Pulsed electrochemical and electroless techniques for efficient removal of Sb and Pb from water

Two innovative electrochemical approaches for removing both antimony and lead from water using sacrificial iron sheets are reported; a pulsed method for fast coagulation and a slower electroless method with high efficiency, low cost and no requirement for electrical energy. The study covers laboratory samples and mine wastewater.

Transfusion Approaches and Mortality in Trauma Patients: A Narrative Review

Trauma is one of the leading causes of mortality in the world, accounting for millions of deaths per year. One of the most frequent causes of death in trauma patients is hemorrhage. The presence of a coagulopathy in trauma patients more than doubles the expected mortality. Coagulation management is a key aspect of care for bleeding trauma patients and has been investigated in many studies. However, it is unclear whether a particular approach to coagulation management is associated with a reduction in mortality. Treatment may be guided (e.g., viscoelastic test-guided administration of coagulation factor concentrates) or nonguided (e.g., treatment with a fixed ratio of plasma:red blood cells). This review aimed to assess the published literature regarding coagulation management technique and mortality rate. From the 41 articles obtained in the literature search, there appeared to be a trend toward lower mortality in studies utilizing a guided approach, despite a higher injury severity score in these patients. There were many methodological variations across studies including coagulation management approaches, inclusion criteria, time and type of measurements, use of early fast coagulation monitoring and damage control surgery principles, additional products to those under study, and potential regional differences. It is essential that controlled trials are performed to ascertain optimal transfusion approaches in trauma patients.

Influence of Coagulation of Polymer Dispersion on the Properties of Polymer-Modified Mortar

The coagulation process of polymer dispersion in cement-based materials is different from that of the pure polymer dispersion during drying and film formation. This process is influenced by the various ions released from cement hydration and the interaction between polymer and cement grain in the water. This paper focuses on the coagulation of polymer dispersion during cement hydrating and the influence on the performances e.g. water absorption, flexural and compressive strength and bonding strength of cement mortar. Commercial anionic styrene-acrylate polymer dispersion was investigated in the coagulation process in the polymer-modified cement paste with polymer to cement ratio (p/c) from 5% to 20% and water to cement ratio of 0.3. The amount of coagulated polymer particles was measured by testing the solid content of the supernatant of the diluted polymer-modified cement paste for a period of time. The calorimetric property was measured by TAM AIR calorimeter. Water absorption and mechanical properties of the modified mortar were also measured according to the China standard. The result showed that the polymer dispersion mixing with cement was found to be coagulated in the very early stage under the low polymer to cement ratio, and the quantity of the polymer particles remained in the liquid is quite low within few minutes during this fast coagulation process. The fast coagulation process undermines the influence of polymer dispersion on the cement hydration and the heat evolution. But it has negative impact on the mechanical properties and water resistance. Adding of surfactant into the polymer dispersion extends the coagulation process and improves these performances.

Effect of synthetic and natural coagulant on lignin removal from pulp and paper wastewater

The effects of synthetic polymer (HE, PEI, and PAM) and natural polymer (chitosan) and chemical (alum) coagulant on the removal of lignin (black liquor color, and TOC) from pulp and paper industrial wastewater were investigated. It was observed that the formation of flocs was rapidly taking place which was an indication of fast coagulation flocculation process. PAM which is a nonionic polymer had poor effect as compared to HE and PEI which are cationic polymers. Both HE and PEI resulted in good brown colored precipitate at pH of about 6. These coagulant resulted in removal of about 80% of color and 30% of TOC from alkaline (black liquor) wastewater by gravity settling in 30 minutes. alum resulted in good precipitate with less than 30 minutes settling time by gravity. The percent color removed by alum was the same as the one removed by HE or PEI, but the TOC removed was higher by this chemical coagulant (about 40%). The natural coagulant, chitosan, resulted in the highest removal in both color and TOC as compared to both synthetic polymers and chemical coagulant. Up to 90% of color and 70% of TOC were observed to be removed by chitosan.