Traditional models of nutrient simulation usually focus on the pollutant sources and precipitation, lacking the quantification of landscape structure. We developed a new prediction model of pollution risks by combing pollutant sources, precipitation, and landscape structure, which was defined as the source-precipitation-landscape model (SPLM). The SPLM was applied to simulate the non-point source (NPS) total nitrogen (TN) exports in one of the largest river basins in China (the Haihe River Basin, HRB). TN concentrations of 35 sampling catchments in 2013 were used to test the accuracy of the SPLM. Simulated results showed that (1) the SPLM had a relative high accuracy in the simulation of NPS TN export and intensity, especially for TN intensity. (2) The mean TN export and intensity of all the 1578 catchments in the HRB were 441.97 t and 2.08 t/km², respectively. (3) The TN export intensities differed greatly among the sub-basins in the HRB, ranging from 0.64 to 6.81 t/km². On the whole, the TN export intensities of the plain sub-basins (e.g., the Tuhaimajia River, the Heilonggang River, and the Beisihe River) were much higher than those of mountainous sub-basins (e.g., the Yongding River, the Beisanhe River, and the Luanhe River). (4) The contributions to TN exports, from high to low, were land use (38.82%), livestock husbandry (33.57%), and rural population (27.61%). Among all the ten pollution sources, arable land (30.87%), rural population (27.61%), and large livestock (17.73%) had the top three contributions to TN exports. This study provides a feasible tool for policymakers and administrators to develop workable management measures for the mitigation of NPS pollution. This SPLM can be extended to other regions in a rapid urbanization context.

Emission utilization permission is an interesting but complex issue regarding the environmental effect of pollution. This paper proposes a mathematical programming–based approach to emission utilization permission taking environmental efficiency into consideration. We use this approach for an environmental efficiency analysis and emission utilization permission (extra emission permission) of selected economic sectors in Iran, namely, agriculture, oil, industry, transportation, and domestic, commercial, and public. We use a gradually decreasing scheme for the process of emission utilization permission to investigate the condition of each sector during the process. The result reveals a vital need of improvement for two sectors, namely, oil sector and transportation sector, at the end of emission utilization permission process that is very tight in terms of emission permission.

In this work, CuWO₄ is prepared and its effect of improving photocatalytic degradation of atrazine by TiO₂ as well as the synergetic mechanism is studied. Results show that the addition of CuWO₄ (50 mg/L) into the reaction system can significantly enhance the efficiency of atrazine degradation, resulting in an increased degradation efficiency of 92.1% after 270 min, which is 1.94 times higher than that of the single TiO₂. As the sintering temperate of CuWO₄ was increased, the degradation efficiency of atrazine increased initially and then deceased after reaching a maximum at 500 °C. The origin of the synergistic effect of TiO₂-CuWO₄ is attributed to the introduction of solid CuWO₄. The photochemical test results indicate that the photogenerated electrons transfer from irradiated TiO₂ to CuWO₄, which is beneficial to the O₂ reduction and H₂O₂ formation in aqueous solution thus promoting the photocatalytic activity of TiO₂. These observations unveil the importance of improving photocatalytic activity of TiO₂ with Cu-bearing semiconductors.

Size-resolved particulate matter (PM) was collected at the Heshan Super-Station in the Pearl River Delta (PRD) region, China, to evaluate their chemical characteristics and potential health risks. The chemical mass closures illustrate that the dominant fraction in coarse (2.5 μm < Dₚ < 10 μm) PM was dust, while organic matter made up a substantial portion of both fine (0.1 < Dₚ < 2.5 μm) and ultra-fine (Dₚ < 0.10 μm) PM fractions. The size distribution of most PM components varied substantially. PM, NO₃⁻, K⁺, Cl⁻, Na⁺ and most of the transition/redox metals displayed bimodal size distributions with the dominant peak at 0.32–0.56 μm plus a small peak at 1.8–3.2 μm. In contrast, unimodal size distributions were found for the rest of the species, such as water-soluble organic carbon (WSOC), NH₄⁺, and SO₄²⁻ and the majority of oxyanion metals with a single peak at 0.32–0.56 μm, and Mg²⁺, Ca²⁺, and dust tracer elements which mainly accumulated in coarse particles. Based on the crustal enrichment factor (CEF) analysis, Cd, Zn, Sb, Sn, As, Pb, Mo, Cu, and Cr primarily originated from anthropogenic activities, while Ti in all size fractions and Sr, Mg, Na, and Fe in fine and ultra-fine particles were mainly emitted from natural sources. The potential health risk assessment of trace metals was performed using the hazard quotient (HQ) and excess lifetime cancer risk (ELCR) indices. Although the adverse health effects of most metals were limited, significant potential carcinogenic risks were found for As and Cr in both fine and coarse particle size fractions, which contributed more than 95% of total ELCR. Therefore, considering that these two elements were mainly emitted from industrial processes, improvements in air quality and health risks in the PRD region can be largely achieved by reducing the emissions of local industrial sources.

The anaerobic biodegradation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was investigated using enrichment cultures from freshwater sediments at two different sites in the region of Halle, central Germany. 2,4,5-T and different organic acids or hydrogen were added as possible electron acceptor and electron donors, respectively. The primary enrichment cultures from Saale river sediment completely degraded 2,4,5-T to 3-chlorophenol (3-CP) (major product) and 3,4-dichlorophenol (3,4-DCP) during a 28-day incubation period. Subcultures showed ether cleavage of 2,4,5-T to 2,4,5-trichlorophenol and its stoichiometric dechlorination to 3-CP only in the presence of butyrate. In contrast, the primary enrichment culture from sediment of Posthorn pond dechlorinated 2,4,5-T to 2,5-dichlorophenoxyacetic acid (2,5-D), which, in the presence of butyrate, was degraded further to products such as 3,4-DCP, 2,5-DCP, and 3CP, indicating ether cleaving activities and subsequent dechlorination steps. Experiments with pure cultures of Dehalococcoides mccartyi and Desulfitobacterium hafniense demonstrated their specific dechlorination steps within the overall 2,4,5-T degradation pathways. The results indicate that the route and efficiency of anaerobic 2,4,5-T degradation in the environment depend heavily on the microorganisms present and the availability of slowly fermentable organic compounds.

A pilot-scale drinking water treatment process for Songhua River, including conventional treatment (coagulation-settlement and rapid sand filtration), ozonation, biological enhanced activated carbon (BEAC) filtration, and chlorination disinfection, was carried out in this study. To investigate the impact of ozonation and BEAC filtration on removing the composition of micropollutants in drinking water, we detected the micropollutant composition from each stage of the treatment process by non-targeted analysis using a GC-MS technique and compared the results between effluents of single BEAC and O₃-BEAC processes. Aromatic compounds and esters could be abated efficiently during single BEAC filtration via biodegradation and adsorption; however, possible metabolic products (i.e., alkenes) were formed by biodegradation. Comparatively, O₃-BEAC process could reduce micropollutants much more significantly than single BEAC process especially for aromatic compounds including substituted benzenes and polycyclic aromatic hydrocarbons (PAHs) without the formation of metabolic products through the coupling effect of oxidation, biodegradation, and adsorption, suggesting that ozonation improved the removal potential of micropollutants in the BEAC process. In addition, conventional and novel chlorinated disinfection by-products were also measured during post-chlorination.

Spatial correlation of pollution of the water resource in Taipei, Taiwan, were examined by analyzing the antibiotic resistance patterns (ARPs) of 96 Escherichia coli colonies, which were isolated from 7 sampling sites in 3 river sections. The ARPs were the growth patterns of isolated E. coli colonies in the medium with seven kinds of antibiotics, including ampicillin, chlortetracycline, erythromycin, oxytetracycline, streptomycin, tetracycline, and salinomycin of different concentrations. The results showed that the survival rate of E. coli decreased with increasing concentration of antibiotics; however, various ARPs under different antibiotics of different concentrations significantly increased both the useful information and complexities. Hierarchical cluster analysis (HCA) and two-stage principal component analysis (PCA) were applied to analyze the spatial correlations and interrelations of distinct ARPs among sampling sites in this study. It was found that the seven sampling sites can be categorized into three groups which may represent three possible pollution characteristics.

The original publication of this paper contains a mistake. The correct image of figure 4 is shown in this paper. The original article has been corrected.

The increased exposure to cadmium (Cd) through environmental pollutants, food and cigarette smoke is a concern worldwide. The association of Cd with impaired learning disabilities led us to hypothesise that cadmium levels in brain tissue could be dose-dependently related to the extent of memory impairment and oxidative stress. In this study, we proposed to study whether cadmium exposure to dams could alter the brain Cd levels, memory parameters, antioxidant enzymes in brain and their gene expression in the F1-F2 generation mice and whether quercetin could modulate this effect. Animals were administered Cd alone and in combination with quercetin for 7 days during their gestation period. Their newborn pups (F1 and F2 mice) were reared until adulthood and were tested for memory using Morris water maze and step-down latency test. The brain tissue of F1 mice was collected. Cd levels were estimated using the atomic absorption spectrophotometer. G-S-transferase (GST) and catalase (CAT) activity were measured and fold increase in their respective gene expression was observed using the RT-PCR method. Cd levels were significantly increased in the brain tissue of animals exposed to Cd but cotreatment with quercetin showed decreased levels in both generations. Memory impairment was observed in animals of F1 generation exposed to Cd and cotreatment with quercetin (100 mg/kg) reversed this effect. Cd exposure significantly enhanced both activity and expression of GST and CAT in the brain tissue of F1 generation mice and quercetin attenuated this effect. In F2 generation, results were variable. GST activity and expression increased with Cd and decreased with quercetin cotreatment. However, CAT activity showed no significant change despite a decrease in gene expression. Quercetin cotreatment enhanced activity as well gene expression in F2 generation. Our study insinuates that Cd levels could act as a predictor of memory impairment and altered enzyme activity and gene expression in brain tissue. Quercetin helped to reduce Cd levels in brain tissue of F1 and F2 generation and modulated the antioxidant system of the cell by affecting expression of antioxidant enzymes at the transcription level.

Bisphenol A (BPA) is an endocrine-disrupting chemical widely used in the production of polycarbonate plastics and epoxy resins, which has been previously linked to diabetes among non-Hispanic populations. As part of a case control study for breast cancer, only controls with BPA information were included in this report. The final sample size comprises 70 self-reported diabetics and 334 non-diabetics. Urinary free bisphenol A (BPA-F) (μg/L) was determined by solid-phase extraction and HPLC/FLD analysis. Logistic regression models were used to evaluate the association between BPA-F and self-reported diabetes. After adjusting by age, urinary BPA-F (4.06–224.53 μg/g creatinine) was associated with diabetes exposure (OR = 1.85; 95% CI 1.04, 3.28) compared with women in the reference category (0.67–4.05 μg/g creatinine). BPA may be an environmental cofactor of diabetes. More studies are needed to confirm this result, especially in Hispanic populations.