High Organic Matter Research Articles

A MODEL FOR SELECTION OF DECENTRALIZED SANITARY SEWER SYSTEMS FOR SMALL MUNICIPALITIES

The precariousness of sanitation services in small Brazilian municipalities is exacerbated by technical and financial limitations. In these places treatment technologies need to be simple, sustainable, economically viable, and socially accessible. This work aims to propose a selection model for decentralized sewage treatment technologies for small municipalities. The PROMETHEE II multi-criteria method was used to rank the technologies with aid decision-making agents to prioritize technical, environmental, economic, and social criteria based on the characteristics of the sewer basins. After validating the method in the sewage catchment areas of four municipalities in Paraíba, the results showed that the constructed wetlands technology occupied the best position in 88.9% of the sewer basins. This technology stands out for its high organic matter and suspended solids removal efficiency, in addition to not generating sludge and performing well in terms of social criteria (odor production and vectors). The septic tank and septic tank + anaerobic filter alternatives ranked lower in the basins studied. The robustness of the method and the assignment of preferences to criteria for sewer basins with different classifications indicate that the model is replicable for small municipalities. Thus, the study contributes to the optimization of decision-making for sewage treatment systems, allowing the better use of resources, the reduction of vulnerabilities, and promotion of municipal development.

Comparative Approach of Staphylococcus Abundance in 3 Different AquaticEnvironments in Kribi (Coastal Area, Cameroon, Central Africa), andPotential Role of Some Abiotic Factors

A study to compare bacterial populations in sea, ground and stream waters and to assess the importance of some abiotic factors on these populations was carried out in the town of Kribi (on the Cameroonian coast) from January to March 2024. The bacteria sought were Aerobic Mesophilic Heterotrophic Bacteria (AMHB) and staphylococci. They were isolated using the surface spreading technique on Petri dishes on PCA media (Rapid Labs, ref CM-PCASP051) and the membrane filtration technique on Chapman mannitol medium (HIMEDIA, ref MH118-500G), for AMHB and staphylococci respectively. Isolated bacteria were identified by standard methods. Some abiotic parameters were measured using standard analytical techniques. These analyses showed that the abiotic variables varied overall from one sampling period to the next and from one point to the next. It was noted that the water was neutral with low mineral content. The high nitrogen values recorded at all the sampling points attest to the high organic matter content of the water analyzed. Bacteriological analyses revealed that the water contains a high-density bacterial microflora consisting of AMHB and bacteria of the Staphylococcus genus. The average densities of AMHB in log (CFU/100 mL) were 5.62, 5.86 and 5.30 in groundwater, stream waters and seawaters respectively. The waters of this coastal area of Cameroon are populated by Staphylococcus species, Staphylococcus aureus and Staphylococcus epidermidis, with mean densities of 2.66 (log (CFU/100 mL)), 3.30 (log (CFU/100 mL)) and 5, 36 (log (CFU/100 m)) for Staphylococcus aureus and 1.66 (log (CFU/100mL)), 1.06 (log (CFU/100mL)) and 5.02 ( log (CFU/100 mL)) for Staphylococcus epidermidis in groundwater, stream waters and seawaters respectively. Comparatively, the densities of staphylococci in seawaters were more abundant and diverse than those in groundwater and stream waters. The deterioration in the quality of these coastal waters seems to be encouraged by their proximity to point sources of pollution linked to discharges of ballast water without prior treatment. These waters are therefore not recommended for human consumption according to WHO standards.

Cascade reservoirs affected chemical compositions of dissolved organic matter and greenhouse gas dynamics in the Lancang River.

Dissolved organic matter (DOM) is an important component in aquatic systems. There has been much debate about the potential effects of cascade reservoirs on the transport and transformation of DOM. Here, through a survey of source to leave-boundary section of Lancang River (LCR) in June and November of 2017-2018, our results revealed that weak spatiotemporal variations were observed for DOC content, whereas DOM parameters were significantly different between natural and reservoir reaches. And DOM showed higher humification degree from allochthonous sources with increasing autochthonous matter in reservoir reach, may due to high particulate organic matter and releasing autochthonous DOM from phytoplankton blooms in the LCR, which can be evidenced by depleted DIC, enriched δ13CDIC and higher BIX. A unique fluorescent fraction (C5) appeared in the reservoir reach and increased along water flow, which was strongly associated with dissolved CO2 and N2O. Meanwhile, BIX value decreased with increasing dam height, hydraulic residence time (HRT), and reservoir capacity, which may promote CH4 production, highlighting variation of DOM compositions in understanding the effect of greenhouse gas (GHG) dynamics in the LCR. The findings were essential for comprehending the influences of cascade reservoirs on carbon cycle, and informed policy development for the sustainable management of transboundary water resources like the LCR.

Mass organic matter accumulation induced by rapid redox variations in lakes: Evidence from the Miaoxi area, Bohai Bay Basin, China

The Member 4 of the Paleogene Shahejie Formation (Es4) in the Bohai Bay Basin is interspersed with a set of high-quality source rocks typified as intercalation of red and black mudstones. A large amount of petroleum (crude oil) originates from these source rocks. The Paleocene–Eocene Thermal Maximum (PETM) event occurred during the deposition of Es4 in the Bohai Bay Basin, and the organic matter enrichment model under this event is worth further investigation due to its relationship with and influence on petroleum accumulations. Well LK25-A, as the first oil exploration well drilled into the Es4 in Miaoxi area, serves as a valuable case to study organic matter accumulation. In this study, we integrate total organic carbon (TOC), Rock-Eval pyrolysis, microscopic observation, vitrinite reflectance (VRo), elemental analysis, and gas chromatography–mass spectrometry (GC–MS) to evaluate the hydrocarbon generation potential, organic matter types, thermal maturity, and sedimentary environment of the Es4 in Miaoxi area. The analysis of maceral and rock pyrolysis data reveals that Type I and Type II organic matter make up the majority of Paleogene mudstones in this region. The TOC and rock pyrolysis data show that mudstones in this area have high organic matter abundance and oil-generation potential. The measured vitrinite reflectance distribution of mudstone samples, which ranges from 0.3% to 0.74%, demonstrates that the Paleogene strata are at the immature to mature stage, and the samples from this area contain a sizable amount of bituminite and mineral-bituminous groundmass. The analysis of biomarkers in the mudstone samples indicates that most of the mudstones in this area are in lacustrine and brackish-hypersaline lacustrine environment under a reducing condition, and some of the red mudstones in the Es4 are formed under a suboxic condition. Based on the size and morphology of the pyrite framboid, the redox conditions of the water mass during deposition or diagenesis are further analyzed. The ratio of the size of framboid pyrite (D) to the size of its micrograins (d) suggests that the Es4 black mudstone developed in an anoxic sulfuretted water environment. Both the inorganic and organic geochemical indexes show that the Paleogene paleoclimate has a great influence on the source rocks of Es4 in this area. The distribution of red–black strata in the area is the result of the combined action of the water redox state and the climatic variation during the PETM event. The development models of organic-rich source rocks from the Es3 and Es4 in this area have been created in light of potential connections between rapid redox variation and the PETM event during the Paleogene. These models may offer a theoretical guidance for petroleum exploration in Miaoxi area of Bohai Bay Basin and other contemporaneous continental basins around the world.

Biomethane Production Through Performance Enhancement of Anaerobic Digestion and Sludge Dewatering Processes in a Wastewater Treatment Plant

Sewage sludge management poses a persistent challenge due to increasing volumes and stringent environmental regulations. Current municipal wastewater treatment technologies are energy intensive, produce large quantities of residuals and fail to recover the potential resources available in wastewater. Anaerobic digestion (AD) is widely recognized for its cost-effective stabilization, high organic matter removal, and biogas production potential. However, the hydrolysis phase remains a bottleneck in AD, limiting methane yield. Furthermore, its application for low strength municipal wastewater is limited. To address such challenges, the effects of combined microwave-ultrasonic and combined microwaveoxidative pre-treatment of thickened excess activated sludge and mixed sludge on the performance enhancement of conventional mesophilic digester and on two-stage digesters are presented in this study. Microwave-ultrasonic pretreatment was optimized for enhanced cell disruption, while microwave oxidation pretreatment incorporated hydrogen peroxide to generate reactive oxygen species for accelerated organic solubilization. Experimental setups included single- and two-stage anaerobic digesters operated under mesophilic and thermophilic conditions. Results demonstrated that combined microwave-ultrasonic pretreatment improved cumulative methane production by 18% and total solids reduction by 31%, compared to microwave-only pretreatment. Microwave oxidation pretreatment with 1% H₂O₂ achieved 40% volatile solids solubilization, significantly enhancing methane yield and sludge dewaterability. The two-stage AD process further improved performance, achieving 76.4 mL/g TCOD methane yield and 58% methane content in biogas, outperforming single-stage systems. Findings indicate that hybrid pretreatments synergistically enhance hydrolys

Co-pyrolysis of coal-derived sludge and low-rank coal: Thermal behaviour and char yield prediction

Coal-derived sludge, a solid waste produced by the coal industry, offers potential opportunities for resource recovery due to its high organic matter. However, its products face challenges related to low utilization efficiency and economic value. Effective and clean treatment of coal-derived sludge is essential for sustainable development. Herein, we studied the co-pyrolysis treatment of coal-derived sludge and low-rank coal at different temperatures (500 °C−900 °C) and pretreatment methods (mechanical mixing and hydrothermal co-treatment). The co-pyrolysis of sludge and coal could increase the pyrolysis char yield and H2 yield, as well as reduce CO2 emissions. The hydrothermal co-treatment significantly improved the cleanliness of the co-pyrolysis treatment. Then we conducted a comprehensive analysis of the properties of the pyrolysis char using different characterization techniques. In order to better evaluate the distribution of co-pyrolysis product yield, six machine learning models were developed to predice co-pyrolysis char yield. The best model-predicted values showed excellent predictive performance when compared to the experimental values at high pyrolysis temperatures (≥700 °C). This study provided a new perspective on the resource utilization of coal-derived sludge and low-rank coal.

Orbital pacing of the early Eocene source rock deposition in Tunisia (Bou Dabbous Formation): Astrobiochronological insights into cyclicities through surface-subsurface integration

The Early Eocene Bou Dabbous Formation (BDF) source rock is an economically important source rock in the SW Neo-Tethys covering most of the Ypresian outer ramp to basin deposits in Tunisia. The main rock types of the BDF in central Tunisia include globigerinids-rich grey to black laminated marl and limestone, which occur with an obvious cyclicity at astronomical timescales. This study examines two high-resolution borehole records from northern and eastern Tunisia and an outcrop analog in central Tunisia. The datasets examined were total organic carbon (TOC), magnetic susceptibility, CaCO3, δ13C, δ18O, and Gamma-Ray (GR). We aim to investigate the relationship between the rhythmic patterns observed at the BDF outcrop and the Milankovitch cycles and contextualize the findings within the Ypresian Astrochronological Time Scale (YATS). Additionally, we will discuss the impact of astronomical forcing on sea-level variations and the upwelling system during a greenhouse world. Field measurements and power spectra of the untuned data reveal a hierarchy of cycles throughout the BDF with ∼11.1 m, 4.1, 2.4 m, 1.1 m, and 0.6 m wavelengths. Tuning the 11.1 m cycles to the 405 kyr eccentricity cycle, the astronomical parameters—eccentricity, obliquity, and the precession index—become apparent. The 405 kyr eccentricity cycle is linked to relative sea-level changes inferred from sequence stratigraphy analysis and sedimentary noise modeling. Periods with increased TOC are associated with strong obliquity forcing inferred from the power decomposition analysis and the strong 173-kyr obliquity modulation cycles. The Ypresian record from Tunisia demonstrates the orbital pacing on the strength of the upwelling system, by affecting both the sea level and the climatic belt (wind regime). From 53.89 Ma to 53.2 Ma (TOC >2 wt %), our model demonstrates that obliquity-driven changes in water stratification led to episodes of varying oxygen levels at the bottom of the basin, affecting organic matter decay and preservation. During the Early Eocene Climatic Optimum, changes in climatic belts and wind patterns, along with rising sea levels, led to a shift in the high organic matter accumulation zone. This resulted in a weakened upwelling system in central Tunisia and reduced organic matter accumulation (TOC <0.5 wt%).

Valorisation of Deinking Paper Sludge for Fertiliser Purposes: New Perspective in Sustainable Agriculture

The growth of the global population, coupled with concomitant economic development, has resulted in the generation of a substantial quantity of waste. The transition of the European Union’s economy towards a closed-loop model is prompting a comprehensive search for waste management concepts across a range of industrial sectors. The objective of this study is to valorise deinking paper sludge, which has a high potential for soil formation due to its high organic matter content. To produce organic–mineral fertiliser, the deinking sludge was subjected to acid hydrolysis, then neutralised with KOH solution and enriched with poultry litter ash. The final products were characterised in terms of their nutrient and heavy metal content. The bioavailability of phosphorus, along with the forms in which it occurs in fertilisers, was determined through the implementation of a five-step fractionation procedure. Furthermore, an eight-week incubation period was conducted to assess the fertilisers’ performance in soil. Soil samples were tested on a weekly basis for pH, water-soluble and bioavailable phosphorus content using the spectroscopic method after previous extraction in water and Bray’s solution, and catalase activity using the titrimetric method. The resulting fertilisers were found to meet the requirements for organo-mineral fertilisers and were categorised as PK-type fertilisers with a total nutrient content of 24.6–39.3%. Fractionation studies demonstrated that the fertilisers contained 20–30% of the total potentially bioavailable phosphorus. Furthermore, the long-term release of phosphorus from the fertilisers was confirmed through incubation studies. Additionally, the fertilisers were observed to contribute to an increase in catalase activity in the soil.

PAH contamination in coastal surface sediments and associated bacterial communities

Polycyclic aromatic hydrocarbons (PAH) are semi-volatile, lipophilic, and harmful compounds that can persist for decades in a range of marine environments. There are several marine and soil microorganisms that possess enzymes involved in arene degradation. Here, we analyzed the structure (16S rRNA amplicons) and metabolic potential (inferred using phylogenetic placement) of the bacterial community in surface marine sediments from coastal waters off Concepción, Chile, and describe how microbial community patterns are shaped and altered by PAH contamination. Two depositional zones were identified, a “High PAH” area containing a mix of high and low molecular weight PAH of up to 10,350 ng∑PAH gdw−1 and with high organic matter content; and a “Low PAH” zone mostly characterized by low molecular weight PAH of up to 1810 ng∑PAH gdw−1 and lower levels of organic matter. We identified 53 hydrocarbonoclastic bacteria genera, with eight showing relatively high abundances at High PAH sites, although known PAH degrader clades were also present at Low PAH sites. With potential enzymes inferred in almost all samples, we suggest that breakdown of PAH is widespread in this area, likely resulting from the long history of local PAH emissions that may have promoted a stored microbial capacity for these degradation processes.

Anaerobic membrane bioreactor (AnMBR) with external ultrafiltration membrane for the treatment of sugar beet vinasse.

Vinasse, a by-product of ethanol production, is generated at significant rates. While rich in nutrients such as calcium, magnesium, and potassium, its high solids, organic matter, acidity, and sulfate content pose challenges when disposed directly on soil, necessitating treatment. Anaerobic digestion is a viable solution, reducing organic pollution while recovering energy in the form of biogas, aligning with the biorefinery concept. Traditionally, sludge bed reactors and anaerobic contact reactors are utilized for vinasse processing, with sludge granulation being vital for treatment success. However, challenges such as sludge wash-out due to recalcitrant compounds, high solids concentration in the influent, low pH, salinity, and temperature hinder granule formation. Anaerobic membrane bioreactors (AnMBR) offer an alternative, simplifying treatment by integrating intensified pre- and post-treatment units. Due to complete sludge retention, AnMBRs achieve high COD removal efficiencies, yielding a suspended solids-free and largely disinfected effluent. Therefore, AnMBRs show promise for vinasse treatment, eliminating the need for sludge granulation and producing nutrient-rich effluent with minimal residual organics and suspended solids. In this study, an AnMBR equipped with an inside-out external crossflow ultrafiltration membrane was proposed for the treatment of vinasse. The AnMBR reached a COD removal efficiency of 95% ± 2.6% and produced 0.3 CH4 L.g COD removed -1 working at organic loading rates of 8g COD. L-1 d-1 and membrane fluxes of 10 LMH. At organic loading rates of 10g COD. L-1 d-1 and fluxes of 12 and 14 LMH, the COD removal efficiency decreased to 77% ± 11% and 73% ± 7.9%, respectively. The AnMBR technology represents an innovation for wastewater treatment, however, more research using the cross-flow configuration and different types of effluents is needed. Literature studies that address the treatment of sugar beet or sugarcane vinasse using AnMBR are still scarce. This study explored the potentials of AnMBR technology for vinasse treatment and contributes to the dissemination of this technology, opening new possibilities for vinasse processing.

Spatial distribution studies on sedimentary organic matter along the shoreline of Arabian Sea: insights from Kollam, Southwest Coast, India.

The present study was aimed at investigating the source, quality, and quantity of organic matter and labile fraction of biochemical constituents in the surficial sediments of Arabian Sea Shoreline at Kollam, India, which gives an input into the processes associated with the subsurface geochemistry pattern. About 15 surface sediment samples were collected from the five beaches for this study during January 2021. The samples were analyzed for CHN, total organic carbon (TOC), and labile fraction such as carbohydrates (CHO), proteins (PRO), and lipids (LIP). The TOC/TN ratio revealed that the source organic matter (OM) in the samples was primarily of marine origin and autochthonous, except TM3 at Thirumullavaram. Thirumullavaram is a sheltered beach, and it has low hydrodynamic process. The high organic matter content in TM3 (13.9) may be the originated from the terrestrial input. The hierarchical cluster analysis revealed that TM3 indicate that unique character to other stations. Principal component analysis revealed that three components accounted for 78% of the total variance. PC1 variance was associated with carbon-based organic compounds. PC2 was predominantly influenced by CHO and LOM, suggesting that PC2 may encompass variability associated with these nutritional profiles. PC3 was influenced by LIP and LIP/CHO, showing it may be a lipid-related component. The PRO to CHO ratio is < 1, exhibiting old aged organic matter deposited in sediments and the meso-oligotrophic status. The LIP to CHO ratio, recorded as < 1, exhibits the poor quality of energetic (food) OM in sediments. The sediment samples exhibit the following trend CHO > PRO > LIP.

Air-drying causes an alteration in density fractionation of soil materials from organic horizons containing volcanic ash

Density fractionation is commonly used to isolate organic matter in soils based on organo-mineral associations. Not only mineral horizons but also organic horizons contain mineral components. Soil samples for density fractionation are sometimes air-dried or freeze-dried, which can introduce unexpected biases in the results. In this study, we compared the density fraction distributions in wet, air-dried, and freeze-dried organic horizon samples rich in reactive Al and Fe minerals. On Mt. Chokai, a volcano in northern Japan, samples were collected from organic horizons from three representative vegetation types: K1 (dwarf pine and dwarf bamboo at the summit), K2 (dwarf bamboo on the back slope), and K3 (snow meadow with predominantly Poaceae at the foot slope). Wet, air-dried, and freeze-dried samples were subjected to sequential density fractionation using cutoff values of 1.6 and 1.8 g cm–3. We then determined the mass, organic carbon, and total nitrogen distributions in the isolated fractions. Air-drying altered the mass, organic carbon, and total nitrogen distribution of each density fraction. Although we observed differences in the mass distributions of the freeze-dried and wet samples in the snow meadow samples (K3), the mass distributions in the K1 and K2 samples did not change significantly between the freeze-dried and wet samples. Therefore, freeze-drying is recommended as a pretreatment to minimize the effects of drying on density fractionation, particularly for soil samples with no drying history, high organic matter content, and/or high levels of reactive Al and Fe minerals.

Recovery of clinically relevant multidrug-resistant Klebsiella pneumoniae lineages from wastewater in Kumasi Metropolis, Ghana.

Antimicrobial resistance (AMR) is under-monitored in Africa, with few reports characterizing resistant bacteria from the environment. This study examined physicochemical parameters, chemical contaminants and antibiotic-resistant bacteria in waste stabilization pond effluents, hospital wastewater and domestic wastewater from four sewerage sites in Kumasi. The bacteria isolates were sequenced. Three sites exceeded national guidelines for total suspended solids, biochemical oxygen demand, chemical oxygen demand and electrical conductivity. Although sulfamethoxazole levels were low, the antibiotic was detected at all sites. Multi-drug-resistant Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated with multi-locus sequence typing identifying K. pneumoniae strains as ST18 and ST147, and P. aeruginosa as ST235, all of clinical relevance. A comparison of ST147 genomes with isolates from human infections in Africa showed remarkable similarity and shared AMR profiles. Thirteen of the twenty-one plasmids from ST147 harbored at least one AMR gene, including blaCTX-M-15 linked to copper-resistance genes. Our study demonstrated high bacterial counts and organic matter in the analysed wastewater. The recovery of clinically significant isolates with multiple antibiotic and heavy metal resistance genes from the wastewater samples raises public health concerns.

Pre-emergence herbicides used in urban and agricultural settings: dissipation and ecological implications

Herbicides are widely recognized as the most cost-effective solution for weed control, but their extensive use in both urban and agricultural settings raise serious concerns about nontarget effects. We assessed the possible hazards associated with pre-emergence herbicides such as dimethenamid–P, metazachlor, and pyroxasulfone, which are frequently applied in both urban and agricultural soils. The dissipation rate constant values (k day−1: 0.010–0.024) were positively linked to total organic carbon (TOC), silt, clay, soil pH, and Al and Fe oxides, but negatively correlated with sand content. In contrast, half-life values (DT50: 29–69 days) of the herbicides showed negative correlations with TOC, clay, silt, soil pH, and Fe and Al oxides, while sand content showed a positive impact. The selected herbicides showed minimal impact on soil dehydrogenase activity (DHA). Mostly, soils with higher organic matter (OM) content exhibited increased DHA levels, highlighting the role of OM in influencing this soil enzyme across different soils. Assessment of environmental indicators like groundwater ubiquity score (GUS:1.69–6.30) and leachability index (LIX: 0.23–0.97) suggested that the herbicides might reach groundwater, posing potential risks to nontarget biota and food safety. Human non-cancer risk evaluation, in terms of hazard quotient (HQ < 1) and hazard index (HI < 1), suggests minimal or no risks from exposure to soil containing herbicide residues at 50% of the initial concentrations. Our data thus help the stakeholders and regulatory agencies while applying these pre-emergence herbicides in soils and safeguarding human and environmental health.

National investigation of bisphenols in the surface soil in China

The long-term production and extensive use have resulted in the widespread presence of bisphenols (BPs) in the environment. In order to clarify the pollution characteristics and potential sources of BPs, the national scale surface soil samples were collected in China in 2019. The results demonstrated that 32 target BPs existed widely in soil with the highest concentration for bisphenol A (BPA), and at least 2 BPs were detected in each sample. The total concentration of Σ32BPs (from 0.387 to 713 ng/g) exhibited a stepwise decrease from southeastern coast to inland regions, and due to the presence of more pollution sources concentrations of Σ32BPs in urban areas were slightly higher than rural areas. The different industrial structures (such as plastics, epoxy resins, and thermal paper) may be the important factors for the different pollution levels between southeastern coast and other regions. In addition, the high organic matter content in soil and low temperature may be the reasons for high concentrations of Σ32BPs in Northeast China. The results of source identification using the Positive Matrix Factorization model indicated that BPs in soil were originated from three sources: old sources represented by BPA, relatively new sources characterized by bisphenol S, and sources from specific industries using bisphenol F. The estimated daily intake indicated that BPA exposure through soil accounted for only a small proportion of the total exposure compared to other exposure routes, and the risk by BPA in soil can be negligible to human health. In summary, the study provided basic pollution information of BPs in Chinese surface soil for future related studies.

Application of Hybrid Conventional Filter and PVDF-TiO&lt;sub&gt;2&lt;/sub&gt;/SBE Hollow Fibre Membrane for Peat Water Treatment

South Kalimantan-Indonesia is known to have extensive peatlands reaching 15% of a total peatland in Kalimantan. Due to that peat land water is mostly found and claim as abundant water sources. However, based on quality, peat land water has poor characteristic with high natural organic matter content. Therefore, peat water treatment is necessary to treat using effective method such as hybrid conventional filter and membrane using hollow fibre PVDF-TiO2/SBE. This study aims to investigate the variation of media filter thickness and filtration pressure of hollow fibre (HF) PVDF-TiO2/SBE membrane peat water treatment by filtration pre-treatment and HF membrane ultrafiltration. HF PVDF-TiO2/SBE membrane was prepared by wet spinning method using spinneret set up. Hybrid process was divided into two steps: 1) conventional filter as pre-treatment and 2) HF ultrafiltration membrane under cross flow system. The filter media was used in this work is silica sand and activated carbon with varied thickness 30:10 and 10:30 cm. The HF membrane structure was analysed via scanning electron microscopy (SEM) to investigate the membrane morphology. The results show the fabricated HF membrane has a finger like-sponge sandwich structure morphology. In addition, 30:10 cm (silica sand: activated carbon) thickness exhibits TDS and turbidity removal of 92.18 and 61.37%, respectively as conventional filter pre-treatment. In other hand, HF membrane successfully removed TDS and turbidity of peat water up to 98.68% and 92.41% at 2 bar of filtration pressure. The highest permeate flux of HF membrane conducted of 13.055 Kg.m-2.h-1 at 3 bar. Conclusion of this work is the peat water treatment using activated carbon: silica filtration pre-treatment and HF membrane ultrafiltration can provide clean water with maximum turbidity and TDS removal.

Multi-omics reveal wild habitat is more favorable for the metabolite accumulation in Astragalus mongolicus

Astragalus mongholicus, a well-known traditional Chinese herbal medicine, has been widely used for more than 2000 years. Although previous studies have revealed that the medicinal quality of wild plants is superior to the cultivated plants, the regulatory mechanism responsible for the variations in metabolite accumulation between wild and cultivated A. mongholicus have not yet been conducted. Here, the roots and rhizosphere soils of cultivated, imitated wild and wild A. mongholicus were used for metabolite, transcript and microbiota analysis. The contents of calycosin-7-O-β-D-glucoside (CG) and astragaloside IV were achieved 0.47±0.02 mg/g and 1.17±0.06 mg/g in wild A. mongolicus, which were more than 1.49- and 1.98-fold higher compared to the cultivated A. mongolicus, respectively. Consistently, there were 424 genes differentially co-expressed at least two types of growth pattern, among which 23 genes (i.e. AmPAL, AmCHS, AmHMGS, AmSQE and AmOSC) directly involved in the biosynthesis of CG and astragaloside were significantly higher expressed in wild/imitated wild plants than in cultivated plants. The soil composition differed by region with higher organic matter, available nitrogen in wild regions, while lower pH, available phosphorus and potassium in cultivated regions. Meanwhile, the microbial diversity in wild rhizosphere were significantly lower than that in cultivated rhizosphere. Notably, the high abundance of biomarkers (i.e. Variovorax, Rhizobium and Lysobacter) were observed in wild rhizosphere, which indirectly boosted the metabolite accumulation in wild plant. Taken together, a regulatory model of soil-plant-microbe in A. mongolicus was established by integrating multi-omics analysis, which were of great guidance on the cultivation of A. mongolicus with high medicinal quality via targeted agricultural management.

The biogeography of soil microbiome potential growth rates

Soil microbial growth, a vital biogeochemical process, governs both the accrual and loss of soil carbon. Here, we investigate the biogeography of soil microbiome potential growth rates and show that microbiomes in resource-rich (high organic matter and nutrients) and acid-neutral soils from cold and humid regions exhibit high potential growth. Conversely, in resource-poor, dry, hot, and hypersaline soils, soil microbiomes display lower potential growth rates, suggesting trade-offs between growth and resource acquisition or stress tolerance. In addition, the potential growth rates of soil microbiomes positively correlates with genome size and the number of ribosomal RNA operons but negatively correlates with optimum temperature, biomass carbon-to-phosphorus and nitrogen-to-phosphorus ratios. The spatial variation of microbial potential growth rates aligns with several macroecological theories. These findings not only enhance our understanding of microbial adaptation to diverse environments but also aid in realistically parameterizing microbial physiology in soil carbon cycling models.

Effect of Soil-pH, temperature and moisture content on sorption dynamics of metformin and erythromycin

The rising soil-groundwater quality issues due to pharmaceuticals and personal care products (PPCPs) contamination have spurred significant concern. To understand the sorption characteristics of metformin (MTN) and erythromycin (ETM) in sandy and sandy loam soils with varying organic matter and particle composition, sorption kinetics (single and competitive), isotherms, and thermodynamics were studied. The effects of pH and soil moisture content (SMC) were also investigated at environmentally relevant concentrations. The equilibrium time of MTN and ETM sorption by the three soils in a competitive solute system was about 4 h, and the sorption process was in line with a pseudo-second-order model. The rate-determining step in the process involved both intraparticle diffusion and liquid film diffusion mechanisms for the two PPCPs. The highest pollutant uptake occurred in soils with higher organic matter, driven by enhanced H-bonding, electrostatic interactions, and π-π and n-π interactions facilitated by the organic matter. The equilibrium data in the three soils was well described by the Freundlich model and confirmed favourable adsorption (1/nf = 1.01–1.90). The sorption coefficient (Kd) on the three soils ranged from 2.1 to 332 L/kg for MTN and from 6.25 to 845 L/kg for ETM. The adsorption process was feasible at 293 K and 303 K (ΔG° = - 0.16 to −10.24 kJ/mol), physical and exothermic in nature (ΔH° = −75.21 to −10.30 kJ/mol) for both the contaminants. Observed alterations in Qe with pH confirmed the participation of electrostatic interactions. A low SMC favoured both MTN and ETM sorption onto the sandy soil. Overall, ETM exhibits higher expected sorption, whereas MTN has a greater tendency for migration in the soils and is thus liable to contaminate the groundwater. The study accentuates novel insights into the transport and fate of MTN and ETM in soil-groundwater systems at environmentally relevant concentrations.

Occurrence and distribution of atrazine in groundwater from agricultural areas in China

There has been heavy application of chemical pesticides to farmland worldwide. As a state with a heavy emphasis on farming, China has extensively applied chemical pesticides to farmlands. Atrazine (ATZ), one of the most widely used herbicide in the world, has been used in large quantities in weed control in many crops, which poses a relatively large threat to groundwater utilization and agricultural safety. A nationwide sampling and analysis of ATZ in 8146 groundwater monitoring wells from 10 main grain producing areas were conducted during 2019. The results showed that the detection rate of ATZ in groundwater was 40.79 %, with detected concentrations up to 2.86 μg/L. ATZ detection rate was significantly higher in phreatic aquifers than confined aquifer. The concentration of ATZ decreased significantly with the depth increasing, the detected depth of ATZ in groundwater was varied from 5 to 1100 m, and 70.27 % of the detected ATZ was distributed in the depth of 0–51.8 m. The detection rate of ATZ in most north regions lower than south regions in China, and ATZ with high concentration was mainly occurred in southern regions. ATZ is more likely to migrate into the groundwater in the water resource rich areas. The concentration of ATZ decreased with TDS increasing, 74.39 % of the ATZ was detected in groundwater with TDS concentration <1 g/L. The hydrochemical type of groundwater in ATZ-enrichment environment were mainly Ca-HCO3 and Mixed type. According to classification and regression tree analysis, the high ATZ detection rate were closely related with groundwater depth (<51.8 m) and high organic matter content.