The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.
Wastewater/toxicity* ; Sewage/chemistry* ; Zinc Oxide/chemistry* ; Waste Disposal, Fluid ; Nanoparticles/chemistry* ; Metal Nanoparticles/chemistry* ; Nitrogen/metabolism* ; Water Purification

Anaerobic granular sludge (AnGS), a self-immobilized aggregate containing various functional microorganisms, is considered as a promising green process for wastewater treatment. AnGS has the advantages of high volume loading rate, simple process and low excess sludge generation, thus shows great technological and economical potentials. This review systematically summarizes the recent advances of the microbial community structure and function of anaerobic granular sludge, and discusses the factors affecting the formation and stability of anaerobic granular sludge from the perspective of microbiology. Moreover, future research directions of AnGS are prospected. This review is expected to facilitate the research and engineering application of AnGS.
Sewage/chemistry* ; Waste Disposal, Fluid ; Anaerobiosis ; Microbiota ; Water Purification ; Bioreactors/microbiology*

We aimed to assess the risks of
China ; Cryptosporidiosis/microbiology* ; Cryptosporidium/isolation & purification* ; Giardia/isolation & purification* ; Giardiasis/microbiology* ; Humans ; Risk Assessment ; Water Microbiology ; Water Supply/statistics & numerical data*

Microbial fuel cell (MFC) is a bioelectrochemical device, that enables simultaneous wastewater treatment and energy generation. However, a few issues such as low output power, high ohmic internal resistance, and long start-up time greatly limit MFCs' applications. MFC anode is the carrier of microbial attachment, and plays a key role in the generation and transmission of electrons. High-quality bioelectrodes have developed into an effective way to improve MFC performance. Conjugated polymers have advantages of low cost, high conductivity, chemical stability and good biocompatibility. The use of conjugated polymers to modify bioelectrodes can achieve a large specific surface area and shorten the charge transfer path, thereby achieving efficient biological electrochemical performance. In addition, bacteria can be coated with nano-scale conjugated polymer and effectively transfer the electrons generated by cells to electrodes. This article reviews the recently reported applications of conjugated polymers in microbial fuel cells, focusing on the MFC anode materials modified by conjugated polymers. This review also systematically analyzes the advantages and limitations of conjugated polymers, and how these composite hybrid bioelectrodes solve practical issues such as low energy output, high inner resistance, and long starting time.
Bacteria ; Bioelectric Energy Sources ; Electricity ; Electrodes ; Polymers ; Water Purification

BACKGROUND: Improved water sources are not equally available in all geographical regions. Populations dependent on unsafe water sources are recommended to treat their water at point-of-use using adequate methods to reduce associated health problems. In Ethiopia, the spatial distribution of households using unimproved water sources have been incomplete or ignored in most of the studies. Moreover, evidence on the point-of-use water treatment practice of households dependent on such water sources is scarce. Therefore, the current study is intended to analyze the spatial distribution of unimproved water sources by wealth quintiles at country level and point-of-use treatment (POU) practices using nationally representative data. METHOD: The data of 2016 Ethiopian Demographic and Health Survey (EDHS) conducted on 16650 households from 643 clusters were used for the analysis. For spatial analysis, the raw and spatially smoothed coverage data was joined to the geographic coordinates based on EDHS cluster identification code. Global spatial autocorrelation was performed to analyze whether the pattern of unimproved water coverage is clustered, dispersed, or random across the study areas. Once a positive global autocorrelation was confirmed, a local spatial autocorrelation analysis was applied to detect local clusters. The POU water treatment is analyzed based on reported use of either boiling, chlorine (bleach), filtration, or solar disinfection (SODIS). RESULTS: There were 5005 households using unimproved water sources for drinking purposes. Spatial variation of unimproved water coverage was observed with high coverage observed at Amhara, Afar, Southern Nations Nationalities and People and Somalia regions. Disparity in unimproved water coverage between wealth quintiles was also observed. The reported point-of-use water treatment practice among these households is only 6.24%. The odds of POU water treatment among household heads with higher education status is 2.5 times higher (95% CI = 1.43-4.36) compared to those who did not attend education. CONCLUSION An apparent clustering trend with high unimproved water coverage was observed between regions and among wealth quintiles hence indicates priority areas for future resource allocation and the need for regional and national policies to address the issue. Promoting households to treat water prior to drinking is essential to reduce health problems.
Drinking Water/analysis* ; Ethiopia ; Socioeconomic Factors ; Spatial Analysis ; Water Purification/methods* ; Water Supply/statistics & numerical data*

Objective: This study aimed to evaluate the genetic diversity, virulence, and antimicrobial resistance of isolates from clinical patients, tap water systems, and food. Methods: Ninety isolates were obtained from Ma'anshan, Anhui province, China, and subjected to multi-locus sequence typing (MLST) with six housekeeping genes. Their taxonomy was investigated using concatenated sequences, while their resistance to 12 antibiotics was evaluated. Ten putative virulence factors and several resistance genes were identified by PCR and sequencing. Results: The 90 isolates were divided into 84 sequence types, 80 of which were novel, indicating high genetic diversity. The isolates were classified into eight different species. PCR assays identified virulence genes in the isolates, with the enterotoxin and hemolysin genes , , , and found in 47 (52.2%), 13 (14.4%), 22 (24.4%), and 12 (13.3%) of the isolates, respectively. The majority of the isolates (≥ 90%) were susceptible to aztreonam, imipenem, cefepime, chloramphenicol, gentamicin, tetracycline, and ciprofloxacin. However, several resistance genes were detected in the isolates, as well as a new variant. Conclusions Sequence type, virulence properties, and antibiotic resistance vary in isolates from clinical patients, tap water systems, and food.
Aeromonas ; drug effects ; genetics ; isolation & purification ; pathogenicity ; Anti-Bacterial Agents ; pharmacology ; China ; Drinking Water ; microbiology ; Drug Resistance, Bacterial ; Food Microbiology ; Genetic Variation ; Gram-Negative Bacterial Infections ; microbiology ; Species Specificity ; Virulence

Objective: Our objective was to investigate the occurrence of opportunistic pathogens and characterize the bacterial community structures in the water system of a pulmonary hospital. Methods: The water samples were collected from automatic and manual faucets in the consulting room, treatment room, dressing room, respiratory ward, and other non-medical rooms in three buildings of the hospital. Quantitative polymerase chain reaction was used to quantify the load of several waterborne opportunistic pathogens and related microorganisms, including spp., spp., and . Illumina sequencing targeting 16S rRNA genes was performed to profile bacterial communities. Results: The occurrence rates of spp., spp., and were 100%, 100%, and 76%, respectively in all samples. Higher occurrence rates of were observed in the outpatient service building (building 1, 91.7%) and respiration department and wards (building 2, 80%) than in the office building (building 3), where no was found. were more abundant in automatic faucets (average 2.21 × 10 gene copies/L) than in manual faucets (average 1.03 × 10 gene copies/mL) ( < 0.01). , , , , , and were the dominant bacterial phyla. Disinfectant residuals, nitrate, and temperature were found to be the key environmental factors driving microbial community structure shifts in water systems. Conclusion This study revealed a high level of colonization of water faucets by opportunistic pathogens and provided insight into the characteristics of microbial communities in a hospital water system and approaches to reduce risks of microbial contamination.
China ; Drinking Water ; microbiology ; Genes, Bacterial ; Hospitals ; Legionella ; isolation & purification ; Microbiota ; Mycobacterium ; isolation & purification ; Mycobacterium avium ; isolation & purification ; RNA, Bacterial ; analysis ; RNA, Ribosomal, 16S ; analysis ; Water Quality ; Water Supply

The aim of this study was to establish a novel technology using microalgae for NO₃⁻ removal from high concentration wastewater and conversion to algal proteins. The effects of cultivation modes and illumination modes on the biomass yield, NO₃⁻ assimilation rate and algal protein yield were first investigated in shaking flasks for mixotrophic cultivation of Chlorella pyrenoidosa, and subsequently the scale-up verification in 5-L photo fermenter was successfully conducted. Fed-batch cultivation without medium recycling was the best cultivation mode in shaking flask system, in which the highest biomass yield (35.95 g/L), the average NO₃⁻ assimilation rate (2.06 g/(L·d)) and algal protein content (up to 42.44% of dry weight) were achieved. By using a staged increase of light intensity as illumination modes, the specific growth rate of cells could be significantly promoted to the highest (0.65 d⁻¹). After a 128-hour continuous cultivation in a 5-L photo fermenter, the highest biomass yield and the average NO₃⁻ assimilation rate were reached to 66.22 g/L and 4.38 g/(L·d) respectively, with the highest algal protein content at 47.13% of dry weight. Our study could provide a photo fermentation technology of microalgae for highly efficient treatment of waste industrial nitric acid and/or high concentration nitrate wastewater. This microalgae-based bioconversion process could coproduce protein-rich microalgal biomass, which facilitates the resource utilization of these type wastewater by trash-to-treasure conversion.
Algal Proteins ; biosynthesis ; Biomass ; Chlorella ; Nitrates ; isolation & purification ; metabolism ; Nitrogen ; metabolism ; Waste Water ; chemistry ; Water Purification ; methods

In this study, taking Cistanche deserticola in Xinjiang as the experimental material, the optimal process for extracting polysaccharides from C. deserticola with water extraction was studied by using single factor and orthogonal experiment. Its effects on protein removal and polysaccharides retaining were investigated by using Sevag, enzymatic method or combination of these two methods, so as to determine the optimal method for protein removal from polysaccharides of C. deserticola; the decolorization and purification methods such as macroporous resin of AB-8 and activated Carbon were used to determine the optimal process. The results showed that the extraction rate of polysaccharides from C. deserticola was 18.40% during the optimal process of the water extraction as follows: extraction temperature 75 ℃, extraction time 165 min and solid-liquid ratio 1∶55. The protein removal rate can reach 31.40% and polysaccharide retention rate can reach 96.00% under the optimal protein removal process: temperature 50 ℃, time 2 h, and papain dosage 0.2%. The decolorization rate of activated Carbon and macroporous resin called AB-8 was 80.37% and 86.43%, and the recovery rate of polysaccharides was 77.05% and 91.93%, respectively, suggesting that macroporous resin was more suitable for decoloration. Macroporous resin named AB-8 increased the purity of the polysaccharide crude extract from 67.70% to 84.80% under the following conditions: concentration of the sample 4 g·L~(-1), concentration of the eluent 60% ethanol, and the flow rate 1 mL·min~(-1), showing significant purification effect.
Cistanche ; chemistry ; Plant Extracts ; chemistry ; Polysaccharides ; isolation & purification ; Temperature ; Water

BACKGROUND: Bacterial contamination of drinking water is a major public health problem in rural areas of sub-Saharan Africa. Unimproved water sources are a major reservoir of Escherichia coli (E. coli) causing severe diarrhoea in humans. This study assessed E. coli counts in drinking water from different sources and their relationship with water source protection status and neighbourhood sanitation and hygiene practices in rural villages of Mohale Basin in Lesotho. METHODS: Thirty drinking water sources were purposively sampled and their water analysed for E. coli counts. The types of water sources, their protection status and neighbourhood sanitation and hygiene practices in their proximity were also assessed. E. coli counts in water samples were compared to water source protection status, neighbourhood sanitation, hygiene practices, livestock faeces and latrine proximity to water sources. RESULTS: E. coli counts were found in all water samples and ranged from less than 30 colony-forming units (cfu)/100 ml to 4800 cfu/100 ml in protected sources to 43,500,000 cfu/100 ml in unprotected sources. A significant association between E. coli counts in drinking water samples and lack of water source protection, high prevalence of open defecation (59%, n = 100), unhygienic practices, livestock faeces and latrine detections in proximity to water sources was found in the study (P < 0.05). CONCLUSION Water sources in studied villages were contaminated with faeces and posed a health risk to consumers of that water. Community-led sanitation and hygiene education and better water source protection are urgently needed.
Drinking Water ; microbiology ; Escherichia coli ; isolation & purification ; Feces ; microbiology ; Health Behavior ; Humans ; Hygiene ; Lesotho ; Rural Health ; Sanitation ; methods ; statistics & numerical data ; Water Microbiology ; Water Quality ; Water Supply ; statistics & numerical data