Agroforestry practices aim to achieve environmentally friendly land use. Fungi play a primarily role in soil organic carbon and nutrient maintenance, while the response of the soil fungi community to land use changes is little explored. Here, a high-throughput sequencing method was applied to understand the fungal community structure distinction in ginkgo agroforestry systems and adjacent croplands and nurseries. Our results showed that the agroforestry systems achieved better soil fertility and carbon contents. The agroforestry practices significantly altered the composition of soil fungal communities comparing with pure gingko plantation, adjacent cropland, and nursery. The dominant fungal phyla were always Ascomycota and Basidiomycota. The relative abundance of Ascomycota was correlated with the TN and AP, while the abundance of Basidiomycota was negatively correlated with the TN and NN. The soil organic carbon, total nitrogen, and nitrate nitrogen explained 59.80% and 63.36% of the total variance in the fungal community composition in the topsoil and subsoil, and the available phosphorus also played a key role in the topsoil. Considering soil fertility maintenance and fungal community survival and stability, the agroforestry systems achieved better results, and the ginkgo and wheat system was the best among the five planting systems we studied. In the ginkgo and wheat system, applying readily available mineral nitrogen fertilizer either alone or in combination with organic amendments will improve the soil quality and fertility.

Indoor air quality (IAQ) is one of important issues in indoor environment due to exposure to inhalable aerosol which is affected by indoor and outdoor factors. To demonstrate the effect of indoor and outdoor to the IAQ, this study presents three fractions of particulate matter (PM) (PM₂.₅, PM₄, PM₁₀), characterization of I/O ratios for PM under potential indoor (average occupancy) and outdoor factors (Asian dust, rain, wind, and snow days) and evaluation of chemical components in aerosols. In the chemical characteristics of PM, organic carbon (OC), elemental carbon (EC), and trace elements were analyzed in indoors and outdoors. There was no significant difference of respirable aerosol (PM₂.₅ and PM₄) concentration in different indoor environments. The concentration of OC in PM₁₀ was lower in indoor than outdoor in summer and winter seasons, while the concentration of OC in PM₂.₅ was higher in indoor than outdoor. Also, the OC/EC ratios in PM₂.₅ were higher than those in PM₁₀. Further, the ratios of trace elements in PM₂.₅ and PM₁₀ were different at various locations within the building. This study demonstrated that the exposure to PM₂.₅ is greatly affected by outdoor environment. Although there was no difference in inhalable and respirable aerosol concentration at different locations within the building, the impact of outdoor factors is strongly supported by OC/EC ratios and PM₂.₅/PM₁₀ ratios of trace elements. This study shows that chemical components through the HVAC system affected the exposure to the indoor respirable aerosol, which could lead to adverse effect on the indoor air quality.

Boron (B) in the irrigation water can be hazardous to human beings and other aquatic or terrestrial organisms when B concentration exceeds a certain level. More importantly, B removal from irrigation water is relatively difficult using conventional processes. In the present experiment, an innovative treatment model based on monoculture and polyculture duckweed wastewater treatment modules was tested for B-rich irrigation water purification and bioelectricity harvesting. Different modules were designed using Lemna gibba L., Lemna minor L., and their combination in order to determine the most optimal duckweed species and vegetation structure for B removal process and bioelectricity generation in a module. In this respect, the module with a monoculture of Lemna gibba achieved the highest net B removal efficiency (71%) when it was exposed to 4 mg/L B (initial concentration). However, B removal efficiencies from all modules decreased when the initial B concentrations reached up to 4 mg/L in the irrigation water. The highest bioelectricity production was measured as 1.04 V with 17783 mWatt/m² power density at a current density of 44.06 mA/m² for module with Lemna gibba in monoculture through sacrificial magnesium anode. Specifically, both monocultures and polyculture removed considerable amounts of organic matter from irrigation water. However, biomass production and total chlorophyll (a + b) concentrations of duckweeds significantly decreased when they were exposed to 32 mg/L B in the irrigation water samples. Consequently, our modules present a holistic perspective to the prevention B toxicity problems in agricultural zones, and are a sustainable strategy for farmers or agricultural experts to produce bioelectricity by a cost-effective and eco-technological method.

The ultrasonic-assisted hydrothermal and ethanol activation method was proposed to synthesize copper-benzene-1,3,5-tricarboxylate (Cu-BTC) metal organic framework and Cu-BTC/graphene oxide (GO) composites (Cu-BTC@GO). The dynamic adsorption behavior of toluene on two adsorbents was studied and compared with that of GO and reduced graphene oxide (RGO). The Cu-BTC@GO exhibited high adsorption capacity (183 mg/g) for toluene, which is nearly three times as much as that of Cu-BTC (62.7 mg/g) with the GO mass fraction of 20%. Furthermore, the adsorption of toluene on Cu-BTC@GO composites was positively correlated with the initial concentration of toluene and the adsorbent dosage, and negatively correlated with the temperature. The adsorption data of toluene on Cu-BTC@GO composites were well in accordance with pseudo-first kinetics model. Langmuir model had a better fit than Freundlich model. The adsorption thermodynamic results showed that the adsorption process was mainly physical adsorption and the adsorption process was spontaneous at low temperature. After five adsorption–desorption cycles, the adsorption efficiency can still reach 82.1%.This study will help to draw a promising roadmap to describe the adsorption performance of Cu-BTC@GO composites for toluene.

The natural clay is an abundant, accessible, and low-cost material that has the potential for use in the water and wastewater industry. In this paper, Iranian natural clay and clay/Fe-Mn composite were used to remove toxic arsenic from the liquid environment. The natural clay and clay/Fe-Mn composite were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray (EDX), X-ray diffractometry (XRD), thermo-gravimetric analysis (TGA), and atomic force microscopy (AFM) techniques. The effects of parameters (initial pH, temperature, sorption dose, and contact time) on the efficiency and behavior of the arsenic(V) adsorption process were studied. Freundlich (R² = 0.945 and 0.989), Langmuir (R² = 0.922 and 0.931), modified Langmuir (R² = 0.921 and 0.929), and Dubinin–Radushkevich (R² = 0.706 and 0.723) models were fitted to evaluate the equilibrium data of arsenic(V) adsorption process by natural clay and clay/Fe-Mn composite, respectively. The Langmuir adsorption capacity of arsenic(V) by the natural clay and clay/Fe-Mn composite was determined to be 86.86 mg/g and 120.70 mg/g, respectively. The arsenic(V) adsorption process followed the pseudo-second-order model. Negative values of ΔG° and ΔH° showed that the arsenic(V) sorption by the studied materials is thermodynamically spontaneous and exothermic. According to the findings, the natural clay and clay/Fe-Mn are suitable and recyclable sorbents for arsenic(V) adsorption from aqueous solutions. Also, the composite of clay with iron and manganese can improve the efficiency of clay in the removal of arsenic.

Conventional activated sludge (CAS) process is one of the most commonly applied processes for municipal wastewater treatment. However, it requires a high energy input and does not promote energy recovery. Currently, high-rate activated sludge (HRAS) process is gaining importance as a good option to reduce the energy demand of wastewater treatment and to capture organic matter for valorizing through anaerobic digestion (AD). Besides, food waste addition to wastewater can help to increase the organic matter content of wastewater and thus, energy recovery in AD. The objective of this study is to evaluate the applicability of co-treatment of municipal wastewater and food waste in a pilot-scale HRAS system as well as to test the minimal hydraulic retention times (HRTs) such as 60 and 30 min. Food waste addition to the wastewater resulted in a 10% increase in chemical oxygen demand (COD) concentration of influent. In the following stages of the study, the pilot-scale system was operated with wastewater solely under the HRTs of 60 and 30 min. With the decrease of HRT, particulate COD removal increased; however, soluble COD removal decreased. The results demonstrated that if the settling process is optimized, more particulate matter can be diverted to sludge stream.

The number of restaurants is increasing rapidly in recent years, especially in urban cities with dense populations. Particulate matter emitted from commercial and residential cooking is a significant contributor to both indoor and outdoor aerosols. The PM₂.₅ emission rates and source profiles are impacted by many factors (cooking method, food type, oil type, fuel type, additives, cooking styles, cooking temperature, source surface area, pan, and ventilation) discussed in previous studies. To determine which cooking activities are most influential on PM₂.₅ emissions and work towards cleaner cooking, an experiment design based on multi-factor and level orthogonal tests was conducted in a laboratory that is specifically designed to resemble a professional restaurant kitchen. In this cooking test, four main parameters (the proportion of meat in ingredients, flavor, cooking technique, oil type) were chosen and five levels for each parameter were selected to build up 25 experimental dishes. Concentrations of PM₂.₅ emission rates, organic carbon/elemental carbon (OC/EC), water-soluble ions, elements, and main organic species (PAHs, n-alkanes, alkanoic acids, fatty acids, dicarboxylic acids, polysaccharides, and sterols) were investigated across 25 cooking tests. The statistical significance of the data was analyzed by analysis of variance (ANOVA) with ranges calculated to determine the influence orders of the 4 parameters. The PM₂.₅ emission rates of 25 experimental dishes ranged from 0.1 to 9.2 g/kg of ingredients. OC, EC, water-soluble ions (WSI), and elements accounted for 10.49–94.85%, 0–1.74%, 10.09–40.03%, and 0.04–3.93% of the total PM₂.₅, respectively. Fatty acids, dicarboxylic acids, n-alkanes, alkanoic acids, and sterols were the most abundant organic species and accounted for 2.32–93.04%, 0.84–60.36%, 0–45.05%, and 0–25.42% of total PM₂.₅, respectively. There was no significant difference between the 4 parameters on PM₂.₅ emission rates, while a significant difference was found in WSI, elements, n-alkanes, and dicarboxylic acids according to ANOVA. Cooking technique was found to be the most influential factor for PM₂.₅ source profiles, followed by the proportion of meat in ingredients and oil type which resulted in significant difference of 183.19, 185.14, and 115.08 g/kg of total PM₂.₅ for dicarboxylic acids, n-alkanes, and WSI, respectively. Strong correlations were found among PM₂.₅ and OC (r = 0.854), OC and sterols (r = 0.919), PAHs and n-alkanes (r = 0.850), alkanoic acids and fatty acids (r = 0.877), and many other species of PM₂.₅.

The effect of air staging strategies on NOₓ control was investigated on a 210-kW small-scale biomass boiler (SBB) and a 1.4-MW medium-scale biomass boiler (MBB). Considering the de-NOₓ effect, as well as the convenience and economy for future wide use, the structures of the secondary air duct and the fuel feed tube were innovatively designed to solve the problems of the traditional prototype. The preliminary experiment showed that the lowest NOₓ emission was achieved when the air excess (ε) was equal to 2.04. Then, additional operating modes were conducted on the MBB to further optimize the air staging strategies. The optimal air staging strategy of the MBB (the secondary to primary air flow ratio (λ) and the ε were equal to 0.13 and 0.76, respectively) could decrease the NOₓ emission from 338.12 to 148.14 mg/m³. Furthermore, the SO₂ emissions and the lowest NOₓ emission of the SBB and the MBB could meet most emission standards of China and some developed countries. The thermogravimetric analysis (TG) and combustion characteristics of the wood fuel showed that the air staging was a suitable de-NOₓ technology for wood combustion, and the slagging was less likely to occur under the selected condition. Hence, the air staging technology was an effective and low-cost method for the emission reduction of biomass boilers. This study provided a practical basis for future research on the gas emission control of biomass boilers.

In the planning and authorization process of industrial plants or agricultural buildings, it needs to be ensured that odor emissions do not annoy nearby residents in an unacceptable way. Previous studies have shown that odor-hour frequency is an important predictor for odor annoyance. However, odor-hour frequencies can be assessed for day and night separately. The present study relates complaint rates with different odor types and different metrics of frequency calculated via a dispersion model. Binary logistic regression analyses show that odor type and frequency of odor-hours are important predictors for complaints, while type of residential area does not increase the predictive value of the model. The combination of calculated frequency of day time odor-hours and type of odor explains complaint rates best. It is recommended to keep odor emissions as low as possible, especially for highly annoying odor types.

Active pharmaceutical ingredients such as tricyclic antidepressants (TCAs) are contaminants of emerging concern which are commonly detected in wastewater effluent and which can disrupt the behavior of non-target organisms. In aquatic snails, the righting response is a critical behavior that has been shown to be inhibited by exposure to SSRI-type antidepressants. We exposed marine and freshwater snails to three tricyclic antidepressants (clomipramine, amitriptyline, and imipramine) for 1 h and measured righting response time. In the marine mud snail (Ilyanassa obsoleta), all three TCAs significantly increased righting time at concentrations as low as 156 μg/L. Similarly, in the freshwater snail Leptoxis carinata, all three TCAs increased righting time at concentrations as low as 263 μg/L. However, exposure to imipramine from 15.8 to 316 μg/L resulted in significantly faster righting time. Such low-dose stimulation and high-dose inhibition are characteristics of a hormetic response. We discuss the possible physiological mechanism of action of TCAs and other antidepressants on snail behavior, and the occurrence of non-monotonic, hormetic dose responses to human pharmaceuticals in the aquatic environment.