Use of sponge iron dosing in baffled subsurface-flow constructed wetlands for treatment of wastewater treatment plant effluents during autumn and winter.

Sponge iron (SI) is widely used in water treatment. As effluents from wastewater treatment plant (WWTP) require advanced treatment methodology, three forms of constructed wetlands (CWs): wetlands with sponge iron (SI), copper sulfate modified sponge iron (Cu/SI), and sponge iron coupled with solid carbon sources (C/SI), have been investigated in this paper for the removal effects of organic matter and nutrients in WWTP effluents, and the corresponding mechanisms have been analyzed. The results showed the effect of baffled subsurface-flow constructed wetland (BSFCW) with SI dosing to purify the WWTP effluents after the stable operation. The water flow of this BSFCW is the repeated combination of upward flow and downward flow, which can provide a longer treatment pathway and microbial exposure time. The average removal rates of total inorganic nitrogen (TIN) were 27.80%, 30.17%, and 44.83%, and the average removal rates of chemical oxygen demand (COD) were 19.96%, 23.73%, and 18.38%. The average removal rates of total phosphorus (TP) were 85.94%, 82.14%, and 83.95%. Cu/SI improved the dissolution of iron, C/SI improved denitrification, and a winter indoor temperature retention measure was adopted to increase the effectiveness of wetland treatment during the winter months. After comprehensively analyzing X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and two-dimensional numerical simulation diagrams, a plausible conjecture that microbes use electrons from SI for autotrophic denitrification is presented. Moreover, the stress effect of wetlands dosed with SI on plants decreased stepwise along the course since C/SI used on wetlands had less impact on plant stress.

1. Treatment of sequencing batch biofilm reactor reaction effluent indoors in low temperature using a combination of three wetland fillers, sponge iron + gravel, copper sulfate modified sponge iron + gravel, and sponge iron coupled carbon source + gravel.2. The use of the baffled subsurface-flow constructed wetland, combined with the distribution simulation diagram, especially the distribution simulation diagram of iron, gives an explanation to the degradation mechanism of the pollutants and the transformation of iron into wetlands.3. An conjecture of electron transport during microbial autotrophic denitrification involving iron is presented, plausibly explaining the variation in treatment effects.

[Concentration and Particle Size Distribution Characteristics of Microbial Aerosol and Bacterial Community Structure During Spring in Lanzhou City, China].

The aim of this study was to analyze the differences in the concentration, particle size, and bacterial community structure of microbial aerosols and further investigated the effects of meteorological conditions and air pollutants on microbial aerosol distribution at different periods during spring in Lanzhou. The results showed that the average aerosol concentrations of total microbes, bacteria, fungi, and actinomycetes in the air environment of Lanzhou were (2730±376), (2243±354), (349±38), and (138±22) CFU·m-3, respectively. The contribution rate of bacteria was 82.16%, which was significantly higher than that of fungi and actinomycetes (P<0.05). The concentrations of total microorganisms, bacteria, and actinomycetes during 08:00-09:00 were significantly higher than those sampled during 18:00-19:00, indicating that meteorological conditions and air pollutants have a remarkable influence on the concentration of microbial aerosols. Aerosol particles of bacteria and fungi were primarily distributed at the first four levels (>2.1 µm), accounting for 85.13% and 83.26%, respectively, while 73.15% of the actinomycetes aerosol particles focused largely on the latter four stages (<4.7 µm). Illumina MiSeq sequencing results indicated that there was no significant difference in the composition of the bacterial community (P>0.05) during the periods of 08:00-09:00 and 18:00-19:00. Lactococcus and Bacillus were the dominant bacteria genus. Enterococcus, Staphylococcus, Pseudomonas, Acinetobacter, Klebsiella, Erwinia, Bacillus cereus, Streptococcus agalactiae, and Clostridium perfringens were potential pathogens detected in the air environment of Lanzhou in the spring. The results could provide fundamental data for further revealing the contamination status of microbial aerosols and the potential harm of the related pathogenic bacteria to human health during the spring in Lanzhou.

SOX5 Regulates Cell Proliferation, Apoptosis, Migration and Invasion in KSHV-Infected Cells.

Kaposi's sarcoma (KS) originates from vascular endothelial cells, with KS-associated herpesvirus (KSHV) as the etiological agent. SRY-box transcription factor 5 (SOX5) plays different roles in various types of cancer, although its role in KS remains poorly understood. In this study, we identified the role of SOX5 in KS tissues and KSHV-infected cells and elucidated the molecular mechanism. Thirty-two KS patients were enrolled in this study. Measurement of SOX5 mRNA and protein levels in human KS tissues and adjacent control tissues revealed lower levels in KS tissues, with KS patients having higher SOX5 level in the early stages of the disease compared to the later stages. And SOX5 mRNA and protein was also lower in KSHV-infected cells (iSLK-219 and iSLK-BAC) than normal cells (iSLK-Puro). Additionally, SOX5 overexpression inhibited cell proliferation and promoted apoptosis and decreased KSHV-infected cell migration and invasion. Moreover, we found that SOX5 overexpression suppressed the epithelial-to-mesenchymal transition of KSHV-infected cells. These results suggest SOX5 is a suppressor factor during KS development and a potential target for KS treatment.

Where do we stand to oversee the coronaviruses in aqueous and aerosol environment? Characteristics of transmission and possible curb strategies.

By 17 October 2020, the severe acute respiratory syndrome coronavirus (SARS-CoV-2) has caused confirmed infection of more than 39,000,000 people in 217 countries and territories globally and still continues to grow. As environmental professionals, understanding how SARS-CoV-2 can be transmitted via water and air environment is a concern. We have to be ready for focusing our attention to the prompt diagnosis and potential infection control procedures of the virus in integrated water and air system. This paper reviews the state-of-the-art information from available sources of published papers, newsletters and large number of scientific websites aimed to provide a comprehensive profile on the transmission characteristics of the coronaviruses in water, sludge, and air environment, especially the water and wastewater treatment systems. The review also focused on proposing the possible curb strategies to monitor and eventually cut off the coronaviruses under the authors' knowledge and understanding.

Toxicity of lindane induced by oxidative stress and intestinal damage in Caenorhabditis elegans.

Lindane, a lipophilic pollutant, may be toxic to organisms. To explore the toxic effects of lindane and the underlying mechanisms of this toxicity, the animal model Caenorhabditis elegans (C. elegans) was exposed to lindane for 3 d at environmentally relevant concentrations (0.01-100 ng/L) and the physiological, biochemical, and molecular indices were evaluated. Subacute exposure to 10-100 ng/L of lindane caused adverse physiological effects on the development, reproduction, and locomotion behaviors in C. elegans. Exposure to 1-100 ng/L of lindane increased the accumulation of Nile red and blue food dye, which suggested high permeability of the intestine in nematodes. Lindane exposure also significantly influenced the expression of genes related to intestinal development (e.g., mtm-6 and opt-2). Moreover, reactive oxygen species production, lipofuscin accumulation, and expression of oxidation resistance genes (e.g., sod-5 and isp-1) were significantly increased in C. elegans exposed to 10-100 ng/L of lindane, which indicated that lindane exposure induced oxidative stress. According to Pearson correlation analyses, oxidative stress and intestinal damage were significantly correlated with the adverse physiological effects of lindane. Therefore, the adverse effects of lindane may have been induced by intestinal damage and oxidative stress, and mtm-6, opt-2, sod-5, isp-1, and mev-1 might play important roles in the toxicity of lindane.

[Effects of Long-term Side Stream Extracton on Phosphorus Removal and Recovery Performance of EBPR System].

A sequencing batch reactor (SBR) with alternating anaerobic/oxic (An/O) operation was employed to investigate nitrogen and phosphorus removal performance and corresponding phosphate recovery effect of an enhanced biological phosphorus removal (EBPR) system when extracting side stream ratios of 0, 1/4, 1/3, 1/2 anaerobic phosphorus supernatant. The operation involved three runs within 310 days. Removal efficiencies of COD and NH4+-N were found to be relatively stable over the entire experimental period and effluent could meet standard A of the national discharge standard of pollutants for municipal wastewater treatment plants. Total nitrogen removal improved due to enhancement of denitrification capability during the anaerobic phase, and the standard-reaching rate increased from 88.2% to 98.6%. Although phosphate releasing capability gradually decreased, phosphorus removal performances of the former two runs were stable and efficient. The removal rate was>90% and the corresponding standard-reaching rate was>75%. Nevertheless, phosphorus removal performance began to fluctuate with a side stream ratio of 1/2 during the third run. The lowest phosphorus removal rate was 54.2%, contributing to a 60% non-standard-reaching rate in this run. This suggests that long-term extraction of 1/2 side stream supernatant is not favorable for maintaining stable effluent of the main process. It was also found that long-term phosphate recovery through side stream extraction allowed reduction of sludge mass and had little impact on sludge settling performance. As a result, it is feasible to extract an appropriate side stream ratio of anaerobic supernatant to recover phosphate, combined with efficient removal of both nitrogen and phosphorus in the main process.

Enhanced phosphorus removal by microbial-collaborating sponge iron.

The collaborative and mutually reinforcing phosphorus removal in domestic wastewater in a sponge iron and microorganisms system was studied through a laboratory and a pilot scale experiment. The results showed that the total phosphorus concentration of the effluent of less than 0.5 mg/L could be achieved. The results also support that the biochemical reaction accelerated the iron electrochemical corrosion. As a driving force, iron bacteria strengthened the chemical oxidation of Fe(II) to Fe(III). The chemical precipitation of Fe(III) is the main form of phosphorus removal. In addition, there exists adsorption phosphorus removal by phosphate-accumulating organisms. The mechanism of the enhanced phosphorus removal by microbial-collaborating sponge iron was thus proposed.