Investigation of high-risk antibiotic resistance bacteria and their associated antibiotic resistance genes in different agricultural soils with biogas slurry from China.

High-risk antibiotic-resistant bacteria (ARB) and their accompanying antibiotic resistance genes (ARGs) seriously threaten public health. As a crucial medium for ARB and ARGs spread, soils with biogas slurry have been widely investigated. However, few studies focused on high-risk multi-drug resistant bacteria (MDRB) and their associated ARGs. This study examined ARB distribution in different agricultural soils with biogas slurry across 12 districts in China. It identified high-risk MDRB in various soil backgrounds, elucidating their resistance and spread mechanism. The findings revealed that diverse cultured ARB were enriched in soils with biogas slurry, especially soil ciprofloxacin ARB, which were enriched (>2.5 times) in 68.4 % of sampling sites. Four high-risk MDRB isolated from Hebei, Zhejiang, Shanxi, and Gansu districts were identified as severe or opportunistic pathogens, which carried abundant mobile genetic elements (MGEs) and 14 known high risk ARGs, including aac(3)-IId, aac(6')-Ib3, aph(6)-Id, aac(6')-Ib3, aadA1, blaOXA-10, blaTEM-1B, dfrA12, dfrA14, cmlA1, sul1, floR, tet(M) and tet(L). The antibiotics accumulation, diverse ARGs and MGEs enrichment, and proliferation of pathogenic bacteria could be potential driving factors of their occurrence and spread. Therefore, the coexistence of the high-risk MDRB and ARGs combined with the associated MGEs in soils with biogas slurry should be further investigated to develop technology and policy for reducing their negative influences on the effectiveness of clinical antibiotics.

Effects of swine manure and straw biochars on fluorine adsorption-desorption in soils.

With increasing global awareness of soil health, attention must be paid to fluorine exposure in soils, which poses a threat to human health. Therefore, this study aimed to study the fluorine adsorption characteristics of swine manure and straw biochars and their impact on fluorine adsorption-desorption in soil with batch experiments. The biochar samples originated from high-temperature anaerobic cracking of swine manure (350°C, 500°C, and 650°C) and straw (500°C). Results indicated that the adsorption of soil fluorine reached adsorption equilibrium at around 4 h after the mixing of swine manure and straw biochar. Fluorine adsorption kinetics using these biochars conformed to the quasi-two-stage kinetic model. The fluorine adsorption kinetics for biochar-treated soils conformed to the double-constant equation and the Elovich equation, and the soil treated with straw biochar showed the fastest fluorine adsorption rate. The adsorption isotherms of fluorine for biochars and biochar-treated soils could be fitted by the isothermal adsorption model of Langmuir and Freundlich. The maximal equilibrium quantity of fluorine was 73.66 mg/g for swine manure biochar. The soil, adding with 2% of swine manure biochar achieved with showed at 650°C had the smallest adsorption. This study also shows that the adsorption of fluorine by biochar gradually decreased with the increase of pH. Comparing with other factors, the mixture pH with biochars added had a significant effect on fluorine adsorption. The decreased fluorine adsorption capacities for soils treated with swine manure and straw biochars were closely related to the increased pH in soils after adding biochars. Considering the fluorine threat in soil, this study provides a theoretical basis for the application of biochars on soil fluorine adsorption.

The Prevalence of Marine Lipophilic Phycotoxins Causes Potential Risks in a Tropical Small Island Developing State.

Tropical small island developing states (SIDS), with their geographical isolation and limited resources, heavily rely on the fisheries industry for food and revenue. The presence of marine lipophilic phycotoxins (MLPs) poses risks to their economy and human health. To understand the contamination status and potential risks, the Republic of Kiribati was selected as the representative tropical SIDS and 55 species of 256 coral reef fish encompassing multiple trophic levels and feeding strategies were collected to analyze 17 typical MLPs. Our results showed that the potential risks of ciguatoxins were the highest and approximately 62% of fish species may pose risks for consumers. Biomagnification of ciguatoxins was observed in the food web with a trophic magnification factor of 2.90. Brevetoxin-3, okadaic acid, and dinophysistoxin-1 and -2 were first reported, but the risks posed by okadaic acid and dinophysistoxins were found to be negligible. The correlation analysis revealed that fish body size and trophic position are unreliable metrics to indicate the associated risks and prevent the consumption of contaminated fish. The potential risks of MLPs in Kiribati are of concern, and our findings can serve as valuable inputs for developing food safety policies and fisheries management strategies specific to tropical SIDS contexts.

Applications of charcoal, activated charcoal, and biochar in aquaculture - A review.

Environmental pollution and poor feed quality pose potential threats to aquatic organisms and human health, representing challenges for the aquaculture industry. In light of the rising demand for aquatic organisms, there is an urgent need to improve aquacultural production and protect the products from contamination. Char, a carbonaceous material derived through pyrolysis of organic carbon-rich biomass, has proven advantages in soil, air, and water remediation. While char's performance and the associated physicochemical characteristics depend strongly on the pyrolysis temperature, residence time, and feedstock type, char generally shows advantages in pollutant removal from the environment and livestock. This enables it to enhance the health and growth performance of livestock. Given the growing attention to char application in aquaculture in recent years, this review summarises major studies on three applications: aquacultural water treatment, sediment remediation, and char-feed supplement. Most of these studies have demonstrated char's positive effects on pollutant removal from organisms and aquacultural environments. Moreover, adopting char as fish feed can improve fish growth performance and the condition of their intestinal villi. However, due to insufficient literature, further investigation is needed into the mechanistic aspects of pollutants removal in aquatic organisms by char as a feed additive, such as the transportation of char inside aquatic organisms, the positive and negative effects of char on these products, and how char alters the gut microbiota community of these products. This paper presents an overview of the current application of char in aquaculture and highlights the research areas that require further investigation to enrich future studies.

The efficient applications of native flora for phytorestoration of mine tailings: a pan-global survey.

Mine tailings are the discarded materials resulting from mining processes after minerals have been extracted. They consist of leftover mineral fragments, excavated land masses, and disrupted ecosystems. The uncontrolled handling or discharge of tailings from abandoned mine lands (AMLs) poses a threat to the surrounding environment. Numerous untreated mine tailings have been abandoned globally, necessitating immediate reclamation and restoration efforts. The limited feasibility of conventional reclamation methods, such as cost and acceptability, presents challenges in reclaiming tailings around AMLs. This study focuses on phytorestoration as a sustainable method for treating mine tailings. Phytorestoration utilizes existing native plants on the mine sites while applying advanced principles of environmental biotechnology. These approaches can remediate toxic elements and simultaneously improve soil quality. The current study provides a global overview of phytorestoration methods, emphasizing the specifics of mine tailings and the research on native plant species to enhance restoration ecosystem services.

Assessment of antibiotic resistance genes in soils polluted by chemical and technogenic ways with poly-aromatic hydrocarbons and heavy metals.

Anthropogenic activities are leaving lots of chemical footprints on the soil. It alters the physiochemical characteristics of the soil thereby modifying the natural soil microbiome. The prevalence of antimicrobial-resistance microbes in polluted soil has gained attention due to its obvious public health risks. This study focused on assessing the prevalence and distribution of antibiotic-resistance genes in polluted soil ecosystems impacted by industrial enterprises in southern Russia. Metagenomic analysis was conducted on soil samples collected from polluted sites using various approaches, and the prevalence of antibiotic-resistance genes was investigated. The results revealed that efflux-encoding pump sequences were the most widely represented group of genes, while genes whose products replaced antibiotic targets were less represented. The level of soil contamination increased, and there was an increase in the total number of antibiotic-resistance genes in proteobacteria, but a decrease in actinobacteria. The study proposed an optimal mechanism for processing metagenomic data in polluted soil ecosystems, which involves mapping raw reads by the KMA method, followed by a detailed study of specific genes. The study's conclusions provide valuable insights into the prevalence and distribution of antibiotic-resistance genes in polluted soils and have been illustrated in heat maps.

Persistent effects of swine manure biochar and biogas slurry application on soil nitrogen content and quality of lotus root.

Using swine manure biochar and biogas slurry in agriculture proves to be an effective strategy for soil improvement and fertilization. In this study, a pot trial on the growth of lotus root was conducted to investigate the persistent effects of applying 350°C swine manure biochar (1% and 2%) and biogas slurry (50% and 100%) on soil nitrogen nutrient and lotus root quality. The results showed that compared to chemical fertilizer alone (A0B0), swine manure biochar significantly increased soil nitrogen content after one year of application. The contents of total nitrogen (TN), alkali-hydrolyzed nitrogen (AHN), ammonium nitrogen (NH4 +-N), and nitrate nitrogen (NO3- -N) increased by 17.96% to 20.73%, 14.05% to 64.71%, 17.76% to 48.68% and 2.22% to 8.47%, respectively, during the rooting period. When swine manure biochar was present, the application of biogas slurry further elevated soil nitrogen content. The co-application of swine manure biochar and biogas slurry significantly increased soil nitrogen content, and the 100% nitrogen replacement with biogas slurry combined with 2% swine manure biochar (A2B2) treatment exhibited the most significant enhancement effect during whole plant growth periods. Soil enzyme activities, including soil protease (NPT), leucine aminopeptidase (LAP), b-glucosidase (ß-GC) and dehydrogenase (DHA), showed a tendency to increase and then decrease with the prolongation of lotus root fertility period, reaching the maximum value during the rooting period. Compared to A0B0, the treatment with 2% swine manure biochar had the most significant effect on enzyme activities and increased the lotus root's protein, soluble sugar, and starch contents. Nitrate content decreased with the application of 2% swine manure biochar as the amount of biogas slurry increased. In conclusion, swine manure biochar effectively improved soil nitrogen content, enzyme activity, and lotus root quality. Even after one year of application, 2% swine manure biochar had the best enhancement effect.

Human health risk assessment based on a total diet study of daily mercury intake in Chengdu, China.

To assess the total daily mercury intake and main exposure sources of residents, six food groups, including marine fish, freshwater fish, poultry, livestock, vegetables, and cereals, were collected from five districts of Chengdu, China. The median concentrations of total mercury (THg) and methylmercury (MeHg) were 12.8 and 6.94 µg kg-1 ww, respectively. Cereals (32.2%), vegetables (30.5%), and livestock (16.2%) contributed to a much larger extent to the total consumption for the participants in Chengdu. All food categories that contributed the most of THg (2.16 µg day-1) and MeHg 1.44 (µg day-1) to the daily intake in Chengdu were cereals and marine fish, respectively. The total Hazard Ratios values below 1 in this study indicate that there is no health risk associated with Hg ingestion from the consumption of these foods for the residents in Chengdu.

Ecological and human health hazards of soil heavy metals after wildfire: A case study of Liangshan Yi autonomous prefecture, China.

Soil samples were collected in at different depths from the conflagration area in Liangshan Yi Autonomous Region, China, to investigate the distribution characteristics and ecological and human health risks of heavy metals after a wildfire. The samples collected comprise wildfire ash (WA) above the soil surface, ash soil (AS) 0-5 cm, and plain soil (PS) 5-15 cm below the soil surface. Additionally, reference soil (RS) was collected from a nearby unburned area at the same latitude as the conflagration area. The results showed that the concentrations of zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd) in the WA and AS were significantly higher than in reference soil (RS) (p < 0.05). Concentrations of Pb in the PS were 2.52 times higher than that in RS (17.9 mg kg-1) (p < 0.05). The AS and WA had the highest Index of potential ecological risks (RI > 600). In addition, The Cd in AS and WA contributed the most to the highest Improved nemerow index (INI) and RI with a contribution of more than 80%. The concentration of heavy metals was used to establish non-carcinogenic effects and cancer risks in humans via three exposure pathways: accident ingestion of soil, dermal contact with soil, and inhalation of soil particles. Hazard index (HI) values of each sample were all less than 1, indicating the non-carcinogenic risk was within the acceptable range and would not adversely affect the local population's health. The Cancer risk (CR) values of Cr, As, Cd, and Ni were all below 1 × 10-6, indicating that heavy metal pollution from this wildfire did not pose a cancer risk to residents.

Microplastics removal mechanisms in constructed wetlands and their impacts on nutrient (nitrogen, phosphorus and carbon) removal: A critical review.

Microplastics (MPs) are now prevalent in aquatic ecosystems, prompting the use of constructed wetlands (CWs) for remediation. However, the interaction between MPs and CWs, including removal efficiency, mechanisms, and impacts, remains a subject requiring significant investigation. This review investigates the removal of MPs in CWs and assesses their impact on the removal of carbon, nitrogen, and phosphorus. The analysis identifies crucial factors influencing the removal of MPs, with substrate particle size and CWs structure playing key roles. The review highlights substrate retention as the primary mechanism for MP removal. MPs hinder plant nitrogen uptake, microbial growth, community composition, and nitrogen-related enzymes, reducing nitrogen removal in CWs. For phosphorus and carbon removal, adverse effects of MPs on phosphorus elimination are observed, while their impact on carbon removal is minimal. Further research is needed to understand their influence fully. In summary, CWs are a promising option for treating MPs-contaminated wastewater, but the intricate relationship between MPs and CWs necessitates ongoing research to comprehend their dynamics and potential consequences.

Effects of sodium selenite, yeast selenium, and nano-selenium on toxicity, growth, and selenium bioaccumulation in Lucilia sericata maggots.

In this study, we investigated the effects of different types of selenium (Se) (sodium selenite [SS], yeast selenium [YS], and nano-selenium [NS]) on the toxicity, growth, Se accumulation, and transformation of Lucilia sericata maggots (LSMs). We found that the 50% lethal concentration of LSMs exposed to SS was 2.18 and 1.96 times that of YS and NS, respectively. LSM growth was significantly promoted at exposure concentrations of 10-50 mg kg-1 in group SS and 10-30 mg kg-1 in group YS, whereas NS inhibited LSMs growth at all concentrations (p < 0.05). Total Se content in LSMs, conversion efficiency to organic and other forms of Se, and bioaccumulation factor of Se were the highest in the SS group when exposed to 50 mg kg-1 (81.6 mg kg-1, 94.6%, and 1.63, respectively). Transcriptomic results revealed that LSMs significantly upregulated the amino acid (alanine, aspartate, glutamic, and tyrosine) and tricarboxylic acid cycle signaling pathways (p < 0.05) on exposure to Se, resulting in a significant increase in LSMs biomass and quality. In conclusion, our study indicates that LSMs exhibit good tolerance to SS and can convert it into bioorganic or other forms of Se.

Nanomaterials and biochar mediated remediation of emerging contaminants.

The unrestricted release of various toxic substances into the environment is a critical global issue, gaining increased attention in modern society. Many of these substances are pristine to various environmental compartments known as contaminants/emerging contaminants (ECs). Nanoparticles and emerging sorbents enhanced remediation is a compelling methodology exhibiting great potential in addressing EC-related issues and facilitating their elimination from the environment, particularly those compounds that demonstrate eco-toxicity and pose considerable challenges in terms of removal. It provides a novel technique enabling the secure and sustainable removal of various ECs, including persistent organic compounds, microplastics, phthalate, etc. This extensive review presents a critical perspective on the current advancements and potential outcomes of nano-enhanced remediation techniques such as photocatalysis, nano-sensing, nano-enhanced sorbents, bio/phyto-remediation, which are applied to clean-up the natural environment. In addition, when dealing with residual contaminants, special attention is paid to both health and environmental implications; therefore, an evaluation of the long-term sustainability of nano-enhanced remediation methods has been considered. The integrated mechanical approaches were thoroughly discussed and presented in graphical forms. Thus, the critical evaluation of the integrated use of most emerging remediation technologies will open a new dimension in environmental safety and clean-up program.

Fostering plant growth performance under drought stress using rhizospheric microbes, their gene editing, and biochar.

Stress due to drought lowers crop yield and frequently leads to a rise in food scarcity. Plants' intricate metabolic systems enable them to tolerate drought stress, but they are unable to handle it well. Adding some external, environmentally friendly supplements can boost plant growth and productivity when it comes to drought-stressed plants. In order to prevent the detrimental effects of drought in agricultural regions, environmentally friendly practices must be upheld. Plant growth-promoting rhizobacteria (PGPR) can exhibit beneficial phytostimulation, mineralization, and biocontrol activities under drought stress. The significant impact of the PGPR previously reported has not been accepted as an effective treatment to lessen drought stress. Recent studies have successfully shown that manipulating microbes can be a better option to reduce the severity of drought in plants. In this review, we demonstrate how modifying agents such as biochar, PGPR consortia, PGPR, and mycorrhizal fungi can help overcome drought stress responses in crop plants. This article also discusses CRISPR/Cas9-modifiable genes, increase plant's effectiveness in drought conditions, and increase plant resistance to drought stress. With an eco-friendly approach in mind, there is a need for practical management techniques having potential prospects based on an integrated strategy mediated by CRISPR-Cas9 editing, PGPR, which may alleviate the effects of drought stress in crops and aid in achieving the United Nation Sustainable Development Goals (UN-SDGs-2030).

Algae decomposition released dissolved organic matter subfractions on dark abiotic mercury methylation.

To understand the mechanism of dark abiotic mercury (Hg) methylation by algae-derived dissolved organic matter (DOM) and effectively manage the environmental risks of mercury methylation in aquaculture areas, we investigated the influence of subfractions of DOM released from algae (Ulothrix sp.) decomposition on mercury methylation. The results showed that the hydrophobic basic component (HOB) in DOM exhibited the most substantial promotion effect on Hg methylation. The methylmercury (MeHg) production in the HOB treatment increased significantly, while the production rate of MeHg (%MeHg represented the concentration ratio of MeHg to THg) in the six subfractions treated solutions decreased significantly with the increase of Hg concentration. The change of the %MeHg was more evident at low Hg concentration, indicating the limited number of binding sites and methyl donors on DOM. As a consequence, Hg(Ⅱ) in the solution could not be converted into MeHg in equal proportion. Furthermore, the production of MeHg in solution was significantly reduced by the decomposed algae DOM, and its concentration was in the range of 0.017-0.085 ng·L-1 (significantly lower than undecomposed algal). The difference between the decomposed and the non-decomposed algae DOM reached a significant level (P < 0.05). When the DOM decayed for 20 and 30 days, the Hg methylation ability of DOM was weakened most obviously. During the decomposition process, considerable variations were observed among the subfractions, with HOB consistently playing a dominant role in Hg methylation. At the same time, the hydrophilic acid component exhibited a significant inhibitory effect on Hg methylation. Generally, the main components (e.g. HOB and HIA (hydrophilic acid component)) of DOM affecting mercury methylation were found in our study, which provided a better understanding of algae-derived DOM subfractions on the Hg methylation, in an attempt to prevent and control water pollution in aquaculture areas.

Hair Heavy Metals and Food Consumption in Residents of Chengdu: Factors, Food Contribution, and Health Risk Assessment.

Heavy metal pollution is one of the most pressing issues threatening food security and human health. This study assesses heavy metal (chromium, cadmium, copper, zinc, nickel, and lead) exposure via hair metal concentrations in Chengdu residents, reflecting metal intake from food consumption. From June 2020 to February 2021, a sampling survey was conducted on residents' hair (n=182) and food (n=301) in six main urban areas of Chengdu. The concentrations of heavy metals in hair and food were analyzed by inductively coupled plasma mass spectrometry, and the results showed that the residents of Chengdu City had high hair concentrations of Cd (0.17±0.03 mg kg-1) and Zn (293±21.3 mg kg-1). Gender significantly affected the hair Cr, Zn, and Ni concentrations. Based on the survey results obtained from Chengdu City residents, the habits and diet structure are assessed for the influence of six heavy metals in the hair of the residents. Adolescents' (13-18 years old) hair had significantly higher Pb concentrations than adults (19-59 years old). The concentration of Ni in hair was affected by perming and dyeing habits. For dietary exposure, cereals and meat were the main contributors to the residents' daily intake of heavy metals. The bioaccessibility of Cr, Cd, Cu, Zn, Ni, and Pb in food was 2.45-74.67%, 10.6-78.7%, 13.4-82.5%, 8.89-89.2%, 7.70-85.1%, and 15.4-86.2%, respectively. In health risk evaluation based on the bioaccessible fraction of six heavy metals, the hazard quotient of each heavy metal in food was less than 1, indicating no potential non-carcinogenic risk.

Application of X-ray based modern instrumental techniques to determine the heavy metals in soils, minerals and organic media.

To evaluate the environmental concerns associated with heavy metals (HMs) during their translocations in food chains, it is crucial to gather data on the types of HMs present in soils in order to ascertain their toxicity and potential to migrate. An overview of the findings from several physical techniques used to determine and identify the HMs, sediments, individual minerals, and organic components in contaminated agricultural and industrial soils, is provided in this review article. These studies cover a variety of X-ray-based analytical techniques, including most widely used ones like X-ray absorption near edge structure, extended X-ray absorption fine structure, X-ray diffraction, and less popular ones X-ray fluorescence, etc. When compared to techniques that rely on laboratory radiation sources, synchrotron radiation offers more precision and efficiency. These methods could pinpoint the primary mechanisms influencing the soil's ability to transport contaminants and track their subsequent migration up the food chain.

Synthesis and properties of nano-cadmium oxide and its size-dependent responses by barley plant.

Present study included technological methods that made it possible to synthesize CdO nanoparticles and carry out their qualitative and quantitative diagnostics, confirming the as-prepared CdO nanoparticles (NPs) were spherical and had a size of 25 nm. Then, under the conditions of the model experiment the effect of CdO in macro and nanosized particles on absorption, transformation, and structural and functional changes occurring in cells and tissues of Hordeum vulgare L. (spring barley) during its ontogenesis was analyzed. Different analytical techniques were used to detect the transformation of CdO forms: Fourier-transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), X-ray fluorescence analysis (XRF), Scanning electron microscopy (SEM-EDXMA and TEM), X-ray diffraction (XRD), and X-ray absorption fine structure, consists of XANES - X-ray absorption near edge structure, and EXAFS - Extended X-ray absorption fine structure. Quantitative differences in the elemental chemical composition of barley root and leaf samples were observed. The predominant root uptake of Cd was revealed. CdO-NPs were found to penetrate deeply into barley plant tissues, where they accumulated and formed new mineral phases such as Cd5(PO4)3Cl and CdSO4 according to XRD analysis. The molecular-structural state of the local Cd environment in plant samples corresponding to Cd-O and Cd-Cd. The toxicity of CdO-NPs was found to significantly affect the morphology of intracellular structures are the main organelles of photosynthesis therefore, destructive changes in them obviously reduce the level of metabolic processes ensuring the growth of plants. This study is an attempt to show results how it is possible to combine some instrumental techniques to characterize and behavior of NPs in complex matrices of living organisms.

Transfer and Degradation of PAHs in the Soil-Plant System: A Review.

Polycyclic aromatic hydrocarbons (PAHs) are highly toxic, persistent organic pollutants that threaten ecosystems and human health. Consistent monitoring is essential to minimize the entry of PAHs into plants and reduce food chain contamination. PAHs infiltrate plants through multiple pathways, causing detrimental effects and triggering diverse plant responses, ultimately increasing either toxicity or tolerance. Primary plant detoxification processes include enzymatic transformation, conjugation, and accumulation of contaminants in cell walls/vacuoles. Plants also play a crucial role in stimulating microbial PAHs degradation by producing root exudates, enhancing bioavailability, supplying nutrients, and promoting soil microbial diversity and activity. Thus, synergistic plant-microbe interactions efficiently decrease PAHs uptake by plants and, thereby, their accumulation along the food chain. This review highlights PAHs uptake pathways and their overall fate as contaminants of emerging concern (CEC). Understanding plant uptake mechanisms, responses to contaminants, and interactions with rhizosphere microbiota is vital for addressing PAH pollution in soil and ensuring food safety and quality.

Co-application of concentrated biogas slurry and pyroligneous liquor mitigates ammonia emission and sustainably releases ammonium from paddy soil.

Biogas production causes vast amounts of biogas slurry (BS). Application of BS to croplands can substitute chemical fertilizers while result in higher ammonia emissions. Tremendous variation of ammonium concentration in different BSs induces imprecise substitution, while concentrated BS holds higher and more stable ammonium. Pyroligneous liquor, an acidic aqueous liquid from biochar production, can be used with concentrated BS to reduce ammonia emission. However, the effects of combining concentrated BS with pyroligneous liquor on ammonia emission and soil (nitrogen) N transformation have been poorly reported. In this study, a field experiment applying concentrated BS only, or combining with 5 %, 10 %, and 20 % pyroligneous liquor (v/v) for substituting 60 % N of single rice cultivation was conducted by contrast with chemical fertilization. The results showed that substituting chemical N fertilizers with concentrated BS increased 24.6 % ammonia emission. In comparison, applying 5 %, 10 %, and 20 % pyroligneous liquor with concentrated BS reduced 4.9 %, 20.3 %, and 24.4 % ammonia emissions, respectively. Applying concentrated BS with more pyroligneous liquor preserved higher ammonium and dissolved organic carbon in floodwater, and induced higher nitrate concentration after fertilization. Whereas soil ammonium and nitrate contents were decreased along with more pyroligneous liquor application before and after the topdressing and exhibited sustainable release until rice harvest. In comparison, the soil N mineralization and nitrification rates were occasionally elevated, while the activities of soil urease, protease, nitrate reductase, and nitrite reductase had multiple responses. Applying concentrated BS only, or combining with 5 %, 10, and 20 % pyroligneous liquor, have little effect on soil basic properties but inorganic N. In summary, applying concentrated BS with >10 % pyroligneous liquor could preserve more N with sustainable release and potentially lower N loss to the atmosphere, and we proposed that applying 13.5 % pyroligneous liquor in concentrated BS could achieve maximum soil fertility and minimum ammonia emission.

A critical review on selenium removal capacity from water using emerging non-conventional biosorbents.

Anthropogenic-driven selenium (Se) contamination of natural waters has emerged as severe health and environmental concern. Lowering Se levels to safe limits of 40 µg-L-1 (recommended by WHO) presents a critical challenge for the scientific community, necessitating reliable and effective methods for Se removal. The primary obectives of this review are to evaluate the efficiency of different biosorbents in removing Se, understand the mechanism of adsorption, and identify the factors influencing the biosorption process. A comprehensive literature review is conducted to analyze various studies that have explored the use of modified biochars, iron oxides, and other non-conventional biosorbents for selenium removal. The assessed biosorbents include biomass, microalgae-based, alginate compounds, peats, chitosan, and biochar/modified biochar-based adsorbents. Quantitative data from the selected studies analyzed Se adsorption capacities of biosorbents, were collected considering pH, temperature, and environmental conditions, while highlighting advantages and limitations. The role of iron impregnation in enhancing the biosorption efficiency is investigated, and the mechanisms of Se adsorption on these biosorbents at different pH levels are discussed. A critical literature assessment reveals a robust understanding of the current state of Se biosorption and the effectiveness of non-conventional biosorbents for Se removal, providing crucial information for further research and practical applications in water treatment processes. By understanding the strengths and limitations of various biosorbents, this review is expected to scale-up targeted research on Se removal, promoting the development of innovative and cost-effective adsorbents, efficient and sustainable approaches for Se removal from water.