Anaerobic membrane bioreactor coupled with polyaluminum chloride for high-strength phenolic wastewater treatment: Robust performance and potential mechanisms.

Anaerobic digestion of phenolic wastewater by anaerobic membrane bioreactor (AnMBR) has revealed increasing attractiveness, but the application of AnMBRs for treating high-strength phenolic wastewater faces challenges related to elevated phenol stress and membrane fouling. In this study, the coupling of AnMBR and polyaluminum chloride (PAC) was developed for efficient treatment of high-strength phenolic wastewater. The system achieved robust removal efficiencies of phenol (99%) and quinoline (98%) at a gradual increase of phenol concentration from 1000 to 5000 mg/L and a constant quinoline concentration of 100 mg/L. The dosing of PAC could effectively control the membrane fouling rate with the transmembrane pressure (TMP) increasing rate as low as 0.17 kPa/d. The robust performances were mainly attributed to the favorable retention of functional microbes through membrane interception, while pulse cross flow buffered against phenol stress and facilitated cake layer removal. Meanwhile, the enriched core functional microbes, such as Syntrophorhabdus, Syntrophus, Mesotoga and Methanolinea, played a crucial role in further reduction of phenol stress. Notably, the significant presence of biomacromolecule degrader, such as Levilinea, contributed to membrane fouling mitigation through extracellular polymer degradation. Moreover, the enlargement of particle size distribution (PSD) by PAC was expected to mitigate membrane fouling. This study provided a promising avenue for sustainable treatment of high-strength phenolic wastewater.

Rapid start-up and excellent performance of anaerobic membrane bioreactor for treating poly (butylene adipate-co-terephthalate) wastewater by using one-step feeding mode.

The traditional anaerobic treatment process for highly concentrated, toxic, and acidic poly (butylene adipate-co-terephthalate) (PBAT) wastewater faces challenges. In contrast, the anaerobic membrane bioreactor (AnMBR) offers the advantage of robust performance, but the influence of start-up modes has not been explored. This study investigated the impact of one-step and stepwise startup (gradual dilution of wastewater) strategies in AnMBR treating PBAT wastewater. The results indicated that the one-step startup group achieved COD removal efficiency of 91.2% ± 2.7% and methane conversion rate of 234.7 ± 8.5 mLCH4/gCOD, which were 21.7% and 81.8 mL CH4/gCOD respectively higher than those achieved by the stepwise start-up group. Furthermore, the one-step startup led to the reduction of startup time by 10 days and the decrease in the average membrane fouling cycle by 6.6 days. Compared to the stepwise start-up group, the one-step startup group exhibited a lower abundance of Bacteroidota (11.3%), and a higher abundance of Proteobacteria (27.1%), Chloroflexi (10.5%), and Actinobacteria (11.8%). The one-step startup strategy facilitated the rapid development of a toxicity-tolerant hydrogenotrophic methanogenic pathway. Consequently, the one-step startup method provided a promising approach for the rapid start-up and excellent performance of AnMBR in PBAT wastewater treatment.

Combined Effects of Tetracycline and Copper Ion on Microorganisms During the Biological Phosphorus Removal.

Tetracycline and copper ion are common pollutants in wastewater, and the effects of mixed pollutants on microorganisms in wastewater biological treatment have been less studied. In order to reveal the effects of mixed pollutants of tetracycline and copper ion on the microorganisms during the biological phosphorus removal, three ratios of tetracycline and copper ions were designed by the direct equipartition ray method. The relative abundance and diversity of microbial community were investigated, and the microbial interactions were revealed through microbiological methods. The results demonstrated that, for three different ratios, the inhibitory effect of specific phosphorus uptake rate became more significant with the increase of the tetracycline-copper ions concentration and the reaction time. The microbial community decreased with the increase of the proportion of tetracycline in different ratios. The relative abundance of Acinetobacter decreased with the increase of the proportion of tetracycline, while the relative abundance of Ca.Competibacter was higher under the conditions of low mixtures concentrations. Positive interactions and symbiotic relationships among microorganisms were predominant for three different ratios. However, as the proportion of tetracycline increased, the community structure of microorganisms shifted from phosphate-accumulating organisms to glycogen accumulating organisms and denitrifying bacteria. This study can provide a reference for the effect of mixed pollutants on microorganisms and the mechanism of wastewater treatment.

Effects of zinc ion concentrations on the performance of SBR treating livestock wastewater and analysis of microbial community.

Zinc ion (Zn2+) is a frequently occurring heavy metal in livestock wastewater. The effects of Zn2+ on the physicochemical properties and the microbial distribution of activated sludge are essential to controlling nitrogen removal performance. Nevertheless, there are raw studies on the effects of Zn2+ on nitrogen removal. This study investigated the effect of Zn2+ on the treatment performance of livestock wastewater in a sequencing batch reactor (SBR). The results indicated the low Zn2+ concentrations could improve nitrogen removal performance. However, as the Zn2+ concentration increased, the total nitrogen (TN) removal performance of the reactor gradually deteriorated. When the Zn2+ concentration was 90.00 mg/L, the TN removal efficiency was the lowest, only 2.40%. The contents of the Extracellular polymeric substance (EPS) presented a trend of first increasing and then decreasing with the increase of Zn2+ concentration, and the main reason was the decrease of protein-like and tryptophan-like. The 16SrRNA analysis indicated that Zn2+ within a specific concentration could increase the operational taxonomic units (OTUs) number, microbial richness, and diversity of microorganisms in the SBR. However, with Zn2+ concentration exceeding 10.00 mg/L, the relative abundance of denitrification functional bacteria (Dechloromonas, Nitrospira, and Thauera) decreased.

The trend of unintentional injury-related mortality among children aged under-five years in China, 2010-2020: a retrospective analysis from a national surveillance system.

BACKGROUND: In this study, we estimated the trend of unintentional injury mortality among children aged under-five years in China during 2010-2020. METHODS: Data were obtained from China's Under 5 Child Mortality Surveillance System (U5CMSS). The total unintentional injury mortality and all specific-causes unintentional injury mortality was calculated, annual numbers of deaths and live births were adjusted by a 3-year moving average under-reporting rate. The Poisson regression model and the Cochran-Mantel-Haenszel method were used to calculate the average annual decline rate (AADR) and the adjusted relative risk (aRR) of the unintentional injury mortality. RESULTS: In 2010-2020, a total of 7,925 unintentional injury-related deaths were reported in U5CMSS, accounting for 18.7% of all reported deaths. The overall proportion of unintentional injury-related deaths to total under-five children deaths has increased from 15.2% to 2010 to 23.8% in 2020 (χ2 = 227.0, p < 0.001), the unintentional injury mortality significantly decreased from 249.3 deaths per 100,000 live births in 2010 to 178.8 deaths per 100,000 live births in 2020, with an AADR 3.7% (95%CI 3.1-4.4). The unintentional injury mortality rate decreased from 2010 to 2020 in both urban (from 68.1 to 59.7 per 100,000 live births) and rural (from 323.1 to 230.0 per 100,000 live births) areas (urban: χ2 = 3.1, p < 0.08; rural: χ2 = 113.5, p < 0.001). The annual rates of decline in rural areas and urban areas were 4.2% (95%CI 3.4-4.9) and 1.5% (95%CI 0.1-3.3), respectively. The leading causes of unintentional injury mortality were suffocation (2,611, 32.9%), drowning (2,398, 30.3%), and traffic injury (1,428, 12.8%) in 2010-2020. The cause-specific of unintentional injury mortality rates decreased with varying AADRs in 2010-2020, except for traffic injury. The composition of unintentional injury-related deaths also varied by age group. Suffocation was the leading cause in infants, drowning and traffic injury were the leading causes in children aged 1-4 years. Suffocation and poisoning has high incidence in October to March and drowning has high in June to August. CONCLUSION: The unintentional injury mortality rate of children aged under-five years decreased significantly from 2010 to 2020 in China, but great inequity exists in unintentional injury mortality in urban and rural areas. Unintentional injuries are still an important public health problem affecting the health of Chinese children. Effective strategies should be strengthened to reduce unintentional injury in children and these policies and programmes should be targeted to more specific populations, such as rural areas and males.

Geographical disparities in infant mortality in the rural areas of China: a descriptive study, 2010-2018.

BACKGROUND: The infant mortality rate (IMR) is considered a basic measure of public health for countries around the world. The specific aim of our study was to provide an updated description of infant mortality rate among different regions in rural China, and assess the trends and causes of the IMR geographical disparities. METHODS: Data were collected from China's Under-5 Child Mortality Surveillance System(U5CMSS). The annual number of deaths and causes of death were adjusted using a 3-year moving average underreporting rate based on annual national data quality control results. The average annual decline rate (AADR) and the relative risk (RR) of the IMR and cause-specific infant mortality were calculated by Poisson regression and the Cochran-Mantel-Haenszel method. Data analysis was completed by SAS software. RESULTS: There was an apparent decrease in infant mortality in rural China from 2010 to 2018, at the AADR of 11.0% (95%CI 9.6-12.4), 11.2% (95%CI 10.3-12.1) and 6.6% (95%CI 6.0-7.3) in the eastern, central and western rural areas, respectively. The IMR was highest in the western rural area, followed by the central and eastern rural areas. Compared with the eastern rural area, the RR of infant mortality in the central rural area remained at 1.4-1.6 and increased from 2.4 (95%CI 2.3-2.6) in 2010-2012 to 3.1 (95% CI 2.9-3.4) in 2016-2018 in the western rural area. Pneumonia, preterm birth /LBW and birth asphyxia were the leading causes of infant deaths in the western rural area. Mortality rates of these three causes fell significantly in 2010-2018 but contributed to a higher proportion of deaths in the western rural area than in the central and western rural ares. CONCLUSIONS: Our study indicated that the infant mortality rate dropped significantly from 2010 to 2018, however, geographical disparities of IMR in rural China are still persist. Therefore, there is an urgent need for public health programmes and policy interventions for infants in western rural China.

Experimental Study of Ghost Imaging in Underwater Environment.

Underwater imaging technique is a crucial tool for humans to develop, utilize, and protect the ocean. We comprehensively compare the imaging performance of twenty-four ghost imaging (GI) methods in the underwater environment. The GI methods are divided into two types according to the illumination patterns, the random and orthogonal patterns. Three-group simulations were designed to show the imaging performance of the twenty-four GI methods. Moreover, an experimental system was built, and three-group experiments were implemented. The numerical and experimental results demonstrate that the orthogonal pattern-based compressed sensing GI methods have strong antinoise capability and can restore clear images for underwater objects with a low measurement number. The investigation results are helpful for the practical applications of the underwater GI.

Breastfeeding practice in China from 2013 to 2018: a study from a national dynamic follow-up surveillance.

BACKGROUND: Breastfeeding is important for the physical and psychological health of the mother and child. Basic data on breastfeeding practice in China are out-of-date and vary widely. This study aimed to evaluate the progress of breastfeeding practice in China, as well as to explore the bottlenecks in driving better practice. METHODS: This was an observational study. We used data from the Under-5 Child Nutrition and Health Surveillance System in China for the period 2013-2018. The prevalence of early initiation of breastfeeding (EIBF) and exclusive breastfeeding (EBF) were calculated for each year for subgroups of China. The Cochran-Armitage test was used to explore the time trends. The annual percent of change (APC) were calculated by log-linear regression followed by exp transformation. RESULTS: The prevalence of EIBF increased significantly from 44.57% (95% CI: 44.07, 45.07) in 2013 to 55.84% (95% CI: 55.29, 56.38) in 2018 (Ptrend < 0.001), with an APC of 4.67% (95% CI: 3.51, 5.85). And the prevalence of EBF increased rapidly from 16.14% (95% CI: 15.10, 17.18) to 34.90% (95% CI: 33.54, 36.26) (Ptrend < 0.001), with an APC of 14.90% (95% CI: 9.97, 20.04). Increases were observed in both urban and rural areas, with urban areas showing greater APCs for EIBF (6.05%; 95% CI: 4.22, 7.92 v.s. 2.26%; 95% CI: 1.40, 3.12) and EBF (18.21%; 95% CI: 11.53, 25.29 v.s. 9.43%; 95% CI: 5.52, 13.49). The highest EBF prevalence was observed in the East, but the Central area showed the highest APC. The prevalence of EBF decreased with increasing age within the first 6 months, especially after 3 months. CONCLUSION: The prevalence of both EIBF and EBF in China are improving in recent years. The rural and West China could be the key areas in the future actions. More efforts should be made to protect and promote breastfeeding to achieve near- and long-term goals for child health.

Social and environmental risk factors for unintentional suffocation among infants in China: a descriptive analysis.

BACKGROUND: This retrospective study aimed to determine the epidemiological features of deaths caused by unintentional suffocation among infants in China. METHODS: The data used in this study were obtained from China's Under 5 Child Mortality Surveillance System (U5CMSS) from October 1, 2015, to September 30, 2016. A total of 377 children under 1 year of age who died from unintentional suffocation were included in the survey. Primary caregivers were interviewed individually using the Unintentional Suffocation Mortality among Children under 5 Questionnaire. EpiData was used to establish the database, and the results were analysed using SPSS 22.0. RESULTS: Most (85.9%) unintentional infant suffocations occurred in rural areas, and 67.5% occurred in infants 0 to 3 months old. Among the primary caregivers of the infants, most (82.7%) had a junior middle school education or below, and 83.1% of them lacked unintentional suffocation first aid skills. Of the 377 unintentional suffocated-infant deaths, the causes of death were accidental suffocation and strangulation in bed (ASSB) (193, 51.2%), inhalation suffocation (154, 40.8%), other unintentional suffocation (6, 1.6%), and unknown (24, 6.4%). Among the infant deaths due to ASSB, overlaying (88.6%) was the most frequently reported circumstance. A total of 93.8% of cases reported occurred during co-sleeping/bed sharing with parents, and in 72.8% of the cases, the infants were covered with the same quilt as their parents. In our study, most inhalation suffocation deaths (88.3%) involved liquid food (such as breast milk and formula milk). A total of 80.5% of infant deaths reportedly occurred after eating; in 28.2% of those cases, the infants were held upright and patted by their caregivers, and 57.2% of them were laid down to sleep immediately after eating. CONCLUSIONS: To reduce the occurrence of unintentional suffocation, local government should strengthen knowledge and awareness of unintentional suffocation prevention and safety among parents and caregivers. Additionally, health care providers should educate parents and caregivers about safety issues of unintentional suffocation, and relevant policies should be introduced to provide environments and activities that reduce the risk of suffocation, such as promoting the Safe to Sleep Campaign. It is important to enhance the focus on infant unintentional suffocation as a health issue.

Effects of Sludge Retention Time on the Performance of Anaerobic Ceramic Membrane Bioreactor Treating High-Strength Phenol Wastewater.

Anaerobic ceramic membrane bioreactor (AnCMBR) is an attractive alternative for the treatment of high-strength phenol wastewater, but the effects of sludge retention time (SRT) on the performance and membrane fouling are still unclear. The results indicated that the AnCMBR was successfully employed to treat high-strength wastewater containing 5 g phenol L-1. The removal efficiencies of phenol and chemical oxygen demand (COD) reached over 99.5% and 99%, respectively, with long SRT and short SRT. SRT had no obvious effect on the performance of the AnCMBR treating high-strength phenol wastewater with long time operation. The strong performance robustness of AnCMBR benefited from the enrichment of hydrogenotrophic methanogens and syntrophic phenol-degrading bacteria. However, the decline of SRT led to a more severe membrane fouling in the AnCMBR, which was caused by the small size of sludge flocs and high concentration of protein in the biopolymers. Therefore, this work presented a comprehensive insight to the feasibility and robustness of the AnCMBR for treating high-strength phenol wastewater.