Gas sparging is used as a traditional way to control membrane fouling in submerged membrane bioreactors (MBRs) in wastewater treatment. However, the gas sparging accounts for the largest fraction in operational cost to run the MBR systems. In this study, membrane fouling was controlled by integrating scouring media with gas sparging to reduce fouling rate at relatively low operational energy. Comparative study was performed using a fluidized membrane reactor treating synthetic feed solutions between polyethylene terephthalate (PET) scouring media (SM) fluidized by gas sparging (GS), liquid recirculation (LR), and combination of them to control membrane fouling. Addition of PET scouring media reduced the gas flow rate by 67% more with 30% less in fouling rate than gas sparing only. Combined usage of gas sparging and liquid recirculation to fluidize the PET scouring media (LR + GS + SM) showed 37% lower in fouling rate than that obtained by the scouring media fluidized by liquid recirculation (LR + SM) only through the reactor. The LR + GS + SM configuration reduced energy consumption by 90% more than that required by gas sparging alone. Mechanical cleaning driven by fluidizing PET scouring media could reduce membrane fouling due to removing deposit of inorganic particles from membrane surface effectively. However, the PET scouring media was not very effective to reduce membrane fouling caused by organic colloids which are expected to contribute pore fouling significantly.

This study aimed to improve the pore size, porosity, and hydrophobicity of polyvinylidene fluoride (PVDF) membranes for desalination by vacuum membrane distillation (VMD). New membranes were prepared via etching PVDF/calcium carbonate (CaCO₃) composite membranes using hydrochloric acid (HCl), depending on the chemical reaction of CaCO₃ and HCl. Etched membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), contact angle (CA), atomic force microscope (AFM), and scanning electron microscopy (SEM). The results showed that CaCO₃ of composite membranes was completely reacted by 1.5 mol/L HCl after composite membranes had been etched 90 min. The crystallinity of etched membranes was the same as that of PVDF/CaCO₃ composite membranes, and no new functional groups appeared in etched membranes, which indicated that etched membranes had good chemical stability. The surface roughness increased and led to the increase of contact angle, which means the hydrophobicity of etched membranes was enhanced. As a result, the increment of permeation flux had been improved in a VMD process. It was found that the maximum flux of etched membrane was enhanced and up to 1.65 times of composite membrane when the concentration of sodium chloride (NaCl) solution was 5.0 wt%, and the maximum flux reached up to 30.9 kg m⁻² h⁻¹.

Cellulose and lignin belongs to refractory organic matters in the traditional composting. In this research, the degradation of lignocellulose in dairy cattle manure was investigated through adding calcium oxide (CaO) and superphosphate (SSP). In the presence of CaO and SSP, the degradation rate of cellulose and lignin were improved by 25.0% and 8.33%, respectively. The results indicated that the pH value in system would be slightly higher with the addition of CaO and SSP. Besides, the pH value of all cow manure piles were about 8.4 after composting rotten, which could be well neutralized by the gradually acidified soil in the southwest of China with the full effect of fertilizer released. In addition, the abundance of Bacillales, Actinomycetes, and Thermoactinomycetaceae in the experimental groups (AR) was slightly better than that in the control groups (CK) during composting, which led to a conclusion that an elaborate physical–chemical–multivariate aerobic microorganism evolution model of cellulose degradation products (PCMC) was deduced and the physical–chemical–multivariate aerobic microorganism model of lignin cycle degradation (PCML) was developed.

Most sulfonamides, widely used around the world, are excreted via feces and urine along with their metabolites in humans and animals. Therefore, understanding the potential removal pathway of sulfonamides and their metabolites in wastewater treatment systems is of importance. The occurrence and fate of four sulfonamides and their acetyl metabolites in wastewater and sludge in a biological aerated filter in Xiamen city were evaluated. Six of the target compounds were detected in wastewater, but only parent compounds were detected in sludge. The highest concentration in wastewater was acetyl-sulfamethoxazole (Ac-SMZ) with a concentration of 75.2 ng/L. Removal efficiency and mass load in wastewater treatment systems were calculated. In terms of the overall removal efficiency, they ranged from 24.4 to 100%. The removal efficiencies of sulfamerazine (SM1), sulfamethazine (SM2), and sulfadiazine (SD) were up to 100% while N-acetyl sulfamerazine (Ac-SM1) showed the lowest removal efficiency. Biodegradation was the dominant remove pathway according to the mass balance analysis while SD and SM2 were sludge adsorption. The results can provide an insight into the fate of target sulfonamides in BAF systems and provide data to assess their potential ecological risks.

Psoriasis, a skin inflammatory disease, originates from dysregulated interactions of the immune system and environmental factors. In the present study, cadmium (Cd) and zinc (Zn) were analyzed in biological samples (blood and scalp hair) of smoker and nonsmoker males who have mild and severe psoriasis. The patients were evaluated according to criteria based on the standard clinical diagnosis and classified into mild and severe psoriasis groups using the Psoriasis Area Severity Index (PASI) score. Both elements were determined by atomic absorption spectrometry after matrix oxidation. In smoker psoriatic patients, the level of Cd in biological samples was significantly increased. The Zn was significantly decreased in smoker mild and severe psoriatic patients as related to nonsmokers’ referents and patients. The resulted data indicated that the levels of Zn in smoker referents were about 5.0% lower than nonsmoker’s referents. While the concentrations of Zn in blood samples of nonsmoker’s mild and severe psoriatic patients have 17.8 to 33.3% lower than nonsmoker’s referents. The results indicate that the level of Cd in blood samples of referent smokers has ≥ 25% than nonsmokers, whereas the psoriatic patients at different stages have two- to threefold higher Cd in both biological samples.

This paper presents findings on uncertainties, introduced through digital elevation model (DEM) resolution and DEM resampling, in watershed-scale flow and water quality (NO₃, P, and total suspended sediment) simulations. The simulations were performed using the Better Assessment Science Integrating Point and Nonpoint Sources/Hydrological Simulation Program Fortran watershed modeling system for two representative study watersheds delineated with both the original DEMs of four different resolutions (including 3.5, 10, 30, and 100 m) and the resampled DEMs of three different resolutions (including 10, 30, and 100 m), creating 14 simulation scenarios. Parameter uncertainties were quantified by means of the GLUE approach and compared to input data uncertainties. Results from the 14 simulation scenarios showed that there was a common increasing trend in errors of simulated flow and water quality parameters when the DEM resolution became coarser. The errors involved in the watershed with a mild slope were found to be substantially (up to 10 times) greater than those of the other watershed with a relatively steep slope. It was also found that sediment was the most sensitive and NO₃ was the least sensitive parameters to the variation in DEM resolution, as evidenced by the maximum normalized root mean square error (NRMSE) of 250% in the simulated sediment concentration and 11% in the simulated NO₃ concentration, respectively. Moreover, results achieved from the resampled (particularly coarser) DEMs were significantly different from corresponding ones from original DEMs. By comparing uncertainties from different sources, it was found that the parameter-induced uncertainties were higher than the resolution-induced uncertainties particularly in simulated NO₃ and P concentrations for studied watersheds. The findings provide new insights into the sensitivity and uncertainty of water quality parameters and their simulation results, serving as the guidelines for developing and implementing water quality management and watershed restoration plans.

This study aims to test the EKC (Environmental Kuznets Curve) hypothesis for the ten states, having the highest levels of carbon dioxide emissions in the USA, through the independent variables of real GDP, population, and renewable energy and fossil energy consumptions. To this aim, the panel estimation method with cross-sectional dependence is applied to data from 1980 to 2015. The empirical findings of the study indicate that the EKC (inverted U-shaped) hypothesis is valid only for Florida, Illinois, Michigan, New York, and Ohio. Interestingly, the negative impacts of fossil energy consumption on CO₂ emission levels in Texas are not detected statistically although this state is the leading oil-producing state. Furthermore, the positive impacts of renewable energy consumption in Florida, officially known as “Sunshine State”, are considerably low when compared with the other states.

In the last years, the upgrading of wastewater treatment plants (WWTPs) could be required in order to comply with the more stringent regulation requirements. Nevertheless, the main issue is related to the surface availability. A proper solution could be represented by the attached biomass processes, in particular the moving bed biofilm reactors (MBBR), that have a significant footprint reduction with respect to conventional activated sludge (CAS). However, MBBR showed an important disadvantage: the poor aeration energy efficiency due to the use of coarse bubble diffusers, which guarantee high reliability and low maintenance costs with respect to fine bubble ones. Moreover, the presence of carriers inside the reactor emphasizes this aspect. The aim of this work is to verify the benefits achievable by installing a fine bubble aeration system inside a MBBR system. The comparison, in terms of oxygen transfer efficiency, between a medium bubble aeration system and a fine ceramic bubble diffuser was studied and the effect of biofilm growth on oxygen transfer was assessed. Several tests were carried out in order to test the operation of a coarse and a fine bubble side aeration at different air flow rates, both in clean water conditions, in order to evaluate the influence of carriers (Chip M type) on the aeration efficiency, both in wastewater conditions with the aim to assess the effect of bacteria growth on the carriers. The main results are the following: (i) the fine bubble system placed off-center ensured good mixing even without using the mixer; (ii) the fine bubble side aeration system compared to the coarse ones did not show significant advantages in terms of oxygen transfer efficiency; (iii) the increase in specific air flow rate negatively influenced the aeration efficiency; (iv) the presence of biomass had a positive effect on the oxygen transfer yield.

Therefore, applying NH₄⁺-N tp PHW-SA caused greater tolerance to Cd toxicity by higher biomass production, photosynthetic capacity, Ca and Cu accumulation, better root development and lower translocation factor of Cd as well as Cd concetration in organelle fraction. The Cd stress inhibited the growth performance of wheat seedlings, the mineral nutrient accumulation, and nitrogen uptake and distribution, and different forms of nitrogen have different protective effects on wheat. In PHW-SA, ANCd treatment caused lower reduction in biomass accumulation, photosynthesis, isotope stable N content, Ca and Cu accumulation, root development inhibition, tissue Cd concentration, and transfer factor, which even led to lower concentrations of Cd in Fcₒ than those in Fcw and Fₛ in comparison with NNCd treatment. On the other hand, the converse growth performance was recorded in J-11 under ANCd treatment. Meanwhile, the nitrogen absorption preference in PHW-SA was altered along with the enhanced absorption efficiency of nitrogen. Therefore, applying NH₄⁺-N to PHW-SA caused greater tolerance to Cd toxicity by higher biomass production, photosynthetic capacity, Ca and Cu accumulation, better root development and lower translocation factor of Cd as well as Cd concetration in organelle fraction..

This study aims to investigate the validity of pollution haven hypothesis for the period from 1982 to 2013 in ten newly industrialized countries. For this purpose, we examine the relationship between real income, foreign direct investment, energy consumption, and ecological footprint using second-generation panel data methodology to take into account the cross-sectional dependence among newly industrialized countries. In doing so, the possible nonlinear relationship between foreign direct investment and environmental degradation is also searched. The results show that increased energy consumption and economic growth lead to increase in ecological footprint. Moreover, the U-shaped relationship between foreign direct investment and ecological footprint is confirmed in newly industrialized countries.