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Rapid identification of emerging infectious pathogens is crucial for preventing public health threats. Various pathogen detection techniques have been introduced; however, most techniques are time-consuming and lack multiple-target detection specificity. Although multiple-target detection techniques can distinguish emerging infectious pathogens from related pathogens, direct amplification methods have not been widely examined. Here, we present a novel arch-shaped multiple-target sensor capable of rapid pathogen identification using direct amplification in clinical samples. In this study, an arch-shaped amplification containing primer sequences was designed to rapidly amplify multiple targets. Further, the sensing platform allowed for sensitive and specific detection of human coronavirus, Middle East respiratory syndrome, Zika virus, and Ebola virus down to several copies. This platform also simultaneously distinguished between Middle East respiratory syndrome and human coronavirus in clinical specimens within 20 min. This arch-shaped multiple-target sensing assay can provide rapid, sensitive, and accurate diagnoses of emerging infectious diseases in clinical applications., Highlights • A novel arch-shaped multiple-target sensing capable of rapid pathogen identification. • An arch-shaped amplification containing primer sequences to rapidly amplify multiple targets. • Allowed sensitive and specific detection of MERS, ZIKV, and EBOV in 20 min. • Validated clinical utility of the platform in MERS patient samples.

We herein describe rapid and accurate clinical testing for COVID-19 by nicking and extension chain reaction system-based amplification (NESBA), an ultrasensitive version of NASBA. The primers to identify SARS-CoV-2 viral RNA were designed to additionally contain the nicking recognition sequence at the 5′-end of conventional NASBA primers, which would enable nicking enzyme-aided exponential amplification of T7 RNA promoter-containing double-stranded DNA (T7DNA). As a consequence of this substantially enhanced amplification power, the NESBA technique was able to ultrasensitively detect SARS-CoV-2 genomic RNA (gRNA) down to 0.5 copies/μL (= 10 copies/reaction) for both envelope (E) and nucleocapsid (N) genes within 30 min under isothermal temperature (41 °C). When the NESBA was applied to test a large cohort of clinical samples (n = 98), the results fully agreed with those from qRT-PCR and showed the excellent accuracy by yielding 100% clinical sensitivity and specificity. By employing multiple molecular beacons with different fluorophore labels, the NESBA was further modulated to achieve multiplex molecular diagnostics, so that the E and N genes of SARS-CoV-2 gRNA were simultaneously assayed in one-pot. By offering the superior analytical performances over the current qRT-PCR, the isothermal NESBA technique could serve as very powerful platform technology to realize the point-of-care (POC) diagnosis for COVID-19.

In this study, the effect of moving-bed biofilm carrier, a membrane, and simultaneous employment to solve the settleability problem derived from readily biodegradable organics application in the biological spatiotemporal phase separation and variation of biomass characteristics by biofilm media application were investigated. No significant differences of the treatability among each case were observed. Although the moving-bed biofilm process is commonly used for the treatment of organics and nitrogen in wastewater, phosphorus was also removed perfectly owing to the detached biomass containing orthophosphate was discarded sufficiently. Additionally, the concentration of the suspended biomass decreased significantly, and the settled volume index was improved dramatically from 700 to 100 mL/g after the addition of the biofilm carrier. Although the extracellular polymeric substance (EPS) concentration increased with media addition, the back-flushing interval of the membrane was lengthened. The increment of polysaccharide in the EPS and the non-existence of protein in the soluble EPS were clearly observed. Thus, the suspended-biomass decrement due to media addition and the protein concentration in the EPS played important roles for fouling control. This study provides valuable information on state alternation of biomass by biofilm media application on biological suspended growth wastewater treatment process.

The ceramic microfiltration membrane which composed of membrane body having macro pore and active layer having micro pore was fabricated successfully by the process including the sintering of tape-casted and laminated mixture of zirconia and polyvinyl butyral binder, and re-sintering after screen coating of zirconia. The average pore size and porosity of the fabricated membrane were 0.1855 μm and 40 %, respectively. A novel membrane microfiltration system adopting the fabricated ceramic membrane was also devised for the treatment of agro-industrial wastewater, and the effects of external air sparging and internal air injection were investigated. A significant improvement of permeability by external air sparging was not observed, and the permeate flux was about 20 L/m2/h. Despite the abnormal biomass status resulted from low water temperature and poor maintenance of facility, however, the system operated at the initial TMP of 0.4 bar and internal air injection intervals of 5 min showed excellent permeability of 100 L/m2/h. In addition, although several periodic internal air injections with inverse pressure was carried out, structural defects of fabricated ceramic membrane were not observed. Thus, it confirmed that the anti-fouling effect by optimum back-flushing strategy in fabricated ceramic membrane was effective for stability enhancement of agro-industrial complex wastewater treatment process suffering from maintenance.

In this study, a novel tubular-type ceramic membrane with higher permeability was fabricated and its physical characteristics for microfiltration were evaluated. The membrane was composed of the support and active layer which is a coating of the support for selective permeation. Many macro pores under 1 μm up to 40 μm in diameter could be successfully formed in the support. Pores having a diameter less than one micrometer were generated by the melting of impurities or by contracting structures through sintering, and pore sizes above 1 μm in diameter were also generated by the poly methyl methacrylate (PMMA) melted through sintering of support. The permeability of ceramic membranes could be enhanced by formation of large-diameter pores in the support. The pressurized-type ceramic membrane filter system with OUT–IN filtration direction was also devised for water and wastewater treatment. Surface flushing of the membrane was performed to solve the clogging. After 40 min of operation, flux recovered to 97% of initial flux (320 L m −2 h −1 ) by surface flushing. To evaluate the feasibility of the ceramic membrane filter system, effluent from the electrolysis process for wastewater treatment was applied. Total suspended solids could be eliminated completely, and 99.8% of colloids causing the turbidity of water could be removed through filtration by the membrane.

In this study, a pilot-scale anoxic/aerobic biofilter system combined with chemical precipitation was devised and applied for the tertiary treatment of nitrogen, and post-treatment of phosphorus and residual organics in effluent from existing wastewater treatment facilities. When the system operated under a system hydraulic retention time (HRT) of 5.98 h, nitrified effluent recirculation ratio of 0.5, average methanol-supplement concentration of 23.2 mg/L, and average aluminum-sulfate concentration of 2.37 mg/L, the average concentration of BOD5, COD, SS, TN, and TP in the system effluent were 3.3, 10.4, 4.2, 6.1, and 0.43 mg/L, respectively. Despite the shorter HRT of 1.35 h in the anoxic filter packed with media, noticeable denitrification was achieved rapidly. A perfect nitrification rate was achieved and no clear deterioration in performance by chemical addition was observed. Thus, the system achieved not only outstanding nitrogen-removal performance, but also the additional removal of residual organics and phosphorus.

A biological spatial-temporal phase separation system without an additional anaerobic reactor was devised for simultaneous removal of nitrogen and phosphorus. The process was operated at hydraulic retention time (HRT) of 8 h, solids retention time (SRT) of 10 days, and cycle time of 4 h (Anoxic/Anaerobic periods : Aerobic period = 1.5 : 2.5). Three types of influents were examined, namely glucose, glucose/acetate/propionate, and domestic wastewater. They were used to evaluate the contribution of organic composition and loading on the system performance. Nitrogen removal was strongly affected by the organic composition upon low influent C/N ratio. However, for influent C/N of 9.2–11.7 and C/P of 53.0–88.1, nitrogen and phosphorus removal noticeably improved regardless of the organic composition. Biological reactions including nitrification, denitrification, phosphate release and uptake, and PHA synthesis and utilization were clearly observed during the cycle with high organic loading, without any decline on organics removal. Furthermore, significant phosphate release and uptake were successfully accomplished without any nitrate interference and carbon competition under high organic loading. Therefore, organic loading is essential for the simultaneous removal of nitrogen and phosphorus in biological spatial-temporal phase separation.

This study was conducted to evaluate the stability and performance response under short-term hydraulic and organic shock load conditions in temporal and spatial phase separated process. The overall removals of BOD, TN, and TP declined slightly despite the hydraulic shock loading, and rapid recovery could be observed again after four cycles of 16 h. It seems that rapid recovery may be achieved by the unique characteristics of the system operated in a fed-batch manner. The effect of shock load on nitrogen removal due to increment of flow rate was higher than that of phosphorus, because of the insufficient reaction time for the nitrification and denitrification. After the organic shock, however, recovery time for phosphorus removal was needed rather than that of organics and nitrogen, because the overload to micro organisms related to the phosphorus release is attained by short-term organic shock loading.

In this study, a cost-effective and eco-friendly route for removal of phosphate in wastewater was demonstrated using an Al alloy foam filter with a mesoporous aluminum hydroxide (Al(OH3) film. The mesoporous Al(OH)3 film on which the ion exchange and adsorption of phosphate occur was generated using a simple alkali surface modification process. For higher phosphate removal by the surface-modified Al alloy foam filter, the number of filters was increased up to 20, which achieved 90% phosphate removal within a very short contact time. As a recycling process, a second alkali surface modification was applied to the used filter after phosphate adsorption. It clearly indicated that the used filter can be recycled via a second alkali surface modification due to the ion exchange mechanism. It was shown that an alkali surface-modified Al alloy foam filter is a powerful candidate for phosphate removal in water treatment facilities.

An innovative phosphorus removal filter made of silica granules was designed and evaluated for advanced wastewater treatment. The silica granules from natural mineral stones were formed into a porous body by sintering with addition of glass powder. The phosphorus was removed by the ionic exchange mechanism between OH− in Si(OH)4 and PO43− in wastewater. The silica filter was very effective in removing phosphorus in wastewater by ion exchange. We found the possibility of a phosphorus removal filter with no sludge production characteristics of flocculation treatment techniques, and it seems to be quite meaningful as a new wastewater treatment.

The objective of this research is to draw the optimal cycle length and evaluate the effect of the fraction of anoxic and anaerobic phases in a cycle maximizing the nutrients removal in a modified temporal and spatial phase separated process. A pilot-scale system operated at HRTs of 10–21 h, SRTs of 16–34 d, cycle times of 2–8 h, and mixed liquor temperature from 9 to 30 °C showed average removals of BOD, TN, and TP as high as 93, 79, and 86%, respectively. Higher nitrogen removal could be achieved for shorter cycle time, while better phosphorus removal could be accomplished for longer cycle time. Optimal cycle time for simultaneous removal of nitrogen and phosphorus conflicted with each other. The effect of ratio of cycle time to system HRT on system performance was also shown to have the same tendency as that of cycle time. Higher TN removal of phased isolation technology could be achieved relative to that of SBR as the cycle length became longer in the same HRT. As the fraction of anoxic/anaerobic phase in a cycle became larger, the removal efficiency of TN and TP simultaneously decreased because of the discharge of untreated ammonia nitrogen and released phosphorus.