Diffusion dialysis for HCl and heavy metals separation from highly concentrated pickling solutions

Disposal of pickling waste solutions strongly affects hot-dip galvanizing industries’ economics and environmental footprint. Thus, the recovery of acid is an important step to enhance the process sustainability. Diffusion dialysis (DD) can be used to separate acids and heavy metals (e.g. iron and zinc) from pickling waters, promoting the circular use of such raw materials. In the present work, two DD modules, a laboratory scale unit operating in batch and a continuous operated large unit, equipped with Fumasep anionic exchange membranes were tested. Results obtained show that zinc and iron affect HCl recovery in opposite way, however reaching high recovery values. In particular, zinc consid…

Experimental investigation on the efficiency of zinc(II) recovery from waste streams by TBP liquid-liquid extraction

In many industrial processes the presence of zinc in the wastewater may represent an obstacle to its high efficient regeneration. This is the case of the treatment of spent pickling solutions aiming the recovery of hydrochloric acid via pyrohydrolysis techniques. Hydrochloric spent pickling solutions from steel processing contain relevant amount of metals such as iron (Fe) and zinc (Zn) that may significantly affect recovery of hydrochloric acid (HCl) through pyrohydrolysis. In fact, although Fe may be recovered as ferric oxide (Fe2O3) and does not have a substantial effect on pyrohydrolysis process, zinc chloride (ZnCl2) evaporating can occlude nozzles and stick to the pyrohydrolysis react…

Evaluation of saltwork ponds operation through brine characterization and geochemical modelling using PHREEQC code integrating the Pitzer correction

Seawater represents a potential resource for the extraction of salts and raw materials [1]. About one-third of the global table-salt production is manufactured in solar saltworks [2], being the most representative product of seawater processing. However, other valuable compounds such as Magnesium, Lithium and trace elements belonging to the alkaline/alkaline-earth metals (e.g. Rb, Cs, Sr) and transition/post-transition metals (e.g. Co, Ga, Ge) are present. Many of these elements are included in the EU Critical Raw Materials (CRM) list, grouping natural assets classified as fundamental for the wealth of the socio-economic structure of Europe [3]. In saltworks, natural evaporation of seawater…

Modeling and Design of Membrane Integrated Processes for HCl and Metals Recovery from Pickling Solutions

Hydrochloric acid pickling is a common practice in steel manufacturing industry. During the process, acid is consumed to dissolve surface oxides and metals are accumulated in the solution. This fact leads to a process efficiency decrease. Continuous regeneration of pickling solutions enhances process rate and performance, but also minimises the highly expensive and environmentally risky wastewater disposal. The recovery of valuable substances (e.g. acid and metals) can be accomplished by coupling diffusion dialysis (DD) and membrane distillation (MD) technologies. In the present work, a steady state process simulator for the integrated process has been developed. The aim is to analyze and p…

REVERSE ELECTRODIALYSIS FOR POWER PRODUCTION FROM OILFIELD WASTEWATERS

Produced waters (PWs) are wastewaters generated by crude-oil extraction processes. They can present very different characteristics depending on the field location and production process. Dispersed oil, dissolved organics and solid particles are usually the main components. Moreover, PWs can contain a very high quantity of dissolved salts 1, with a total dissolved solid (TDS) concentration up to 300 g/L. Each barrel of extracted oil requires the simultaneous extraction of 3 barrels of produced water2 on average. PWs are often discharged into the sea, or sent in evaporation ponds thus leading to a dramatic environment impact3. Reinjection in the extraction well is currently the most common an…

Modeling and Design of Membrane Process Recovery of HCl and Metals from Pickling Solutions

Abstract Hydrochloric acid pickling is one of the key steps in the hot-dip galvanizing process. It is a process widely used as a chemical pre-treatment method for cleaning, where metal surfaces with oxides are immersed into an acid solution. During the pickling process, the acid concentration decreases with time while the metal is accumulated. Thus, the efficiency of the pickling solution decreases and fresh solution must be used. Continuous regeneration of pickling solutions enhances pickling rate and process performance, but also minimises industrial wastewater disposal and chemicals consumption. The recovery and recycling process of valuable substances (e.g. acid and metals) can be accom…

Potentials for critical raw materials recovery from Mediterranean saltworks bitterns

Minerals extraction from seawater brines is currently regarded as the most practical approach to reduce European dependency from the import of many Critical Raw Materials. The technical feasibility of such approach has been widely demonstrated in several different research and development projects but the economic sustainability has always been found to depend on the local demand for sodium chloride, which is always the most abundant product of the extraction. Starting from this crucial node, the SEArcularMINE project has investigated the possibility to use the residual brines originated by sea-salt extraction in traditional saltworks, regarded as an already well-established marketplace. Th…

Recovering of zinc(II) from spent pickling solutions by liquid-liquid extraction

Hydrochloric acid can be successfully recovered from spent pickling liquors with high efficiencies via pyrohydrolysis techniques. In the pickling solution feed, other metallic ions are typically present besides iron (mainly Fe2+) such as zinc(II). In order to avoid undesirable effects, zinc(II) has to be removed, because zinc chloride evaporates and sticks to the reactor walls, as well as it contaminates iron oxides product1. Moreover, zinc recovery is economically affordable because it allows the marketing of some products such as ZnCl2 and ZnSO4. In the present work, liquid-liquid extraction process has been selected to recover zinc(II) from pickling liquors, using suitable extractant age…

Treatment of electroplating wastewater by combining membrane technologies and reactive precipitation process at pilot scale

Recovery of pickling acid solutions by membrane technology: the EU REWACEM Project

Resource recovery from industrial waste water by cutting edge membrane technologies

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

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…

Sustainable recovery of critical elements from seawater saltworks bitterns by integration of high selective sorbents and reactive precipitation and crystallisation: Developing the probe of concept with on-site produced chemicals and energy

The availability of raw mineral resources containing elements included in the Critical Raw Materials (CRMs) list is a growing concern for the European Union. Sea mining has been identified as a promising secondary source. In particular, brines obtained in solar saltworks (bitterns) contain relevant amounts of valuable CRMs such as Mg(II), B(III), other alkaline/alkaline earth metals (Rb(I), Cs(I), Sr(II)) and transition/post-transition elements (Co(II), Ga(III), Ge(IV)). However, the low concentration of some of these elements (µg/L) requires an effort to develop recovery routes that are sustainable and economically feasible where the required chemicals and energy are produced on-site from …

Experimental investigation and modelling for sulphuric acid recovery by diffusion dialysis

Sulphuric acid is known to be one of the key inorganic acid and has been widely used in chemical reaction and metal industries for surface treatments as in the copper electroplating process. During these processes, large amounts of waste sulphuric acid solution are generally generated, containing high concentrations of metals and acid. The possibility of recover and reuse the sulphuric acid in the process could avoid environmental contamination and reduce costs of the disposal. Among several separation methods, diffusion dialysis (DD) is becoming more and more attractive thanks to the recent important advances in ion exchange membranes (IEMs) field and because of its clean nature and operat…

Simulation of a regeneration plant for spent pickling solutions via spray roasting

Nowadays, pyrohydrolysis techniques are widely applied for regeneration of spent pickling liquors providing an excellent environmental and economical strategy to the problem of waste disposal/recovery, also thanks to the high acid recovery efficiencies (>99%) achieved1. In fact, in these processes, iron chlorides are converted into iron oxides and hydrogen chloride at high temperature in spray roasting or fluidized bed reactors2. Though the state-of-the-art technologies have been successfully applied only to large scale plants, the development of small scale units, able to perform a delocalized regeneration of spent solutions where these latter are actually produced, would be strongly ne…

A feasibility study of table salt production from seawater reverse osmosis brine

Adherence issues related to sublingual immunotherapy as perceived by allergists.

Silvia Scurati1, Franco Frati1, Gianni Passalacqua2, Paola Puccinelli1, Cecile Hilaire1, Cristoforo Incorvaia3, Italian Study Group on SLIT Compliance 1Scientific and Medical Department, Stallergenes, Milan, Italy; 2Allergy and Respiratory Diseases, Department of Internal Medicine, Genoa; 3Allergy/Pulmonary Rehabilitation, ICP Hospital, Milan, ItalyObjectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered…

An integrated approach for HCl and metals recovery from waste pickling solutions: pilot plant design and operations

Continuous regeneration of industrial pickling solutions and recovery of valuable materials are implemented in a pilot-scale plant including diffusion dialysis, membrane distillation and reactive precipitation units. The main results of the preliminary assessment of on site operation are presented. Different hydrochloric acid concentration and metals composition were investigated and the performance of the system were analysed in terms of quality of recovered compounds, energy efficiency and environmental footprint.

Use of tailored intraperitoneal ePTFE dual mesh in permagna inguinal hernia

Here we report a case of a giant inguinoscrotal hernia in an elderly patients treated by means of an open positioning of intraperitoneal ePTFE dual mesh. In patients with giant inguinoscrotal hernia the forceful introduction of viscera in abdominal cavity and primary wall closure is burnened from respiratory complication, abdominal compartment syndrome, and defects in wound healing thus exposing the patients to further morbidity and mortality risk. The management of these patients is difficult because of the high occurrence of morbidity factors that affect the success on intervention independently of the technique of surgical repair. The tension- free technique we adopted consented us to ob…

Societal and economic aspects of a novel circular system for the valorisation of desalination brine and waste heat from a power plant

Direct disposal of concentrate brines produced in industrial plants can have a relevant impact to environmental systems. For this reason, brine treatment and valorisation could help to avoid disposal and produce marketable salts, thus representing a possible economic benefit. With this aim, a novel process, where advanced separation technologies are combined with waste heat recovery, is proposed within the EU-funded WATER MINING project. The Case Study presented in this work concerns the power plant in Lampedusa island, where waste heat and desalination brine are available to implement the process via a pilot plant to be installed for alternative thermal treatment of the brine. The aim is t…

Experimental investigation and modelling of diffusion dialysis process for regeneration of acidic pickling solutions

Pickling is one of the key steps in metal finishing industries, where HCl solutions are largely used thus generating significant amounts of spent waste solutions containing high concentrations of metals and acid. The recovery of acid from such waste solutions is thus one of the most beneficial steps for reducing the environmental and economical impact of these processes. Among several separation methods, diffusion dialysis (DD) is becoming more and more attractive thanks to the recent important advances in ion exchange membranes (IEMs) field and because of its clean nature and operational simplicity, low installation and operating costs and low energy consumption [1,2]. In the present work,…

A SIMPLE TECHINIQUE TO IMPROVE RESIDUAL SKIN PLASTICITY FOR SCROTAL RECONSTRUCTION IN FOURNIER'S GANGRENE

A 50 years-old man developed 24 hours after hemorrhoidectomy a severe Fournier's gangrene of the scrotum necessitating surgical exeresis of more than 2/3 of scrotal skin followed by hyperbaric oxygen therapy. After the resolution of the septic phase, scrotum reconstruction was obtained by tissue expansion to avoid more invasive advanced reconstructive techniques. The procedure consisted of an enzymatic and mechanical debridement and progressive skin expansion by package of gauzes of increasing volume covered with a collagenasecloramphenicol ointment (Iruxol®- Smith and Nephew, Italy), then closing the wound edges by temporary stitches to put under tension the skin. The reestablishment of th…

Design, construction and operational results of a pilot plant for the treatment and valorization of pickling waste solutions

An innovative hybrid technology for both minimizing the waste production and optimizing the pickling process through the continuous control of pickling baths composition has been proposed by means of a pilot-plant installed at the Tecnozinco Srl, Carini (PA) hot-dip galvanizing plant. The recovery process has been accomplished by coupling a diffusion dialysis (DD), where HCl is recovered, a membrane distillation (MD), where HCl is concentrated, and a reactive precipitation (RP), where metal ions are recovered as iron hydroxide and ammonium/zinc chloride solution, to be used in the fluxing baths of the plant. The pilot plant was commissioned and operated using synthetic HCl solutions first a…

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…

La fase ricostruttiva dopo duodenocefalopancreasectomia: l’anastomosi pancreatico-digiunale. Nostra esperienza.

Su di un caso clinico di stipsi cronica dell’adulto dopo trattamento chirurgico per MAR in età neonatale

The management of postoperative pain after hemorrhoidectomy: Analysis of three methodics

Postoperative pain is one of the most common and disabling complications following hemorrhoidectomy. This study divided a total of 90 patients, undergone Milligan and Morgan hemorrhoidectomy, in three groups of 30 patient: Group A, undergone internal sphincterotomy after hemorrhoidectomy; Group B, treated with Diosmin 500 mg; Group C, treated with Paracetamol 1000 mg when required. The analysis of the median VAS score (Visual Analogic Scale) of postoperative pain, in every group pointed out a relationship between postoperative pain reduction and time at the three set checkpoints (1st, 3rd, 9th postoperative day) (R2= 0.9231 for Group A; R2= 0.9423 for group B; R2= 0.9423 for group C). Mean …