Effective stabilization of electrochemically prepared ecological oxidizing agent-ferrate(VI)-by encapsulation in zeolite and its application to water containing SARS-CoV-2 virus.

Improper and insufficient treatment of infectious hospital wastewater could seriously endanger public health and the environment. Ferrate(VI), a strong oxidizing, disinfecting, and coagulating agent, has the potential as a green solution for decontamination of water and wastewater. In this paper, electrochemically prepared potassium ferrate (K2 FeO4 ) with high purity was successfully encapsulated and applied to the water contaminated by SARS-CoV-2. Natural zeolite was chosen as an appropriate ecological material for ferrate encapsulation. The stability of encapsulated ferrate (in tablet form) was monitored for an extended time period (290 days) and has significantly increased in contrast with free potassium ferrate by almost 30%. Subsequently, the K2 FeO4 encapsulated with zeolite in tablet form was applied to the water and municipal water samples containing the SARS-CoV-2 virus. The removal efficiency reached up to 98.5% and 86.7%, respectively, under natural conditions. Combination of environmentally friendly oxidizing agent and natural excellent adsorbent leads to the creation of very effective water treatment matter. These findings are essentially immediate and especially important for immediate water treatment in urgent situations such as natural disasters or military conflict. PRACTITIONER POINTS: Electrochemical preparation of oxidizing agent, K2 FeO4 , in high purity by own constructed electrolyzer. Encapsulation of ferrate(VI) to natural zeolite threefold improving the stability during 9 months. SARS-CoV-2 virus was successfully removed from various contaminated types of water. High degradation efficiency of virus fragments by Fe(VI) was achieved without additional water adjustment, in natural pH range.

Industrial wastewater as a source of external organic carbon for the biological nutrient removal.

Addition of external organic carbon source for denitrification is generally used in wastewater treatment plants (WWTPs) to intensify nitrogen removal processes. The aim of the laboratory survey was to measure the composition of concentrated industrial wastewater, determine the possibilities of its use as an external denitrification substrate, and assess its overall impact on WWTP. The obtained results demonstrate that the analysed industrial wastewater is biodegradable, and can be used as a denitrification substrate without special adaptation of biomass. The denitrification rates with tested wastewater were in the range of 1.6 to 1.9 mgN/g·h. Negative influence of long-term dosing of industrial wastewater on activated sludge were not confirmed. The effect of imported wastewater on WWTP must be assessed comprehensively, including the impact of heavy metals from wastewater on the sludge quality. The instructions on how to calculate this balance are provided in the article.

Desorption of pharmaceuticals and illicit drugs from different stabilized sludge types across pH.

Pharmaceutical and illicit drug residues in sewage sludge may present important risks following direct application to agricultural soils, potentially resulting in uptake by plants. Leaching/desorption tests were performed on different types of stabilized sewage sludge originating from multiple treatment technologies in the Slovak Republic. Acid rain and base-rich condition of soil with different pH conditions were simulated to model the effect of widely varying pH (pH 2, 4, 7, 9, and 12) on the leaching/desorption of pharmaceuticals and illicit drugs. Twenty-nine of 93 target analytes were found above the limit of quantification in sludge or associated leachates. Total desorbed amounts of pharmaceuticals and illicit drugs ranged from 810 to 4000 µg/kg, and 110 to 3600 µg/kg of the dry mass of anaerobic and aerobic sludge, respectively. Desorbed fractions were calculated as these values are normalized to initial sludge concentration and, therefore, were more suitable for qualitative description of the behavior of individual compounds. Using principal component analysis, qualitative analysis of the desorbed fraction confirmed the differences among sludge types, pharmaceuticals, and desorption pH. Desorbed fractions could not be related to the octanol/water distribution coefficient. Desorbed fractions also did not reflect the expected ionization of studied molecules unless converted into their relative values. Generally, the lowest mobility was observed within the environmentally relevant pH range of 4-9, and high pH generally resulted in high desorption, especially in anaerobically stabilized sludges.