Rainfall can affect influent flow rate and compositions of wastewater, and thus further affect wastewater treatment performance and the effluent quality. This study aims to study the influence of rainfall on the environmental impacts of centralized wastewater treatment plants. The correlations between rainfall, and influent flow rate and compositions of wastewater in wet and dry seasons with two sewer systems, i.e. combined and separate sewer systems, were primarily established. Environmental impacts were assessed with life cycle assessment (LCA) to understand the temporal environmental burdens in wet and dry seasons. Functional units as per m³ treated wastewater (FU1) and as per kg PO₄³-eq. removed (FU2), respectively, were used to evaluate impacts of wastewater treatment to the environment. Strong correlation between rainfall and the influent flow rate was found in the wastewater treatment plants with either a combined sewer system (with Pearson correlation coefficient r at 0.66) or a separate sewer system (with r at 0.84), where r represents the strength of the association between two variables. The rainfall effect is more obvious on the eutrophication potential and global warming potential than on other environmental indicators while sewer system, i.e. combined or separate, seems not important in the two cases studied. Both wastewater treatment plants (WWTPs) show a lower environmental burden in the wet season than in the dry season partially due to the dilution of wastewater by using FU1. The WWTP receiving high strength wastewater, however, demonstrates higher environmental impacts in the wet season by using FU2 than FU1, due to the less efficient treatment caused by heavy rainfall. Meanwhile, it is found that environmental impacts from the WWTP receiving low strength wastewater have no difference when using either FU1 or FU2. The results indicate that the environmental burdens particularly eutrophication and global warming caused by WWTPs are dependent on the correlations of rainfall intensity with wastewater quantity and quality instead of combined or separate sewer system. This could be used to guide a stricter control of eutrophication in a more sensitive season in more vulnerable receiving waters.

The presence of drugs in the environment is an emerging issue in the scientific community. It has been shown that these substances are active chemicals that consequently affect aquatic organisms and, finally, humans as end users. To evaluate the toxicity of these compounds and how they affect the environment, it is important to perform systematic ecotoxicological and physicochemical studies. The best way to address this problem is to conduct studies on different aquatic trophic levels. In this work, an ecotoxicological study of six drugs (anhydrous caffeine, diphenhydramine hydrochloride, gentamicin sulphate, lidocaine hydrochloride, tobramycin sulphate and enalapril maleate) that used three aquatic biological models (Raphidocelis subcapitata, Aliivibrio fischeri and Daphnia magna) was performed. Additionally, the concentration of chlorophyll in the algae R. subcapitata was measured. Furthermore, EC50 values were analysed using the Passino and Smith classification (PSC) method, which categorized the compounds as toxic or relatively toxic. All of the studied drugs showed clear concentration-dependent toxic effects. The toxicity of the chemicals depended on the biological model studied, with Raphidocelis subcapitata being the most sensitive species and Aliivibrio fischeri being the least sensitive. The results indicate that the most toxic compound, for all the studied biological models, was diphenhydramine hydrochloride. Graphical abstract

Pre-oxidation in water treatment is considered an effective method to enhance the removal of algal cells and their exuded organic matters. However, pre-oxidation also alters the characteristics of algae and consequently influences disinfection processes. The existing studies mainly focused on the stationary growth phase, but little is known for the exponential and declined phases. The objectives of this study were to examine the effects of pre-ozonation on the integrity of algal cells, the release of algal organic matters, and the formation of disinfection by-products like N-nitrosodimethylamine (NDMA) from Microcystis aeruginosa (M. aeruginosa) at three growth phases. The results demonstrated that pre-ozonation was efficient to inactivate M. aeruginosa cells. The severity of M. aeruginosa cell damage increased as the ozone dosage increased from 0.5 to 2.0 mg/L. The damage of cell membranes resulted in the release of intracellular organic matters. Excitation-emission matrix spectra (EEMS) analysis indicated that ozone mainly reacted with soluble microbial products (SMP). With the increase of ozone concentration, although the trend of NDMA formation was similar for all three growth phases, more production of NDMA by algal cells was observed at the declined phase. In the post-disinfection process, chloramine showed the potential as a more suitable disinfectant than chlorination after pre-ozonation to minimize the NDMA formation. Therefore, appropriate pre-ozonation is beneficial to reduce the NDMA formation from exponential algae, while has no significant change during both stationary and declined phases.

The subchronic exposure to fine particulate matter (PM₂.₅) and high-fat diet (HFD) consumption lead to glucose intolerance by different mechanisms involving oxidative stress and inflammation. Under stressful conditions, the cells exert a heat shock response (HSR), by releasing the 72-kDa heat shock proteins (eHSP72), fundamental chaperones. The depletion of the HSR can exacerbate the chronic inflammation. However, there are few studies about the early effects of the association of HFD consumption and exposure to low concentrations of PM₂.₅ in the oxidative stress and HSR, in the genesis of glucose intolerance. Thus, we divided 23 male B6129SF2/J mice into control (n = 6), polluted (n = 6), HFD (n = 6), and high-fat diet + polluted (HFD + polluted) (n = 5) groups. Control and polluted received a standard diet (11.4% of fats), while HFD and HFD + polluted received HFD (58.3% of fats). Simultaneously, polluted and HFD + polluted received 5 μg/10 μL of PM₂.₅, daily, 7×/week, while control and HFD were exposed to 10 μL of saline solution 0.9% for 12 weeks. At the 12th week, animals were euthanized. We collected the metabolic tissues to analyze oxidative parameters, total blood to the hematological parameters, and plasma to eHSP72 measurement. The association of HFD and PM₂.₅ impaired glucose tolerance in the 12th week. Besides, it triggered an antioxidant defense by the adipose tissue, which was negatively correlated with eHSP72 levels. In conclusion, a low concentration of PM₂.₅ exposure associated with HFD consumption leads to glucose intolerance, by impairing adipose tissue antioxidant defense and systemic eHSP72 levels.

Microplastic pollution has attracted more and more people’s attention, and it exists widely in our living environment. Microplastics are difficult to be degraded, most of them migrate from the land to the water, and finally deposit in the sediment. They are easy to have a great impact on water bodies and aquatic organisms, and even affect the daily life of human beings. Based on the research literature on microplastics in recent years, this paper reviews the research progress of microplastics in freshwater sediments in China, discusses several commonly used methods of sampling, separation, and detection of microplastics in freshwater sediments, summarizes the distribution characteristics of microplastics in freshwater sediments in China, analyzes the toxicological effects of microplastics, and introduces the degradation methods of microplastics. This study will provide valuable reference for further study of microplastics in freshwater environment in the future.

The status of technical efficiency (TE) of environmental protection enterprises is crucial to the sustainable economic development. Based on the micro-survey data of China’s environmental protection enterprises from 2003 to 2013, through a systematic calculation and comparison about TE level under stochastic frontier analysis, this article investigated the distribution characteristics and heterogeneous sources of them comprehensively and found that first, there are wide-ranging technical efficiency differences among sub-sectors, ownership, and regions within China’s environmental protection industry, and this type of heterogeneity was significantly interfered by the institution and policy environment. Second, there is obvious scale economy effect and no scope economy effect in the TE distribution of China’s environmental protection enterprises, and their TE level has a positive response to management improvement and competition enhancement, but has a negative feedback on heavy asset expansion and debt-driven growth mode. Third, the overall TE levels of non-state-owned enterprises are higher than that of state-owned enterprises; the overall TE levels of enterprises located in the eastern provinces are higher than those of enterprises located in the central and western provinces. Fourth, reducing tax burdens of environmental protection enterprises is more effective to promote their TE level than providing governmental subsidies directly. Therefore, to promote the quality of the development for China’s environmental protection industry, it is necessary to emphasize the market mechanism. Based on the market power, we should accelerate the industry integration, cultivate the market demand, and promote market competition. Furthermore, the government should also need to design a targeted support system and differentiated policy arrangements for the development of environmental protection enterprises.

Acute toxicity of chlorpyrifos (CP) and its principal metabolite 3,5,6-trichloro-2-pyridinol (TCP) alone and in combination have been evaluated using a test battery comprising aquatic organisms from different trophic levels: luminescent marine bacteria Aliivibrio fischeri, freshwater unicellular alga Pseudokirchneriella subcapitata, and cladoceran Daphnia magna. As expected, D. magna was the more sensitive organism to the compounds tested, being CP more toxic than its metabolite. On the contrary, TCP was found to be more toxic than its parental compound to A. fischeri and P. subcapitata. In all cases, the mixture of CP and its metabolite was more toxic than the compounds tested separately, multiplying between 5 and 200 times CP toxicity level and up to 15 times TCP toxicity level. These results indicate that the co-existence of parent chemical and its degradation product in the environment can result in a synergic interaction involving high risk to the aquatic ecosystems. Graphical abstract

This research work reconnoiters the impact of nonrenewable energy (NRE) consumptions, environmental pollution, and mortality rate on human capital in the presence of economic growth and two common diseases, measles and tuberculosis (TB) in Pakistan. The study uses data from 1995 to 2017 and employs the Autoregressive Distributive Lag (ARDL) model to investigate cointegration and long-run dynamics. Results indicate that nonrenewable energy (oil, coal, and gas) increase air pollution, measles, TB cases, and mortality rate, which affect the human capital in Pakistan. The results of the ARDL confirm the long-run and short-run effects of fossils fuels, air pollution, and diseases on human capital. The results of the Granger Causality confirm the feedback hypothesis between nonrenewable consumption and human capital, between air pollution and human capital. Measles and TB diseases Granger cause human capital. The study recommends some essential points for energy management, environmental management, and diseases control programs to uplift the human capital in Pakistan.

In this study, we evaluated atmospheric particulate matter (PM) concentration predictions at a regional scale using a simplified Lagrangian particle dispersion modeling system and the Bayesian and multiplicative ratio correction optimization (Bayesian-RAT) method to improve the mixing ratio forecast of PM₁₀ and PM₂.₅. We first examined the forecast performance of the LPD (i.e., the simplified FLEXPART model combined with the Bayesian-RAT method) by comparing the model predictions with the PM concentration observations from 95 observation stations in Xingtai city and its surrounding areas. The first 2 months (i.e., Oct. and Nov. 2017) of the study period represented the typical spin-up time period, and the analysis period was December 2017. The LPD forecast system was much better (correlation coefficient: R=0.64 vs. 0.48 and 0.67 vs. 0.50 for PM₁₀ and PM₂.₅, respectively; root mean square error: RMSE = 74.98 vs. 105.96 μg/m³ for PM₁₀ and 54.89 vs. 72.81 μg/m³ for PM₂.₅) than the pre-calibration results. We also compared the LPD forecasting model with other models (WRF-Chem and Camx) using data from monitoring stations in Xingtai, China, and the LPD forecasting model had higher accuracy than the other models. In particular, the RMSE scores for hourly PM₁₀ concentrations were reduced by 36.51% and 42.21% compared to WRF-Chem and to Camx, respectively. The PM₂.₅ forecast results, as in the case of PM₁₀, showed a better performance when applying the LPD model to the data from the monitoring stations. The RMSE was reduced by 26.44% and 18.47% relative to the WRF-Chem and Camx, respectively. The results confirm that there is much advantage of the LPD forecast system for predicting PM and may be for other pollutants.

Indoor air quality in museums and historical buildings is of great concern for curators, since it can be a source of various alterations on artworks. In spite of their importance, very few studies study simultaneously the concentration of main gaseous pollutants, the composition of suspended (PM), and deposited (DPM) particulate matter. The aim of this article is to carry out a first environmental assessment in French museums or monuments. Three sites representative of contrasting environments (urban, marine, semi-rural) have been selected: the Cluny Museum (Paris), the Villa Kérylos (Beaulieu-sur-Mer), and the Château de Fontainebleau. The main results show that the input of terrigenous particles (calcite, clay) due to the surrounding restoration works dominates in Cluny; the external environment (O₃, RH, and marine particles) influences the interior atmosphere of the Villa Kérylos and the deliquescence of the deposited salts; against all expectations, anthropogenic particles (mascagnite and soot) are largely dominant in Fontainebleau. They are emitted in winter, when the warm, pulsating air gets dirty as it passes through the old heating ducts. This research shows the importance of particle mixtures in the environmental signature of the sites. These mixtures must be taken into account in order to reproduce indoor atmospheres in simulation chambers to achieve realistic artificial aging. This study also makes it possible to target the sources of pollution on which to act.