Contamination of feed by mycotoxins is a global epidemic that has a sizeable impact on animal health and causes economic losses. Mycotoxins, including aflatoxins (AFs), zearalenone (ZEN), fumonisins (FUMs), deoxynivalenol (DON), and ochratoxin A (OTA), lead to acute and chronic adverse effects in pigs. Animal feed and feed ingredients are commonly contaminated by one or more mycotoxins worldwide; however, the prevalence of mycotoxin contamination in feed and feed ingredients in Taiwan remains unclear. A total of 820 cornmeal and corn-based swine feed (pregnancy and nursery diets) samples provided by feed and animal producers were analyzed using the enzyme-linked immunosorbent assay method between January 2015 and December 2017 to determine the presence of mycotoxins. The results revealed that the most prevalent mycotoxin in Taiwan was DON, with 91.4% of positive samples between 2015 and 2017, followed by ZEN, AFs, and FUMs, with 70.2%, 58.0%, and 50.4% of positive samples, respectively. A similar prevalence of mycotoxins was observed in cornmeal and corn-based swine feed. Furthermore, 7.7% of the analyzed feed samples contained one mycotoxin, and 91.3% contained multiple mycotoxins. DON was the most prevalent mycotoxin in cornmeal and corn-based swine feed in Taiwan. Moreover, a high incidence of contamination by multiple mycotoxins was observed in swine feed. Awareness of mycotoxin presence in feed and development of mycotoxin detoxification strategies are unmet needs.

TiO₂-based nanomaterials have attracted prodigious attention as a photocatalysts in numerous fields of applications. In this thematic issue, the mechanism behind the photocatalytic activity of nano-TiO₂ as well as the critical properties have been reviewed in details. The synthesis routes and the variables that affect the size and crystallinity of nano-TiO₂ have also been discussed in detail. Moreover, a newly emerged class of color TiO₂, TiO₂ in aerogel form, nanotubes form, doped and undoped form, and other forms of TiO₂ have been discussed in details. Photocatalytic and photovoltaic applications and the type of nano-TiO₂ that is more suitable for these applications have been discussed in this review.

It is reported that the accumulated polycyclic aromatic hydrocarbons (PAHs) can cause wheat leaf chlorosis, and we identified that carotenoid (Car) and superoxide dismutase (SOD) are the two most active factors in antioxidant system in the previous study. Herein, we applied Car as an exogenous chemical added to alleviate the toxicity triggered by phenanthrene (a model PAH) in wheat seedlings. In the exogenous Car addition groups, we found that the leaf number would grow three, and the relative biomass and the relative root length of 20 mg L⁻¹ Car added would take positive changes that increased by 171.35% and 108.08% of the phenanthrene-treated group at day 9, respectively. Under the subcellular structure, vacuole would be clear and clean, chloroplast and mitochondria shapes turned normal in the exogenous Car addition groups, and their osmophilic particle densities were much lower than the phenanthrene-treated group. Chlorophyll a, chlorophyll b, and total chlorophyll concentrations also recovered after Car was added in the phenanthrene treatments for 9 days. The activity of SOD, another active factor, also decreased when Car was added, and the values dropped to 16.54 and 24.61 U g⁻¹ for the 10 and 20 mg L⁻¹ Car addition groups, respectively. Like the SOD activity, malondialdehyde (MDA) concentrations of the two Car addition groups decreased to 26.50% and 26.87% of the phenanthrene treatment. The relative concentrations of 5 kinds of amino acids (valine, alanine, proline, aspartic acid, and lysine) recovered significantly, and the principal component analysis suggested that amino acid concentrations were in recovery progress when Car was added in phenanthrene treatments. Therefore, it is concluded that Car is an effective PAH toxicity relief. Our result offers a new way to improve the plant resistance to PAH pollution in the environment. Graphical abstract

The effects of Fire Phoenix (a mixture of Festuca L.) and Purple coneflower (Echinacea purpurea (L.) Moench) on the remediation of two different high concentrations of PAH-contaminated soils were studied under the effect of strain N12 (Mycobacterium sp.), and the changes in rhizosphere enzymatic activity were preliminarily studied. The results of three culture stages (60 d, 120 d, and 150 d) showed that N12 has a promotional effect on the biomass of Fire Phoenix and E. purpurea, and the effect of N12 on the biomass of Fire Phoenix is better. Under the strengthening of N12, the maximum removal rates of Fire Phoenix reached 86.77% and 67.82% at two high PAH concentrations (A and B, respectively). The activity of dehydrogenase (DHO) is positively correlated with the degradation rate of PAHs at the A concentration (P < 0.05). The activity of DHO in soil will continue to increase at a higher level of the B concentration, but the positive correlation between the activity of DHO and the degradation rate of PAH is weakened. In the rhizosphere soil of the two plants, the change in polyphenol oxidase (PPO) activity with time has a significant negative correlation with the degradation rate of PAHs (P < 0.05). The experiment proved that Fire Phoenix is more suitable for the remediation of heavy PAH-contaminated soil under the condition of microorganism-strengthening, and it can achieve a better degradation effect when the concentrations of PAHs are < 150 mg·kg⁻¹. Results provide a further scientific basis for the remediation of contaminated sites.

The main purpose of this study was to analyze the perceived outcomes of Good Agricultural Practices (GAPs) technologies adoption in order to sustain citrus farms in Mazandaran province, Iran. Study population consisted of all citrus growers in the villages of 12 counties of Mazandaran province, which a sample of 290 orchardmen were selected through a proportional random sampling technique. A questionnaire was designed to collect data which was both valid and reliable according to expert opinion and Cronbach’s alpha coefficient respectively. The results of the factor analysis showed that “market access and safe product exports,” “consumer’ health and environment-friendly behavior,” “safe production and public demand,” and “information sharing and strengthening local associations” were the four perceived outcomes of GAPs technologies adoption in citrus farms of Iran. These factors explained 65.02% of the total variance. These four perceived outputs of GAPs support economic, environmental, and social sustainability dimensions respectively.

In this work, the effect of supporting electrolytes on the simultaneous electrochemical oxidation of the pharmaceuticals sulfamethoxazole (SMX), propranolol (PRO), and carbamazepine (CBZ) in aqueous solutions has been studied. Based on the identified by-products, the degradation mechanisms were proposed and the acute toxicity was evaluated for each electrolyte. Assays were carried out in batch mode in a 2 L undivided reactor using a niobium coated with boron-doped diamond (Nb/BDD) mesh anode and Ti cathode at 2.5 A in presence of different supporting electrolytes (Na₂SO₄, NaCl, or NaBr) at the same concentration of 7 mM. The degradation rates were higher in the assays with NaCl and NaBr. Reaction by-products were identified by gas chromatography–mass spectrometry. Indirect oxidation by electrogenerated reactive halogen species (RHS) was the main mechanism when halide ions were used as electrolytes. Ten by-products were detected using Na₂SO₄ as electrolyte, while 19 (12 non-halogenated and 7 halogenated) and 20 (10 non-halogenated and 10 halogenated) using NaCl and NaBr respectively. The proposed degradation pathways involve transformation (hydroxylation, deamination, desulfonation, and halogenation) and bond rupture to produce less molecular weight compounds and their further transformation until total degradation. Chlorinated and brominated by-products confirm halogenation reactions. The electrogenerated RHS presented a significant inhibition effect on Vibrio fischeri; nevertheless, acute toxicity was not presented using Na₂SO₄ as electrolyte and a pharmaceutical concentration of 5 μg/L. In this view, the role of the supporting electrolyte in electrochemical oxidation process is crucial since it strongly influence degradation rate, by-products, and acute toxicity.

In this study, aqueous solutions of gallic acid (GA) were irradiated in an electron beam (EB) accelerator under different experimental conditions (various initial GA concentrations, presence or absence of oxidant and oxygen). For an initial GA concentration of 50 μM, complete GA degradation was achieved with an absorbed dose of 850 Gy in the presence of dissolved oxygen. Both GA removal and mineralization are favored when oxygen is present. The addition of persulfate anions (S₂O₈²⁻) or hydrogen peroxide (H₂O₂) also increased the efficiency of GA degradation and mineralization. For an absorbed dose of 14 kGy, GA mineralization reached approximately 45%, 55%, and 72% for the EB, EB/H₂O₂, and EB/S₂O₈²⁻systems, respectively. Three transformation products were tentatively identified in the presence of oxygen, these are the result of hydroxylation and ring opening reactions. No specific transformation product was found for the sulfate radical anion (SO₄–●) reaction. Four additional compounds, including a dimer, were identified in oxygen-free solutions. These findings demonstrate that water radiolysis based on EB irradiation is an efficient process to activate H₂O₂ and S₂O₈²⁻ anions and is an advanced oxidation process (AOP).

Water quality prediction is an effective method for managing and protecting water resources by providing an early warning against water quality deterioration. In general, the existing water quality prediction methods are based on a single shallow model which fails to capture the long-term dependence in historical time series and is more likely to cause a high rate of false alarms and false negatives in practical water monitoring application. To resolve these problems, a new model combining recurrent neural network (RNN) with improved Dempster/Shafer (D-S) evidence theory (RNNs-DS) is proposed in this paper. Among them, the RNNs which can handle the long-term dependence in historical time series effectively are used to realize the preliminary prediction of water quality. And the improved D-S evidence theory is used to synthesize the prediction results of RNNs. In addition, an improved strategy based on correlation analysis method is presented for evidence theory to obtain the number of evidence, which reduces uncertainty in evidence selection effectively. Besides, a new basic probability assignment function which based on modified softmax function is proposed. The new function can effectively solve the problems of weight allocation failure in the traditional function. Then, data about permanganate index, pH, total phosphorus, and dissolved oxygen from Jiuxishuichang monitoring station near Qiantang River, Zhejiang Province, China is used to verify the proposed model. Compared with support vector regression (SVR) and backpropagation neural network (BPNN) and three RNN models, the new model shows higher accuracy and better stability as indicated by four indices. Finally, the engineering application of the RNNs-DS algorithm has been realized on the self-developed water environmental monitoring and forecasting system, which can provide effective support for early risk assessment and prevention in water environment.

Pollution of aquatic ecosystems with heavy metals is now of global concern due to their dangers to human health and persistence in the environment. An investigation on the spatial distribution of heavy metals in water and sediments and the bioaccumulation potential of heavy metals by plant parts (i.e. roots, stems and leaves) of aquatic macrophyte Typha domingensis (Pers.) Steud in a tropical reservoir was carried out. The results showed no difference in spatial distribution of heavy metals (Fe, Cu, Cd, Cr, Pb, Zn, Mn) in water and sediments from the riverine to the dam wall. The concentration of heavy metals Fe, Cu, Cr and Zn in T. domingensis was of the order root > stem > leaves, but for Pb, Cd and Mn, it followed the order root > leaf > stem. The metal transfer between roots and shoots of T. domingensis followed the order Zn > Pb > Fe > Cu > Cd > Cr. The bio-concentration factor (BCF) was low (BCF < 1) for all the selected metals while the transfer factor (TF) varied among metals suggesting that T. domingensis is not an accumulator of the studied metals. The high concentration of heavy metals found in the water (0.7–16.14 mg L⁻¹) and sediments (43.6–569.18 mg kg⁻¹) present a potential risk to both ecological health and human health for the population living in the area. The results of metal concentration in water and sediments from this study are important as a baseline for future monitoring studies. Further studies on bioavailability of metals to other macrophytes and aquatic organisms are recommended.