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As humic substances left in treated water tend to form trihalomethans during chlorination, their removal in water treatment processes is a significant concern for drinking water supplies. One of the removal technologies, the biofilm reactor is studied for the microbial decomposition of aquatic fulvic acid (AFA). The AFA is characterized by elemental analysis. UV-Vis, 13C-NMR, and IR spectroscopic methods. The spectroscopic and elemental investigation was capable of characterizing the microbial decomposition of AFA. Biologically treated fulvic acid was in a more oxidized state; its spectra displayed a higher degree of condensation of aromatic constituents than influent fulvic acid. Microbial degradation of AFA was more active in the low molecular weight fractions and intensively occurred in the aliphatic fraction.

A pilot plant of SBR (Sequencing Batch Reactor) and MF (microfiltration) process was operated in order to treat and reuse the greywater produced from an office building. The performance of SBR for greywater was satisfactory as the effluent had 20 mg/l, 5 mg/l, and 0.5 mg/l of SCOD, BOD, and ammonia, respectively. The cyclic operation of SBR used in this study proved more effective in nitrification and denitrification than the conventional SBR operation. However, the most effective mode was step-feed SBR for denitrification. The decanting system of this SBR discharged the effluent fairly well without sludge washout. However, it was difficult to maintain constant concentration of suspended solid from the SBR process. Thus, additional filtration was needed to get adequate water quality for water reuse. MF could remove residual suspended solids and pathogens as well from the SBR effluent. The suspended solids of final effluent were around 1 mg/l and allowed using the treated water for some purposes.

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Aim: The present study was performed to determine the inhibitory interaction of fever-relieving medicines with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) essential proteins. Materials & methods: Structure-based drug repositioning was performed using PYRX 0.9 and these drugs were directed toward the predicted active site of SARS-CoV-2 spike glycoprotein receptor-binding domain, main protease and RNA-dependent RNA polymerase. Results: Results showed that acetaminophen and naproxen have considerable inhibitory activity and show a high affinity for active residues of these proteins. The prediction of activity spectra for substances (PASS) studies showed that these drugs are anti-inflammatory, antiviral and immunostimulant. Conclusion: Hence, it is proven that these drugs have antiviral activity against SARS-CoV-2 and can stimulate the immune and anti-inflammatory response against this disease.

As the quality of raw water deteriorates, a number of additional treatment techniques have been developed and adapted to water treatment for producing a safe and aesthetically satisfactory drinking water. One of the various alternatives is to use a biological process, such as a submerged bed filter, as the first process in the treatment train followed by conventional treatment processes. Biofilm process for the pretreatment of water is suitable for advanced treatment as the biofilm can keep microorganism, at low organic concentrations. This article examines the application of biological treatment strategies to tackle the current problems of the water industry. Pilot-scale biofilm reactors were evaluated with various contaminants frequently encountered in water supplies. The studies focused on the production of biologically stable water, increased disinfectant stability, and reduced formation of disinfection by-products. Results showed that the finished water became more biologically stable even though the reduction of organics was relatively low. Biofilm grown on natural water supplies was effective in removing THMP (trihalomethane precursor) as well as taste and odour compounds, such as geosmin.

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