Search

To understand the impact of the Fukushima nuclear accident (FNA), 137 Cs, 134 Cs, 90 Sr, and gross beta were analyzed in the northeast South China Sea (NSCS), the Luzon Strait (LS) and its adjacent areas. 137 Cs, 90 Sr, and gross beta values in the NSCS were similar to those prior to the FNA. 90 Sr and 137 Cs in the LS and its adjacent areas were consistent with those in the NSCS. The high 137 Cs-peak values occurred at depth of 150 m whereas the high 90 Sr-peak values occurred at depth of 0.5 m. The 137 Cs and gross beta mean values in Cruise I were higher than those in Cruise II whereas the 90 Sr mean value was just the reverse. 134 Cs in all seawater were below the minimum detectable activity. The past and present data since the 1970s suggested 137 Cs and 90 Sr in the study areas still originated from global fallout and the FNA influence were negligible. [ABSTRACT FROM AUTHOR]

Oil fingerprints have been a powerful tool widely used for determining the source of spilled oil. In most cases, this tool works well. However, it is usually difficult to identify the source if the oil spill accident occurs during offshore petroleum exploration due to the highly similar physiochemical characteristics of suspected oils from the same drilling platform. In this report, a case study from the waters of the South China Sea is presented, and multidimensional scaling analysis (MDS) is introduced to demonstrate how oil fingerprints can be combined with mathematical methods to identify the source of spilled oil from highly similar suspected sources. The results suggest that the MDS calculation based on oil fingerprints and subsequently integrated with specific biomarkers in spilled oils is the most effective method with a great potential for determining the source in terms of highly similar suspected oils. [ABSTRACT FROM AUTHOR]

A novel halophilic bacterium capable of heterotrophic nitrification–aerobic denitrification was isolated from marine sediments and identified as Vibrio diabolicus SF16. It had ability to remove 91.82% of NH 4 + -N (119.77 mg/L) and 99.71% of NO 3 − -N (136.43 mg/L). The nitrogen balance showed that 35.83% of initial NH 4 + -N (119.77 mg/L) was changed to intracellular nitrogen, and 53.98% of the initial NH 4 + -N was converted to gaseous denitrification products. The existence of napA gene further proved the aerobic denitrification ability of strain SF16. The optimum culture conditions were salinity 1–5%, sodium acetate as carbon source, C/N 10, and pH 7.5–9.5. When an aerated biological filter system inoculated with strain SF16 was employed to treat saline wastewater, the average removal efficiency of NH 4 + -N and TN reached 97.14% and 73.92%, respectively, indicating great potential of strain SF16 for future full-scale applications. [ABSTRACT FROM AUTHOR]

Abstract: The abundance and composition of marine debris including floating marine debris (FMD), seafloor marine debris (SMD) and beached marine debris (BMD) were investigated in coastal seawaters/beaches around the northern South China Sea during 2009 and 2010. The FMD density was 4.947 (0.282–16.891) items/km2, with plastics (44.9%) and Styrofoam (23.2%) dominating. More than 99.0% of FMD was small or medium size floating marine debris. The SMD and BMD densities of were 0.693 (0.147–5.000) and 32.82 (2.83–375.00) items/km2, respectively. SMD was composed of plastics (47.0%), wood (15.2%), fabric/fiber (13.6%) and glass (12.1%), while BMD was composed of plastics (42.0%) and wood (33.7%). More than 90% of FMD, 75% of SMD and 95% of BMD were not ocean-based sources but land-based sources, mostly attributed to coastal/recreational activity, because of the effect of human activities in the areas. [Copyright &y& Elsevier]

Abstract Bivalves are extensively employed as biomonitors of coastal pollution, but the comparability among different species and geographic environments needs to be further scrutinized. The present study conducted a meta-analysis of trace metals (Ag, Cd, Cr, Cu, Ni, Pb, Ti, and Zn) in the soft tissues of three groups of marine bivalves (oysters, mussels, and clams) collected from China and worldwide. By conducting cumulative frequency distribution analysis of metal distribution, we modeled the 5% cumulative values as the bio-baseline metal concentrations in these bivalves. We further modeled their potential baseline concentrations using a well-developed biokinetic model. The baseline concentrations of Cd, Cu, and Zn in the tissue-specific Environmental Quality Standards (EQSs) for China were 0.99, 34.5, and 340 μg/g dw in oysters, 0.38, 4.32, and 49.6 μg/g dw in mussels, and 0.35, 3.02, 51.4 μg/g dw in clams, respectively. Of the 8 metals examined in this study, the calculated baseline concentrations of Ag, Cr, Cd, Cu and Zn in the oysters were 3.7–48, 2.7–3.6, 2.6–2.8, 8.0–11.4, 6.6–6.8 times higher than those in the mussels and clams, and only Ti showed comparable baseline concentrations among the three bivalves (8.43–9.67 μg/g dw). These data strongly suggested the inter-group as well as inter-metal difference in the baseline metal concentrations in marine bivalves. Further, the potential baseline concentrations of Cd and Cu predicted by the biokinetic model were comparable to those modeled by the probability frequency distribution. Combined statistical frequency analysis and biokinetic modeling therefore provided an innovative method to establish the baseline metal concentrations in bivalves and the tissue-specific EQSs, which are now urgently needed for coastal management, biomonitoring, and geochemical records in the world. Graphical abstract Unlabelled Image Highlights • Meta-analysis of trace metals in the soft tissues of three marine bivalves was conducted. • Bio-baseline metal concentrations in the bivalves were modeled using probability frequency distribution. • Baseline metal concentrations in marine bivalves varied among groups and metals. • Biokinetic and probability frequency distribution models predicted comparable baseline concentrations. [ABSTRACT FROM AUTHOR]

• Low OLR promoted ARGs spread by boosting ARB proliferation and functional profiles. • System instability can induce the accumulation of antibiotics, ARGs, and HPB. • A high OLR operation without digestate recirculation enriched HPB and MGEs. • Digestate recirculation reduced antibiotics abundance by 19.66–31.69 % at high OLR. • Digestate recirculation reduced effects of functional profiles and ARBs on ARGs HGT. Organic loading rate (OLR) is crucial for determining the stability of dry anaerobic digestion (AD). Digestate recirculation contributes to reactor stability and enhances methane production. Nevertheless, the understanding of how OLR and digestate recirculation affect the abundance and diversity of antibiotics and antibiotic resistance genes (ARGs), as well as the mechanisms involved in the dissemination of ARGs, remains limited. This study thoroughly investigated this critical issue through a long-term pilot-scale experiment. The metabolome analyses revealed the enrichment of various antibiotics, such as aminoglycoside, tetracycline, and macrolide, under low OLR conditions (OLR ≤ 4.0 g·VS/L·d) and the reactor instability. Antibiotics abundance decreased by approximately 19.66–31.69 % during high OLR operation (OLR ≥ 6.0 g·VS/L·d) with digestate recirculation. The metagenome analyses demonstrated that although low OLR promoted reactor stability, it facilitated the proliferation of antibiotic-resistant bacteria, such as Pseudomonas, and triggered functional profiles related to ATP generation, oxidative stress response, EPS secretion, and cell membrane permeability, thereby facilitating horizontal gene transfer (HGT) of ARGs. However, under stable operation at an OLR of 6.0 g·VS/L·d, there was a decrease in ARGs abundance but a notable increase in human pathogenic bacteria (HPB) and mobile genetic elements (MGEs). Subsequently, during reactor instability, the abundance of ARGs and HPB increased. Notably, during digestate recirculation at OLR levels of 6.0 and 7.0 g·VS/L·d, the process attenuated the risk of ARGs spread by reducing the diversity of ARGs hosts, minimizing interactions among ARGs hosts, ARGs, and MGEs, and weakening functional profiles associated with HGT of ARGs. Overall, digestate recirculation aids in reducing the abundance of antibiotics and ARGs under high OLR conditions. These findings provide advanced insights into how OLR and digestate recirculation affect the occurrence patterns of antibiotics and ARGs in dry AD. [Display omitted] [ABSTRACT FROM AUTHOR]

The organic loading rate (OLR) is a critical parameter affecting the stability of dry anaerobic digestion (AD) of kitchen waste (KW), and significantly impacting the variations in physicochemical parameters and microbial communities. However, the evolution of quorum sensing (QS) and their role on anaerobic biochemical metabolism during the increase in OLR in dry AD remain unknown. Therefore, this study systematically elucidated the matter through multi-omics analysis based on a pilot-scale dry AD of KW. The results demonstrated that fluctuations in the OLR significantly influenced the microbial QS in dry AD. When the OLR ≤4.0 g·VS/L·d, the system operated stably, and methane production increased. The enrichment of Proteobacteria was crucial for sustaining high levels of functional genes associated with various types of QS, including acyl-homoserine lactones (AI-1), autoinducer-2 (AI-2), autoinducer-3 (AI-3), and gamma-aminobutyric acid (GABA). This enabled cooperative communication among microbes under low OLR. Furthermore, most genes associated with these QS processes positively affected hydrolysis, acidogenesis, and methanogenesis. When the OLR increased to 6.0 g·VS/L·d, the fatty acids and hydrogen partial pressure increased significantly. The autoinducing peptides (AIP)-type became the predominant QS and was positively correlated with fatty acids abundance. Syntrophaceticus and Syntrophomonas may promote syntrophic oxidation of acetate at high OLR through AIP-type QS. These findings provided new insights into the QS processes of microbes during dry AD of KW and a theoretical foundation for optimizing biochemical metabolic processes in dry AD through QS. [Display omitted] • The changes in OLR obviously affected the QS process of microbes in dry AD. • QS processes were dominated by AI-1, AI-2, AI-3, GABA, PQS, and others, at low OLR. • The AIP-type was the predominant QS system at high OLR. • Syntrophaceticus and Syntrophomonas may promote the SAO via AIP-type QS. • QS led by AI-1, AI-2, GABA, and other peptides enhanced AD biochemical metabolism. [ABSTRACT FROM AUTHOR]

Eco-toxicity investigation of polymer materials was considered extremely necessary for their potential menace, which was widely use as mulching materials in agricultural. In this study, polyethylene (PE), polystyrene (PS) and synthetic biomaterials-Ecoflex and cellulose were applying into soil cultivated with two potential indicator plants species: oat (A v ena sati v a) and red radish (Raphanus sativum). Variety of chemical, biochemical parameters and enzyme activity in soil were proved as effective approach to evaluate polymers phytotoxicity in plant-soil mesocosm. The F-value of biomass, pH, heavy metal and electoral conductivity of Raphanus behaved significant different from T0. Significant analysis results indicated biodegradation was fast in PE than PS, besides, heavy metals were dramatically decrease in the end implied the plant absorption may help decrease heavy metal toxicity. The increase value at T2 of Dehydrogenase activity (0.84 higher than average value for Avena & 0.91 higher for Raphanus), Metabolic Index (3.12 higher than average value for Avena & 3.81 higher for Raphanus) means during soil enzyme activity was promoted by biodegradation for its heterotrophic organisms' energy transportation was stimulated. Statistics analysis was carried on Biplot PC1 (24.2% of the total variance), PC2 (23.2% of the total variance), versus PC3 (22.8% of the total variance), which indicated phosphatase activity and metabolic index was significant correlated, and high correlation of ammonium and protease activity. Furthermore, the effects were more evident in Raphanus treatments than in Avena , suggesting the higher sensitivity of Raphanus to polymers treatment, which indicate biodegradation of polymers in Raphanus treatment has produced intermediate phytotoxic compounds. [Display omitted] Variety of chemical, biochemical parameters and enzyme activity in soil were proved as effective approach to evaluate polymers phytotoxicity in plant-soil mesocosm. Biodegradation was fast in PE than PS, besides, heavy metals were dramatically decrease in soil at the end of experiment implied the plant absorption of metal may help decrease heavy metal toxicity of soil. During experiments, soil enzyme activity was promoted by polymer biodegradation for its heterotrophic organisms' energy transportation was stimulated. The effects were more evident in Raphanus treatments than in Avena , suggesting the higher sensitivity of Raphanus to the polymers treatment, which indicate biodegradation of polymers in Raphanus treatment has produced intermediate phytotoxic compounds [ABSTRACT FROM AUTHOR]

Cadmium (Cd) and arsenic (As) are two of the most toxic elements. However, the chemical behaviors of these two elements are different, making it challenging to utilize a single adsorbent with high adsorption capacity for both Cd(II) and As(V) removal. To solve this problem, we synthesized HA/Fe-Mn oxides-loaded biochar (HFMB), a novel ternary material, to perform this task, wherein scanning electron microscopy (SEM) combined with EDS (SEM-EDS) was used to characterize its morphological and physicochemical properties. The maximum adsorption capacity of HFMB was 67.11 mg/g for Cd(II) and 35.59 mg/g for As(V), which is much higher compared to pristine biochar (11.06 mg/g, 0 mg/g for Cd(II) and As(V), respectively). The adsorption characteristics were investigated by adsorption kinetics and the effects of the ionic strength and pH of solutions. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR) revealed that chelation and deposition were the adsorption mechanisms that bound Cd(II) to HFMB, while ligand exchange was the adsorption mechanism that bound As(V). Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract Phosphorus loss during food production and consumption and the effect of urbanization on cropland loss have been widely studied. However, the effect of urbanization on phosphorus metabolism in agricultural areas has received little attention. Using substance flow analysis, this paper reveals the effect of urbanization on food phosphorus metabolism. By developing comprehensive mass balance models, we quantify P flows in a typical agricultural area after summarizing the critical pathways for the effect of urbanization on P metabolism. Then, based on indicators such as per capita food P demand or loss, we discuss the effect of urbanization on food consumption, food production, food export and food waste management. Urbanization resulted in the growth of urban population, the increase of animal-derived food proportion in diet, the increase of food export and its animal-derived food proportion, more emission and declined recycling rate of urban excreta and food waste. Quantitative analysis of urbanization and P metabolism reveals that the increase of P loss driven by urbanization was mainly due to the expansion of animal-derived food production and the increase of food export. The sum of their contribution reached 99.2% of the cumulative urbanization-related P loss over the 20 years. These factors led to more P demand and losses in the regional food consumption-production system. Opportunities for sustainable phosphorus use in food production and consumption system rely on the improvement of P use efficiency in agricultural production, especially animal-derived foods. In this case, the increase of P loss from animal production accounted for 84.5% of total increase of cumulative urbanization-related P loss during the period, due to much lower P use efficiency in livestock feeding and aquaculture than grain planting. Moreover, it was more useful to recycle food waste P and excreta P (as crop fertilizer) than to enhance P removal in wastewater treatment plants. Graphical abstract Image 1 Highlights • P flows for the food system in Zhangzhou steadily grew from 1995 to 2014. • Urbanization affected diet pattern, population structure, trade and waste and excreta reuse. • Urbanization significantly increased local average per capita food P consumption. • Increasing food P consumption caused greater P input and loss within the production-consumption system. • A closed P loop mainly relied on reusing lost P in agriculture rather than removing P in WWTPs. [ABSTRACT FROM AUTHOR]

A sediment core was collected and dated using 210 Pb ex dating method off the waterspout of nuclear power base of Daya Bay, northeastern South China Sea. The γ-emitting radionuclides were analyzed using HPGe γ spectrometry, gross alpha and beta radioactivity as well as other geochemical indicators were deliberated to assess the impact of nuclear power plants (NPP) operation and to study the past environment changes. It suggested that NPP provided no new radioactivity source to sediment based on the low specific activity of 137 Cs. Two broad peaks of TOC, TC and LOI accorded well with the commercial operations of Daya Bay NPP (1994.2 and 1994.5) and LNPP Phase I (2002.5 and 2003.3), implying that the mass input of cooling water from NPP may result into a substantial change in the ecological environment and Daya Bay has been severely impacted by human activities. [ABSTRACT FROM AUTHOR]

• FNA + PF pretreatment increased TSS removal of WAS than either FNA or PF pretreatment. • FNA + PF pretreated WAS showed extremely high BMP during subsequent anaerobic digestion. • FNA + PF pretreatment promoted the enrichment of Methanolinea, Mesotoga , and Methanobacterium. • FNA + PF pretreatment stimulated flexible pathways of methanogenesis during anaerobic digestion. The increasing production of waste activated sludge (WAS) from wastewater treatment plants presents an inherent environmental burden. In this study, Free nitrous acid combined with potassium ferrate (FNA + PF) pretreatment was used to enhance solubilization and biochemical methane potential of WAS. Results indicated that the maximum removal rates of total suspended solid by PF, FNA, and PF + FNA pretreatment were 21.84%, 38.09%, and 56.17%, respectively. The biochemical methane potential of WAS without pretreatment reached 61.22 L CH 4 /kg VSS added while this value increased to 147.07 L CH 4 /kg VSS added after FNA + PF pretreatment (0.06 g/g TSS NaNO 2 and 0.25 g/g TSS K 2 FeO 4). Shotgun metagenomic analysis revealed that FNA + PF pretreatment could increase the diversity and stability of microbial communities by shifting methanogenic pathways from strictly acetoclastic to acetoclastic/hydrogenotrophic, thereby enhancing methane production. This study suggested that FNA + PF pretreatment is a promising technology to reduce WAS and enhance methane production by pretreated WAS during anaerobic digestion. [ABSTRACT FROM AUTHOR]