Evaluation of Front-Face Fluorescence for Assessing Cyanobacteria Fouling in Ultrafiltration

Abstract

Cyanobacteria fouling in ultrafiltration (UF) drinking water treatment poses a significant threat to the stability and sustainability of the process. Both phycocyanin found in cyanobacteria and the polymer membrane exhibit strong fluorescence, which could be readily detected using front-face excitation–emission matrix (FF-EEM) spectroscopy. In this study, FF-EEM was employed for the nondestructive and in situ characterization of algae fouling evolution in UF, while also analyzing fouling mechanisms and reversibility. The results indicated that phycocyanin fluorescence on the membrane surface showed a linear correlation with the specific algal cell count on the membrane surface before reaching saturation. As fouling progressed, membrane fluorescence decreased, which was associated with the extent of the surface coverage on the membrane. The plateau in membrane fluorescence indicated full coverage, coinciding with the cake filtration mechanism, cake compression, and deterioration of fouling reversibility. These findings highlight the promise of FF-EEM as a valuable tool for monitoring and evaluating fouling of cyanobacteria in UF systems.

Habitat Disturbance Drives the Feedback of Aquatic Plants on the Microbial Community after Lake Degradation

“…Submerged macrophytes can improve water quality and remove 50% of P content in overlying water and sediment, mainly dissolved P and Ca–P, respectively . Bioremediation, which encompasses biosorption, biouptake, and biotransformation processes carried out by plants and microorganisms, presents several advantages, including cost-effectiveness and superior removal efficiency compared to alternative remediation techniques. − …”

High-Selective Microbial Electrocatalytic Ammonia Synthesis from Nitrite: Unlocking Electron Allocation Mechanisms in Controllable Biocatalysts

“…At the end of the fourth cycle, the EABs were stained with a LIVE/DEAD BacLight bacterial viability kit (Invitrogen, CA) for 20 min, rinsed twice with 50 mM PBS, and imaged using confocal laser scanning microscopy (CLSM; LSM880, Zeiss, Germany) under the z-stack mode . Biofilm samples for microbial analysis and protein quantification were collected by scraping different locations on the electrode surface inside 3 parallel reactors using sterile blades.…”

“…At the end of the fourth cycle, the EABs were stained with a LIVE/DEAD BacLight bacterial viability kit (Invitrogen, CA) for 20 min, rinsed twice with 50 mM PBS, and imaged using confocal laser scanning microscopy (CLSM; LSM880, Zeiss, Germany) under the z-stack mode. 28 Biofilm samples for microbial analysis and protein quantification were collected by scraping different locations on the electrode surface inside 3 parallel reactors using sterile blades. The genomic DNA of biofilm samples was extracted using the Soil Genomic DNA kit (CW2091S, Com Win Biotech Co., Ltd., China) and amplified for PCR, targeting the highly variable V4 region of the 16S rRNA gene with forward primers 515F (5′-GTGYCAGCMGCCGCGGTAA-3′) and 806R (5′-GGACTACNVGGGTWTCTAAT-3′).…”

Mass Concentration and Removal Characteristics of Microplastics and Nanoplastics in a Drinking Water Treatment Plant

“…To achieve this objective, samples of raw water and treated water from various treatment processes, including coagulation/sedimentation, filtration, and disinfection, were collected from a DWTP in China. Microfiltration with pore sizes of 50 and 1000 μm and ultrafiltration with a molecular weight cutoff of 100 kDa (approximately 0.01 μm according to the manufacturer) , were used to collect NPs (0.01–1 μm), sub-MPs (1–50 μm) and large MPs (50–1000 μm). Hydrogen peroxide digestion was employed to eliminate the interference from the organic matrix.…”