The exposures of pharmaceutical antibiotics in water solution caused potential risks for ecological environment and human health. In the present study, porous covalent triazine frameworks (CTFs) were synthesized and the adsorption behavior of sulfamethoxazole (SMX) and tylosin (TL) was investigated. The CTFs were characterized by X-ray diffraction, transform infrared and N2 adsorption/desorption. Sulfamethoxazole displayed much stronger adsorption than tylosin on microporous CTF-1 adsorbent due to the pore-filling effect. While the adsorption of bulky tylosin on microporous CTF-1 was suppressed because of the size exclusion effect. Additionally, the porous CTFDCBP showed stronger adsorption affinity and faster adsorption kinetics than other porous adsorbents, which was attributed to wide pore size distribution and open pore structure. Findings in this study highlight the potential of using porous CTFs as a potential adsorbent to eliminate antibiotics from water, especially for selective adsorption of bulky molecular pollutant.

In this study, the feasibility of employing an integrated bioremediation approach in contaminated river sediment was evaluated. Sequential addition of co-substrate (acetate) and electron acceptor (NO3−) in a two-phase treatment was capable of effectively removing polycyclic aromatic hydrocarbons (PAHs) in river sediment. The residual concentration of total PAHs decreased to far below effect range low (ERL) value within 91 days of incubation, at which concentration it could rarely pose biological impairment. The biodegradation of high molecular weight PAHs were found to be mainly occurred in the sediment treated with co-substrates (i.e. acetate or methanol), in which acetate was found to be more suitable for PAHs degradation. The role of co-substrates in influencing PAHs biodegradation was tentatively discussed herein. Additionally, the sediment odorous problem and blackish appearance were intensively addressed by NO3− injection. The results of this study demonstrated that integrating two or more approaches/processes would be a helpful option in sediment remediation. It can lead to a more effective remediation performance, handle multiple contamination issues, as well as mitigate environmental risks caused by one of the single methods.

Cigarette smoke-triggered inflammatory cascades and consequent tissue damage are the main causes of chronic obstructive pulmonary disease (COPD). There is no effective therapy and the key mediators of COPD are not identified due to the lack of translational animal models with complex characterization. This integrative chronic study investigated cardiopulmonary pathophysiological alterations and mechanisms with functional, morphological and biochemical techniques in a 6-month-long cigarette smoke exposure mouse model. Some respiratory alterations characteristic of emphysema (decreased airway resistance: Rl; end-expiratory work and pause: EEW, EEP; expiration time: Te; increased tidal mid-expiratory flow: EF50) were detected in anaesthetized C57BL/6 mice, unrestrained plethysmography did not show changes. Typical histopathological signs were peribronchial/perivascular (PB/PV) edema at month 1, neutrophil/macrophage infiltration at month 2, interstitial leukocyte accumulation at months 3–4, and emphysema/atelectasis at months 5–6 quantified by mean linear intercept measurement. Emphysema was proven by micro-CT quantification. Leukocyte number in the bronchoalveolar lavage at month 2 and lung matrix metalloproteinases-2 and 9 (MMP-2/MMP-9) activities in months 5–6 significantly increased. Smoking triggered complex cytokine profile change in the lung with one characteristic inflammatory peak of C5a, interleukin-1α and its receptor antagonist (IL-1α, IL-1ra), monokine induced by gamma interferon (MIG), macrophage colony-stimulating factor (M-CSF), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) at months 2–3, and another peak of interferon-γ (IFN-γ), IL-4, 7, 13, 17, 27 related to tissue destruction. Transient systolic and diastolic ventricular dysfunction developed after 1–2 months shown by significantly decreased ejection fraction (EF%) and deceleration time, respectively. These parameters together with the tricuspid annular plane systolic excursion (TAPSE) decreased again after 5–6 months. Soluble intercellular adhesion molecule-1 (sICAM-1) significantly increased in the heart homogenates at month 6, while other inflammatory cytokines were undetectable. This is the first study demonstrating smoking duration-dependent, complex cardiopulmonary alterations characteristic to COPD, in which inflammatory cytokine cascades and MMP-2/9 might be responsible for pulmonary destruction and sICAM-1 for heart dysfunction.

Silicon (Si) may decrease the uptake and accumulation of arsenic (As) in rice. However, the effects of Si/As ratios in growth medium on arsenic uptake, arsenite efflux to the external medium and translocation of arsenite in rice are currently unclear. Rice seedlings (Oryza sativa L.) were exposed to nutrient solutions with 10 μM arsenite [As(III)] or 10 μM arsenate [As(V)] to explore the influence of different silicic acid concentrations (0, 10, 100, 1000 μM) on arsenic uptake and translocation of arsenite with or without 91 μM phosphate for 24 h. Arsenic speciation was determined in nutrient solutions, roots, and shoots. In the arsenite treatments, different Si/As ratios (1:1, 10:1, 100:1) did not affect As(III) uptake by rice roots, however they did inhibit translocation of As(III) from roots to shoots significantly (P < 0.001) in the absence of P. In the arsenate treatments, a Si/As ratio of 100:1 significantly decreased As(V) uptake and As(III) efflux compared with the control (Si/As at 0:1), accounting for decreases of 27.4% and 15.1% for –P treatment and 47.8% and 61.1% for + P treatment, respectively. As(III) is the predominant species of arsenic in rice roots and shoots. A Si/As ratio of 100:1 reduced As(III) translocation from roots to shoots markedly without phosphate. When phosphate was supplied, As(III) translocation from roots to shoots was significantly inhibited by Si/As ratios of 10:1 and 100:1. The results indicated that in the presence of P, different silicic acid concentrations did not impact arsenite uptake and transport in rice when arsenite was supplied. However, a Si/As ratio of 100:1 inhibited As(V) uptake, as well as As(III) efflux and translocation from roots to shoots when arsenate was supplied.

Biomagnification of some persistent organic pollutants (POPs) has been found in marine and freshwater food chains; however, due to the relatively short food chains in high-altitude alpine lakes, whether trophic transfer would result in the biomagnification of POPs is not clear. The transfer of various POPs, including organochlorine pesticides and polychlorinated biphenyls (PCBs), along the aquatic food chain in Nam Co Lake (4700 m), in the central Tibetan Plateau, was studied. The POPs levels in the water, sediment and biota [plankton, invertebrates and fish (Gymnocypris namensis)] of Nam Co were generally low, with concentrations comparable to those reported for the remote Arctic. The composition profiles of POPs in the fish were different from that in the water, but similar to their food. DDEs, DDDs, PCB 138, 153 and 180 displayed significant positive correlations with trophic levels, with trophic magnification factors (TMFs) ranged between 1.5 and 4.2, implying these chemicals can undergo final biomagnification along food chain. A fugacity-based dynamic bioaccumulation model was applied to the fish with localized parameters, by which the simulated concentrations were comparable to the measured data. Modeling results showed that most compounds underwent net gill loss and net gut uptake; only when the net result of the combined gut and gill fluxes would be positive, bioaccumulation could eventually occur. The net accumulation flux increased with fish age, which was caused by the continuous increase of gut uptake by aged fish. Due to the oligotrophic condition, efficient food absorption is likely the key factor that influences the gut POPs uptake. Long residence times with half-lives up to two decades were found for the higher chlorinated PCBs in Gymnocypris namensis.

Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; i.e., ambient 24-h PM2.5 concentrations have exceeded 150 μg/m3 in the winter season and the top concentration reached 372 μg/m3 in 2010. Annual mean concentrations have decreased but are still above 30 μg/m3. For the very first time, a molecular marker source apportionment of ambient organic carbon (OC) and PM2.5 was conducted in Temuco. Primary resolved sources for PM2.5 were wood smoke (37.5%), coal combustion (4.4%), diesel vehicles (3.3%), dust (2.2%) and vegetative detritus (0.7%). Secondary inorganic PM2.5 (sulfates, nitrates and ammonium) contributed 4.8% and unresolved organic aerosols (generated from volatile emissions from incomplete wood combustion), including secondary organic aerosols, contributed 47.1%. Adding the contributions of unresolved organic aerosols to those from primary wood smoke implies that wood burning is responsible for 84.6% of the ambient PM2.5 in Temuco. This predominance of wood smoke is ultimately due to widespread poverty and a lack of efficient household heating methods. The government has been implementing emission abatement policies but achieving compliance with ambient air quality standards for PM2.5 in southern Chile remains a challenge.

Exposure experiments were conducted to evaluate the influence of dissolved organic matter (DOM) on the toxicity of ZnO-NPs (10–30 nm) and dissolved Zn at sub-lethal doses (50 and 5 ppm, respectively) to zebrafish (Danio rerio). Humic acid, alginic acid, bovine serum albumin and various natural DOM isolated from rivers as the Milwaukee River-WI (NOMW), Yukon River-AK (NOMA) and Suwannee River-GA DOM (NOMS) were used to represent humic substances (HA), carbohydrates (CHO), proteins (PTN), and natural organic matter (NOM), respectively. Initial experiments were carried out to confirm the toxic effect of ZnO-NPs at 50 ppm, followed by mitigation experiments with different types and concentrations of DOM (0.4–40 mg-C/L). Compared to 0% hatch of 50 ppm ZnO-NPs exposed embryos at 72 h post fertilization (hpf), NOMS, NOMW and HA had the best mitigative effects on hatching (53–65%), followed by NOMA, CHO and PTN (19–35%); demonstrating that the mitigation effects on ZnO-NPs toxicity were related to DOM's quantity and composition. At 96 hpf, 20% of embryos exposed to 50 ppm ZnO-NPs hatched, 100% of embryos reared in embryo medium hatched, and close to 100% of the embryos hatched upon mitigation, except for those mitigated with PTN which had less effect. Dissolved Zn (5 ppm) also exhibited the same toxicity on embryos as ZnO-NPs (50 ppm). However, in the presence of HA, NOM and CHO, the hatching rates at 72 and 96 hpf increased significantly compared to 5% hatch without DOM. The overall mitigation effects produced by DOM followed the order of HA ≥ NOMS > NOM (A&W) > CHO >> PTN, although specific mitigation effects varied with DOM concentration and functionalities. Our results also indicate that the toxicity of ZnO-NPs to embryos was mostly derived from NPs although dissolved Zn released from ZnO-NPs also interacted with embryos, affecting hatching, but to a less extent.

Over the past decade, studies have shown that exposure to endocrine disrupting chemicals (EDCs) can cause gonadal intersex in fish. Smallmouth bass (Micropterus dolomieu) males appear to be highly susceptible to developing testicular oocytes (TO), the most prevalent form of gonadal intersex, as observed in various areas across the U.S. In this study, prevalence and severity of TO was quantified for smallmouth bass sampled from the St. Joseph River in northern Indiana, intersex biomarkers were developed, and association between TO prevalence and organic contaminants were explored. At some sites, TO prevalence reached maximum levels before decreasing significantly after the spawning season. We examined the relationship between TO presence and expression of gonadal and liver genes involved in sex differentiation and reproductive functions (esr1, esr2, foxl2, fshr, cyp19a, star, lhr and vtg). We found that vitellogenin (vtg) transcript levels were significantly higher in the liver of males with TO, but only when sampled during the spawning season. Further, we identified a positive correlation between plasma VTG levels and vtg transcript levels, suggesting its use as a non-destructive biomarker of intersex in this species. Finally, we evaluated 43 contaminants in surface water at representative sites using passive sampling to look for contaminants with possible links to the observed intersex prevalence. No quantifiable levels of estrogens or other commonly agreed upon EDCs such as the bisphenols were observed in our contaminant assessment; however, we did find high levels of herbicides as well as consistent quantifiable levels of PFOS, PFOA, and triclosan in the watershed where high TO prevalence was exhibited. Our findings suggest that the observed TO prevalence may be the result of exposures to mixtures of nonsteroidal EDCs.

Substituted phenylamines (SPAs) are incorporated into a variety of consumer products (e.g., polymers, lubricants) in order to increase the lifespan of the products by acting as a primary antioxidant. Based on their physicochemical properties, if SPAs were to enter the aquatic environment, they would likely partition into sediment. No studies to date have investigated the effect of sediment-associated SPAs on aquatic organisms. The current study examined the effect of four SPAs (diphenylamine (DPA); N-phenyl-1-napthylamine (PNA); N-(1,3-dimethylbutyl)-N’-phenyl-1,4-phenylenediamine (DPPDA); 4,4’-methylene-bis[N-sec-butylaniline] (MBA)) on three different life stages of the freshwater mussel, Lampsilis siliquoidea. The viability of larvae (glochidia) of L. siliquoidea and Lampsilis fasciola was assessed after 48 h of exposure to SPAs in water. The 48-h EC50s for glochidia viability of L. siliquoidea were 5951, 606, 439, and 258 μg/L for DPA, PNA, DPPDA, and MBA, respectively, and 7946, 591, 137, and 47 μg/L, respectively, for L. fasciola. Juvenile (7–15 months) and adult L. siliquoidea were exposed to sediment-associated SPAs for 28 d. LC50s for juvenile mussels were 18, 55, 62, and 109 μg/g dry weight (dw) of sediment for DPA, PNA, DPPDA, and MBA, respectively. Adult mussels were exposed to sub-lethal concentrations of sediment-associated SPAs in order to investigate reactive oxygen species (ROS), lipid peroxidation and total glutathione in the gill, gonad, and digestive gland tissue, and viability and DNA damage in hemocytes. No significant concentration-dependent trend in any of these biochemical and cellular endpoints relative to the concentration of sediment-associated SPAs was observed in any tissues. Investigations into the concentration of SPAs in the aquatic environment are required before a conclusion can be made on whether these compounds pose a hazard to the different life stages of freshwater mussels.

Sludge dewatering is an important process in municipal wastewater treatment and critically influences the subsequent transportation and disposal. Thermal treatment coupled with other chemical processes has been widely used to improve sludge dewaterability. However, information about the response of sludge extracellular polymeric substances (EPS) to thermal treatment and its role in sludge dewatering is still limited. In this work, the effects of thermal treatment on anaerobic and aerobic sludges were investigated with an emphasis on the colloid properties of released EPS in sludge dewatering process. The results indicate that sludge dewaterability became deteriorated with the increased temperature in the range of 30–170 °C, which was ascribed to the disintegration of sludge flocs and change of EPS characteristics. Disintegrated sludge induced the release of the negatively charged EPS, resulting in the weakened bridging interaction and lower compactness. After thermal treatment, the EPS with a higher average molecular weight and stretched coil configuration retained more water. In addition, difference in dewaterability between anaerobic and aerobic sludges was found to be attributed to their different contents and structures of EPS components. These results provide an insight into thermal-dependent sludge dewatering process and are useful to facilitate water-sludge separation.