Total Nitrogen Levels Research Articles

2-Hydroxy-1,4-Naphthoquinone: A Promising Redox Mediator for Minimizing Dissolved Organic Nitrogen and Eutrophication Effects of Wastewater Effluent.

Researchers and engineers are committed to finding effective approaches to reduce dissolved organic nitrogen (DON) to meet more stringent effluent total nitrogen limits and minimize effluent eutrophication potential. Here, we provided a promising approach by adding specific doses of 2-hydroxy-1,4-naphthoquinone (HNQ) to postdenitrification bioreactors. This approach of adding a small dosage of 0.03-0.1 mM HNQ effectively reduced the concentrations of DON in the effluent (ANOVA, p < 0.05) by up to 63% reduction of effluent DON with a dosing of 0.1 mM HNQ when compared to the control bioreactors. Notably, an algal bioassay indicated that DON played a dominant role in stimulating phytoplankton growth, thus effluent eutrophication potential in bioreactors using 0.1 mM HNQ dramatically decreased compared to that in control bioreactors. The microbe-DON correlation analysis showed that HNQ dosing modified the microbial community composition to both weaken the production and promote the uptake of labile DON, thus minimizing the effluent DON concentration. The toxic assessment demonstrated the ecological safety of the effluent from the bioreactors using the strategy of HNQ addition. Overall, HNQ is a promising redox mediator to reduce the effluent DON concentration with the purpose of meeting low effluent total nitrogen levels and remarkably minimizing effluent eutrophication effects.

Soil and plant attributes under grazing exclusion in semi-steppic semi-arid rangelands, Iran

The aim of this study was to investigate the effect of exclusion (20 years) on the attributes of soil and vegetation in northwest of Iran. Three sites in grazed and three sites in exclusion areas were selected. At each site, three 100 m transects were established for sampling purposes. Soil attributes, including electrical conductivity, pH, calcium carbonate, organic carbon, nitrogen, phosphorus, potassium, clay, silt, calcium, magnesium, and bicarbonate were measured in the lab. Additionally, the primary and secondary attributes of vegetation including density, canopy cover, aboveground net primary production (ANPP) of plant functional types (PFTs), diversity, richness and evenness indices were recorded. The findings of our study indicate that the exclusion site exhibited significantly higher levels of soil organic carbon (1.91%), total nitrogen (0.95%), available phosphorus (1.75 ppm), and soluble potassium (163.52 ppm) compared to the grazed site. However, no significant differences were observed in other soil characteristics between the two sites. Density, canopy cover percentage, ANPP of PFTs (p < .01), diversity (1.92), and richness index (9.64), were higher in the exclusion area (p < .05), while, evenness showed no significant difference. The total species density and canopy cover within the exclusion area were also found to be higher than in grazed areas. Results suggest that exclusion in semi-arid semi-steppes plays an important role in rangeland management.

Effect of Fertilizer, Furrow Length, and Irrigation Flow Rate on Soil Nutrient and Yield of Apple Orchard

The objective of this study was to evaluate the impact of furrow irrigation with a length of 96, 144, and 192 m and a flow rate of between 0.2 and 0.4 Ls−1 on the leaching of nitrogen, phosphorus, and humus from dry subtropical soils in Azerbaijan. Moreover, the impact of six fertilizer levels, namely, control (without fertilizer), 10 t ha−1 of cow manure, N90P90K90 + 10 t ha−1 of cow manure, N120P90K90 + 10 t ha−1 of cow manure, N120P120K90 + 10 t ha−1 of cow manure, and N120P90K120 + 10 t ha−1 of cow manure, on the performance of apple orchards, has been examined. The findings indicate that the brown soils of the irrigated grassland exhibit normal humus, total nitrogen, and weak phosphorus levels, with a gradual decline observed in the lower layers. Applicable to the agricultural and subsurface layers, the aggregates are 0.25–1.0 mm in diameter, with an agricultural value of 12.9% and 21.8%, respectively. This indicates a poor structural condition of the apple orchard soil. The elevation of the water flow rate from 0.2 to 0.4 Ls−1 resulted in a greater extraction of humus, nitrogen, and phosphorus from the soil. Both water flow rates increased the nutrients and humus leaching from the soil. By extending the furrow length to 192 m, the losses of humus (3.25%), nitrogen (0.36%), and phosphorus (0.30%) from the soil in both water flows significantly increased in comparison to the 96‐m length. By extending the length of furrows to 192 m, the yield (21.97 t ha−1) was significantly reduced in comparison to the 96‐m length (22.31 t ha−1). As a consequence of the application of N120P90K120 + 10 t ha−1 of cow manure, the yield of 27.3 t ha−1 was significantly elevated in comparison to other fertilizer treatments and the control treatment (17.9 t ha−1). Therefore, management of fertilizer systems, furrow length, and water flow can improve soil fertility and plant yield by reducing erosion in the meadow‐brown soil of Azerbaijan.

Remediation of Remains Place Gold Mining Land Using Boiler Ash and Sludge from Palm Oil Liquid Waste Processing

The activity of placer gold mining has ruined the ecosystem by disturbing the upper soil layers, contaminating waterways, and leading to sedimentation downstream. This study is being carried out in order to improve soil quality in Tanoh Mirah Village, Sungai Mas Subdistrict, West Aceh Regency, Aceh Province, Indonesia. The main objective is to explore the impact of applying boiler ash and sludge from the palm oil liquid waste processing on enhancing the fertility of soil in areas previously used for mining activites. Infertile soil samples from the remains mining site were treated with a specific composition of boiler ash and sludge, placed in 5 kg plastic containers, and stored for 15 days. Subsequently, soil pH, accessible phosphorus (P), organic carbon (C), total nitrogen (N), and exchangeable potassium (K) analyses were performed. The research findings demonstrate that after the remediation treatment, soil quality improved significantly. The soil's organic carbon content increased from 0.42% to 2.92% after applying 1,500 grams of sludge. The total nitrogen level increased from 0.02%. to 0.2% after treated with 1,500 grams of sludge, and 500 grams of boiler ash. The phosphorus content of the soil increased up to 123.13 mg/kg from original condition of 1.3 mg/kg, when 1,500 grams of boiler ash were added. In summary, boiler ash and sludge remain from the palm oil industry’s waste processing activities have the potential to be used for enhacing the quality of soil damaged by placer gold mining processes.

Spatial distribution and variability of soil agrochemical properties in Botevgrad valley

The paper deals with spatial analysis that evaluates the main agrochemical properties of the Botevgrad valley. The soil samples were taken along a pre-selected grid so as to cover the areas selected for research. The interpolation of the data was done according to geostatistical interpolation method and the output value is using Inverse Distance Weighting (IDW). Spatial distribution is a valuable tool for determining nutrient availability and nutrient management practices to optimize crop production and minimizing environmental impacts. As a general guideline, total nitrogen content in soil is commonly found in the range of 0.1% to 0.2% on a weight basis. Soils with higher organic matter content often have higher total nitrogen levels because organic matter is a significant source of nitrogen. It’s important to note that the optimal levels of available potassium and phosphorus can vary depending on the specific soil type.

Distribution characteristics of microorganisms in sediments of Dagu River and their biological indicator function for evaluating eco-environmental quality of rural river

The microorganisms in sediments play a crucial role in biogeochemical cycle processes, and numerous studies have shown that microbial community is closely related to environmental factors. However, the usability of sediment microorganisms to evaluate the eco-environment quality of rural rivers has not been adequately explored. This study investigated the distribution characteristics and response of sediment microorganisms to environmental parameters and benthic organisms. Based on the environmental parameters and benthic community indices, the 12 stations were divided into high-polluted group A, moderate-polluted group B and low-polluted group C. Station DG01 and DG02 in group A had the highest level of As and Ni pollution and nutrient concentration, and DG09 in group A had the lowest benthic diversity. Correspondingly, group A had the lowest abundance of Proteobacteria, which has a higher requirement for the environment than Planctomycetes. Group B had the highest sulfide level (97.45 mg/kg), and bacteria (Thiobacillus, Sulfurisoma and Sulfuritalea) with genes involved in sulfur cycling were more enriched in this group. Group C had the lowest level of total nitrogen (243.36 mg/kg), and Rhodanobacteraceae in Xanthomonadales might be a key bioindicator for low nitrogen. In addition, Chlorophyta was found to be more susceptible to heavy metals, and moreover co-occurrence networks showed that microeukaryotes were more sensitive to heavy metal pollution compared to benthic animals and prokaryotes. Therefore, this study suggested that benthic microorganisms especially microeukaryotes could be used as good indicators for evaluating the eco-environmental quality of rural rivers.

RETRACTED: The effect of different Capsicum annuum components on the quality and shelf-life of chicken breast meat

The pericarp of chili pepper contains phenols and alkylamides, which are potential sources of antioxidant compounds. Although these compounds are recognized as primary antioxidants in chili pepper, there is limited knowledge about their use in real food systems. The purpose of this study was to identify and isolate the polyphenol fractions (PF) and alkylamide fraction (AF) from chili pepper and assess their impact on the shelf-life of refrigerated chicken breast meat over a 12-day period with analysis at 4-day intervals. Through the use of HPLC-MS2, 10 polyphenols and 2 alkylamides were identified in both pepper fractions. The study examined four treatments: Control, AF at 30 mg/mL, PF at 1.5 mg/mL, and PF at 6 mg/mL. All treatments significantly reduced the levels of bacteria, such as psychrotrophic, lactic acid, and Pseudomonas spp, as well as yeasts-molds, compared to the control group during the storage period. Additionally, the levels of total volatile basic nitrogen, protein oxidation, and Thiobarbituric acid reactive substance were significantly lower in PF at 6 mg/mL and PF at 1.5 mg/mL treatments compared to those of the control and AF at 30 mg/mL. Furthermore, PF at 6 mg/mL and PF at 1.5 mg/mL had a favorable effect on sensory attributes, with PF at 6 mg/mL significantly improving sensory scores. The findings of this study suggest that using PF as a natural preservative can enhance the shelf-life of chicken breast meat.

Water Quality, Nutritional, Hematological, and Growth Profiles of Ompok pabda Fish Fry Reared in Biofloc Technology and Traditional Culture System with Different Stocking Densities.

The present study evaluated water quality, immune responses, nutritional condition, and production of Ompok pabda fry (0.29-0.31 g) reared in a Biofloc technology (BFT) system (C:N = 20:1; molasses as organic carbon source), compared to the traditional culture system (TS; farmer's practice). The experiment had stocking densities for the treatments of 17 (TS1) and 22 (TS2), 17 (BFTS1), 22 (BFTS2), and 27 (BFTS3) fish/m2. The fishes were fed at 3-10% of their body weight, and reared in cemented tanks for 90 days. Regarding water quality, dissolved oxygen (DO), pH, and total ammonia nitrogen (TAN) levels varied significantly (p < 0.05) between the traditional and BFT tanks. The highest specific growth rate (SGR) was in the BFTS1-reared fishes (4.11 ± 0.17) but the lowest was in the TS2-fish (3.51 ± 0.05). The fish reared in BFT had higher levels of protein, lipids, polyunsaturated fatty acids, essential amino acids, hematocrit, and neutrophil than the fish reared in TS tanks. Moreover, 98.33% survival was recorded in the BFTS1 while 86.67% was in the TS2. The highest BCR was estimated for the BFTS2 (1.22). Taking into account FCR and BCR values, a stocking density of 22 fry/m2 is likely practicable for an O. pabda BFT system.

Occurrence of antibiotics and antibiotic-resistant bacteria in the Lebanese polluted Litani River.

Antibiotic contamination in polluted rivers is well recognized as an environmental and public health challenge. In this study, the occurrence, distribution, and ecological risk assessment of three commonly used antibiotics (amoxicillin, ciprofloxacin, and azithromycin) were assessed in the Litani River, the most important and highly polluted river in Lebanon. Physicochemical and microbiological water quality parameters including the antibiotic-resistant ones were in parallel determined in the same sites. Water samples from five sites stretching across the river upper basin were analyzed for the antibiotics under study using high-performance liquid chromatography, with both fluorometric and UV detectors post-extraction using a solid-phase method with a hydrophilic-lipophilic balance cartridges. The disc diffusion method and standardized water quality methods were used for antibiotic-resistant bacteria and water quality assessment, respectively. Amoxicillin and ciprofloxacin were found at concentrations of 250 ng/L and 107.2 ng/L, while azithromycin was not detected in any of the sites under study. Varying levels of antibiotic resistance were detected with the isolated Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) while the total coliforms showed resistance to multiple antibiotics. COD, TP, PO43-, TN, NO3-, NH4 + , E. coli, total coliform, P. aeruginosa, and Cd levels surpassed permissible levels. Correlation analysis with water quality parameters (COD, total phosphate, phosphate, total nitrogen, and cadmium) showed a significant positive correlation with ciprofloxacin (r > 0.5, p value < 0.05). Also, the resistant P. aeruginosa showed a significant positive correlation with cadmium (r > 0.5, p value < 0.05) while the resistant E. coli was positively correlated with total nitrogen, nitrate, and lead levels (r > 0.5, p value < 0.05). The ecological risk assessment revealed that all the tested antibiotics pose low risks (ecological risk quotient RQ < 0.1) except ciprofloxacin, which could pose a medium risk (0.1 < RQ < 1). Future research concerning the long-term assessment of antibiotics' residues and the identification of resistance genes in the river is recommended.

Analysis and evaluation of sediment pollutants of Euphrates River at Al-Nasiriyah city, south of Iraq

In this work, total phosphorus (TP), total nitrogen (TN) and organic matter (OM) were detected in the sediment of Euphrates River in different period’s time. Then we did the analysis and the characterization of these pollutants for this river. In addition, . The findings of this study showed that the sediment levels of total phosphorus in Euphrates river were 2.05 ~ 6.50 mg/g, 1.65 ~ 3.17 mg/g and 0.71 ~ 0.93 mg/g the sediment levels of total nitrogen were 5.06 ~ 8.98 mg/g, 6.07 ~ 8.56 mg/g and 5.02 ~ 7.99 mg/g. Also, organic matter levels in sediment were 40.54 ~ 70.1 mg/g, 58.70 ~ 85.63 mg/g and 11.32 ~ 30.17 mg/g in Clearly, from that analysis and comparison of pollutants level, the sediment of Euphrates River is the main source of contamination. This may be able to result from increasing the human activities and the increment of industrial actions in this region.

Soil nutrient conditions alter viral lifestyle strategy and potential function in phosphorous and nitrogen metabolisms

As one of the most abundant members of microbial communities, viruses are considered to influence prokaryotic mortality and biogeochemical cycles. While extensive research has been conducted to explore viral diversity and community dynamics in marine ecosystems, our understanding of soil viruses, particularly within agroecosystems, remains limited. Here, we conducted metagenomics and viromics analyses in a paddy ecosystem subjected to four different levels of soil nutrient modification by pig manure applications (PM0: 0 kg ha−1, PM1: 1930 kg ha−1, PM2: 3860 kg ha−1 and PM3: 5790 kg ha−1) over a period of 9 years. We aimed to investigate viral community adaptation and virus-host interactions in response to varying soil nutrient conditions. Our findings revealed that the viral communities are more adaptable to changes in soil nutrient contents compared to prokaryotic communities. Specifically, the relative abundance of Caudoviricetes decreased significantly with increasing levels of soil available phosphorus and total nitrogen. The ratio of lytic-lysogenic cycles increased with higher manure application rates, accompanied by an elevated prevalence of functional genes related to cell processes and viral protein structure. Moreover, we identified several putative auxiliary metabolic genes (AMGs) associated with phosphorus and nitrogen cycles, including phoA, phoH, phoB, and gdh, with the first discovery of phoB and gdh as soil viral-encoded AMG. Notably, the association between viruses and phoB-encoding bacteria displayed greater similarity within nutrient-deficient environments compared to nutrient-enriched environments, while the converse interaction pattern emerged between viruses and gdh-encoding bacteria. Collectively, our study highlights the importance of soil nutrient conditions in driving the transition between lytic-lysogenic cycles, as well as the interaction patterns between viruses and key bacteria. The insights gleaned from our findings significantly enrich our understanding of viral ecology within agricultural ecosystems.

Development and production of cowpea inoculated with Bradyrhizobium strains in a traditional cultivation system in Southwestern Amazonia

Traditional cowpea cultivars are conserved in the Juruá Valley (Acre) by farmers who adopt a "beach" production system, in lowland areas on the banks of the Juruá River and tributaries. Cowpea inoculation is a sustainable and low-cost technique that has provided an increase in the growth and productivity of the crop, but that has not yet been tested in this production system. The objective of this work was to evaluate the development and production of cowpea inoculated with Bradyrhizobium strains in a traditional cultivation system in Southwestern Amazonia. A randomized block design with three replications and four treatments was used: seeds inoculated with strains BR 1808, BR 3262, and BR 3267, and a control without inoculation. Inoculation provided an increase in the majority of the studied variables. The productivity obtained in the treatments with BR 3262 and BR 1808 was superior to the other treatments. The strain BR 3262 showed higher levels of total chlorophyll and nitrogen. Inoculation with Bradyrhizobium proved to be a promising technology for the cultivation of cowpea beans in lowland soils of the Juruá River.

Exogenous mobile genetic elements and their associated integrons drive the enrichment of antibiotic-resistant genes in the river of a valley basin city (Lanzhou, China).

River is a unique source of drinking water in valley-type cities, affecting local urban development and human lifestyles. However, the key driving factors for dissemination of antibiotic-resistant genes (ARGs) in valley-type urban environments remain unclear. This study aimed to investigate the distribution of ARGs in the Yellow River and to clarify the driving factors of ARGs in a typical valley basin city (Lanzhou, China). The seven selected ARGs with higher abundances including tetracycline resistance genes (tetM, tetX), macrolide resistance genes (ermB, ermF, ereA), and sulfonamide resistance genes (sul1, sul2) were detected. The results showed that the total absolute abundance of all the selected ARGs varied from 9.97 × 1012 to 1.04 × 1015 copies/L in the water body, with higher abundances in the wet season, relative to the dry season. Among these, sulfonamide resistance genes (sul1, sul2) displayed the highest absolute abundance in the river and soil. The ARGs and mobile genetic elements (MGEs) were significantly correlated with bacterial abundance, dissolved organic carbon (DOC), ammonia nitrogen (NH4+), and total nitrogen (TN) levels in the water environment (Mantel test, P < 0.01). Structural equation modeling revealed the direct input of point-source and nonpoint-source ARGs in this area contributed less to the overall level of the ARGs in the water. Among the multiple drivers, the MGEs derived from wastewater treatment plant and anthropogenic nonpoint area positively and directly affected the ARG profiles in water (P < 0.01), rather than the factors of bacterial abundance and physicochemical properties. According to this study, the exogenous MGEs from anthropogenic activities are the main driver for the enrichment of ARGs in the valley-type urban river environment.

Study on remote sensing inversion and temporal-spatial variation of Hulun lake water quality based on machine learning

Hulun Lake is facing significant water quality degradation, necessitating effective monitoring for safety. Traditional methods lack the necessary spatial and temporal coverage, underscoring the need for a remote sensing model. In this study, we utilized the Landsat 8 OLI dataset, incorporating cross-section monitoring and field sampling data comprehensively. Employing the random forest algorithm, we constructed a remote sensing inversion model for six water quality parameters in Hulun Lake: chlorophyll-a (Chl-a), total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH3−N), chemical oxygen demand (COD), and dissolved oxygen (DO). The model was applied to the non-freezing period of Hulun Lake from 2016 to 2021, exhibiting commendable performance and generating high-resolution maps. Time series analysis revealed that during the study period, the pollution levels of TN, TP, and COD in Hulun Lake were extremely serious, exceeding the Class V water standard of China's surface water environmental quality standard. Regional analysis indicated lower pollutant concentrations in the central lake area compared to the lake inlet. The inflowing rivers with high pollution adversely impacted Hulun Lake's water quality. To ensure the continued health of Hulun Lake's water quality, it is imperative to monitor lake water quality attentively and implement necessary measures to prevent further deterioration. This study holds crucial importance for shaping and executing ecological protection and restoration strategies for Hulun Lake.

Facilitating mitigation of agricultural non-point source pollution and improving soil nutrient conditions: The role of low temperature co-pyrolysis biochar in nitrogen and phosphorus distribution

The current study generated co-pyrolysis biochar by pyrolyzing rice straw and pig manure at 300 °C and subsequently applying it in a field. Co-pyrolysis biochar demonstrated superior efficiency in mitigating agricultural non-point source pollution compared to biochar derived from individual sources. Furthermore, it displayed notable capabilities in retaining and releasing nutrients, resulting in increased soil levels of total nitrogen, total phosphorus, and organic matter during the maturation stage of rice. Moreover, co-pyrolysis biochar influences soil microbial communities, potentially impacting nutrient cycling. During the rice maturation stage, the soil treated with co-pyrolysis biochar exhibited significant increases in available nutrients and rice yield compared to the control (p < 0.05). These findings emphasize the potential of co-pyrolysis biochar for in-situ nutrient retention and enhanced soil nutrient utilization. To summarize, the co-pyrolysis of agricultural waste materials presents a promising approach to waste management, contributing to controlling non-point source pollution, improving soil fertility, and promoting crop production.

Substrate microorganisms can be an ideal tool for improving green roof sustainability

Green roof (GR) ecosystems function as a result of a series of complex interactions between plants and substrates, which are poorly understood. This ambiguity hinders the scientific application of GRs to tackle urban eco-environmental problems. The goal of this study was to clarify the response of plants to various abiotic and biotic characteristics of GR substrates, including physical properties, nutrients, and microbes. We systematically analyzed the statistical association between 43 indicators of plant and substrate characteristics using four GR substrates and one common plant type (Sedum lineare Thunb) in a subtropical monsoon climate. Height, coverage, root-shoot ratio, total carbon, total nitrogen, total phosphorus, total potassium, root vitality, and malondialdehyde levels were considered sensitive indicators of the plant’s response to the substrate. Substrate nutrients and microbial biomass were most closely associated with the plant response, whereas the material properties of the substrate could indirectly affect plant growth by influencing substrate microbes and plant nutrients. Our results suggest that when optimizing GR substrates for plant responses, it is necessary to respect the plants and account for the abiotic and biotic relationships. It may be possible to manage GR performance in a more scientific and effective manner through the control of substrate microorganisms.

Growth Performance of Critically Endangered Hypselobarbus pulchellus in Biofloc Systems with Various C/N Ratios

Background: Biofloc technology relies on adding a carbon source to maintain optimal carbon to nitrogen ratio for transforming the waste into microbial biomass that aquatic animals can use. In the present study, the growth performance of the critically endangered Hypselobarbus pulchellus in biofloc-based seed rearing with different Carbon to Nitrogen ratio was studied. Methods: Healthy early fry (0.01 g) was randomly stocked into 15 circular FRP tanks (1000 L) at a density of 100 individuals/m3 and reared for 90 days. The carbon to nitrogen ratios of 5:1(CN5), 10:1(CN10), 15:1(CN15) and 20:1(CN20) were maintained using jaggery without considering carbon content derived from the feed and the control group received no additional source of carbon. Result: The results indicated that H. pulchellus had better growth performance in biofloc systems having higher C/N ratios. The highest weight gain (0.48±0.01 g) and weight gain percentage (3931.15±120.68%) and specific growth rate (4.11±0.03% per day) were found in the CN10 group (P less than 0.05), followed by CN15 and CN20, while the control group values were lowest. In terms of survival, all treatments had high survival rates ranging from 92% to 94.67%, with no significant variations (P greater than 0.05). The CN10, CN15 and CN20 treatments had significantly higher amylase, protease and lipase activities than control (P less than 0.05). Moreover, the immunological and antioxidant activity increased with CN ratios. The CN10, CN15 and CN20 groups had significantly lower total ammonia nitrogen, nitrite and nitrate levels than control group (P less than 0.05). Overall, this study suggests that C/N ratios of 10:1 to 20:1 are optimal for rearing H. pulchellus fingerlings from early fry, with 10:1 presenting the best growth results.

Effects of environmentally relevant concentrations of micro(nano)plastics on aquatic microorganisms: Changes in potential function but not in overall composition

Micro(nano)plastics (MNPs) are a growing problem as persistent environmental pollutants. Here, we investigated the impact of MNPs on microorganisms in aquatic microbial floc exposed to NPs (80 ​nm) and MPs (8 ​μm) for 35 days. Water quality indicators were tested weekly and microbiological analyses were conducted on Day 7 and 28 after exposure. The results showed that there were significant differences in the levels of total ammonia nitrogen or nitrite between the MNPs groups and the control group, spanning from Day 7 to Day 28. For the microbial response, microbial community richness in the NPs and MPs groups were significantly increased at Day 7. Functional prediction showed that the relative abundances of bacteria associated with the “Forms Biofilms”, “Potentially Pathogenic”, “Plastic Degradation” and nitrogen cycle processes were significantly different after MNPs exposure. The results suggest that MNPs had no significant effect on the microbial diversity of mature microbial flocs. Findings suggest MPs could cause an increase in the relative abundance of potentially pathogenic bacteria, while NPs do not. In addition, stress associated with MNPs affected the nitrogen cycle of microorganisms, and NPs exerted greater impacts than MPs. Findings from this study further our understanding of the impact of MNPs at environmentally relevant concentrations on microorganisms in aquatic ecosystems.

Nutritional richness of sediments from crude oil impacted Iko River Estuary, Eastern Obolo L.G.A, Nigeria

This was a longitudinal study that lasted twelve calendar months;and conducted in three selected stations along the course of a crude oil impacted Iko river estuary, Eastern Obolo LGA, Akwa Ibom State, Nigeria.Standard protocols were followed in collection and analysis of sediment samples. There were spatio-temporal variations in total hydrocarbon content (THC): lowest value (101.40 mgkg-1) recorded at Station 2 in October while the highest value (219.60 mgkg-1) was obtained atStation 1 in April; dry season mean value of 162.31 ± 22.67 mgkg-1 was significantly (p&lt;0.05) higher than that of wet season (137.19 ± 34.59 mgkg-1). The levels of Total Nitrogen (TN) in the study area were quite low, with values that ranged from 0.19 - 0.50 %, 0.20 - 0.44 % and 0.15 - 0.046 % in Station 1, 2 and 3 respectively with no significant differences observedirrespective of seasons. Levels of Ammonium ions (NH4+) recorded in the sediments were 2.28 - 5.11 mgkg-1, 2.96 - 6.01 mgkg-1and 2.41 - 5.72 mgkg-1 in Station 1, 2 and 3 respectively. Nitrate (NO3-) lowest value of 11.60 mgkg-1 was recorded in Station 2 while the highest value of 36.00 mgkg-1 was recorded in Station 3. Wet season NO3- mean value was higher (27.51 ± 4.62 mgkg-1) than that of the dry season (18.38 ± 4.06 mgkg-1). Phosphate levels in sediments were not significantly different among stations and seasons. The mean concentrations of Sulphate in sampling stations were 48.53 ± 4.62 mgkg-1, 36.96 ± 6.93 mgkg-1 and 42.25 ± 5.98 mgkg-1 for Stations 1, 2 and 3 respectively. There was no remarkable spatial variation in the Chloride levels of the sediments. Nevertheless, influence of season was significant (p&lt; 0.05) as dry season mean value of 173.16 ± 12.53 mgkg-1 exceeded that of wet season (131.78 ± 20.76 mgkg-1). Both negative and positive associations between pollutants and nutritive salt levels in the sediments were recorded across sampling stations irrespective of the season. From the results, it can be concluded that higher level of nutritive salts were in the sediments at seasons where hydrocarbon contamination of the sediment was lowest.

Decoupling livestock and poultry pollution emissions from industrial development: A step towards reducing environmental emissions

China has implemented policies like Leading areas for Agricultural Green Development (LAGD) to mitigate livestock and poultry farming pollution while promoting industry growth. However, it remains uncertain whether LAGDs have successfully balanced emission reduction with stable development. This study examines 165 LAGDs to analyze changes in emissions, assess the decoupling of emission reduction from output value, and identify influencing factors. Findings reveal that emissions from livestock and poultry in LAGDs initially increased and then decreased between 2010 and 2019. Cattle were responsible for over 40% of fecal emissions, and pigs for more than 20%. Additionally, pigs contributed to over 61% of urine emissions. From 2010 to 2014, increases in chemical oxygen demand were mainly due to pigs and cattle. Total nitrogen levels were significantly impacted by cattle, while pigs were affected by total phosphorus. From 2014 to 2019, reductions in emissions were largely attributed to a decrease in pig-related pollutants. The decoupling status shifted from strong to weak and then back to strong between 2014 and 2019. Production efficiency played a crucial role in reducing emissions, while changes in industrial structure moved from supporting to hindering this reduction. Economic development was a primary factor in driving these changes. Standard emissions in Chinese regions showed a rising and then declining trend from 2010 to 2019. The Northeast and Northwest regions of China demonstrated emission trends that were in sync with the growth in rural income. This study offers insights into the successes and challenges of LAGDs in achieving a balance between reduced emissions and development, using quantitative analysis. The findings are instrumental in informing policies for a sustainable livestock and poultry industry. Recommendations include evaluating coordinated approaches to pollution reduction and industrial growth, setting decoupling goals, designing policies based on influential factors, conducting regional assessments of livestock and poultry demand, and implementing region-specific strategies.