Storage of wheat in conventional packaging materials is not safe as seeds gain moisture from surrounding air of high relative humidity which promotes growth of fungal and insect pests and loss of quality during storage. Implementing the dry chain, initial drying to low moisture content followed by storage in hermetic bags to maintain low moisture may prevent these losses without using fumigants or chemicals. Different levels of initial moisture contents (SMC), i.e., 8, 10, 12, and 14% and packaging materials, including hermetic super bags along with paper, woven polypropylene (PP), jute, and cloth bags were used as two factors for this experiment. After 4 months of storage, small variation in SMC of seed was observed in super bags while SMC increased significantly in conventional packaging materials. Higher storage losses (≈9%), grain quality losses and aflatoxin B₁, B₂, G₁, and G₂ contamination (1–2 ppb) in conventional packaging materials were linked to high seed moisture contents. Storage in hermetic bags at 8 and 10% SMC ideally preserved seed quality. In conclusion, hermetic storage of wheat at low seed moisture maintains a dry chain and prevents aflatoxin contamination and grain quality losses and offers an organic approach to avoid contamination of food grains.

It is important to study the fate and transport of antibiotics in aquatic environments to reveal their pollution status. The premise behind fate and transport studies is to evaluate the reaction processes of the target antibiotics. However, available research on the environmental behaviors of antibiotics in certain natural waters, such as estuarine water, is scarce. In this study, single reactions such as sorption, biodegradation, and photolysis and multiple degradation reactions of sulfamethoxazole (SMX), trimethoprim (TMP), and ciprofloxacin (CIP) in the estuarine water were studied. The sorption rates of the target antibiotics in the estuarine water-sediment system were very fast, and the sorption amounts varied among sediments and antibiotics. Hydrolysis did not contribute to the degradation of the target antibiotics. Biodegradation had a low contribution to the degradation of the target antibiotics in the estuarine water. In comparison, photolysis was the dominant degradation process for SMX, TMP, and CIP. The rates of photolysis of the tested antibiotics in the estuarine water were greater than those in pure water; thereby, indicating photolysis of these antibiotics was more prone to occur in the estuarine water. In the multiple degradation experiments, it was found that there may be synergistic effects between the single degradation processes. Thus, the aqueous concentrations of antibiotics decreased rapidly by sorption after entering the estuarine water and then decreased relatively slowly by photolysis and biodegradation. This study provides information for evaluating the environmental behaviors of antibiotics in estuarine environments.

Molecular biomarkers, like gene transcripts or enzyme activities, are potentially powerful tools for early warning assessment of pollution. However, a thorough understanding of response and baseline variation is required to distinguish actual effects from pollution. Here, we assess the freshwater mussel Anodonta anatina as a biomarker model species for freshwater ecosystems, by testing responses of six transcriptional (cat, gst, hsp70, hsp90, mt, and sod) and two biochemical (AChE and GST) biomarkers to environmentally relevant Cu water concentrations. Mussels (n = 20), collected from a stream free from point source pollution, were exposed in the laboratory, for 96 h, to Cu treatments (< 0.2 μg/L, 0.77 ± 0.87 μg/L, and 6.3 ± 5.4 μg/L). Gills and digestive glands were extracted and analyzed for transcriptional and biochemical responses. Biological and statistical effect sizes from Cu treatments were in general small (mean log₂ fold-change ≤ 0.80 and Cohen’s f ≤ 0.69, respectively), and no significant treatment effects were observed. In contrast, four out of eight biomarkers (cat, gst, hsp70, and GST) showed a significant sex:tissue interaction, and additionally one (sod) showed significant overall effects from sex. Specifically, three markers in gills (cat, mt, GST) and one in digestive gland (AChE) displayed significant sex differences, independent of treatment. Results suggest that sex or tissue effects might obscure low-magnitude biomarker responses and potential early warnings. Thus, variation in biomarker baselines and response patterns needs to be further addressed for the future use of A. anatina as a biomarker model species.

This study aims to determine the effects of deforestation, economic growth, and urbanization on carbon dioxide (CO₂) emissions levels in the South and Southeast Asian (SSEA) regions for the 1990–2014 period. The data was divided into five sub-panels. Three of them are income-based groups (namely low-, middle- and high-income panels), and the remaining two are South and Southeast Asian regions. The Pedroni cointegration test confirms a long-run relationship between deforestation, economic growth, urbanization, and CO₂ emissions in the SSEA regions. Further, empirical results reveal the existence of a U-shaped relationship between CO₂ emissions and economic growth for all panels (excepting low-income countries). This means that these countries can grow in a sustainable path, but they must be aware of long-term risks of this economic growth, as this sustainable path could be compromised when reaching the turning point of the “U”. Moreover, our results suggest that deforestation and urbanization can aggravate environmental pollution in these regions and can further affect sustainable development in the long run. Besides, the most appropriate and cost-effective method to minimize CO₂ emissions is found to be through the improvement of forest activities.

The study aimed to determine eight hazardous heavy metals in surface water and sediment samples collected from the Naf River, Shah Porir Dwip (estuary), and mostly around Saint Martin’s Island in the Bay of Bengal. The results of heavy metals in water samples were ranged as Pb 14.7–313.0, Cd 33.0–70.0, Cr < 11.0–37.0, Cu 38.0–57.0, Zn 26.8–69.2, Ni 102.0–285.0, and Hg 0.3–1.6 μg L⁻¹. The concentrations of metals in sediment samples were ranged as Pb < 10.0–37.5, Cd 0.2–1.0, Cr < 5.0–30.1, Cu < 3.0–30.9, Zn 24.1–88.0, Ni < 4.0–48.3, As 0.1–7.3, and Hg < 0.01–0.08 mg kg⁻¹ dw. Ni and Cr were strongly correlated, suggesting that this pair of metals might diffuse from a common origin. The contamination factor (Cⁱf) demonstrated that sediment samples were mostly contaminated by Cd and slightly contaminated by Pb and Zn. The geoaccumulation index (Igₑₒ) revealed considerable values for Cd on Saint Martin’s Island. Cd as a single regulator posed moderate to considerable risk frequently among the sampling stations. Pollution load index (PLI) values remained below 1 (< 1), which indicated a decrease from baseline pollution value among all stations. However, potential ecological risk (PER) was graded for two stations (St1 and St13) with a moderate-risk zone due to the Cd contribution. However, shipping emission and lithogenic sources were the most predominant for heavy metals in the sediment, which were determined by applying the principal component analysis-absolute principal component score (PCA-APCS). Graphical abstract

It is very necessary to produce bio-activated carbon for special use with easy procedure and low cost. One kind of huge surface area microporous bio-material was successfully prepared from agricultural residues (peanut shell, Arachis hypogaea Linn.) and beneficially applied to control elemental mercury (Hg⁰) in simulated coal-fired flue gas in this study. The possible effects of experimental factors including activator, reaction temperature, and flue components were investigated. The physicochemical properties of the prepared adsorbents were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDX), and X-ray photoelectron spectroscopy (XPS). The results indicated that the peanut shell activated carbon presented excellent Hg⁰ removal efficiency near 90% at 150 °C. The characterization analysis indicated that the removal characteristics were governed by both physical adsorption and chemical adsorption. The chemisorbed mercury on the activated carbon was mainly distinguished into mercuric chloride (HgCl₂) and mercuric oxide (HgO). The presence of C-Cl and O* promoted Hg⁰ into HgCl₂ and HgO. Zinc chloride could not only improve the micropore quantity of activated carbon but also have remarkably positive effects on the elemental mercury removal. This study provided a practical and easy preparation method of bio-activated carbon for Hg⁰ removal with low cost. Graphical Abstract

The co-placement of mine tailings and fly ash (CMF) can reduce acid mine drainage (AMD) production and decrease metal mobilization. This aids in waste management construction. However, few people have studied a large number of tailing sand–fly ash mixtures under the condition of neutral saturated solution in tailing ponds, wherein the pozzolanic reaction is highly gradual. In this study, a series of tests were conducted to determine the monotonic and cyclic shear characteristics of a mixture of fly ash and tailings. In particular, the effects of the fly ash content on the monotonic shear peak, shear strength parameters, dynamic modulus, and damping ratio of the mixture were analyzed. The results reveal that in a monotonic shear test, the peak shear strength of the saturated CMF mixture decreases as the fly ash content increases. The shear strength parameters (cohesion c and internal friction angle φ) were observed to increase and decrease linearly, respectively, as the fly ash content increased. Furthermore, the maximum dynamic shear modulus was observed to decrease by 41.4% as the fly ash content increased from 0 to 50%, during the cyclic cutting process. Moreover, the experimental results fit well with the fitting formula for the variation in shear modulus in the cyclic shear process of the saturated CMF mixture with varying fly ash content. Meanwhile, the initial damping ratio of the cyclic shear was observed to increase from 10.3 to 13.6% as the fly ash content increased. Therefore, when the CMF method is used to treat AMD waste, it is necessary to consider the extent to which the design stability of the tailing pond may be reduced. These experimental results can be used as a reference for similar CMF projects.

Under the rapid social-economic development process, the income structure and arable land size among rural households are facing with increasing differentiation in China. How the regional-scale arable land use intensity and environmental risk triggered by the rural households’ differentiation would be is a question that has not been widely discussed. To fill this research gap, this study established three step-by-step indexes, rural households’ ER index, arable land use intensity (LUI), and environmental risk index (RI), to measure rural households’ differentiation, regional arable land use intensity, and environmental risk, respectively. By gathering data from questionnaire investigation of 950 rural households in Shandong Province, China, the result showed a wide range of ER index (0.006–0.056), LUI (2748.90–6361.54), and RI (0.0966–0.5032). ER index based on farm income, nonfarm income, and arable land size among rural households showed different distributions among cities. Though huge differences of arable land use existed in different rural households, including land area, crop species, use of production materials (agro-machinery, fertilizer, pesticide), and attitude towards land transferring, the farmers’ sense of belonging to farmland and their dependence on agriculture did not disappear in the process of rural households’ differentiation. Moreover, as aggregated effects of rural households’ behavior, differentiation of regional arable land use intensity and environmental risk appeared later and lower than the level of rural households’ differentiation in the same city. Among this process, Laiwu, Weihai, and Yantai became “hotspots” with higher level of rural households’ differentiation, arable land use intensity, and agro-environmental risk, respectively. This study pointed out a possibility of policy designation that prior controlling environmental risk of arable land use could be realized by identifying the rural households’ differentiation on arable land use.

Proteins of extracellular polymeric substances (EPS) in sewage sludge play a key role in the sludge dewatering. Ethanol can denature proteins and improve sludge dewaterability. In this study, ethanol was used to precondition and combined with Fe³⁺ and rice husk (RH) for dewatering enhancement. The experimental results of the capillary suction time (CST) reduction efficiency indicated that the sewage sludge pretreated with ethanol and Fe³⁺-RH revealed well cooperative formation mechanism with regard to dewatering performance. Using the response surface methodology (RSM) determined that CST reduction efficiency of sewage sludge reached 78.5% under optimal conditions of ethanol 25.21 g/g dry solid (DS), Fe³⁺ 185.70 mg/g DS, and RH 406.02 mg/g DS, respectively. Moreover, the results showed that the composite conditioner is effective for the specific resistance to filtration decreased from initial 1.66E + 13 m/kg to 2.44E + 11 m/kg. The analysis of EPS showed that extractable proteins in EPS increased to maximum when the sludge was pretreated by Fe³⁺-RH because EPS were destroyed and proteins in EPS were released. After the addition of ethanol, extractable protein content was reduced because of protein precipitation and released interstitial water and bound water. The sludge morphology analysis indicated that the RH as a skeleton builder provided the outflow passages, which enhanced the dewatering performance of sludge. From these results, the combination treatment of ethanol and Fe³⁺-RH is a promising synergetic strategy to enhance the dewaterability of sewage sludge.

In this study, pot experiments were conducted to determine the effects of industrial solid wastes (ISWs) (ceramic, stone, and sugar factory wastes) and organic wastes (rice husk and wheat straw) on growth and heavy metals uptake by tomato (Lycopersicum esculentum) plants. The soil was treated with 10% of ISWs and 5% of organic wastes. The fractionation of heavy metals also has been studied in all treated soils. It was observed that the addition of ISWs in soil increased heavy metal contents in all fractions. The addition of organic wastes to control and treated soils decreased exchangeable fraction and increased organic matter and residual fractions. Following the ceramic factory and stone cutting waste addition, tomato yield significantly decreased as compared to control soil. The application of ISWs caused an increase in heavy metal contents of tomato plants. In control and ISWs-treated soils, dry matter yield of tomato grown in the presence of wheat straw was significantly restricted, while the application of rice husk increased tomato shoot and root dry weight. Results of experiments indicated that the application of both organic wastes significantly decreased heavy metal uptake by tomato plants. The investigation of health risk index (HRI) values indicated that in these industrial areas, potential health risk by intake of heavy metals from tomato for both adults and children generally assumed to be safe. The values of HRI were lesser when rice husk was applied to the soil. In general, these results highlighted that the application of rice husk in soils contaminated with ISWs increased the growth and yield of tomato and reduced the heavy metal toxicity for tomato consumption in contaminated soils.