + PFS was taking advantage of the flocculation function of PFS and the adsorption function of PFS and J₃p. In which, the flocculation mechanism was mainly charge neutralization; adsorption mechanism was mainly physical and chemical adsorption.

The spectral characteristics, spatial distribution, and bioavailability of water-soluble organic matter (WSOM) in suspended solids and surface sediments of Lihu Lake, China, were investigated through excitation–emission matrix spectra and parallel factor analysis. The average content of dissolved organic carbon (DOC) in the sediments reached 643.28 ± 58.34 mg C/kg and that in suspended solids was 714.87 ± 69.24 mg C/kg. The fluorescence intensity of WSOM totaled 90.87 ± 5.65 and 115.42 ± 8.02 RU/g for the sediments and suspended solids, respectively. The DOC and fluorescence intensity of the WSOM showed an increasing trend moving from the west to the east of the lake. The WSOM in sediments and suspended solids contained two humic-like (C1 and C2) and one tryptophan-like (C3) components. These components had different fluorescent peaks and relative proportions. In the sediments, the relative proportions of C1, C2, and C3 were 33.71% ± 0.71, 26.83% ± 0.68, and 39.50% ± 0.71%, respectively. Meanwhile, C1 (35.77 ± 0.84%), C2 (34.07 ± 0.61%), and C3 (30.16 ± 0.75%) had similar relative percentages in suspended solids. The sediments had a lower humification index (3.02 ± 0.08) than the suspended solids (4.04 ± 0.15). Exchangeable nitrogen for the sediments and suspended solids was dominated by exchangeable ammonium nitrogen and soluble organic nitrogen, respectively. WSOM plays an important role in migration and transformation of nitrogen in sediments and suspended solids. The sediment-derived WSOM exhibited higher lability and biological activity than did the suspended solid-derived WSOM. The relative ratio of the intensity of protein-like fluorescent component to that of the humic-like one can be used as a reference index to evaluate the lability and biological activity of WSOM in sediments and suspended solids.