Microbiome reengineering by four environmental factors for the rapid biodegradation of trichloroethylene.

Trichloroethylene (TCE) was once a widely applied industrial solvent, but is now an infamous contaminant in groundwater. Although anaerobic reductive dechlorination is considered a greener remediation approach, the accumulation of toxic intermediates, such as vinyl chloride (VC), and a longer remediation period are highly concerning. Biostimulation and bioaugmentation have been developed to solve these problems. The former method may not be effective, and the latter may introduce foreign genes. Here, we propose a new approach by applying environmental stresses to reshape the indigenous microbiome. In this study, by using the Taguchi method, the effects of heating, pH, salinity, and desiccation were systematically examined. The optimum conditions were defined as 50 °C, pH 9, 3.50% salinity (w/v), and 21% volumetric water content (θW). The top performing group, G7, can complete the conversion of 11.81 mg/L TCE into ethene in 3.0 days with a 1.23% abundance of Dehalococcoides mccartyi 195 (Dhc 195). Redundancy analysis confirmed that temperature and salinity were the predominant factors in reorganizing the microbiomes. The microbiome structure and its effectiveness can last for at least 90 d. The repetitive selection conditions and sustainable degradation capability strongly supported that microbiome reengineering is feasible for the rapid bioremediation of TCE-contaminated environmental matrices.

Infodemiology of Influenza-like Illness: Utilizing Google Trends' Big Data for Epidemic Surveillance.

Background: Influenza-like illness (ILI) encompasses symptoms similar to influenza, affecting population health. Surveillance, including Google Trends (GT), offers insights into epidemic patterns. Methods: This study used multiple regression models to analyze the correlation between ILI incidents, GT keyword searches, and climate variables during influenza outbreaks. It compared the predictive capabilities of time-series and deep learning models against ILI emergency incidents. Results: The GT searches for "fever" and "cough" were significantly associated with ILI cases (p < 0.05). Temperature had a more substantial impact on ILI incidence than humidity. Among the tested models, ARIMA provided the best predictive power. Conclusions: GT and climate data can forecast ILI trends, aiding governmental decision making. Temperature is a crucial predictor, and ARIMA models excel in forecasting ILI incidences.

Hierarchical cluster analysis of polychlorinated dioxins and furans in Michigan, USA, soils: evaluation of industrial and background congener profiles.

As part of the University of Michigan Dioxin Exposure Study, soil samples were collected from 766 residential properties near the Tittabawassee River between Midland and Saginaw; near the Dow Chemical Facility in Midland; and, for comparison, in the other areas of Midland and Saginaw Counties and in Jackson and Calhoun Counties, all located in the state of Michigan, USA. A total of 2,081 soil samples were analyzed for 17 polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). In order to better understand the distribution and sources of the PCDD/F congeners in the study area, hierarchical cluster analysis (HCA) was used to statistically group samples with similar congener patterns. The analysis yielded a total of 13 clusters, including: 3 clusters among the soils impacted by contamination present in the Tittabawassee River sediments, a cluster comprised mainly of samples collected within the depositional area of the Dow incinerator complex, a small cluster of samples with elevated 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD), and several clusters exhibiting background patterns. The clusters related to the Tittabawassee River floodplain contamination all contained elevated PCDF levels and were differentiated from one another primarily by their relative concentrations of higher-chlorinated PCDDs, a difference likely related to both extent and timing of impacts from Tittabawassee sediments. The background clusters appear to be related to combustion processes and are differentiated, in part, by their relative fractions of TCDD. Thus, HCA was useful for identifying congener profile characteristics in both contaminated and background soil samples.

Effective removal of Aroclor 1254 and hexachlorobenzene in river sediments by coupling in situ phase-inversion emulsification with biological reductive dechlorination.

River sediment contamination is a critical environmental problem. Concentrations of certain hydrophobic organic compounds (HOCs) in sediments in Taiwan are ranked at the top in the world. In this study, we proposed a novel in situ phase-inversion emulsification and biological reductive dechlorination (ISPIE/BiRD) method that integrates (1) heating contaminated sediments by hot water-in-oil emulsion to increase the contact between hydrophobic organic contaminants (HOCs), to accelerate the mass transfer between two phases, and to select heat-tolerant hydrogen-producing bacteria, (2) ISPIE forming oil-in-water emulsion to enhance recovery of HOCs by pushing cool water and nutrient buffer through the sediment column, and (3) subsequent BiRD using residual emulsion in sediment. Aroclor 1254 and hexachlorobenzene (HCB) were selected due to significantly higher human health and ecological risks in sediments. Batch biological dechlorination tests were conducted using an L9(34) orthogonal table according to the Taguchi method. The results showed that significant controlling factors for biological dechlorination were temperature and emulsion concentration. A single operation of ISPIE can achieve the removal of Aroclor 1254 and HCB at as high as 58.2% and 56.5%, respectively. Column study on BiRD further removed about 30% of the residual Aroclor 1254 and HCB at the upper and middle sections of the sediment cores in 35 days. These results supported that ISPIE/BiRD is feasible for HOC-contaminated sediments remediation.

Persistent organic pollutant lindane degradation by alkaline cold-brew green tea.

The environmental persistence of hazardous organochlorine pesticides (OCPs) such as lindane has resulted in a need for the development of reliable remediation technology for the removal of OCPs. Green tea extract/Fe2+ under alkaline conditions is a potential green chemistry technology proven to be effective in reducing lindane. This study investigated the feasibility of directly using green tea leaves (GT-leaf) or cold-brew tea solution (GT-sol) with Fe2+ additives at (bi)carbonate buffered pH 10 to treat lindane in the aqueous phase. The polyphenol was gradually released in the GT-leaf system and reached a similar concentration as that in the GT-sol system (∼800 mg L-1 at pH 6.5). Based on the analytical results of lindane degradation byproducts, it was recognized that the reductive mechanism acts as a major pathway and alkaline hydrolysis is a minor pathway. However, physical adsorption rapidly removes lindane from the GT-leaf system. A comprehensive evaluation of lindane degradation, chlorobenzene formation, degradation kinetics, and chloride liberation were conducted for the alkaline GT-sol/Fe2+ system. The nonlinear simulations of the models developed showed good fits, with R2 > 0.96. This study highlights the potential for GT-sol/Fe2+ systems to remediate OCPs contamination.

A Method to Prepare Magnetic Nanosilicate Platelets for Effective Removal of Microcystis aeruginosa and Microcystin-LR.

Algal toxin is a unique type of toxin generated with harmful algal blooms in water bodies. This phenomenon is worsened by eutrophication caused by excessive discharge of nutrients into surface water bodies. Since algal toxins are hard to remove after they enter the water treatment processes, an efficient method is required to inhibit the growth of algal cells, to settle the cells at the bottom of the water body and to removes the toxin from the water. We report an efficient way to prepare a novel nanohybrid material, i.e., magnetic nanosilicate platelet (MNSP), and its effects on the removal of microcystin toxins as well as the cells of Microcystis aeruginosa. MNSP was fabricated by a special treatment of a clay mineral, montmorillonite, and then its surface was decorated with magnetite nanoparticles by in situ synthesis. The nanohybrid can efficiently inhibit the growth of M. aeruginosa-a typical species that can generate one of the most notorious algal toxins, i.e., microcystins. Algal cells can be settled with minimal 500 ppm MNSP, and the turbidity can be reduced by more than 67%. The removal of microcystin-LR (MC-LR) was as high as 99.39% at an concentration of 100 ppm, while the pristine nanosilicate platelet could only remove 36.84% at the same dosage.

Effective removal of Microcystis aeruginosa and microcystin-LR using nanosilicate platelets.

Drinking water safety has been threatened by increasing harmful algal blooms (HABs) in water sources. HABs are closely associated with eutrophication in freshwater lakes, e.g. Lake Tai in China, and marine environments as well, e.g. Baltic Sea in Europe. Among all HABs, Microcystis aeruginosa attracted much attention due to its easy proliferation and potent toxins, microcystins. Most of the current control technologies can result in immediate release of microcystins which are hard to remove by drinking water treatment processes. Here we propose to simultaneously remove M. aeruginosa and its toxin, microcystin-LR (MC-LR), using nanosilicate platelet (NSP) derived from natural clay mineral. In this study, NSP showed strong selective growth inhibition and good settling enhancing effects on M. aeruginosa and highly efficient removal of MC-LR. NSP can inhibit the growth of M. aeruginosa (initial cell concentration at 3.00×10(6)cellmL(-1)) with a LC50 at 0.28ppm after 12h exposure. At the dosage of 100ppm, NSP can enhance settling of suspended M. aeruginosa. Bacterial growth inhibition tests showed NSP had very mild growth inhibition effects on Escherichia coli at high dosage but promoted the growth of Pseudomonas aeruginosa and Bacillus halodurans. For MC-LR removal, at an initial concentration of 100µgL(-1), NSP achieved higher than 99% removal. Thus, the results suggest that NSP could be an excellent candidate for controlling M. aeruginosa-related HABs in water bodies.

Highly efficient arsenic removal using a composite of ultrafine magnetite nanoparticles interlinked by silane coupling agents.

Arsenic (As) contamination in groundwater is a great environmental health concern and is often the result of contact between groundwater and arsenic-containing rocks or sediments and from variation of pH and redox potentials in the subsurface. In the past decade, magnetite nanoparticles (MNPs) have been shown to have high adsorption activity towards As. Alerted by the reported cytotoxicity of 5­12 nm MNP, we studied the adsorption behavior of 1.15 nm MNP and a MNP composite (MNPC), MNPs interlinked by silane coupling agents. With an initial concentration of As at 25 mg L(-1), MNPs exhibited high adsorption capacity for As(V) and As (III), 206.9 mg·g(-1) and 168.6 mg·g(-1) under anaerobic conditions, respectively, and 109.9 mg·g(-1) and 108.6 mg·g(-1) under aerobic conditions, respectively. Under aerobic conditions, MNPC achieved even higher adsorption capacity than MNP, 165.1 mg·g(-1) on As(V) and 157.9 mg·mg(-1) on As(III). For As(V) at 50 mg L(-1), MNPC achieved an adsorption capacity as high as 341.8 mg·g(-1), the highest in the literature. A kinetic study indicated that this adsorption reaction can reach equilibrium within 15 min and the rate constant of As(V) is about 1.9 times higher than that of As(III). These results suggested that MNPC can serve as a highly effective adsorbent for fast removal of As.

Residences with anomalous soil concentrations of dioxin-like compounds in two communities in Michigan, USA: a case study.

Most contamination of residential property soil with dioxin-like compounds occurs as a result of proximity to industrial activity that produces such compounds and, outside the industrially impacted zone, the soil concentrations are at background levels. However, as part of the University of Michigan Dioxin Exposure Study, residential properties in the lower peninsula of Michigan, USA, were identified that were located far enough from known sources of these compounds that the soil concentrations should have been at background levels and yet the toxic equivalent (TEQ) of some properties' soil was greater than 2.5 standard deviations above the mean background level. In the three cases presented here from Midland/Saginaw Counties, the anomalously high-TEQ values were primarily due to the presence of polychlorinated dibenzofurans. Based on interviews with the residents and a comparison of soil congener profiles, it was deduced that these values resulted from anthropogenic soil movement from historically contaminated areas. In the cases from Jackson/Calhoun Counties, the unusually high-TEQ values were primarily due to polychlorinated biphenyls. In the case profiled here, it appears that the soil became contaminated through sandblasting to remove paint from the swimming pool. This study identified two mechanisms for soil contamination outside zones of industrial impact; thus, an assumption of background levels of soil contamination outside industrial zones may not be valid.

Geostatistical modeling of the spatial distribution of soil dioxin in the vicinity of an incinerator. 2. Verification and calibration study.

A key component in any investigation of cause-effect relationships between point source pollution, such as an incinerator, and human health is the availability of measurements and/or accurate models of exposure at the same scale or geography as the health data. Geostatistics allows one to simulate the spatial distribution of pollutant concentrations over various spatial supports while incorporating both field data and predictions of deterministic dispersion models. This methodology was used in a companion paper to identify the census blocks that have a high probability of exceeding a given level of dioxin TEQ (toxic equivalents) around an incinerator in Midland, MI. This geostatistical model, along with population data, provided guidance for the collection of 51 new soil data, which permits the verification of the geostatistical predictions, and calibration of the model. Each new soil measurement was compared to the set of 100 TEQ values simulated at the closest grid node. The correlation between the measured concentration and the averaged simulated value is moderate (0.44), and the actual concentrations are clearly overestimated in the vicinity of the plant property line. Nevertheless, probability intervals computed from simulated TEQ values provide an accurate model of uncertainty: the proportion of observations that fall within these intervals exceeds what is expected from the model. Simulation-based probability intervals are also narrower than the intervals derived from the global histogram of the data, which demonstrates the greater precision of the geostatistical approach. Log-normal ordinary kriging provided fairly similar estimation results for the small and well-sampled area used in this validation study; however, the model of uncertainty was not always accurate. The regression analysis and geostatistical simulation were then conducted using the combined set of 53 original and 51 new soil samples, leading to an updated model for the spatial distribution of TEQ in Midland, MI.

Comparing recovering efficiency of immunomagnetic separation and centrifugation of mycobacteria in metalworking fluids.

The accurate detection and enumeration of Mycobacterium immunogenum in metalworking fluids (MWFs) is imperative from an occupational health and industrial fluids management perspective. We report here a comparison of immunomagnetic separation (IMS) coupled to flow-cytometric enumeration, with traditional centrifugation techniques for mycobacteria in a semisynthetic MWF. This immunolabeling involves the coating of laboratory-synthesized nanometer-scale magnetic particles with protein A, to conjugate a primary antibody (Ab), specific to Mycobacterium spp. By using magnetic separation and flow-cytometric quantification, this approach enabled much higher recovery efficiency and fluorescent light intensities in comparison to the widely applied centrifugation technique. This IMS technique increased the cell recovery efficiency by one order of magnitude, and improved the fluorescence intensity of the secondary Ab conjugate by 2-fold, as compared with traditional techniques. By employing nanometer-scale magnetic particles, IMS was found to be compatible with flow cytometry (FCM), thereby increasing cell detection and enumeration speed by up to two orders of magnitude over microscopic techniques. Moreover, the use of primary Ab conjugated magnetic nanoparticles showed better correlation between epifluorescent microscopy counts and FCM analysis than that achieved using traditional centrifugation techniques. The results strongly support the applicability of the flow-cytometric IMS for microbial detection in complex matrices.