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Solid-phase denitrification is a promising alternative denitrification technology when facing a shortage of carbon sources. Nevertheless, it is still unclear whether there is a certain interaction between the denitrification process and the carbon release process in a solid-phase denitrification system. In this study, the concept of "Self-adaptation" was proposed for the relationship between denitrification and carbon release. At various influent nitrate loads, the PCL-supported denitrification system achieved an average nitrate removal rate of over 90.59 ± 7.01 % and a maximum denitrification rate of 0.67 ± 0.06 gN/(L·d). Microorganisms can spontaneously regulate the carbon release rate of PCL in response to changes in influent nitrate load, demonstrating "self-adaptation" of the PCL-supported solid-phase denitrification system. Regulation of carbon release rate via the "Self-adaptation" was achieved by changes in extracellular depolymerase activity. Acidovorax_sp. played a key role in "Self-adaptation", for its function of both denitrification and PCL degradation.

Background: Epinephelus fuscoguttatus is one of the rare marine economic fishes with high economic value. At present, the researches on grouper mainly focus on artificial propagation, physiology and biochemistry, diseases and so on. However, there are few reports on mitochondrial genome level. The research aimed to analyze composition characteristics and usage preference of codon of mitochondrial genome in E. fuscoguttatus, and explored main factors of affecting the formation of codon preference, thereby providing theoretical basis for studying species evolution, genetics and breeding, and improving expression efficiency of exogenous genes. Results: GC content of mitochondrial genome of E. fuscoguttatus changed between 44.00% and 46.30%, with 45.40% of mean. Change range of CAI value was between 0.125 and 0.202, and the mean was 0.155. Effective number of codons (ENC) changed between 36.08 and 49.55, with 44.98 of mean. There were 32 codons that relative synonymous codon usage (RSCU) was more than 1, mainly ended with A/C. ENC-plot analysis found that all the genes were in the lower middle of the standard curve, and there was larger difference between actual and theoretical ENC, illustrating that codon bias was mainly affected by the choice. Correspondence analysis showed that the first axis contributed 58.85% of the difference, while the second, third and fourth axes contributed 14.59%, 7.66% and 5.43% of the difference respectively. Cumulative contribution rate of the first four vectors was 85.53%. Finally, nine optimal codons were selected: CUU, AUC, GUU, CCU, GCA, UAU, CGC, AGC and GGC.Conclusions: Codon usage preference of mitochondrial genome of E. fuscoguttatus was weak, and it preferred to use A/C terminated codon, and preference was mainly influenced by choice.

Objective: This meta-analysis aimed to compare the efficacy and safety of ultrasound-guided (US-guided) versus landmark-guided (LM-guided) local corticosteroid injection for carpal tunnel syndrome (CTS). Methods: Database including Pubmed, Embase, and Cochrane Library were searched to identify relevant randomized controlled trials (RCTs). The outcomes mainly included Boston Carpal Tunnel Questionnaire (BCTQ): Symptom Severity Scale (BCTQs), Functional Status Scale (BCTQf); and electrophysiological indexes: distal motor latency (DML), sensory distal latency (SDL), compound muscle action potential (CAMP), sensory nerve action potential amplitude (SNAP), and sensory nerve conduction velocity (SNCV). Adverse events were also recorded. Results: Overall, nine RCTs were finally screened out with 469 patients (596 injected hands). Pooled analysis showed that US-guided injection was more effective in BCTQs (SMD, −0.69; 95% CI, −1.08 to −0.31; P = 0.0005), BCTQf (SMD, −0.23; 95% CI, −0.39 to −0.07; P = 0.005), CAMP (MD, 0.64; 95% CI, 0.35−0.94; P Conclusions: US-guided injection was superior to LM-guided injection in symptom severity, functional status, electrodiagnostic, and adverse events improvement for CTS. To some extent, the in-plane approach yields better results compared with the out-plane process under US guidance.

Carbon source production from primary sludge in wastewater treatment plants (WWTPs) via anaerobic fermentation process has been paid more attention. However, slow hydrolysis rate and low yield of short-chain fatty acids (SCFAs) limited its application. This study aimed at improving the anaerobic fermentation efficiency of primary sludge by alkali regulation (NaOH, Na2CO3 and Ca(OH)2), and revealing the mechanism. Results showed that three kinds of alkalis allowed enhancing hydrolysis and acidification, and reducing methane production in the anaerobic fermentation process of primary sludge. The Na2CO3 regulation contributed to highest yield and productivity of SCFAs, reaching 1626 mg COD/L and 0.189 g COD/g VSS at 4th day, respectively. Microbial community structure analysis indicated that the relative abundance of fermentative microbial community was improved in the alkali regulation system, where methanogenic archaea was effectively inhibited. The continuous flow experiment further verified that the Na2CO3 regulation could steadily increase yield of SCFAs in the anaerobic fermentation process of primary sludge, and the yield was also the highest among three kinds of alkali regulation.

The flexible strain sensor is of significant importance in wearable electronics, since it can help monitor the physical signals from the human body. Among various strain sensors, the foam-shaped ones have received widespread attention owing to their light weight and gas permeability. However, the working range of these sensors is still not large enough, and the sensitivity needs to be further improved. In this work, we develop a high-performance foam-shaped strain sensor composed of Ti

Lysine acetylation is critical in regulating important biological processes in many organisms, yet little is known about acetylome evolution and its contribution to phenotypic diversity. Here, we compare the acetylomes of baker’s yeast and the three deadliest human fungal pathogens, Cryptococcus neoformans, Candida albicans, and Aspergillus fumigatus. Using mass spectrometry enriched for acetylated peptides together with public data from Saccharomyces cerevisiae, we show that fungal acetylomes are characterized by dramatic evolutionary dynamics and limited conservation in core biological processes. Notably, the levels of protein acetylation in pathogenic fungi correlate with their pathogenicity. Using gene knockouts and pathogenicity assays in mice, we identify deacetylases with critical roles in virulence and protein translation elongation. Finally, through mutational analysis of deactylation motifs we find evidence of positive selection at specific acetylation motifs in fungal pathogens. These results shed new light on the pathogenicity regulation mechanisms underlying the evolution of fungal acetylomes., Yanjian Li and Hailong Li, et al. report interspecific comparisons of the acetylomes of yeast and three human fungal pathogens. Through evolutionary analysis and experimental validation, they show that pathogen-specific aceylation motifs and deacetylase genes are required for normal virulence in an animal infection model.

Natural adsorbent was optimized from four natural adsorption materials (kaolin, bentonite, diatomite, and natural zeolite) through the comparison of their ability to recover organic matter from an ultra-short-sludge-retention-time (ultra-short-SRT) activated sludge process effluent. Natural zeolite was modified by the loading of three types of chemical coagulants (Fe2(SO4)3, Al2(SO4)3, and ZnSO4) and was used for the study of the advanced recovery of organic matter. The results of Brunauer–Emmett–Teller surface area (SBET) measurements, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses showed that natural zeolite was successfully modified, with decrease in the specific surface area of the modified zeolite (MZ), but some metal ions/metal oxides were loaded onto the surface of natural zeolite. Compared with chemical coagulant and natural zeolite, the organic recovery efficiency from the effluent of the MZs improved, and after the optimization process, the organic recovery efficiency of MZ4 (Zeolite:Fe2(SO4)3 = 4:1), MZ9 (Zeolite:Al2(SO4)3 = 4:1), and MZ13 (Zeolite:ZnSO4 = 2:1) reached 72.0%, 67.6%, and 61.2%, respectively. The MZs can allow a significant amount of recovery of soluble chemical oxygen demand (SCOD) from the effluent, with SCOD recovery efficiencies for MZ4, MZ9, and MZ13 of 44.8%, 44.3%, and 39.4%, respectively. The E4/E6, UV253/UV203, and SUVA analyses after the organic recovery experiments indicated that the generation potential of disinfecting byproducts or halogenated products was reduced in the treated effluent by the MZs. The mechanism can be considered in two ways: the coagulation effect of the loaded metal ions/metal oxides and the physical and chemical adsorption effect based on the hydrogen bond and π π bond between the MZ and organic matter. This study facilitated the application of organic recovery from wastewater and the advanced treatment of effluent.

Background Sepsis is a major cause of death in ICU, and intestinal barrier dysfunction is its important complication, while the treatment is limited. Recently, mesenchymal stem cell-derived microvesicles (MMVs) attract much attention as a strategy of cell-free treatment; whether MMVs are therapeutic in sepsis induced-intestinal barrier dysfunction is obscure. Methods In this study, cecal ligation and puncture-induced sepsis rats and lipopolysaccharide-stimulated intestinal epithelial cells to investigate the effect of MMVs on intestinal barrier dysfunction. MMVs were harvested from mesenchymal stem cells and were injected into sepsis rats, and the intestinal barrier function was measured. Afterward, MMVs were incubated with intestinal epithelial cells, and the effect of MMVs on mitochondrial dynamic balance was measured. Then the expression of mfn1, mfn2, OPA1, and PGC-1α in MMVs were measured by western blot. By upregulation and downregulation of mfn2 and PGC-1α, the role of MMVs in mitochondrial dynamic balance was investigated. Finally, the role of MMV-carried mitochondria in mitochondrial dynamic balance was investigated. Results MMVs restored the intestinal barrier function by improving mitochondrial dynamic balance and metabolism of mitochondria. Further study revealed that MMVs delivered mfn2 and PGC-1α to intestinal epithelial cells, and promoted mitochondrial fusion and biogenesis, thereby improving mitochondrial dynamic balance. Furthermore, MMVs delivered functional mitochondria to intestinal epithelial cells and enhanced energy metabolism directly. Conclusion MMVs can deliver mfn2, PGC-1α, and functional mitochondria to intestinal epithelial cells, synergistically improve mitochondrial dynamic balance of target cells after sepsis, and restore the mitochondrial function and intestinal barrier function. The study illustrated that MMVs might be a promising strategy for the treatment of sepsis.

This study evaluated the influence of different volume ratios of the anoxic-to-aerobic zone (Vano/Vaer) on the enhancement of nitrogen and phosphorus removal in an integrated fixed-film activated sludge (IFAS) system. As the Vano/Vaer increased from 1:2 to 2:1, the removal of organic carbon, nitrogen and phosphorus nutrients of the IFAS system was improved. At Vano/Vaer = 1:1, the removal effect of nitrogen and phosphorus nutrients was optimal, and the average removal rates of COD, NH4+-N, TN, and TP of the system reached 90 ± 3.2%, 98.2 ± 1.4%, 88.9 ± 2.2%, and 89.1 ± 2.7%, respectively. As the volume of the anoxic zone continued to increase, the denitrifying phosphate-accumulating capacity of the system was enhanced, and the highest ratio of specific anoxic and aerobic phosphorus uptake rate could reach 65.3%. Analysis of the molecular evaluation showed that, the proportion of nitrifying bacteria in the biofilm gradually increased as Vano increased. Moreover, denitrifying phosphate-accumulating organisms (DNPAOs), ammonia-oxidizing archaea (AOA), and anaerobic ammonium oxidizing (Anammox) bacteria were all enriched all showed enrichment in the biofilm of fiber carriers, which further strengthened the system's synergistic removal of nitrogen and phosphorus.

Overall understanding of microbial community structure in activated sludge (AS) system at regional level is of great significance for operation regulation of wastewater treatment plants (WWTPs). In this study, 110 AS samples from 21 cities in different Chinese regions were analyzed based on high-throughput 16S ribosomal DNA (rDNA) sequencing to explore effects of different regions on microbial community structure. Results showed that the regions with different characteristics (south and north, coastal and inland, high GDP and low GDP) had great impact on AS bacterial community in China. Core bacterial communities (101 OTUs) in south China were more abundant than those in north China (49 OTUs), and many core species in south China were associated with nutrient removal. Coastal WWTPs possessed unique bacterial communities due to the influence of marine bacteria. Phyla Chloroflexi and Acidobacteria were observed to be main biomarkers in coastal WWTPs. Compared with low GDP regions, more diverse microbial community and effective wastewater treatment were discovered in high GDP regions, and environmental factor analysis suggested that they were mainly correlated with high capacity and influent TP in the WWTPs. β nearest taxon index (βNTI) analysis showed that microbial community assembly in the analyzed AS samples was dominated by deterministic factors (70.67%) and influent quality was observed to be main factor.

The wastewater treatment industry in urban China generally faces certain common problems. To provide a comprehensive analysis on common problems of the wastewater treatment industry, survey data from 467 wastewater treatment plants (WWTPs) and field investigation reports of 38 WWTPs were analyzed. The research results showed that, the common problems of the wastewater treatment industry are mainly concentrated in WWTPs and the drainage system. The length of per capita drainage networks is insufficient, only 0.85 m; approximately 63.17% WWTPs have hydraulic load rates (HLRs) are greater than 80%, and the ratio of water quality between the design value and actual value is approximately 0.7; and there is still a considerable gap in construction of wastewater treatment facilities compared to those in developed countries. These are still major common problems perplexing the wastewater treatment industry in urban China. In this study, the common problems that hinder improving the operation efficiency of WWTPs were investigated, the causes of the discrepancy were analyzed, and three countermeasures, such as refinement design, optimization facilities and reasonable process control were jointly explored to solve them. This study may provide valuable insights and methods for the wastewater treatment industry to effectively address the discrepancy between the design and actual operation of WWTPs.

Lipids in sewage sludge are considered to be high-class raw materials for biodiesel or other valuable products. We profiled the characteristics and assessed the reutilization potential of lipids from different sludge sources, including sludge from the primary sedimentation tank (PST sludge) and sludge from the secondary sedimentation tank in a conventional activated sludge system (CAS sludge), as well as sludge from ultrashort-sludge retention time (SRT) activated sludge systems with different SRTs (USAS sludge, with SRTs of 0.5, 1.0, 2.0, 3.0 and 4.0 d). The results showed that the lipids in the sludges were mainly composed of cellular lipids, free fatty acids (FFAs), wax and gum. The highest lipid content was found in the PST sludge (156.8 ± 11.9 mg/g, dry basis), followed by the USAS sludges (67.9 ± 11.0–132.2 ± 11.8 mg/g) and the CAS sludge (46.0 ± 16.5 mg/g). Lipid species such as Cer, So, PE, PC, and TG were abundant, comprising over 80% of the cellular lipids in the sludges. With higher lipid contents, the PST sludge and USAS sludge (0.5 d SRT) were suggested to have a higher reutilization potential for use in producing biodiesel. In addition, the CAS sludge was promising for resource reutilization and energy recovery due to the large amount of excess sludge.

Aiming at the requirements of gas detection in petroleum, petrochemical, power equipment and air pollution monitoring, some key technologies in passive uncooled gas leakage infrared imaging detection system are analyzed. Based on the gas absorption line intensity and absorption peak position in the standard infrared database, the key components such as MW and LW infrared optical lens and wide band uncooled infrared focal plane detector are optimized. Considering the imaging signal-to-noise ratio and signal contrast, the filter used in several typical gas detections is analyzed, and an online and handheld gas leakage infrared imaging detection system capable of detecting multiple gases is designed. Theoretically, it is possible to detect gas with characteristic absorption in the range of 3-14 μm. The imaging effects of carbon dioxide gas, methane gas and sulfur hexafluoride gas with absorption peaks in MW and LW bands were measured. The test results show that the uncooled infrared gas detection system designed in this paper not only has good imaging detection ability for sulfur hexafluoride gas and ethylene gas (near 10.5 μm) with large absorption intensity and absorption peak in conventional LW band, but also for methane gas (near 7.5μm or 3.3μm) and carbon dioxide gas (near 4.2 μm) with absorption peak in unconventional LW band. In the laboratory environment, with the black body as the background, the gas flow rate is controlled by the gas mass flow meter to observe the imaging detection effects under different temperature differences and different flow rates. When the target and background temperature difference is 5K, the gas detection ability is ≤100mL/min.

Fogging widely occurs in industrial processes, surgical treatment, and human daily lives. Due to the reduction in transmittance, fogging induces adverse effects or even disaster. Traditional anti-fogging methods face the limitations of large energy consumption and sensitive to contamination. This paper proposes a method of using rotating freestanding triboelectric nanogenerator (RF-TENG) which is capable of converting arbitrary mechanical energy into electricity to drive an electrowetting-on-dielectric (EWOD) device to achieve anti-fogging. The RF-TENG could generate variable open-circuit voltage (0.73–5.26 kV) and frequency (20–100 Hz) by changing the contact area and the rotating speed of the input mechanical energy. The fog droplets coalescence and shedding processes were captured by a high-speed camera, revealing that the droplet oscillation and lateral movement on the EWOD device mainly contribute to the anti-fogging phenomenon. The effects of open-circuit voltage and frequency of the RF-TENG on anti-fogging performance are discussed. The experimental results show that when the open-circuit voltage is greater than ± 1 kV and a frequency larger than 60 Hz is able to achieve a large dry area fraction from 34% to 98% in a very short time (

A large amount of heavy metal-contained wastewater (HMW) was discharged during Chinese industry development, which has caused many environmental problems. This study reviewed discharge, management and treatment of HMW in China through collecting and analyzing data from China's official statistical yearbook, standards, technical specifications, government reports, case reports, and research paper. Results showed that industry wastewater discharged by an amount of about 221.6 × 108 t (in 2012), where emission of heavy metals including Pb, Hg, Cd, Cr(VI), T-Cr was around 388.4 t (in 2012). Heavy metal emission with wastewater in east China and central south China was observed to be graver than that in other areas. However, control of heavy metals in Pb and Cd in northwest China was more difficult compared with other areas. In terms of management, China's government has issued many wastewater discharge standards, strict management policies for controlling HMW discharge in recent years, resulting in reduced HMW discharge. In addition, main HMW treatment technology in China was chemical precipitation, and other technologies such as membrane separation, adsorption, ion exchange, electrochemical and biological methods were also occasionally applied. In the future, chemical industries will be concentrated in northwest China, therefore control of HMW discharge should be paid much more attention in those areas. In addition, more effective and environment-friendly heavy metal removal and regeneration technologies should be developed, such as biomaterials adsorbent.

A pilot-scale study on start-up and stable operation of mainstream partial nitrification-anammox biofilter (PN/AF) system was conducted. The partial nitrification system was controlled based on online pH-dissolved oxygen (DO) linkage control strategy for nitrite oxidizing bacteria (NOB) out-selection. The immobilized anammox system was an upload biofilter reactor where anammox bacteria were immobilized on the volcanic carriers. The results showed that the nitrite accumulation ratio (NAR) was maintained above 90%, and the NO2—N/NH4+-N value was kept at 0.96 ± 0.18 in the effluent of the partial nitrification system; the mean ammonia concentration of the effluent was below 5 mg/L, and total inorganic nitrogen (TIN) removal loading could achieve 0.11 kg/m3·d after the stable operation in the whole system. The results of high-throughout sequencing showed that the NOB (mainly Nitrospira, Nitrotoga) was out of the partial nitrification system after 30-day operation, the relative abundance of which is less than 1% observed from Krona maps, and ammonia oxidizing bacteria (AOB, mainly Nitrosomonas) became the dominant species of nitrobacteria, the 8% of AOB stabilized finally. Dominant anammox bacteria was identified as genus Candidatus Brocadia, and one kind of rare anammox named Asahi BRW_2 was found to be at the downside of the volcanic biofilter reactor. It could be found the online pH-DO linkage control strategy allowed out-selection of NOB from the mainstream SBR system, and realized a stable partial nitrification. In addition, high DO (2.5 ± 0.5 mg/L) condition was found to be favorable for NOB out-selection and the stabilization of nitritation. The anammox bacteria could be well immobilized in volcanic carriers, with an ability of low ammonia resistance. The study was helpful for engineering application of mainstream anammox process.

A sequencing batch reactor (SBR)-anaerobic ammonium oxidation (anammox) system was started up with the paddy soil as inoculated sludge. The key microbial community structure in the system along with the enrichment time was investigated by using molecular biology methods (e.g., high-throughput 16S rRNA gene sequencing and quantitative PCR). Meanwhile, the influent and effluent water quality was continuously monitored during the whole start-up stage. The results showed that the microbial diversity decreased as the operation time initially and increased afterwards, and the microbial niches in the system were redistributed. The anammox bacterial community structure in the SBR-anammox system shifted during the enrichment, the most dominant anammox bacteria were CandidatusJettenia. The maximum biomass of anammox bacteria achieved 1.68×109copies/g dry sludge during the enrichment period, and the highest removal rate of TN achieved around 75%.

Triboelectric nanogenerators (TENGs) have been demonstrated promising as flexible, portable, and wearable devices in energy harvesting and self-powered sensing, providing a new possibility in wearable electronics and human-machine interaction. To reduce the environmental pollution, many sustainable and natural materials have been applied as friction materials in TENGs; however, it is still challenging to fabricate fully sustainable and high-performance TENGs, possibly due to the difficulty in choosing suitable sustainable friction pairs. Herein, we develop a general method to fabricate a flexible, transparent, fully sustainable, and high-performance fish gelatin-based TENG with its friction layers all composed of the fish gelatin films prepared from kitchen waste fish scales. These films can degrade completely within 30 days in the soil. Modifying the two friction layers with dopamine and fluorinated silane respectively to serve as a promising triboelectric pair, the obtained TENG shows remarkable output performances, which could be further enhanced via surface structuralization and dimension optimization. An open circuit voltage of 500 V and a short circuit current of 4 μA are realized, and the power density reaches up to 100 μW cm−2. To the best of our knowledge, the output voltage is much higher than that of the reported sustainable TENGs. Our fully sustainable TENG can directly light up 300 light-emitting diodes. Moreover, the device is also used in self-powered wearable sensing of human movements and in human-machine interaction. Our work demonstrates the great potential of utilizing the cost-efficient and sustainable fish scales in flexible, green, and wearable electronics, particularly in human-machine interaction.

Leidenfrost phenomenon has been observed since 1756. Diverse Leidenfrost phenomenon based heat engines were developed for converting the thermal energy into mechanical form. Limited to the weak force, the Leidenfrost heat engines are rarely reported with usable electric power output. Here we propose an elastic Leidenfrost heat engine based power generator for the demonstration of thermal-to-electric power conversion. A saturated sodium polyacrylate super absorbing polymer sphere is employed as hydrogel piston for harvesting thermal energy to trigger elastic deformation and mechanical bouncing. A lightweight contact separation mode triboelectric nanogenerator (TENG) plays a role for the conversion from the tiny mechanical input into usable electric power. The dynamics of the hydrogel piston on hot plates, force generation during bouncing and electric power output are measured experimentally. The effects of piston stroke, working temperature, and water absorption rate of the hydrogel piston are discussed. A maximum open-circuit voltage of 22 V and peak power of 280 μW was obtained by a single 2-gram hydrogel piston and the output electric power from the hydrogel piston based power generator successfully lights up 22 commercial LEDs.

Convenient, rapid, and accurate detection of cardiac troponin I (cTnI) is crucial in early diagnosis of acute myocardial infarction (AMI). A paper-based electrochemical immunosensor is a promising choice in this field, because of the flexibility, porosity, and cost-efficacy of the paper. However, paper is poor in electronic conductivity and surface functionality. Herein, we report a paper-based electrochemical immunosensor for the label-free detection of cTnI with the working electrode modified by MXene (Ti3C2) nanosheets. In order to immobilize the bio-receptor (anti-cTnI) on the MXene-modified working electrode, the MXene nanosheets were functionalized by aminosilane, and the functionalized MXene was immobilized onto the surface of the working electrode through Nafion. The large surface area of the MXene nanosheets facilitates the immobilization of antibodies, and the excellent conductivity facilitates the electron transfer between the electrochemical species and the underlying electrode surface. As a result, the paper-based immunosensor could detect cTnI within a wide range of 5–100 ng/mL with a detection limit of 0.58 ng/mL. The immunosensor also shows outstanding selectivity and good repeatability. Our MXene-modified paper-based electrochemical immunosensor enables fast and sensitive detection of cTnI, which may be used in real-time and cost-efficient monitoring of AMI diseases in clinics.

Chlorine bleaching technology (C process, CEH process, H process and theirs combination), which was identified as a primary formation source of PCDD/Fs, is still widely used by the vast majority of Chinese non-wood pulp and paper mills (non-wood PMs). The purpose of this study was to provide information and data support for further eliminating dioxin for non-wood PMs in China, and especially to evaluate the PCDD/Fs release reduction for those mills converting their pulp bleaching processes from CEH to ECF. The PCDD/Fs concentrations of the bleached pulp and bleaching wastewater with ECF bleaching were in the ranges of 0.13–0.8 ng TEQ kg −1 , and 0.15–1.9 pg TEQ L −1 , respectively, which were far lower than those with CEH process, indicating that the ECF process is an effective alternative bleaching technology to replace CEH in Chinese non-wood PMs to reduce dioxin release. The release factor via flue gas of the alkali recovery boiler in Chinese non-wood PMs was first reported to be 0.092 μg TEQ Ad t −1 in this study. On the assumption that pulp bleaching processes of all Chinese non-wood PMs were converted from CEH to ECF, the annual release of PCDD/Fs via the bleaching wastewater and bleached pulp would be reduced by 79.1%, with a total of 1.60 g TEQ.

The variation of carotenoid and bacteriochlorophyll in photosynthetic bacteria (PSB) by high salinity stress (20–100 g L −1 ) was investigated. Results showed that PSB could grow in high salinity wastewater and the productions of two pigments were affected by the salinity significantly. Suitable salinity stress could enhance their productions while excessive salinity would impede the productions. When the NaCl concentration was 50 g L −1 , the PSB were stimulated continuously during the whole culture period, and the productions of carotenoid and bacteriochlorophyll were 1.17 and 1.45-fold of the control group. The variation of dehydrogenase activity indicated that high salinity changed the metabolic activity greatly, and the highest level of dehydrogenase activity appeared at 50 g L −1 NaCl condition. Mechanisms analysis showed that the variations of pigments and dehydrogenase were related to self-protection. At the same time, pollutants in high salinity wastewater were removed by PSB. The COD and NH 3 -N removals under 20–100 g L −1 NaCl concentration were around 33.5–66.1%. The biomass yields were over 0.2 mg-biomass (mg-COD-reduction) −1 under all situations and salinity benefitted the biomass yield.

In wastewater treatment plants (WWTPs) using the activated sludge process, two methods are widely used to improve aeration efficiency - use of high-efficiency aeration devices and optimizing the aeration control strategy. Aeration efficiency is closely linked to sludge characteristics (such as concentrations of mixed liquor suspended solids (MLSS) and microbial communities) and operating conditions (such as air flow rate and operational dissolved oxygen (DO) concentrations). Moreover, operational DO is closely linked to effluent quality. This study, which is in reference to WWTP discharge class A Chinese standard effluent criteria, determined the growth kinetics parameters of nitrifiers at different DO levels in small-scale tests. Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3mg/L, and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions, as indicated by the oxygen half-saturation constant and nitrification ability. Based on nitrifier growth kinetics and on the oxygen mass transfer dynamic model (determined using different air flow rate (Q'air) and mixed liquor volatile suspended solids (MLVSS) values), theoretical analysis indicated limited potential for energy saving by improving aeration diffuser performance when the activated sludge system had low oxygen consumption; however, operating at low DO and low MLVSS could significantly reduce energy consumption. Finally, a control strategy coupling sludge retention time and MLVSS to minimize the DO level was discussed, which is critical to appropriate setting of the oxygen point and to the operation of low DO treatment technology.

Huge amount of aging biogas slurry is in urgent need to be treated properly. However, due to high NH3-N concentration and low C/N ratio, this aging biogas slurry is refractory for traditional methods. Its denitrification has become a big challenge. In this paper, photosynthetic bacteria (PSB) were employed to handle this problem. The results showed denitrification of aging biogas slurry by PSB treatment was promising. The highest removal efficiency of NH3-N reached 99.75%, much higher than all other treatments. The removal of NH3-N followed pseudo zero order reaction under dark-aerobic condition. The better inoculation rate for NH3-N removal was 30%; and aerobic condition was more beneficial for NH3-N removal than anaerobic condition because of different metabolic pathways.

Precisely probing mercury ions (Hg2+) is of essential importance to human health and environmental protection. Although numerous methods have been developed to detect Hg2+ in water, challenges still remain for rapid, accurate, and reliable detection of Hg2+ at the ppt level. In this study, a novel label-free Fe3O4@Ag based surface-enhanced Raman resonance scattering (SERRS) nanosensor has been developed for ultrasensitive and highly selective detection of Hg2+. The detection mechanism is on the basis of competitive binding interaction of Hg2+ and malachite green (MG) with nano-sliver on Fe3O4@Ag magnetic beads (MBs). In the absence of Hg2+, the Raman signal intensity of MG is significantly enhanced by the nano-silver when MG adsorbs on the nano-silver surface via one nitrogen atom. In the presence of Hg2+, the redox reaction occurring between zero-valent nano-silver and Hg2+ leads to the formation of a Ag/Hg amalgam at the Fe3O4@Ag surface, which prevents the adsorption of MG on the nano-silver surface. Thereby, the SERRS signal intensity of MG proportionally decreased with increasing Hg2+ concentration. Under optimized conditions, the proposed label-free nanosensor showed unprecedented Hg2+ detection sensitivity of 10 pM (2 ppt) with excellent selectivity. This simple sensor system can be directly applied for an inexpensive and easy-to-use monitoring method of Hg2+ in drinking water and wastewater treatment effluents that contains complicated organic and inorganic interferents.

China has the world’s largest and still growing wastewater sector and water market, thus its future development will have profound influence on the world. The high-speed development of China’s wastewater sector over the past 40 years has forged its global leading treatment capacity and innovation ability. However, many problems were left behind, including underdeveloped sewers and sludge disposal facilities, low sustainability of the treatment processes, questionable wastewater treatment plant (WWTP) effluent discharge standards, and lacking global thinking on harmonious development between wastewater management, human society and the nature. Addressing these challenges calls for fundamental changes in target design, policy and technologies. In this mini-review, we revisit the development history of China’s municipal wastewater management and identify the remaining challenges. Also, we highlight the future needs of sustainable development and exploring China’s own wastewater management path, and outlook the future from several aspects including targets of wastewater management, policies and technologies, especially the new concept WWTP. Furthermore, we envisage the establishment of new-generation WWTPs with the vision of turning WWTP from a site of pollutant removal into a plant of energy, water and fertilizer recovery and an integrated part urban ecology in China.

Wastewater treatment plants (WWTPs) in urban China generally face operational difficulties. To comprehensively analyze the current operation status and determine the factors that caused difficulties in urban domestic WWTPs, we conducted a questionnaire survey, and 18 operating conditions of scale-level WWTPs in seven regions in China were investigated. The research results showed that, of the 467-urban domestic WWTPs surveyed in China, approximately 63.17% of the WWTPs' hydraulic loading rates (HLRs) are greater than 80%, 67.02% of the WWTPs have mixed liquor suspended solids (MLSS) concentrations greater than 4000 mg/L, and 95.93% of the WWTPs' mixed liquor volatile suspended solids to mixed liquor suspended solids (MLVSS/MLSS) ratios are lower than 0.7. The WWTP energy consumption accounts for approximately 1% of the national electricity consumption, and approximately 100,000 tons of various chemicals are consumed every year. A high HLR, a high activated sludge concentration and low sludge activity, design value mismatches with actual values, high energy and material consumption, etc. have become the main operational difficulties of urban domestic WWTPs. In this study, the main barriers that hinder improving the operating efficiency of WWTPs were investigated, the causes of operational dilemmas were analyzed, and pathways were jointly explored to solve them. This study may provide valuable implications for industry practitioners with a comprehensive grasp of the industry's current status and related policy formulation.

Concentrator photovoltaics (CPV) has great competitiveness in replacing the conventional flat-panel PV system due to its high conversion efficiency and small cell active area. However, the accessory beam steering and concentrating optics are bulky and costly. Here we propose a programmable compound prism (PCP) powered by triboelectric nanogenerator (TENG) for solar beam steering. A disc TENG with a RC circuit could produce DC voltage signal, and the voltage signal could be tuned by varying the resistance in RC circuit. By connecting the variable DC output to the left, right and back walls of the PCP filled with DC 550 silicone oil, DI water and PMX 200 silicone oil, the two oil/water interfaces could be modulated in a programmable manner. A maximum deflection angle range of 15° was achieved in the PCP, which is 38% greater than conventional single prism with only one oil/water interface. The proposed TENG-PCP was employed to deflect an oblique incident laser beam to trigger the power generation in a multi-junction solar cell. With the operation of the proposed TENG-PCP, a 1.2 mW increment was achieved by the multi-junction solar cell, indicating the potential of boosting the CPV by the presented TENG−PCP.

Anaerobic digestion (AD) can be used to derive renewable energy from biomass in wastewater treatment plants, and the produced biogas represents a valuable end-product that can greatly offset operation costs. However, AD is a complex biological process involving many different kinds of microbial communities and biotransformation processes, and it is easily affected by start-up and operation conditions. In order to facilitate improvements in the AD process and enable predictions of biogas production quantities, this review discusses the microbial dynamics, scientific models, and reinforcement strategies of AD biogas production (i.e., sludge pre-treatment, bio-electrochemical and Fe/Fe3O4 technologies). During sludge pre-treatment, the focused-pulsed method can be introduced to promote cell lysis, and this requires specific treatment chamber designs. The bio-electrochemical method, especially in regard to the use of microbial electrolysis cells (MECs), can obviously improve biogas production while only consuming small amounts of energy. Mechanisms of AD-MEC systems and associated influencing factors are described in detail in this review. Engineered nanomaterials, which are increasingly being used in commercial products, may have detrimental or even beneficial effects on the sludge AD process. The use of low doses of Fe/Fe3O4 nanomaterials (≤0.5% (w/w)) as an economically viable and environmentally sustainable method for improving biogas production is discussed. In addition, removal methods for dissolved methane, which can have a negative environmental impact if not handled properly, in the anaerobic digester effluents are discussed in this review.

A single paragraph of about 200 words maximum. For research articles, s should give a pertinent overview of the work. We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: Place the question addressed in a broad context and highlight the purpose of the study, (2) Methods: Describe briefly the main methods or treatments applied, (3) Results: Summarize the article's main findings, and (4) Conclusion: Indicate the main conclusions or interpretations. The abstract should be an objective representation of the article: it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions.

Activated sludge processes with an ultra-short sludge retention time (ultra-short-SRT) are considered to have potential for energy and resource recovery from wastewater. The present study focused on the sludge characteristics, system performance and microbial kinetics in ultra-short-SRT activated sludge (USSAS) processes using typical domestic wastewater (SRT = 0.5, 1, 2, 3 and 4 d). The results showed that compared with the sludge in conventional activated sludge (CAS) processes, the sludge structure in USSAS system was looser (fractal dimension, D2P, 1.19–1.33), the boundary was rougher (pore boundary fractal dimension, DB, 1.44–1.59), the sludge concentration was lower, and the sludge volume index (SVI) was higher; bacteria such as Thiothrix and Trichococcus that cause sludge bulking, which poses an operation risk, were extensively detected, especially at SRTs of 0.5 d and 1.0 d. The performance in terms of total chemical oxygen demand (tCOD) and phosphorus removal increased with increasing SRT, and the highest removal rate (approximately 85% for tCOD and 90% for phosphorus) was observed when the SRT was 4 d. Both bioconversion and biosorption were responsible for the C/P separation, and their roles were different for different types of organic matter and phosphorus under different SRT conditions. The proportion of phosphate-accumulating organisms (PAO) reached 2.4% when the SRT was 3 d, resulting in highly effective biological phosphorus removal. The values of microbial kinetic parameters such as YH and KdH in USSAS systems were higher than those in CAS systems, indicating faster microbial community renewal. This study was helpful for understanding the characteristics of USSAS process.

In this paper, the enhancement of sodium glutamate (SG) on activity of anaerobic ammonia oxidizing (anammox) bacteria was investigated by batch tests. The results illustrated that SG played an important role in enhancing anammox bacterial activity when the SG dosage ranged from 0.50 to 1.25 mM, and the optimal SG concentration was 1.00 mM. The performance of anammox was the best and the total nitrogen removal rate (TNRR) was 138.2 mg N g−1·VSS·d−1 when the concentration of SG was 1.00 mM. The results of EPS and anammox bacterial biomass measurement indicated that protein (PN), polysaccharide (PS), total EPS and the bacterial abundance reached the maximum of 1.00 mM SG addition. Compared to the control tests, the EPS content and bacterial abundance increased by 38.2% and 75.8%, respectively. In addition, the cloning results showed that the community structure of anammox bacteria evolved in species level of Candidatus Brocadia genus under the condition of SG enhancement.

With a conceptual shift in sewage treatment from ‘waste pollution’ to ‘vehicle of resource and energy recovery’ and the further intensification of the energy crisis, the separation and recovery of carbon resources from discharged sewage has gained increasing recent attention in the field of water treatment. The ultra-short Solids Retention Time (SRT) activated sludge process (SRT ≤ 4 d) is highly efficient for separating organic matter and improving the energy recovery rate in wastewater treatment plants, but the effluent quality is relatively poor. If organics in the ultra-short SRT effluent can be reduced further to separate and recover carbon resources, the process may soon replace the traditional activated sludge process. We conducted physical adsorption carbon recovery experiments in an ultra-short SRT (SRT = 2 d) activated sludge system using three carbon nanotubes. Considering that Chemical Oxygen Demand (COD) arises from a mixture of organic compounds, and because humic acid (HA) makes up a large fraction of the effluent and can cause great environmental harm, further experiments were conducted on the adsorption of HA in the effluent COD to three nanotubes. This study proposes a novel method to completely remove organics from the effluent from ultra-short SRT activated sludge processes and reveals nanotube adsorption properties and mechanisms.

The enhancement of gibberellin (GA) on the activity of anaerobic ammonium oxidation(anammox) bacteria in short-term batch experiments(500 mL serum bottle) was studied in this paper. To make sure the accuracy of the data, each experiment group was conducted some statistical analysis. The results showed that GA played an important role in improving anammox activity when the GA dosage ranged from 0.1 to 1.5 mg L−1, and the total nitrogen removal rate (NRR) was increased by 34% when the GA dosage was 1 mg L−1. The monitoring results of extracellular polymeric substances (EPS) and biomass of anammox bacteria indicated that GA addition improved the secretion of EPS and the biomass increasing, whose amount achieved maximum under the GA dose of 1 mg L−1. Compared to the control test, the maximum improvement ratio of the EPS and biomass was 28.6% and 34%, respectively. In addition, the cloning results also indicated that the anammox bacterial community structure shifted in species level of Candidatus Brocadia genus during the experiment, and the most dominant anammox bacteria were Candidatus Brocadia fulgid.

Chinese authorities and the public have largely ignored sewer networks; however, various problems are emerging nationwide with the increase construction of new sewers. The current state of sewer network construction, administration, and maintenance in China is comprehensively reviewed in this study. Serving about 444 million people, 511,200 km of sewer lines are located in urban areas. In 2014, $7 billion was invested in sewer network construction. However, both the sewer pervasion rate and the per capita sewer length were significantly lower than those in developed countries. Sewer administrative agencies in local governments are uncoordinated. Laws, regulations, and standards are incomplete, and some practices are unscientific. The future situation of sewer maintenance is extremely grim because sewer corrosion control measures have not been launched. Moreover, inspection and rehabilitation chiefly rely on traditional approaches. In contrast, the overall market share of innovative technologies is very low owing to high cost, funds shortage, and technical limitations. Approaches such as liner inversion cured-in-place pipe, pull-in ultraviolet light cured liners, and spiral wound lining are applied mostly in economically developed regions. According to status and problem analyses, China’s top priority will be to conduct aggressive maintenance work in sewer networks in the future. New technical route, corrosion control - periodic visualized inspection - trenchless rehabilitation, could be the best option for future sewer maintenance in China. Instructions and opportunities for applying this technical route are discussed in detail in this study. Finally, additional factors in the development of sewer networks in China are suggested.

Three laboratory-scale moving bed biofilm reactors (MBBR) with different carrier filling ratios ranging from 40% to 60% were used to study the effects of carrier-attached biofilm on oxygen transfer efficiency. In this study, we evaluated the performance of three MBBRs in degrading chemical oxygen demand and ammonia. The three reactors removed more than 95% of NH4+-N at an air flow-rate of 60 L·h–1. The standard oxygen transfer efficiency (αSOTE) of the three reactors was also investigated at air flow-rates ranging from 60 to 100 L·h–1. These results were compared to αSOTE of wastewater with a clean carrier (no biofilm attached). Results showed that under these process conditions, αSOTE decreased by approximately 70% as compared to αSOTE of wastewater at a different carrier-filling ratio. This indicated that the biofilm attached to the carrier had a negative effect on αSOTE. Mechanism analysis showed that the main inhibiting effects were related to biofilm flocculants and soluble microbial product (SMP). Biofilm flocs could decrease αSOTE by about 20%, and SMP could decrease αSOTE by 30%–50%.

Hollow nanomaterials have attracted significant attention because of their high chemical and thermal stability, high specific surface area, high porosity, low density, and good biocompatibility. These state-of-the-art nanomaterials have been shown to efficiently adsorb heavy metals, and volatile hazardous substances, photodegrade persistent organic pollutants, and other compounds, and inactivate bacteria. Such properties have enabled the use of these materials for environmental remediation, such as in water/wastewater treatment, soil remediation, air purification, and substance monitoring, etc. Hollow nanomaterials showed higher photocatalytic activity than those without hollow structure owing to their high active surface area, reduced diffusion resistance, and improved accessibility. And, the Doping method could improve the photocatalytic performance of hollow nanomaterials further under visible light. Moreover, the synthetic mechanisms and methods of these materials are important because their size and morphology help to determine their precise properties. This article reviews the environmental applications and potential risks of these materials, in addition to their syntheses. Finally, an outlook into the development of these materials is provided.

Large amount of sludge has been a great trouble and raised significant concerns in China. This paper reviewed the current situation of sludge production, management, treatment and disposal in China. Total sludge production in China had an average annual growth of 13% from 2007 to 2013, and 6.25 million tons dry solids was produced in 2013. Per Capita sludge production in China is lower than that in developed countries. However, sludge management is poor in China. Administrative agents of sludge are not in accordance with each other. Laws and regulations of sludge management are incomplete and sometimes unrealistic. As to sludge treatment and disposal, many technical routes have been applied in China. Thickening, conditioning, and dewatering are three most used treatment methods, while application ratios of stabilization and drying are low in China. More than 80% of sludge is disposed by improper dumping in China. Regarding proper disposal, sanitary landfill is the commonest, followed by land application, incineration and building materials. According to the overall situation of China, "thickening-anaerobic digestion-dewatering-land application" is the priority technical route of sludge treatment and disposal. Good changes, current challenges and future perspectives of this technical route in China were analyzed and discussed in details.

An improved Daugman iris recognition algorithm is provided in this paper, which embodies in two aspects: ➀ Improvement for iris localization and ➁ The improvement for both iris encoding and matching algorithms. In Step 1, the localization and shape of the pupil are roughly determined in iris image, which is used as prior knowledge to quickly locate the inner and outer boundary of iris from rough to fine scale. Eyelids, eyelashes areas and the spot in the pupil are automatically detected and removed to improve the localization accuracy. In Step 2, the possible noise from residual eyelashes is further filtered by selecting a “pure” iris area as a reference and making a validation judgment pixel-wise. Furthermore, the validation flag for each pixel is introduced into the iris encoding and matching computation, as a result, the rejection rate of iris recognition is reduced. Compared with Daugman algorithm, iris recognition test on collected human eye images shows that our proposed algorithm has an obvious improvement both on boosting the speed and reducing the rejection rate.

Asthma is a chronic respiratory disease, commonly treated with inhaled therapy. Better understanding of the mechanisms of aerosol deposition is required to improve inhaled drug delivery. Three-dimensional ultrashort echo time (UTE) MRI acquisitions at 1.5 T were combined with spontaneous nose-only inhalation of aerosolized gadolinium (Gd) to map the aerosol deposition and to characterize signal enhancement in asthmatic rat lungs. The rats were sensitized to ovalbumin (OVA) to develop asthmatic models and challenged before imaging by nebulization of OVA to trigger asthmatic symptoms. The negative controls were not sensitized or challenged by nebulization of saline. The animal lungs were imaged before and after administration of Gd-based aerosol in freely breathing rats, by using a T1 -weighted 3D UTE sequence. A contrast-enhanced quantitative analysis was performed to assess regional concentration. OVA-sensitized rats had lower signal enhancement and lower deposited aerosol concentration. Their enhancement dynamics showed large inter-subject variability. The signal intensity was homogeneously enhanced for controls while OVA-sensitized rats showed heterogeneous enhancement. Contrast-enhanced 3D UTE was applied with aerosolized Gd to efficiently measure spatially resolved deposition in asthmatic lungs. The small administered dose (around 1 μmol/kg body weight) and the use of standard clinical MRI suggest a potential application for the exploration of asthma.

Sludge settling and thickening occur simultaneously in secondary settling tanks (SSTs). The ability to accurately calculate the settling and thickening capacity of activated sludge was of great importance. Despite extensive studies on the development of settling velocity models for use with SSTs, these models have not been applied due to the difficulty in calibrating the related parameters. Additionally, there have been some studies of the thickening behavior of the activated sludge in SSTs. In this study, a novel settling and thickening model for activated sludge was developed, and the model was validated using experimental data (R2 = 0.830 to 0.963, p < 0.001), which is more reasonable for the characterization of the settling and thickening behavior of the activated sludge in an SST. The application of these models requires only one critical parameter, namely, the stirred sludge volume index SSVI3.5, which is readily available in a water resource recovery facility.

Denitrifying biofilter (DNBF) is widely used for advanced nitrogen removal in the reclaimed wastewater treatment plants (RWWTPs). Manual control of DNBF easily led to unstable process performance and high cost. Consequently, there is a need to automatic control of two decisive operational processes, carbon dosage and backwash, in DNBF. In this study, online control of DNBF was investigated in the pilot-scale DNBF (600 m3·d–1), and then applied in the full-scale DNBF (10 × 104 m3·d–1). A novel simple online control strategy for carbon dosage with the effluent nitrate as the sole control parameter was designed and tested in the pilot-scale DNBF. Backwash operation was optimized based on the backwash control strategy using turbidity as control parameter. Using the integrated control strategy, in the pilot-scale DNBF, highly efficient nitrate removal with effluent TN lower than 3 mg·L–1 was achieved and DNBF was not clogged any more. The online control strategy for carbon dosage was successfully applied in a RWWTP. Using the online control strategy, the effluent nitrate concentration was controlled relatively stable and carbon dosage was saved for 18%.

In wastewater treatment plants (WWTPs), a secondary settler acts as a clarifier, sludge thickener, and sludge storage tank during peak flows and therefore plays an important role in the performance of the activated sludge process. Sludge thickening occurs in the lower portions of secondary clarifiers during their operation. In this study, by detecting the hindered zone from the complete thickening process of activated sludge, a simple model for the sludge thickening velocity, u s = aX b (a = 0.9925SSVI 3.5, b = 3.541ln(SSVI 3.5)+12.973), describing the potential and performance of activated sludge thickening in the hindered zone was developed. However, sludge thickening in the compression zone was not studied because sludge in the compression zone showed limited thickening. This empirical model was developed using batch settling data obtained from four WWTPs and validated using measured data from a fifth WWTP to better study sludge thickening. To explore different sludge settling and thickening mechanisms, the curves of sludge thickening and sludge settling were compared. Finally, it was found that several factors including temperature, stirring, initial depth, and polymer conditioning can lead to highly concentrated return sludge and biomass in a biologic reactor.

Bisphenol A (BPA), a xenoestrogenic endocrine-disrupting chemical, is used in many consumer products worldwide and is widely detected in the environment and in food. Combining the advantages of evanescent wave fiber optic sensor and microfluidic technology, an all-fiber optofluidics-based bioassay platform (AFOB) was developed for the rapid immunoassay and assessment of BPA. The captured molecular BPA-bovine serum albumin was covalently immobilized on the surface of the fiber optic sensor. A mixture of different concentrations of BPA and a certain concentration of fluorescence-labeled anti-BPA monoclonal antibodies after pre-reaction was introduced to the optofluidic cell. A higher concentration of BPA reduced the fluorescence-labeled antibodies bound to the sensor surface and thus reduced fluorescence signals. Under optimal conditions, the BPA quantified as 0.5-100 μg/L, with a detection limit of 0.06 μg/L. The high selectivity of the sensor was evaluated in terms of its response to several potentially interfering chemicals. The potential interference of an environmental sample matrix was assessed by spiked samples, and the recovery of BPA ranged from 90% to 120% with relative standard deviation values of9.1%. The AFOB and high-performance liquid chromatography had a desired correlation (R(2)=0.9958). The sensing platform was successfully used to assess BPA leaching from polycarbonate bottles at 45 °C and 80 °C, indicating that more BPA was substantially leached at elevated temperature and extend time. Thus, the developed sensing strategy can be an alternative method to rapidly analyze and assess the migration mechanism and fate of BPA or other pollutants.

A hapten-grafted graphene-based biosensor by integrating both the graphene nanosheets and immunoassay sensing technologies was developed for ultrasensitive homogeneous competitive immunoassay of small molecules. The structure of hapten-grafted graphene avoids the activity loss of biomolecules immobilized onto the graphene surface and is beneficial to preserve the binding affinity between small molecule and its specific antibody. The sandwich structure formed between hapten-grafted graphene nanosheets and fluorescence-labeled antibody increases the quenching efficiency of the organic dye, thereby resulting in high signal-to-background ratios and improved sensitivity for Bisphenol A (BPA) detection. On the basis of fluorescence resonance energy transfer (FRET) and homogeneous competitive immunoassay mechanism, high BPA concentrations in the sample reduce the amount of fluorescence-labeled anti-BPA antibody bound to graphene-BPA nanosheets, thus resulting in remarkable fluorescence signals. The linear quantification of BPA over concentration ranges from 0.5 to 50 nM with a detection limit determined as 0.12 nM. These findings show that the proposed method provides a powerful tool for the rapid and sensitive detection of small molecules in biological and environmental samples.