Search

Vertical and horizontal flow constructed wetlands (VF and HF CWs) are most widely used in the treatment of domestic sewage, storm runoff and selected industrial wastewaters. Current research focuses on the search for new applications, alternative substrates and developing mathematical and statistical methods to model the process of removing pollutants in CWs. This is important from a scientific and practical point of view. The performance of VF CWs with two types of substrate (gravel and Certyd - a waste material) was investigated over a two-year period. The following parameters were analyzed: biological oxygen demand (BOD5), chemical oxygen demand (COD), ammonia nitrogen (N-NH4), total nitrogen (N-Total), total phosphorus (P-Total) and dissolved oxygen (DO). At the same time, both the temperature of the inlet sewage and the air temperature were monitored. A support vector machine with a Gaussian kernel function was used to model the treatment efficiency. To select the model parameters, a 10-fold cross-validation was applied. The models applied were characterized by a very good fit. The expected average efficiency of organic removal was 88.3 % (BOD5) and 80.8 % (COD) in the bed filled with Certyd, and 83.8 % (BOD5) and 76.9 % (COD) in the bed with a classic filling. The predicted average efficiency of N-NH4 and N-Total removal in CWs filled with Certyd and gravel were 80.4 % and 74.2 %, and 59.6 % and 57.0 % respectively.

Background: Continuous veno-venous hemodiafiltration (CVVHDF) is used in critically ill patients, but its impact on O₂ and CO₂ removal, as well as the accuracy of resting energy expenditure (REE) measurement using indirect calorimetry (IC) remains unclear. This study aims to evaluate the effects of CVVHDF on O₂ and CO₂ removal and the accuracy of REE measurement using IC in patients undergoing continuous renal replacement therapy. Design: Prospective, observational, single-center study. Methodology: Patients with sepsis undergoing CVVHDF had CO₂ flow (QCO₂) and O₂ flow (QO₂) measured at multiple sampling points before and after the filter. REE was calculated using the Weir equation based on V̇CO₂ and V̇O₂ measured by IC, using true V̇CO₂ accounting for the CRRT balance, and estimated using the Harris-Benedict equation. The respiratory quotient (RQ), the ratio of V̇CO₂ to V̇O₂, was evaluated by comparing measured and true values. Results: The mean QCO₂ levels measured upstream of the filter were 76.26 ± 17.33 ml/min and significantly decreased to 62.12 ± 13.64 ml/min downstream of the filter (p < 0.0001). The mean QO₂ levels remained relatively unchanged. The mean true REE was 1774.28 ± 438.20 kcal/day, significantly different from both the measured REE of 1758.59 ± 434.06 kcal/day (p = 0.0029) and the estimated REE of 1619.36 ± 295.46 kcal/day (p = 0.0475). The mean measured RQ value was 0.693 ± 0.118, while the mean true RQ value was 0.731 ± 0.121, with a significant difference (p < 0.0001). Conclusions: CVVHDF may significantly alter QCO₂ levels without affecting QO₂, influencing the REE and RQ results measured by IC. However, the impact on REE is not clinically significant, and the REE value obtained via IC is closer to the true REE than that estimated using the Harris-Benedict equation. Further studies are recommended to confirm these findings. [ABSTRACT FROM AUTHOR]

Implant abutments are essential components of implant prosthetic restorations. The golden standard for abutment material is titanium; however, due to its properties, the esthetic result can be compromised. The most popular esthetic material alternatives are one- and two-piece zirconia. The study aimed to answer the questions of whether zirconia abutments can be used interchangeably with titanium in both anterior and posterior regions and how aging of the abutment affects durability. For this study, an electronic search of MEDLINE (PubMed) and Scopus (Embase) was conducted. The PRISMA guidelines were followed, and a systematic review was registered with PROSPERO. The search revealed 4031 results, of which 17 studies were selected. The strongest material for abutments is titanium, closely followed by two-piece zirconia. One-piece zirconia abutments were the weakest. The cyclic loading above 1,000,000 cycles decreased the fracture resistance of the abutments. Differences in implant diameter, angulation, and restoration affected the fracture strength of all compared materials. The main mode of failure for titanium abutments was screw bending or screw fracture. One-piece zirconia most often presented catastrophic failure with internal hexagon fracture below the implant neck. Two-piece zirconia exhibits a combination of failure modes. Two-piece zirconia abutments may be suitable for use in the posterior region, given their comparable fracture resistance to titanium abutments. Despite the fact that one-piece zirconia is capable of withstanding forces that exceed those exerted during mastication, it is recommended that it be employed primarily in the anterior dentition due to its propensity for unfavorable failure modes. [ABSTRACT FROM AUTHOR]

The problem of recovering water from treated wastewater may concern an increasing number of countries, especially those with low water resources. After costly treatment processes, water taken from surface and underground intakes is used and then largely discharged to receivers in the form of treated wastewater. Advanced wastewater treatment methods ensure that the treated wastewater is characterized by very low physical and chemical pollution, sometimes better than the water quality in the receiving basin. The research was conducted under a cooperation agreement between Bialystok University of Technology and Bialystok Waterworks Ltd. The recovery of water from wastewater was one of the topics pursued. This paper analyzes the parameters of treated wastewater from the largest municipal wastewater treatment plant in the Podlaskie Province. The analysis of the treated wastewater composition was based on monitoring studies conducted by the company Bialystok Waterworks Ltd. between 2020 and 2023. The analysis concerned the basic parameters of wastewater, namely the content of organic matter and total suspended solids. This was due to the requirements for the recyclability of treated wastewater. Linear modeling was performed to determine if a sufficiently strong correlation was detected;otherwise output distribution characteristics were provided.In all cases, the output concentrations were far below the class A limits for irrigation in the whole research period. [ABSTRACT FROM AUTHOR]

Badania prowadzono w trzech czyszczalniach hydrofi towych z powierzchniowym przepływem ścieków typu Lemna System, zbudowanych według projektu Lemna Corporation. Składają się one ze stawu napowietrzanego i stawu rzęsowego wyposażonego w system barier mających na celu równomierne rozmieszczenie roślin. Stawy poprzedzone są osadnikiem wstępnym. Według projektantów odpowiednia praca tych oczyszczalni związana jest z występowaniem rzęsy na powierzchni stawu rzęsowego. Badano efektywność oczyszczania ścieków komunalnych w trzech oczyszczalniach Lemna System usytuowanych w centralnej Polsce ze szczególnym uwzględnieniem roli stawu rzęsowego i samej rzęsy. Oczyszczalnie różniły się między sobą występowaniem rzęsy. W dwóch z nich (w Rakowie i Bąkowcu) w trakcie całego okresu badań rzęsa nie występowała, natomiast w trzeciej (w Falęcinie Starym) w okresie wegetacyjnym pokrywała do 90%.powierzchni stawu. Efektywność oczyszczanie ścieków nie różniła się w oczyszczalni z rzęsą i bez rzęsy. Rzęsa nie wpływała istotnie na efektywność oczyszczania ścieków. We wszystkich oczyszczalniach główną rolę w redukcji zanieczyszczeń odgrywał staw napowietrzany

Constructed wetlands (CW) plants are successfully used for treating various types of wastewater. Their most popular use is for the treatment of domestic sewage. The main aim of this research is to assess the change of microbiological parameters (total coliform, faecal coliform, total number of mesophilic and cryophilic bacteria, number of enterococci) during domestic sewage treatment in two CW beds with different fillings. The concentration of organic matter BOD5, COD), total Kjeldahl nitrogen TKN, ammonia nitrogen NH4-N, and total phosphorus were also analyzed. The research installation was based on two vertical subsurface flow constructed wetlands (VS-SF CW) -- the first one filled with a Certyd aggregate and the second one with mineral material. Both beds were planted with reeds and worked in parallel with the same hydraulic load 0.1 m³/m²·d (m/d). The research was conducted during vegetative and non-vegetative seasons. Both beds showed a high effectiveness of reduction of most microbiological parameters, amounting to over 95%. The removal efficiency of the total coliform (TC) and faecal coliform (FC) parameters for the Certyd bed during the vegetative season was 99.9%, 98.3% and 97.51%, respectively in the non-vegetative season. In contrast, for the mineral-filled bed, the TC and FC removal efficiency during the vegetative season were, respectively 78.1% and 74.3%, respectively, 65.7% and 58.9% in the non-vegetative season. A difference in efficiency was observed depending on the season. High removal efficiencies of organic matter (measured by BOD5, COD values) and nutrient compounds was observed during the study. The conducted research proved a high efficiency of constructed wetlands in removing microbiological and chemical parameters. Overall, higher efficiency was observed in the bed filled with Certyd. [ABSTRACT FROM AUTHOR]