Given that previous studies have neglected the mechanism of ecological network succession, the research team from Beijing University of Chemical Technology and Beijing Technology and Business University evaluated the effects of elevated salinity on ecological networks of activated sludge system by performing a novel RMT-based network analysis. Their research identified that higher salinity reduced microbial diversity, leading to poor performance of the treatment process, and that the keystone species playing crucial roles in maintaining process stability were dynamic. This work improved our understanding of the relationship between system performance and microbial interaction dynamics of activated sludge microbial communities in response to elevated salinity.
The adverse effects of excess nitrate in water on human productivity and lives have received increasing attention due to the discharge of industrial wastewater and the overuse of farmland fertilizers. An international team of researchers has conducted an in-depth study of the significant need and challenge of efficient nitrate removal. Several techniques have been used to eliminate nitrate from water, such as biological denitrification is technologically mature, cost-effective, and widely used. However, biological processes are often sluggish and easily affected by variable environmental conditions, such as temperature and the availability of carbon supplies. The researchers suggested that electrocatalytic technology is a promising method for nitrate removal because no chemicals are needed, no sludge is produced, and implementation of the methodology is convenient.
Sand filters are commonly applied in drinking water treatment and can efficiently remove suspended solids, organic matter, and microorganisms from source water. During the process, particulate matter and microbes can attach to filter sands and develop a thick biofilm in both rapid and slow sand filters. To prevent clogging and restore pollutant removal efficiency, backwashing using air, water, or a combination of both is usually required for sand filters. However, backwashing can induce a loss in biomass, thus decreasing the pollutant removal efficiency of sand filters. Slow sand filters whose empty bed contact times (EBCTs) are typically longer than 1 h, have a higher removal efficiency of micropollutants than rapid sand filters, whereas clogging issues are more severe.
Polycyclic aromatic hydrocarbons (PAHs) are typical organic compounds found in cigarette smoke and vehicle exhaust. In addition, PAHs are produced from incomplete combustion of organic material and cooking. The highest concentrations of PM-bound PAHs ranged from 550 ng/m3 to 39000 ng/m3, were observed in Chinese kitchens, fire stations, and ships. Polycyclic aromatic hydrocarbons may combine with ultrafine particles (UFPs) in the air to form particle-bound PAHs. PM0.1 may adsorb large amounts of toxic organic compounds, and long-term exposure to indoor UFPs from cooking resulted in nervous responses by the human brain. PAHs were detected in the venous blood of people exposed to combustion by-products in rural areas of China at concentrations up to 762 ng/mL.
On February 3, 2023, a train derailed in the United States near East Palestine, Ohio, leading to the combustion of vinyl chloride. Following that accident, an international team of researchers undertook an in-depth analysis of the environmental consequences of the accident. Their analysis is published in the journal Frontiers of Environmental Science & Engineering on March 15, 2023.