In this study, lead (Pb) and antimony (Sb) sorption experiments were conducted to elucidate the mechanisms of Pb and Sb sorption by combined applications using single or combined applications of hydroxyapatite (HAP) and ferrihydrite (FH), to evaluate the contribution of each material in Pb and Sb sorption, and to assess the chemical stability of the sorbed Pb and Sb. In the combined application, isotherms of Pb sorption and Sb sorption were well fitted to Langmuir and Freundlich isotherm models, respectively. The Pb and Sb amounts sorbed in the combined application were the same levels as the summed totals of those sorbed in the single applications, indicating that in the combined application, Pb sorption and Sb sorption were not suppressed. Pb was mainly sorbed on HAP in the combined application, at a 90 % level of the total adsorbed Pb. The HAP and FH contributions to Sb sorption were 32 and 68 % of the total adsorbed Sb, respectively, and Sb was sorbed on each material independently even in the combined application. The percentages of both Pb and Sb dissolved from the sorbed materials in the combined applications at pH 4 and 6 were the same levels as those in the single applications. However, the percentages of Sb dissolved in both combined and single applications were high at an alkaline pH. These results suggest that HAP and FH in a combined application would be useful for simultaneous Pb and Sb immobilization in soil with acidic to neutral pH, but not in soil with an alkaline pH.

Imidacloprid, a water-soluble neonicotinoid pesticide used globally in many applications, has been the subject of numerous studies (1) to determine its sublethal effects (5–100 ppb, LD₅₀∼200 ppb) on honeybees. This study was undertaken to determine, by ELISA assay, the presence of imidacloprid in water sources potentially frequented by honeybees in urban, suburban, and rural environments across the state of Maryland. Eighteen sites (six samples/site) were chosen which spanned diverse habitats including golf courses, nursery, livestock and crop farms, residential neighborhoods, and cityscapes. Hives were present either at or within 0.5 miles of each site. Imidacloprid was quantifiable in 8 % of the samples at sublethal levels (7–131 ppb). They were not clustered at any one type of site. Results for 13 % of the samples were at the threshold of detection; all others were below the detection limit of the assay (<0.2 ppb).

In this study, we investigated the microbiological quality of the small urban Zenne River which flows through the city of Brussels (Belgium). The abundances of faecal indicator bacteria (FIB) (Escherichia coli and intestinal enterococci) revealed high levels of faecal contamination of the Zenne River, especially in Brussels area and downstream from this area where FIB were in the range of what is usually observed in secondary treated wastewaters. The origin of this faecal contamination is mainly attributed to the effluents of the two wastewater treatment plants (WWTPs) located along the river in Brussels. Comparison of the present situation with the 1990s situation (before the implementation of Brussels WWTPs) showed a sharp improvement of the river microbiological quality. This improvement should however be regarded with care as it was also observed that, during rain events, combined sewer overflows (CSO) outfalls were responsible of a strong increase of faecal contamination in the river downstream from Brussels, and such CSO occur frequently in Brussels. Altogether, these results document the variations of the microbiological quality of a sewage-polluted urban river in relation with long-term changes (implementation of WWTP) and the short-term disturbances (CSO).

A methodology to determine economically the spatial concentration distribution of the air pollutants of carbon monoxide (CO), sulphur dioxide (SO₂), nitrogen monoxide (NO), nitrogen dioxide (NO₂), oxides of nitrogen (NOₓ) and traffic rates (TR) is described. It involves the immediate transfer of samples from field to analysers for measurement and a subsequent statistical treatment. The proposed methodology has been applied in Patras using 5 and 50-l Teflon air sample bags, sampling at least 12 to 36-l actual volumes within a 20-min time interval. Totally, 221 pairs of 5-l and 112 single 50-l samples were randomly picked in morning rush hours of working days from 64 locations of a 40.0-km²area during a winter period, when peaks of primary air pollutants usually occur due to high traffic rates and systematic inversions. Measurements were used to statistically calculate spatial average levels approximating 1-h mean concentrations with acceptable mean probable errors less than 25 % for indicative random sampling. The 1-h levels were strongly correlated to the corresponding traffic rates. Iso-concentration diagrams indicated possible zones susceptible to high pollution levels and helped to check the location appropriateness of the existing monitoring stations for (a) fixed urban-background measurements at the Vas. Georgiou A’ Sq., which was ideal, and (b) fixed traffic-oriented measurements, which should be relocated to the Ipsilon Alonion Sq. In addition, data helped to determine other points where indicative measurements should be performed. Data could be very useful for the Patras air quality assessment in conjunction with model predictions and/or objective estimation methods.

The incineration fly ash (IFA), molten fly ash (MFA), thermal power plant fly ash (TPP-FA), and nonferrous metal processing plant ash (MMA) have been screened in terms of the following rare-termed metal contents: B, Ce, Co, Dy, Eu, Ga, Gd, Hf, In, Li, Lu, Mn, Nb, Nd, Ni, Pr, Rb, Sb, Se, Sm, Sr, Ta, Tb, Te, Ti, Tm, V, W, Y, and Yb. The pseudo-potential for recycling of the waste ashes, as compared to the cumulative concentration in the crust (mg kg⁻¹), was determined as follows: MMA > IFA > MFA > TPP-FA. The comparison with the crude ore contents indicates that the MMA is the best resource for reprocessing. The recovery of the target metals using aminopolycarboxylate chelants (APCs) has been attempted at varying experimental conditions and ultrasound-induced environment. A better APC-induced extraction yield can be achieved at 0.10 mol L⁻¹ concentration of chelant, or if the system temperature was maintained between 60 to 80 °C. Nevertheless, the mechanochemical reaction induced by the ultrasound irradiation has been, so far, the better option for rare metal dissolution with chelants as it can be conducted at a minimum chelant concentration (0.01 mol L⁻¹) and at room temperature (25 ± 0.5 °C).

Photocatalytic degradation of bisphenol A (BPA) in waters and wastewaters in the presence of titanium dioxide (TiO₂) was performed under different conditions. Suspensions of the TiO₂ were used to compare the degradation efficiency of BPA (20 mg L⁻¹) in batch and compound parabolic collector (CPC) reactors. A TiO₂ catalyst supported on glass spheres was prepared (sol–gel method) and used in a CPC solar pilot plant for the photodegradation of BPA (100 μg L⁻¹). The influence of OH·, O₂ ·⁻, and h ⁺ on the BPA degradation were evaluated. The radicals OH· and O₂ ·⁻ were proved to be the main species involved on BPA photodegradation. Total organic carbon (TOC) and carboxylic acids were determined to evaluate the BPA mineralization during the photodegradation process. Some toxicological effects of BPA and its photoproducts on Eisenia andrei earthworms were evaluated. The results show that the optimal concentration of suspended TiO₂ to degrade BPA in batch or CPC reactors was 0.1 g L⁻¹. According to biological tests, the BPA LC₅₀ in 24 h for E. andrei was of 1.7 × 10⁻² mg cm⁻². The photocatalytic degradation of BPA mediated by TiO₂ supported on glass spheres suffered strong influence of the water matrix. On real municipal wastewater treatment plant (MWWTP) secondary effluent, 30 % of BPA remains in solution; nevertheless, the method has the enormous advantage since it eliminates the need of catalyst removal step, reducing the cost of treatment.

A comparative study using native garlic peel and mercerized garlic peel as adsorbents for the removal of Pb²⁺has been proposed. Under the optimized pH, contact time, and adsorbent dosage, the adsorption capacity of garlic peel after mercerization was increased 2.1 times and up to 109.05 mg g⁻¹. The equilibrium sorption data for both garlic peels fitted well with Langmuir adsorption isotherm, and the adsorbent–adsorbate kinetics followed pseudo-second-order model. These both garlic peels were characterized by elemental analysis, Fourier transform infrared spectrometry (FT-IR), and scanning electron microscopy, and the results indicated that mercerized garlic peel offers more little pores acted as adsorption sites than native garlic peel and has lower polymerization and crystalline and more accessible functional hydroxyl groups, which resulted in higher adsorption capacity than native garlic peel. The FT-IR and X-ray photoelectron spectroscopy analyses of both garlic peels before and after loaded with Pb²⁺further illustrated that lead was adsorbed on the through chelation between Pb²⁺and O atom existed on the surface of garlic peels. These results described above showed that garlic peel after mercerization can be a more attractive adsorbent due to its faster sorption uptake and higher capacity.

To better assess and understand potential health risk of urban residents exposed to urban street dust, the total concentration, sources, and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in 87 urban street dust samples from Tianjin as a Chinese megacity that has undergone rapid urbanization were investigated. In the meantime, potential sources of PAHs were identified using the principal component analysis (PCA), and the risk of residents’ exposure to PAHs via urban street dust was calculated using the Incremental Lifetime Cancer Risk (ILCR) model. The results showed that the total PAHs (∑PAHs) in urban street dust from Tianjin ranged from 538 μg kg⁻¹to 34.3 mg kg⁻¹, averaging 7.99 mg kg⁻¹. According to PCA, the two to three- and four to six-ring PAHs contributed 10.3 and 89.7 % of ∑PAHs, respectively. The ratio of the sum of major combustion specific compounds (ΣCOMB) / ∑PAHs varied from 0.57 to 0.79, averaging 0.64. The ratio of Ant/(Ant + Phe) varied from 0.05 to 0.41, averaging 0.10; Fla/(Fla + Pyr) from 0.40 to 0.68, averaging 0.60; BaA/(BaA + Chry) from 0.29 to 0.51, averaging 0.38; and IcdP/(IcdP + BghiP) from 0.07 to 0.37, averaging 0.22. The biomass combustion, coal combustion, and traffic emission were the main sources of PAHs in urban street dust with the similar proportion. According to the ILCR model, the total cancer risk for children and adults was up to 2.55 × 10⁻⁵and 9.33 × 10⁻⁵, respectively.