In the treatment of wastewater from vehicle washing, the coagulation/flocculation process using inorganic coagulant is mostly applied; it may or may not be combined with other processes. In literature, few studies use natural coagulants and assess the surfactants’ removal among the physical-chemical parameters, particularly using the adsorption process. In order to fill this knowledge gap, this work aimed to treat the car wash wastewater, applying a combined process of coagulation/flocculation/sedimentation (C/F/S) and adsorption. Process efficiency was evaluated according to the removal of color, turbidity, total solids, volatile solids, total dissolved solids, chemical oxygen demand and surfactants. For primary effluent treatment, C/F/S experiments were performed with Tanfloc SG to investigate the influence of the natural coagulant concentration in color and turbidity removal efficiency. The results showed that 220 mg L⁻¹ was the best coagulant concentration (turbidity = 97.5%; color = 92.5%) (p < 0.05). The supernatant of the C/F/S process was applied to the sequential adsorption process (kinetics and isotherm) with mineral activated carbon. The equilibrium time of the kinetic experiment was established after 2 h of contact, and the Langmuir isotherm model best described the surfactant adsorption behavior (R² = 0.93; qₘₐₓ = 5.65 mg g⁻¹). The combined process enhanced the treatment efficiency achieving an overall removal efficiency of 97.3% for color, 98.8% for turbidity, 92.6% for chemical oxygen demand, and 97.2% for surfactants. The combined process proved to be promising for the treatment of car wash wastewater, presenting a reduction surfactant concentration and on the other parameters evaluated, contributing to environmental sustainability.

Logistics sustainability is increasingly becoming a central focus of businesses, when most societies are aware of the influence of industry on both the environment and human health. To address the drawbacks of the way logistics systems have been designed, a new logistics system called Physical Internet has been proposed. This system relies on the creation of hyperconnected logistics systems. It aims to improve in an order of magnitude the way physical objects are transported, handled, stored, supplied, realized, and used to be more sustainable and efficient economically, environmentally, and socially. This paper focuses on the product realization using a hyperconnected mobile production mode in the context of Physical Internet, an open global logistics system. It addresses its dynamic deployment of production modules and resource allocation and sharing. It then proposes a make-to-order bi-objective optimization model which minimizes costs and greenhouse gases (GHGs) related to the product realization of a manufacturer to serve its customers given the availability of the open fabs. Experimental results are presented to identify the computational performance of the established model, as well as the economic and environmental benefits of using the facilities enabled by the PI. Finally, it concludes and provides directions for future research.

The critical role of electricity consumption in influencing and reshaping the economic and environmental landscape of the global economy cannot be underestimated. Electricity is the most beneficial and commonly transformed energy source; however, the strength, weakness, opportunities and threat of its consumption require scientific scrutiny. This study investigates electricity-led growth hypothesis vis-à-vis its impact on economic growth and environmental quality of Turkey. The annual time series data set from 1970 to 2014 were employed in the analysis with a battery of unit root and stationary tests. The equilibrium relationship in the study is explored using Maki and Bayer-Hanck combined cointegration tests under multiple structural breaks along with the Pesaran’s ARDL bounds test procedure for robust check. The study confirms the existence of cointegration relationship between electricity consumption, economic growth, capital, labour and ecological footprint. To detect the direction of causal relations, the VECM Granger causality test is employed. The causality analysis provides empirical evidence that supports the electricity-induced growth hypothesis in Turkey. This implies that embarking on conservative energy-efficient policies will slow down Turkey’s economic growth. Thus, precautionary measures that ensure adequate policy on energy mix to guarantee availability and accessibility to modern electricity will sustain economic growth and improve environmental sustainability.

Herein, three different types of zinc ferrite (ZnFe₂O₄) magnetic nanoparticles as photocatalysts were synthesized from iron and zinc sulfate using a co-precipitation method. Tri ethylene glycol (TEG) was utilized as a capping/stabilizing agent in the presence of ammonium hydroxide. The as-prepared nanoparticles were annealed at 400 °C for 4 h followed by acid etching with HCl (for 15 min in I M solution). The thermally treated magnetic nanostructure was subjected to surface modification by treating with 3-aminopropyl (triethoxysilane) 3-(APTES) at 60 °C for 2 h. Various characterization techniques including Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET), and X-rays diffraction (XRD) were carried out to examine the structural properties of the pristine and functionalized nanocrystals. XRD pattern assessed the crystalline and nano size of the ZnFe₂O₄ recording particle sizes of 13.5, 23.3, and 106.5 nm for functionalized, annealed, and pristine ZnFe₂O₄ nanoparticles, respectively. FTIR spectral analysis corroborated the modifications and functionalization of the samples. BET analysis revealed a surface area of 0.6719 (functionalized), 45.21 (annealed), and 155.38 (pristine nanoparticles). The photocatalytic activity of the prepared nanostructures was investigated for Eriochrome Black T (EBT) dye under the unfiltered sunlight. At optimal reaction parameters, the photocatalytic rates of EBT dye for functionalized, annealed, and blank NP’s were 92, 91, and 83%, respectively. Kinetic models demonstrate that the degradation processes followed pseudo-first-order kinetics. The energies of the band gap in the acidic and basic media, as determined from the Tauc plot, were 2.47 and 2.7 eV, respectively. Taken together, the results showed that newly fabricated nanostructures are considered as promising photocatalysts in degrading organic pollutants for a sustainable environment.

The Beijing-Tianjin-Hebei urban agglomeration is one of the most water-scarce regions in China, because of the frequent human activities. Water scarcity and pollution have weakened the service functions of water ecosystems and hindered the regional economic development. As the “lifeline” of the economic development of Beijing-Tianjin-Hebei region, the water quality of Beiyun River has been widely concerned. River water quality assessment is one of the most important aspects to enhance water resources management plans. Water quality index (WQI), as one of the most frequently used evaluation tools, was used to comprehensively analyze the water quality in the Beiyun River. Between January 2017 and October 2018, we collected samples from 16 typical sampling sites along the main rivers of the watershed, covering four seasons. Seventeen water quality parameters, including temperature, pH, conductivity, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD₅), ammonia nitrogen (NH₃-N), total phosphorus (TP), oil, volatile phenol (VP), fluoride, sulfide, surfactant, lead (Pb), copper (Cu), zinc (Zn), and arsenic (As), were used to calculate WQI. The average WQI values of Beiyun River in winter, spring, summer, and autumn were 88.15, 71.70, 78.92, and 90.12, respectively, explaining the water quality was “good” generally. There were significant differences in the spatial distribution of WQI values from Beiyun River, and water quality of upstream and downstream was better than that of midstream. In addition, correlation analysis was applied to explore the correlation between land use types and water quality. Water quality was significant negatively correlated with agriculture land and rural residential land, and a positive relationship between urban land and water quality. Generally, we believe that people’s related activities on different land use are major elements impacting the water quality. Water environment improvement ought to increase the wastewater collection rate and sewage treatment capacity in rural areas, especially in the midstream of the Beiyun River. Graphical abstract

Highly efficient and effective treatments of hazardous dye-based color effluents are a major problem in the industrial sector. In this research, the cobalt ferrite (CoFe₂O₄) catalyst was produced and used for the degradation of Congo red (CR) as a model dye from aqueous solution. For a said purpose, cobalt ferrite (CoFe₂O₄) nanostructures with photocatalytic degradation potential were engineered via co-precipitation method using Fe₂(SO₄)₃, CoO₂, and triethylene glycol (as a stabilizing agent). As prepared, CoFe₂O₄ nanostructures were further surface-functionalized with 3-APTES and tested for CR degradation. The prepared CoFe₂O₄ nanostructures were characterized by X-ray diffraction, Fourier transform infra-red (FT-IR), scanning electron microscopy (SEM), and Brunauer-Emmitt-Teller (BET) analysis. UV-visible absorption was used to measure the optical band gap of prepared CoFe₂O₄ nanostructures through Tauc plots. The as-prepared CoFe₂O₄ nanostructure bandgap was found to be 2.71 EV while using an acidic medium. The degradation rates of CR dye for bs-CoFe₂O₄, as-CoFe₂O₄, and fs-CoFe₂O₄ nanostructures at pH 9 were 84, 87, and 92%, respectively. Furthermore, the influences of various process parameters, i.e., the effect of catalyst dose, contact time, dye dose/concentration, pH effect, and effect of different acids, were checked for the prepared three types of nanostructures, i.e., bs-CoFe₂O₄, as-CoFe₂O₄, and fs-CoFe₂O₄. The kinetics models properly explained that the reaction of degradation following pseudo-first-order kinetics.

Eggshells (ESs), a low-cost biosorbent rich in calcium carbonate (CaCO₃), were used to sustainably reduce the acidity and remove the Fe₍ₜₒₜₐₗ₎, Al³⁺, and Mn₍ₜₒₜₐₗ₎ ions from coal mine-impacted water (MIW). The surface area and pore volume of ES biomaterial were 5.692 m² g⁻¹ and 0.0567 cm³ g⁻¹, respectively. The remediation process was performed in two consecutive stages, with Fe₍ₜₒₜₐₗ₎ and Al³⁺ ions being removed in the first stage (treatment I) and the Mn₍ₜₒₜₐₗ₎ ions in the second one (treatment II). The best treatment conditions, statistically determined through a central composite rotatable design (CCRD), were 6.59 g L⁻¹ ES and 95 rpm agitation rate for treatment I and 28 g L⁻¹ ES and 280 rpm agitation rate for treatment II. However, the high ES dosage in treatment II, determined by extrapolation, led in practice to the formation of particle aggregates that decreased the treatment efficiency. Therefore, the best values experimentally determined for treatment II were 25 g L⁻¹ ES and 250 rpm. In these conditions, the overall treatment provided complete MIW acidity neutralization, total removal of the Fe₍ₜₒₜₐₗ₎ and Al³⁺ ions, and 58% Mn₍ₜₒₜₐₗ₎ ion removal, providing treated fluvial water adequate for non-potable use based on the analyzed parameters.

In this work, titanium dioxide nanoparticles (TiO₂ NPs) and modified TiO₂ NPs with silver (Ag) or platinum (Pt) dopant were developed through photodeposition method for the NOₓ conversion into nitric acid (HNO₃) under visible light irradiation. The formed photocatalysts TiO₂, Ag/TiO₂, and Pt/TiO₂ nanocomposites were characterized by utilizing TEM, SEM, energy-dispersive X-ray analysis (EDX), XRD, UV/visible diffuse reflectance spectroscopy (UV-Vis DRS), and FT-IR. It had been investigated that an enhancement within the conversion of NOₓ into HNO₃ was increased from 34.3 to 78.3% for Ag/TiO₂ and from 35.2 to 78.5% for Pt/TiO₂ under visible light irradiation conditions at room temperature for less than 2 h. The photodegradation rate order of NOₓ under visible light irradiation is Pt/TiO₂ ~ Ag/TiO₂ > TiO₂. A possible mechanism for the catalytic conversion of NOₓ gases has been proposed, which depends on the photogeneration of electrons and holes after the excitation of nanocatalysts under visible radiation that promoted superoxide and hydroxyl ions, which can depredate NOₓ gases. This approach of NOₓ photocatalytic conversion is characterized by its chemical stability, low cost, high efficiency, simple operation, and strong durability than traditional methods.

Electrolysis systems have been widely investigated for treating wastewater in laboratory-scale experiments, and most researchers reported efficient treatment outcomes. However, industrial scale implementation often necessitates assessing and prioritising various options involving different combinations of input parameters, which often requires mathematical models. This study presents mathematical models for predicting removal efficiencies of four different pollutants using electrolysis. Parametric equations were developed based on experimental results conducted in a previous study. Proposed equations are dependent on treatment retention time and current intensity (voltage). Results revealed that the experimental data followed consistent patterns, which lead to the derivations of generalised equations which were able to closely predict pollutants’ removal efficiencies obtained through experimental measurement. The developed equations also confirmed that beyond an optimum voltage, a further increase in voltage does not render higher removals of the pollutants, which is essential for enhancing the feasibility of industrial scale applications.

As a recently discovered process of nitrogen cycling, anaerobic ammonium oxidation coupled to ferric iron reduction (Feammox) has attracted more attentions. This study investigated the spatial variation of Feammox in the sediment of different zones of a shallow freshwater lake and the effect of organic matter derived from algae and macrophyte on Feammox process. The potential Feammox rates showed significant differences among sediments from algae-dominated area (ADA), transitional area in the center of the lake (TDA), and macrophyte-dominated area (MDA), and in a descending order, ADA, MDA, and TDA. The potential Feammox rate ranged from 0.14 to 0.34 mg N kg⁻¹day⁻¹ in the freshwater lake sediment. The potential Feammox rates of the sediment with algae or macrophyte amendment were 12.29% and 15.31% higher than the control test without algae and macrophyte amendment. The addition of algae or macrophyte to the sediment from TDA could improve the amount of HCl-extractable total Fe, Fe(III) reduction rate, and the abundance of FeRB. These results demonstrated that organic matter is one of the key regulators of Feammox process.