Treatment of high-ammonium anaerobic digester supernatant by aerobic granular sludge and ultrafiltration processes

Anaerobic sludge digester supernatant characterized by 569 mg TKN L^?1, high color and a COD/N ratio of 1.4 was treated in granular sequencing batch reactors (GSBRs) followed by post-denitrification (P-D) and ultrafiltration (UF) steps. The use of granular sludge allowed for the oxidation of ammonium in anaerobic digester supernatant at all investigated GSBR cycle lengths of 6, 8 and 12 h. The highest ammonium removal rate (15 mg N g^?1 VSS h^?1) with removal efficiency of 99% was noted at 8 h.Since the GSBR effluent was characterized by a high concentration of nitrites, slowly-degradable substances and biomass, additional purification steps were applied. In P-D stage, the microbial activity of granular biomass in the GSBR effluent was implemented. The P-D was supported by external carbon source addition and the most advantageous variant comprised dosing of half of the theoretical acetate dose for nitrite reduction in the 3-h intervals. The use of the system consisting of the GSBR with 8 h, an optimal P-D variant and a UF for the treatment of anaerobic digester supernatant allowed for the 99%, 71% and 97% reductions of TKN, COD and color, respectively.     

Effects of soil amendment with PCB-contaminated sediment on the growth of two cucurbit species

Environmental Science and Pollution Research - The aim of the study was to evaluate the influence of the application of increasing proportions (0%, 10%, 25%, 50%, 75%, and 100%) of an admixture of...     

Residential emissions predicted as a major source of fine particulate matter in winter over the Yangtze River Delta,China

Environmental Chemistry Letters - Air pollution is an increasingly critical health issue responsible for numerous diseases and deaths worldwide. In China, to address severe air pollution in the...     

Bioconcentration factors of mercury by Parasol Mushroom (Macrolepiota procera)

To examine bioconcentration factors (BCFs) of mercury by Parasol Mushroom (Macrolepiota procera) roughly similarly sized (a cap diameter) fruiting bodies of this fungus and underlying soil (0–10 cm) samples were collected at 15 sites in Poland between 1995 and 2003. The total mercury content of the individual caps and stipes of Parasol Mushroom ranged from 0.05 to 22 mg Hg/kg dry matter (d.m.) and from 0.05 to 20 mg Hg/kg d.m., while the means were from 1.1 to 8.4 mg Hg/kg d.m. and from 0.83 to 6.8 mg Hg/kg d.m., respectively. The caps generally contained higher concentrations of mercury when compared to stipes, and the means of the cap to stipe mercury concentration quotient ranged from 1.3 to 4.6. The range of mercury concentration in topsoil samples collected at the sites where the fruiting bodies were collected was from 0.01 to 0.54 mg/g d.m. (means ranged from 0.022 to 0.36 mg/g d.m.). The BCFs factors for total mercury varied from 0.52 to 470 for individual caps and 0.52 to 360 for stipes, while average values, depending on the site, were from 16 to 220 and from 7.6 to 130 for caps and stipes, respectively.     

Construction Job Safety Analysis

Job Safety Analysis (JSA), which is also known as Job Hazard Analysis, is an efficient proactive measure for safety risk assessment used in industrial manufacturing settings. However, unlike the manufacturing settings for which JSA was developed, at construction sites the physical environment is constantly changing, workers move through the site in the course of their work, and they are often endangered by activities performed by other teams. To address this difficulty, a structured method for hazard analysis and assessment for construction activities, called “Construction Job Safety Analysis” (CJSA), was developed. The method was developed within the framework of research toward a lean approach to safety management in construction, which required the ability to predict fluctuating safety risk levels in order to support safety conscious planning and pulling of safety management efforts to the places and times where they are most effective. The method involves identification of potential loss-of-control events for detailed stages of the activities commonly performed in construction, and assessment of the probability of occurrence for each event identified. It was applied to explore 14 primary construction activities in an extensive trial implementation that included expert workshops and a series of 101 interviews with site engineers and superintendents. Detailed quantitative results were obtained for a total of 699 possible loss-of-control events; the most frequent events are those related to exterior work at height.     

Solomon versus selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome: A systematic review and meta-analysis

This meta-analysis aims to compare the perinatal outcome of twin-twin transfusion syndrome (TTTS) pregnancies undergoing selective versus vascular equator (Solomon) fetoscopic laser photocoagulation (FLP). We performed a systematic search in PubMed and Web of Science from inception up to 25 July 2021. Studies comparing the Solomon and selective techniques of FLP for treatment of TTTS pregnancies were eligible. Random-effects or fixed-effect models were used to pool standardized mean differences (SMD) and log odds ratio. Seven studies with a total of 1664 TTTS pregnancies (n = 671 undergoing Solomon and n = 993 selective techniques) were included. As compared to the selective FLP, Solomon was associated with a lower risk of recurrent TTTS compared to the selective technique (Log odds ratio [OR]: −1.167; 95% credible interval [CrI]: −2.01, −0.33; p = 0.021; I²: 67%). In addition, Solomon was significantly associated with a higher risk of placental abruption than the selective technique (Log [OR]: 1.44; 95% CrI: 0.45, 2.47; p = 0.012; I²: 0.0%). Furthermore, a trend for the higher risk of preterm premature rupture of membranes was observed among those undergoing Solomon (Log [OR]: 0.581; 95% CrI: −0.43, 1.49; p = 0.131; I²: 17%). As compared to selective FLP, the Solomon technique for TTTS pregnancies is associated with a significantly lower recurrence of TTTS; however, it significantly increases the risk of placental abruption.