Search results for " dialysis."

Effective recovery of HCl and metals from pickling solutions by cutting-edge membrane technologies

2018

The pickling process is an essential step in the hot-dip galvanizing process.It is performed by immersing manufacturedsteel pieces inacid bathsin order todissolve the oxidized layers. During the pickling process, acid attacks metal oxides on the surface, dissolving them in the pickling bath. Thus, the efficiency of the pickling liquor decreases due to the accumulation of metal salts and the consumption of free acid in the solution. When hydrochloric acid is used,ferrous chloride is producedduring the pickling treatment, reaching concentrations up to 250 g/l, while the acid concentration decreases by 75-85%. A pickling bath in this condition is considered spent [1] due to thevery low picklin…

Novel poly (ionic liquid)-based anion exchange membranes for efficient and rapid acid recovery from industrial waste

2020

Abstract Owing to the less energy consumption, positive impact on the environment, and prospect of providing clean water resources, anion exchange membranes (AEMs) are promising materials for acid recovery from various industrial wastewater/effluent. Based on the diffusion dialysis process, AEMs selectively allow rapid proton permeation while efficiently retaining metal ions. To enhance the efficiency of the acid recovery process, precise control of macromolecular architecture and chemical composition that enables high hydrophilicity, proton conductivity through the membrane, and ion exchange capacity is required. In this direction, we report on the one-step fabrication of novel poly (ionic…

CFD PREDICTION OF SCALAR TRANPORT IN THIN CHANNELS FOR REVERSE ELECTRODIALYSIS

2014

Reverse ElectroDialysis (RED) is a very promising technology allowing the electrochemical potential difference of a salinity gradient to be directly converted into electric energy. Fluid dynamics optimization of the thin channels to be devoted for the RED process is still an open problem. The present preliminary work focuses on the Computational Fluid Dynamics (CFD) simulation of the flow and concentration fields in these channels. In particular three different configurations were investigated: a channel unprovided with a spacer and two different spacer (made of either overlapped filaments or woven filaments) filled channels. Two passive scalars were transported along with the water in orde…

Application of diffusion dialysis in separation of sulfuric acid and copper from electroplating wastewater

Electroplating industry creates large volumes of wastewater that contain acids and heavy metallic ions which are toxic but valuable. Diffusion dialysis (DD) can be used to separate acids from heavy metals. In this work, two single-cell DD modules equipped with Fumasep FAD membranes were used for the first time for the separation of sulfuric acid from copper. The first module consisted of a laboratory-scale DD unit operated in a batch configuration to study the effect of process parameters on the efficiency of sulfuric acid recovery. The latter one was a large-scale DD unit operated in a continuous configuration to simulate the process operation at the industrial scale. Results showed that F…

Diffusion dialysis for the treatment of H2SO4-CuSO4 solutions from electroplating plants: Ions membrane transport characterization and modelling

2021

Diffusion dialysis (DD) is proposed to separate and recover mineral acids and transition metals from electroplating industry process waters promoting a circular approach of resources recovery. In this work, a DD module with two anionic membranes (Fumasep FAD and Neosepta AFN) are used for the separation of H2SO4 from Cu2+ containing solutions. The membrane performances with sole H2SO4 solutions (0.2–2 M) and sole CuSO4 solutions (0.8–1.1 M Cu2+) and with mixtures of H2SO4 (0.6 M) and CuSO4 (0.2–1.1 M Cu2+) as feed are studied. H2SO4 recovery efficiency decreases as the concentration of acid increases. For H2SO4 solutions, the water drag flux from the retentate to the diffusate prevails agai…

CFD prediction of scalar transport in thin channels for reverse electrodialysis

2014

Reverse ElectroDialysis (RED) is a very promising technology allowing the electrochemical potential difference of a salinity gradient to be directly converted into electric energy. The fluid dynamics optimization of the thin channels used in RED is still an open problem. The present preliminary work focuses on the Computational Fluid Dynamics (CFD) simulation of the flow and concentration fields in these channels. In particular three different configurations were investigated: a channel unprovided with a spacer (empty channel) and two channels filled with spacers, one made of overlapped filaments the other of woven filaments. The transport of two passive scalars, representative of the ions …

Economic Benefits of Waste Pickling Solution Valorization

2022

An integrated hybrid membrane process, composed of a diffusion dialysis (DD), a membrane distillation (MD) and a reactive precipitation unit (CSTR), is proposed as a promising solution for the valorization and onsite recycling of pickling waste streams. An economic analysis was performed aiming to demonstrate the feasibility of the developed process with a NPV of about EUR 40,000 and a DPBP of 4 years. The investment and operating costs, as well as the avoided costs and the benefits for the company operating the plant, were analyzed with an extensive cost tracking exercise and through face-to-face contact with manufacturers and sector leaders. A mathematical model was implemented using the …

[The role of the anesthesiologist in secondary hyperparathyroidism].

2010

In the last years the increasing of diabetes and hypertension has produced a considerable increase of patients with chronic renal failure; secondary hyperparathyroidism is one of the major complications. The resection of hyperfunctioning parathyroid tissue is the ultimate goal of the treatment. The preoperative examination by the anesthetist is the starting-point of the treatment. The anesthetist programs hemodialysis, the correction of fluid and electrolyte abnormalities and of the anaemia. In the operating room the anesthetist is involved in the careful monitoring of liquid infusion and anesthesiological procedure. The intraoperative parathyroid hormone (PTH) assay is an essential tool be…

A randomized multicenter trial on a lung ultrasound-guided treatment strategy in patients on chronic hemodialysis with high cardiovascular risk

2021

Lung congestion is a risk factor for all-cause and cardiovascular mortality in patients on chronic hemodialysis, and its estimation by ultrasound may be useful to guide ultrafiltration and drug therapy in this population. In an international, multi-center randomized controlled trial (NCT02310061) we investigated whether a lung ultrasound-guided treatment strategy improved a composite end point (all-cause death, non-fatal myocardial infarction, decompensated heart failure) vs usual care in patients receiving chronic hemodialysis with high cardiovascular risk. Patient-Reported Outcomes (Depression and the Standard Form 36 Quality of Life Questionnaire, SF36) were assessed as secondary outcome…

Nitric oxide metabolites (nitrite and nitrate) in several clinical condition.

2013

We determined the concentration of nitric oxide metabolites (NO2-+NO3-), expressed as NOx, in several clinical conditions. Regarding this, we have examined 25 subjects with arterial hypertension, 41 subjects with chronic kidney disease in conservative treatment, 106 subjects with metabolic syndrome subdivided according to the presence (n = 43) or not (n = 63) of diabetes mellitus, 48 subjects with obstructive sleep apnea syndrome (OSAS), 14 women with systemic sclerosis complicated with Raynaud's phenomenon, 42 dialyzed subjects and 105 young subjects with acute myocardial infarction (AMI). In subjects with arterial hypertension, chronic kidney disease, metabolic syndrome, systemic sclerosi…