Effect of Organic Substances on Nutrients Recovery by Struvite Electrochemical Precipitation from Synthetic Anaerobically Treated Swine Wastewater

Anaerobically treated swine wastewater contains large amounts of orthophosphate phosphorus, ammonium nitrogen and organic substances with potential nutrients recovery via struvite electrochemical precipitation post-treatment. Lab-scale batch experiments were systematically conducted in this study to investigate the effects of initial pH, current density, organic substances upon nutrients removal, and precipitates quality (characterized by X-ray diffraction, scanning electron microscopy and element analysis via acid dissolution method) during the struvite electrochemical precipitation process. The optimal conditions for the initial pH of 7.0 and current density of 4 mA/cm2 favoured nutrients removal and precipitates quality (struvite purity of up to 94.2%) in the absence of organic substances. By contrast, a more adverse effect on nutrients removal, morphology and purity of precipitates was found by humic acid than by sodium alginate and bovine albumin in the individual presence of organic substances. Low concentration combination of bovine albumin, sodium alginate, and humic acid showed antagonistic inhibition effects, whereas a high concentration combination showed the accelerating inhibition effects. Initial pH adjustment from 7 to 8 could effectively mitigate the adverse effects on struvite electrochemical precipitation under high concentration combined with organic substances (500 mg/L bovine albumin, 500 mg/L sodium alginate, and 1500 mg/L humic acid); this may help improve struvite electrochemical precipitation technology in practical application for nutrients recovery from anaerobically treated swine wastewater.

Influence of organic colloids on uptake, accumulation and effects of benzophenone-3 in aquatic animals

The environmental behavior of pollutants in water is associated with aquatic colloids, especially organic colloids, which may be swallowed by aquatic organisms. In this study, bovine albumin (BSA) and phycocyanin...

Evaluation of survival of Candida albicans on PVC surfaces in the test of yeasticidal activity of disinfectant

Introduction: Candida albicans survival tests on PCV carriers are necessary for the proper determination of the effectiveness yeasticidal activity of disinfectants. C. albicans is a pathogenic microorganism that causes fungal diseases and therefore its spread in the medical and non-medical areas should be limited by disinfection. Methods: Survival of C. albicans was estimated with using principles of PN-EN 16615 standard. Suspension of C. albicans with interfering substances (0,3 g/l bovine albumin) was dry on PCV carriers under a laminar chamber without fan, at the ambient temperature for no longer than 60 minutes. C. albicans was recovered from the carriers immediately after drying and after contact time (1; 5, 10, 20, 40; 60 minutes). Results: The drying conditions applied reduced the recovery of C. albicans from 1.21 to 2.07 on a logarithmic decimal scale with respect to the test suspension with interfering substances. The difference between the recovery immediately after drying and the recovery after the tested contact times (up to 60 minutes) was insignificant. Conclusions: Achieving the number of C. albicans after the drying process, as provided for in PN-EN 16615, requires further improvement of the drying conditions or an increase of C. albicans suspension density before drying.

Importance of the PN-EN 16615: 2015 standard in the assessment of bactericidal activity of disinfectants intended for soaking wipes in medical area

Introduction: The PN-EN 16615: 2015 standard is intended to determine the acting parameters of disinfectants used for surfaces disinfection with the wiping technique using wipes. It takes into account the application method of disinfectants on the non porous surfaces to be disinfected. The aim of the study was to assess the compliance of the obtained results of control tests with the limit values set in the PN-EN 16615: 2015 standard and to determine the disinfection parameters of the tested product against Staphylococcus aureus. Method: The disinfectant product tests were carried out using standard wipes described in PN-EN 16615: 2015 standard in four contact times of 1, 5, 10, 15 minutes under clean conditions: 0,3 g / l of bovine albumin solution. Results: Obtained results of control and validation of the dilution-neutralization method met the criteria of limit values of the PN-EN 16615: 2015 standard. The test product was active against Staphylococcus aureus within 15 minutes contact time under clean conditions (reduction > 5,59 lg). Conclusions: PN-EN 16615: 2015 standard ensures proper determination of acting parameters of disinfectants intended for use in the form of wipes, what contributes to effective disinfection of the surfaces, especially high-touch surfaces, and prevents the occurrence of cross-contamination of other surfaces in the medical area.