The utilization of construction and demolition waste materials for the radionuclide immobilization by sorption processes was investigated. Given that the liquid radioactive waste usually has a complex composition and that effects of competition may significantly influence the efficiency of the treatment, the Simplex Centroid experimental design was used to explore ions sorption from multi-component solutions. For the purpose of this study, the common components of construction and demolition waste, such as pathway concrete and different bricks samples, were used along with the multi-component Sr²⁺, Co²⁺, and Ni²⁺ ions solutions. The equations for the prediction of metal ions sorption capacities were derived. The coefficients that correspond to the linear and interaction terms were obtained using a special cubic model. Likewise, by analysis of variance, statistically significant terms of the obtained polynomial were defined. The investigation has shown that the most effective sorption was onto the pathway concrete for all three cations, while the highest sorption capacity was found for Co²⁺ ions. Also, it has been determined that concerning Sr²⁺ ion removal there was a competition with coexisting Co²⁺ and Ni²⁺ ions, reducing its sorption capacity, while sorption of Co²⁺ and Ni²⁺ occurred more independently on other cations in multi-component solutions. Based on the obtained results, the applied experimental design can be efficiently used for the description of competitive sorption process and could be a powerful tool for the prediction of cation immobilization in liquid radioactive waste treatment.

Widely consumed benzodiazepine drugs are emerging contaminants, some of them being endocrine disruptors. Although many of these drugs remain in wastewater even after conventional treatment, innovative treatability studies are still sparse. The aim of this study was to investigate the efficiency of heterogeneous photocatalysis using synthesized composites based on TiO₂ and activated carbon (TiO₂/AC) as catalysts under sunlight-simulated irradiation. Different ratios and calcination temperatures were tested for the synthesis, and the composite with the best photocatalytic efficiency (based on methylene blue dye removal from water solution) was the one formed by 10% AC calcined at 400 °C (TiO₂/AC10%). This composite was applied in heterogeneous photocatalysis to remove bromazepam, clonazepam, and diazepam at environmentally relevant concentrations (100 μg/L). Such treatment approach has not been reported in the literature to date. Independent variables such as catalyst concentration, pH, and sunlight-simulated irradiation were studied using design of experiments (DoE) to find conditions that provide maximum removal efficiency. TiO₂/AC10% powder was characterized by SEM, XRD, BET, and diffuse reflectance. Under feasible optimized conditions, the efficiency of TiO₂/AC10% to remove benzodiazepine drugs from water was > 97.5%, which is much higher than the removal obtained with commercial catalyst and all controls.

Three-dimensional fluorescence spectrometer was adopted for the content analysis of different types of organics in coking wastewater before biochemical treatment and through biochemical treatment, and the model of parallel factors was employed to analyze fluorescence components and contents. It was found that tryptophan-like components were the most easily degraded by biology, while humic-like components were the least easily degraded. Meanwhile, it had been seen that the change trends over time of total fluorescence densities of proteinoid fluorescence, and degradable organic fluorescence were highly consistent with that of parameter values of COD, NH₃-N in this wastewater after analyzing the trends of the two indexes. It was proved that the three-dimensional fluorescence spectrum method was appropriate for the accurate degradation analysis of wastewater components.

The aim of this work was to study the adsorption kinetic, isotherm, and thermodynamic of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide in raw and boiling-treated sterile bracts of Araucaria angustifolia as novel alternative natural adsorbents. The sterile bracts were characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy. The adsorption and removal of 2,4-D from aqueous solutions were conducted at different contact times, bract granulometries, solution pH, bract masses, initial 2,4-D concentrations, and temperatures. The adsorption kinetic, mechanism, and thermodynamic were evaluated using pseudo-first- and pseudo-second-order kinetic models, non-linear Langmuir, Freundlich, Redlich-Peterson and Sips isotherm models, and Gibbs free energy, enthalpy, and entropy. The maximum removal efficiency of 2,4-D was found with 720 min of contact, 5.0 g of bract containing 31 micron particle sizes, pH = 2.0, and room temperature. The best kinetic and isotherm fits were found with the non-linear pseudo-second-order kinetic model and non-linear Freundlich isotherm model, respectively. Therefore, the adsorption mechanism in the bract structure takes place with multi-layer formation and multi-site interactions due to chemisorption reactions. The adsorption process is thermodynamically favorable, spontaneous, and exothermic. Overall, sterile bract of Araucaria angustifolia could be useful as alternative natural adsorbent for the treatment of water and wastewater contaminated with 2,4-D, mitigating the environmental pollution caused by agricultural crops. Graphical Abstract

Electrochemical reduction is currently one of promising methods for nitrate removal from water, yet most treatment approaches have problems of high cost and energy consumption. In this work, a low current density was applied in electrochemical reduction of nitrate. Copper-modified titanium (Cu/Ti) electrodes with optimal electrochemical activity and fastest kinetics were firstly screened. Thirty minutes of electrodeposition time and neutral pH were found to have the greatest nitrate reduction rate of 83.14%. To further improve the removal of nitrate, activated carbon (AC) and copper-modified activated carbon (Cu/AC) particles were applied to construct three-dimensional reaction systems, with removal rates of nitrate of 88.72% and 96.05%, respectively. The average conversion rates of nitrate to ammonia nitrogen increased from 15.28% to 42.68% and 62.64% in AC- and Cu/AC-based reaction systems, respectively. Oxidation of Cu(0) on surfaces of Cu/Ti cathode and Cu/AC particles to Cu(I) was revealed by X-ray photoelectron spectroscopy (XPS) and Cu LMM spectra analysis. Besides, results of water chemistry characteristics indicated the conversion of AC to carbonate ion. It could be concluded that enhanced nitrate reduction of Cu/Ti-based reaction system was attributed by Cu particle- and AC-mediated electron transfer. This study provided a reference for low-cost electrochemical reduction of nitrate.

Epoxiconazole (EPX) is a triazole fungicide commonly used in agriculture and for domestic purposes around the world. The excessive application of this pesticide may result in a variety of adverse effects on non-target organisms, including humans. Since, the liver and kidneys are the target organs of this fungicide, potential hepatotoxic and nephrotoxic effects are of high relevance. Thus, our study aimed to investigate the toxic effects of EPX on the liver and kidney of Wistar rats. The exposure of rats to EPX at these concentrations (8, 24, 40, 56 mg/kg bw representing, respectively, NOEL (no observed effect level), NOEL × 3, NOEL × 5, and NOEL × 7) for 28 days significantly enhances hepatic and renal lipid peroxidation which is accompanied by an increase in the level of protein oxidation. Furthermore, the results of the present study clearly indicated that EPX administration induces an increase in the levels of DNA damage in a dose-dependent manner. In addition, the activities of liver and kidney antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione S-transferase (GST) are increased significantly in EPX-treated rats at concentrations of 8, 24, and 40 mg/kg bw. However, with the dose NOEL × 7 (56 mg/kg bw of EPX), the activities of CAT, GPx, and GST are decreased. Indeed, EPX-intoxicated rats revealed a significant reduction in acetylcholinesterase (AChE) activity in both liver and kidney compared with the control group. Also, our results demonstrated that the EPX administration leads to a disruption of the hepatic (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH)) and renal (uric acid and creatinine) functions. The biochemical perturbations obtained in the present study are corroborated with the histopathological modifications. Since EPX treatment caused severe damage in the overall histo-architecture of liver and kidney tissues, these results suggest that administration of EPX induced a marked deregulation of liver and kidney functions. Graphical abstract

Cadmium (Cd) is a heavy metal that poses a huge potential threat to human and animal health. Therefore, it is necessary to study its damage mechanism. In the present study, we have examined the protective effects of Ganoderma lucidum triterpenoids on oxidative stress and apoptosis in the spleen of chickens induced by Cd. One hundred and twenty healthy Hailan white chickens (7-day-old) were randomly divided into the following four groups: control group, Cd group, triterpenoid group, and Cd–triterpenoid group. The chickens were euthanized on the 20th, 40th, and 60th days, and the spleens were removed. Cd and malondialdehyde (MDA) content, antioxidant enzyme (superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px)) activities, and inflammatory factor (tumor necrosis factor alpha (TNF-α) and interleukin (IL-1β and IL-6)) and apoptotic factor (caspase-3, BAX, and Bcl-2) expressions were detected. The results showed that Ganoderma lucidum triterpenoids could reduce the content of Cd and MDA; increase the antioxidant enzyme activities (SOD and GSH-Px); decrease the expression of inflammatory factors (TNF-α) and interleukin (IL-1β and IL-6); increase the expression of apoptotic factor (Bcl-2); and decrease the expression of apoptotic factors (caspase-3 and Bax). It showed that the triterpenoids of Ganoderma lucidum had significant protective effects on oxidative stress and apoptosis of chicken spleen, which provided a theoretical basis for further prevention and treatment of cadmium poisoning.

A waste–struvite/diatomite compound (MAP@Dia) recovered from nutrient-rich wastewater treated by MgO-modified diatomite (MgO@Dia) was provided to immobilize lead in aqueous solution and contaminated soil. The mechanism and effectiveness of lead immobilization was investigated, and the pHₛₜₐₜ leaching test and fixed-bed column experiments were carried out to assess the risk of MAP@Dia reuse for lead immobilization. The results showed that MAP@Dia were effective in immobilizing lead in aqueous solution with adsorption capacity of 832.47–946.50 mg/g. The main mechanism of Pb immobilization by MAP@Dia could be contributed by surface complexation and dissolution of struvite followed by precipitation of hydroxypyromorphite Pb₁₀(PO₄)₆(OH)₂. Lead(II) concentration reduced from 269.61 to 78.26 mg/kg, and residual lead(II) increased to 53.14% in contaminated soil when the MAP@Dia application rate was 5%. The increased neutralization capacity (ANC) and lower lead extraction yields in pHₛₜₐₜ leaching test in amended soil suggested 5 times of buffering capacity against potential acidic stresses and delayed triggering of “chemical time bombs.” The results of column studies demonstrated that amendment with MAP@Dia could reduce the risk of lead and phosphorus (P) leaching. This study revealed that MAP@Dia could provide an effective solution for both P recycling and lead immobilization in contaminated soil.

Municipal solid waste incineration (MSWI) generates bottom ash, fly ash (FA), and air pollution control (APC) residues as by-products. FA and APC residues are considered hazardous due to the presence of soluble salts and a high concentration of heavy metals, and they should be appropriately treated before disposal. Physicochemical characterization using inductively coupled plasma mass spectroscopy (ICP-MS), X-ray diffraction (XRD), and X-ray fluorescence (XRF) have shown that FA and APC have potential for reuse after treatment as these contain CaO, SiO₂, and Al₂O₃. Studies conducted on treatment of FA and APC are categorized into three groups: (i) separation processes, (ii) solidification/stabilization (S/S) processes, and (iii) thermal processes. Separation processes such as washing, leaching, and electrochemical treatment improve the quality and homogeneity of the ash. S/S processes such as chemical stabilization, accelerate carbonation, and cement solidification modify hazardous species into less toxic constituents. Thermal processes such as sintering, vitrification, and melting are effective at reducing volume and producing a more stable product. In this review paper, the treatment processes are analyzed in relation to ash characteristics. Issues concerning mixing FA and APC residues before treatment, true treatment costs, and challenges are also discussed to provide further insights on the implications and possibilities of utilizing FA and APC as secondary materials.

Considerable researches on removal of azo dyes have been reported in recent years, but few researchers have documented adsorption and/or transformation of anthraquinone dyes by physical, chemical, or biological treatment methods due to their fused aromatic structures. In this study, tea residue was found to have significant enhancement effect on the decolorization of anthraquinone dye reactive blue 19. This effect worked on different dye decolorizing bacterial florae and the natural bacterial flora from surface water and exhibited universal feature. Six single bacterial strains were isolated from bacterial flora DDMY2. Unexpectedly, all of them had poor decolorization capacity. High-throughput sequencing results revealed the community evolution of bacterial flora DDMY2 cultured with tea residue after 6 months and 12 months. It was found that the community structure changed dramatically because the influence of tea residue and the dominant functional genera, such as unclassified_o_Pseudomonadales, Stenotrophomonas, Bordetella, and Brevibacillus, was significantly enriched. Meanwhile, the evolved community structure could keep stable for a long time, resulting in the decolorization effect stabilized for a long time. This study provides the tea residue as the bioactivator that can be applied to boost the decolorization of dyes by various potential bacterial florae. It also enlarges our knowledge of making full use of biowaste in biological wastewater treatment.