Comprehensive Study of Crystal Growth from Solution

Crystal growth is an essential phase in crystallization kinetics. The rate of crystal growth provides significant information for the design and control of crystallization processes; nevertheless, obtaining accurate growth rate data is still challenging due to a number of factors that prevail in crystal growth. In industrial crystallization, crystals are generally grown from multi-componentand multi-particle solutions under complicated hydrodynamic conditions; thus, it is crucial to increase the general understanding of the growth kinetics in these systems. The aim of this work is to develop a model of the crystal growth rate from solution. An extensive literature review of crystal growth focuses on themodelling of growth kinetics and thermodynamics, and new measuring techniques that have been introduced in the field of crystallization. The growth of a singlecrystal is investigated in binary and ternary systems. The binary system consists of potassium dihydrogen phosphate (KDP, crystallizing solute) and water (solvent), and the ternary system includes KDP, water and an organic admixture. The studied admixtures, urea, ethanol and 1-propanol, are employed at relatively highconcentrations (of up to 5.0 molal). The influence of the admixtures on the solution thermodynamics is studied using the Pitzer activity coefficient model. Theprediction method of the ternary solubility in the studied systems is introduced and verified. The growth rate of the KDP (101) face in the studied systems aremeasured in the growth cell as a function of supersaturation, the admixture concentration, the solution velocity over a crystal and temperature. In addition, the surface morphology of the KDP (101) face is studied using ex situ atomic force microscopy (AFM). The crystal growth rate in the ternary systems is modelled on the basis of the two-step growth model that contains the Maxwell-Stefan (MS) equations and a surface-reaction model. This model is used together with measuredcrystal growth rate data to develop a new method for the evaluation of the model parameters. The validation of the model is justified with experiments. The crystal growth rate in an imperfectly mixed suspension crystallizer is investigatedusing computational fluid dynamics (CFD). A solid-liquid suspension flow that includes multi-sized particles is described by the multi-fluid model as well as by a standard k-epsilon turbulence model and an interface momentum transfer model. The local crystal growth rate is determined from calculated flow information in a diffusion-controlled crystal growth regime. The calculated results are evaluated experimentally.

Gold recovery from cyanideand chloride solution using activated carbon

Uusia keinoja kullan erottamiseksi malmista on etsitty viimeaikoina taloudellisista ja ympäristöllisistä syistä kautta maailman. Syanidointimenetelmä on hallinnut kullan talteenottoayli sata vuotta. Menetelmässä kulta liuotetaan laimeaan syanidiliuokseen, jostase otetaan talteen aktiivihiilen avulla. Syanidin käyttöä pyritään kuitenkin vähentämään sen myrkyllisyyden takia. Lisäksi nykyään louhitaan enenemässä määrin malmia, josta on hankala rikastaa kulta kustannustehokkaasti syanidia käyttäen. Kullan talteenottoa syanidi- ja kloridiliuoksesta on selvitetty kirjallisuuden avulla. Kullan kemiaan liuotuksen aikana on perehdytty ennen kullan talteenottoa aktiivihiilellä. Aktiivihiilen elinkaari kullan adsorbenttinaon käsitelty valmistuksesta hylkäämiseen mukaan lukien hiilen myrkyttyminen prosessissa ja regenerointi. Aktiivi-hiilen käyttäytyminen syanidi- ja kloridiliuoksessa on selvitetty erikseen. Kullan talteenottoa kuparipitoisista malmeista on käsitelty. Kullan talteenottoa kloridiliuoksesta aktiivihiiltä käyttäen on tutkittu kokeellisesti. Pääasialliset tutkimuskohteet ovat adsorption kinetiikka, kuparin vaikutus adsorptioon, aktiivihiilen vaikutus adsorptioonja adsorboituneiden metallien strippaus hiilestä selektiivisesti. Hapettavan stippauksen vaikutus kullan desorptioon hiilestä on tutkittu yksityiskohtaisesti. Kullan erotusmenetelmät kuparimalmista aktiivihiiltä käyttäen on selvitetty diplomityön tulosten pohjalta. Diplomityön keskeisten tulosten perusteella kulta ei välttämättä saostu aktiivihiilen pinnalle kloridiliuoksesta. Havainto varmistettiin ladattujen hiilipartikkelien pyyhkäisyelektronimikroskooppikuvista ja partikkeleille tehdyistä mikroanalyyseistä. Kullan pelkistyminen metalliseksi kullaksi aktiivihiilessä voitaneen välttää käyttämällä erittäin hapettavia olosuhteita. Aktiivihiili ilmeisesti hapettuu näissä olosuhteissa, mikä mahdollistaa kultakloridin adsorboitumisen hiileen.

Designing the transformation from a boiler supplier into a solution seller

Competition for customers in business-to-business markets is rough, and in order to survive a seller has to be able to deliver more value to its customers than its competitors. This thesis is done for the sales department of an energy technology company operating in business-to-business markets. The company is a relatively small in its field, and it aims to expand internationally and differ itself from its competitors by providing better service for its customers and selling solutions. This study aims to design the transformation from a product seller into a solution seller by defining what is a solution and how solutions are sold, and creating an action plan for sales. Data for the study is collected in ten theme interviews, and analyzed with thematic and content analysis. The action plan is constructed based both on the data and theory. According to the findings of the study, solution is defined as a specially designed unique combination of elements – such as products, services, knowledge, experience and thinking – that work with and complement each other, and bring value to a particular customer. Solution sales requires capabilities to anticipate; build relationships with customers; identify needs and define requirements; cocreate solutions by customizing and integrating elements; and provide postdeployment support. Vision for the change is to sell solution through sensing customers’ needs and responding to them, and the steps of the action plan are to (1) cascade customer-focus, (2) involve other departments in solution sales, (3) develop customer relationship management, and (4) involve the whole organization in solution business.

From network pictures to network insight in solution business – the role of internal communication

Operating in business-to-business markets requires an in-depth understanding on business networks. Actions and reactions made to compete in markets are fundamentally based on managers‘ subjective perceptions of the network. However, an amalgamation of these individual perceptions, termed a network picture, to a common company level shared understanding on that network, known as network insight, is found to be a substantial challenge for companies. A company‘s capability to enhance common network insight is even argued to lead competitive advantage. Especially companies with value creating logics that require wide comprehension of and collaborating in networks, such as solution business, are necessitated to develop advanced network insight. According to the extant literature, dispersed pieces of atomized network pictures can be unified to a common network insight through a process of amalgamation that comprises barriers/drivers of multilateral exchange, manifold rationality, and recursive time. However, the extant body of literature appears to lack an understanding on the role of internal communication in the development of network insight. Nonetheless, the extant understanding on the amalgamation process indicates that internal communication plays a substantial role in the development of company level network insight. The purpose of the present thesis is to enhance understanding on internal communication in the amalgamation of network pictures to develop network insight in the solution business setting, which was chosen to represent business-to-business value creating logic that emphasizes the capability to understand and utilize networks. Thus, in solution business the role of succeeding in the amalgamation process is expected to emphasize. The study combines qualitative and quantitative research by means of various analytical methods including multiple case analysis, simulation, and social network analysis. Approaching the nascent research topic with differing perspectives and means provides a broader insight on the phenomenon. The study provides empirical evidence from Finnish business-to-business companies which operate globally. The empirical data comprise interviews (n=28) with managers of three case companies. In addition the data includes a questionnaire (n=23) collected mainly for the purpose of social network analysis. In addition, the thesis includes a simulation study more specifically achieved by means of agent based modeling. The findings of the thesis shed light on the role of internal communication in the amalgamation process, contributing to the emergent discussion of network insights and thus to the industrial marketing research. In addition, the thesis increases understanding on internal communication in the change process to solution business, a supplier‘s internal communication in its matrix organization structure during a project sales process, key barriers and drivers that influence internal communication in project sales networks, perceived power within industrial project sales, and the revisioning of network pictures. According to the findings, internal communication is found to play a substantial role in the amalgamation process. First, it is suggested that internal communication is a base of multilateral exchange. Second, it is suggested that internal communication intensifies and maintains manifold rationality. Third, internal communication is needed to explicate the usually differing time perspectives of others and thus it is suggested that internal communication has role as the explicator of recursive time. Furthermore, the role of an efficient amalgamation process is found to be emphasized in solutions business as it requires a more advanced network insight for cross-functional collaboration. Finally, the thesis offers several managerial implications for industrial suppliers to enhance the amalgamation process when operating in solution business.

Industrial solution business – transition from product to solution offering

The business logic in the manufacturing industry has changed in the 21st century. In the current industrial market, manufacturers are driven to provide more comprehensive offerings that go beyond the traditional product-orientation by providing capacity and availability for their customers. From incidental merchandise, services have become the core of manufacturers’ offerings with long-lasting service agreements over the life-cycles of their products. This change is driven both by the need of providers to grow and gain competitive advantage and by increased customer demand caused by customers’ outsourcing trends. The three key drivers for manufacturers’ service strategies are outsourcing trends, saturation of the installed base, and commoditization in product markets. Thus, manufacturers focus on providing industrial solutions which are delivered through relational processes with customers by using solution-driven business models. In the management of marketing activities, this can be regarded as closer customer relationships, service-dominant business logic, and collaboration in solving customers’ problems. However, there are few studies on comprehensive conceptualizations of a solution offering that include different elements and their roles, especially in the context of capital goods industry. Also the transition process needs further studies in a real life context. This study explores the transition process of an industrial company from product to solution business and, as an aid to managing the solution business, explicates the structure and management of an industrial solution offering. There are two themes, the industrial transition process and industrial solution offering. Regarding the industrial transition process, the aim is to understand the supplier view on the process and its execution and to determine the challenges related to the transition process. The industrial solution offering is discussed by its elements and characteristics, as well as management. Furthermore, a special type of build-own-operate-transfer business model is presented and its suitability in the industrial context analyzed. The study includes findings achieved by qualitative methods and from four case companies. Based on the results, it is tentatively suggested that in the industrial solution business, the transition from product to solution business is not a linear project but an evolving process that varies according to customer needs, which suggests that companies need to possess an ability to develop new business models for different customer needs. The industrial solution offering is dynamic as it evolves in collaboration according to the prevailing and latent customer needs, which suggest restructuring of the organization from a product-centric to a customer-centric one. Furthermore, based on the findings, the concept of industrial solutions is defined as an ongoing relational process to satisfy a customer’s particular business or operational requirements, and the concept of industrial solution offering as an entity comprising the customized goods, services, collaboration, and finance needed to fulfill the industrial solution. Finally, the study offers several managerial implications for industrial managers involved in the transition and management of the solution business and its offering.

Unlicensed Mobile Access Concept from Testing Point of View

Viime vuosikymmenien aikana kommunikaatioteknologiat ovat kehittyneet erittäin paljon. Uusia verkkoja, liityntätekniikoita, protokollia ja päätelaitteita on luotu alati kehittyvällä vauhdilla, eikä hidastumisen merkkejä ole näkyvissä. Varsinkin mobiilisovellukset ovat kasvattaneet markkinaosuuksiaan viime aikoina. Unlicensed MobileAccess (UMA) on uusi liityntätekniikka mobiilipäätelaitteille, joka mahdollistaa liitynnän GSM- runkoverkkoon WLAN- tai Bluetooth - tekniikoiden avulla. Tämä diplomityö keskittyy UMAan liittyviin teknologioihin, joita tarkastellaan lähemmin ensimmäisissä kappaleissa. Tavoitteena on esitellä, mitä UMA merkitsee, ja kuinka eri tekniikoita voidaan soveltaa sen toteutuksissa. Ennenkuin uusia teknologioita voidaan soveltaa kaupallisesti, täytyy niiden olla kokonaisvaltaisesti testattuja. Erilaisia testausmenetelmiä sovelletaan laitteistonja ohjelmiston testaukseen, mutta tavoite on kuitenkin sama, eli vähentää testattavan tuotteen epäluotettavuutta ja lisätä sen laatua. Vaikka UMA käsittääkin pääasiassa jo olemassa olevia tekniikoita, tuo se silti mukanaan uuden verkkoelementin ja kaksi uutta kommunikaatioprotokollaa. Ennen kuin mitään UMAa tukevia ratkaisuja voidaan tuoda markkinoille, monia erilaisia testausmenetelmiä on suoritettava, jotta varmistutaan uuden tuotteen oikeasta toiminnallisuudesta. Koska tämä diplomityö käsittelee uutta tekniikkaa, on myös testausmenetelmien yleisen testausteorian käsittelemiselle varattu oma kappale. Kappale esittelee erilaisia testauksen näkökulmia ja niihin perustuen rakennetaan myös testausohjelmisto. Tavoitteena on luoda ohjelmisto, jota voidaan käyttää UMA-RR protokollan toiminnan varmentamiseen kohdeympäristössä.

Logistics Development in Finnish and Swedish Companies with Respect of Russia and Four Asian Countries: Traffic Flow and Warehousing Analysis from Current Situation and Likely Development Trends

On selvää, että tänä päivänä maailmankaupan painopiste on hiljalleen siirtymässä Aasiaan ja varsinkin Kiina on ollut huomion keskipisteessä. Erityisesti valmistavien yritysten perspektiivistä muutos on ollut merkittävä ja tämä tosiasia kasvattaa yrityksissä paineita luoda kustannustehokkaita toimitusketjuratkaisuja,joiden vasteaika on mahdollisimman lyhyt. Samaan aikaan kun tarkastellaan kuljetusvirtoja, huomattaan että maanosien välillä on suuri epätasapaino. Tämä on enimmäkseen seurausta suurten globaalisti toimivien yritysten toimitusketjustrategioista. Useimmat näistä toimijoista optimoivat verkostonsa turvautumalla 'paikalliseen hankintaan', jotta he voisivat paremmin hallita toimitusketjujaan ja saada näitä reagointiherkimmiksi. Valmistusyksiköillä onkin monesti Euroopassa pakko käyttää kalliita raaka-aineita ja puolivalmisteita. Kriittisiksi tekijöiksi osoittautuvat kuljetus- ja varastointikustannukset sekä näiden seurauksena hukka-aika, joka aiheutuu viivästyksistä. Voidakseen saavuttaa optimiratkaisun, on tehtävä päätös miten tuotteet varastoidaan: keskitetysti tai hajautetusti ja integroida tämä valinta sopivien kuljetusmuotojen kanssa. Aasiasta Pohjois-Eurooppaan on halpaa käyttää merikuljetusta, mutta operaatio kestää hyvin pitkään - joissain tapauksessa jopa kahdeksan viikkoa. Toisaalta lentokuljetus on sekä kallis että rajoittaa siirrettävien tuotteiden eräkokoa.On olemassa kolmaskin vaihtoehto, josta voisi olla ratkaisuksi: rautatiekuljetus on halvempi kuin lentokuljetus ja vasteajat ovat lyhyemmät kuin merikuljetuksissa. Tässä tutkimuksessa tilannetta selvitetään kyselyllä, joka suunnattiin Suomessa ja Ruotsissa toimiville yrityksille. Tuloksien perusteella teemme johtopäätökset siitä, mitkä kuljetusmuotojen markkinaosuudet tulevat olemaan tulevaisuudessa sekä luomme kuvan kuljetusvirroista Euroopan, Venäjän, Etelä-Korea, Intian, Kiinan ja Japanin välillä. Samalla on tarkoitus ennakoida sitä, miten tarkastelun kohteena olevat yritykset aikovat kehittää kuljetuksiaan ja varastointiaan tulevien vuosien aikana. Tulosten perusteella näyttää siltä, että seuraavan viiden vuoden kuluessa kuljetuskustannukset eivät merkittävissä määrin tule muuttuman ja meri- sekä kumipyöräkuljetukset pysyvät suosituimpina vaihtoehtoina.Kuitenkin lentokuljetusten osuus laskee hiukan, kun taas rautatiekuljetusten painotus kasvaa. Tulokset paljastavat, että Kiinassa ja Venäjällä kuljetettava konttimäärä kasvaa; Intiassa tulos on saman suuntainen, joskaan ei niin voimakas. Analyysimme mukaan kuljetusvirtoihin liittyvä epätasapaino säilyy Venäjän kuljetusten suhteen: yritykset jatkavat tulevaisuudessakin vientiperusteista strategiaansa. Varastoinnin puolella tunnistamme pienemmän muutoksen, jonka mukaan pienikokoisten varastojen määrät todennäköisesti vähenevät tulevaisuudessa ja kiinnostus isoja varastoja kohtaan lisääntyy. Tässä kohtaa on mainittava, että suomalaisilla yrityksillä on enemmän varastoja Keski- ja Itä-Euroopassa verrattuna ruotsalaisiin toimijoihin, jotka keskittyvät selkeämmin Länsi-Euroopan maihin. Varastoja yrityksillä on molemmissa tapaukissa paljolti kotimaassaan. Valitessaan varastojensa sijoituskohteita yritykset painottavat seuraavia kriteereitä: alhaiset jakelukustannukset, kokoamispaikan/valmistustehtaan läheisyys, saapuvan logistiikan integroitavuus ja saatavilla olevat logistiikkapalvelut. Tutkimuksemme lopussa päädymme siihen, että varastojen sijoituspaikat eivät muutu satamien rakenteen ja liikenneyhteyksien takia kovinkaan nopeasti.

Recovery of Hemicelluloses from Wood Hydrolysates by Membrane Filtration

Hemicelluloses are among the most important natural resources that contain polysaccharides. In this study the separation and purification of hemicelluloses from water extraction liquors containing wood hemicelluloses, lignin compounds and monosaccharide by using membrane filtration was investigated. The isolation of the hemicelluloses from the wood hydrolysates was performed in two steps: concentration of high molar mass hemicelluloses by ultrafiltration and separation of low molar mass hemicelluloses from monomeric sugars using tight ultrafiltration membranes. The purification of the retained hemicelluloses was performed by diafiltration. During the filtration experiments, the permeate flux through ultrafiltration and tight ultrafiltration membranes was relatively high. The fouling ability of the used membranes was relatively low. In our experiments, the retention of hemicelluloses using two filtration steps was almost complete. The separation of monosaccharides from hemicelluloses was relatively high and the purification of hemicelluloses by diafiltration was highly efficient. The separation of lignin from hemicelluloses was partially achieved. Diafiltration showed potential to purify retained hemicelluloses from lignin and other organics. The best separation of lignin from hemicelluloses in the first filtration step was obtained using the UC005 membrane. The GE-5 and ETNA01PP membranes showed potential to purify and separate lignin from hemicelluloses. However, the feed solution of the second filtration stages (from different ultrafiltration membranes) affected the permeate flux and the separation of various extracted compounds from hemicelluloses. The GE-5 and ETNA01PP membranes gave the efficient purification of the hemicelluloses when using diafiltration. Separation of degraded xylan from glucomannan (primary spruce hemicelluloses) was also possible using membrane filtration. The best separation was achieved using the GE-5 membrane. The retention of glucomannan was three times higher than xylan retention.

Separation of Gas Bubbles from Circulation Waters and Pulp Suspensions in Open Channel Flow

The objective of this thesis was to study the removal of gases from paper mill circulation waters experimentally and to provide data for CFD modeling. Flow and bubble size measurements were carried out in a laboratory scale open gas separation channel. Particle Image Velocimetry (PIV) technique was used to measure the gas and liquid flow fields, while bubble size measurements were conducted using digital imaging technique with back light illumination. Samples of paper machine waters as well as a model solution were used for the experiments. The PIV results show that the gas bubbles near the feed position have the tendency to escape from the circulation channel at a faster rate than those bubbles which are further away from the feed position. This was due to an increased rate of bubble coalescence as a result of the relatively larger bubbles near the feed position. Moreover, a close similarity between the measured slip velocities of the paper mill waters and that of literature values was obtained. It was found that due to dilution of paper mill waters, the observed average bubble size was considerably large as compared to the average bubble sizes in real industrial pulp suspension and circulation waters. Among the studied solutions, the model solution has the highest average drag coefficient value due to its relatively high viscosity. The results were compared to a 2D steady sate CFD simulation model. A standard Euler-Euler k-ε turbulence model was used in the simulations. The channel free surface was modeled as a degassing boundary. From the drag models used in the simulations, the Grace drag model gave velocity fields closest to the experimental values. In general, the results obtained from experiments and CFD simulations are in good qualitative agreement.

Estimation of existing cable systems in generator-busbar unit and choice the optimal solution for its modernization

The aim of this master’s thesis is to develop an algorithm to calculate the cable network for heat and power station CHGRES. This algorithm includes important aspect which has an influence on the cable network reliability. Moreover, according to developed algorithm, the optimal solution for modernization cable system from economical and technical point of view was obtained. The conditions of existing cable lines show that replacement is necessary. Otherwise, the fault situation would happen. In this case company would loss not only money but also its prestige. As a solution, XLPE single core cables are more profitable than other types of cable considered in this work. Moreover, it is presented the dependence of value of short circuit current on number of 10/110 kV transformers connected in parallel between main grid and considered 10 kV busbar and how it affects on final decision. Furthermore, the losses of company in power (capacity) market due to fault situation are presented. These losses are commensurable with investment to replace existing cable system.

The concept of solution: Industry’s insights compared to theoretical views

Many manufacturing companies have started to offer complete solutions to their customers’ unique needs due to toughening competition and customer demand. Discourse on this kind of solution business is still developing, hence, there is not an established definition for the concept of solution. The aim of the study is to profoundly identify the concept of solution and to understand how the industry’s current views differ from the theoretical concepts. The describing dimensions are identified from selected 13 theoretical notions, and from responses, that the employees of five different companies have given. The 32 interview transcripts are analyzed with thematic analysis and qualitative content analysis. According to the findings, the concept of solution is characterized by integration, customization, risk-sharing, value co-creation, long-term orientation, and desired outcomes. The industry’s insights differ in terms of them all. The results illustrate, that a solution is a bundle, and the whole solution is customized on some level for a client. A solution supplier needs to be customer-focused, in which value co-creation is only a part. The solution solves the customer’s problem, and improves both the customer’s, and the supplier’s business. Neither long-term focus nor risks-sharing were directly employed to characterize the concept of solution. Differences are mainly due to the different approaches to the definitions and inexperience of the companies.

Recovery of carboxylic acids from aqueous solutions

Carboxylic acids are commonly used organic acids and have many applications in industries producing food and pharmaceutical products, surfactants and detergents. Especially formic, acetic, propionic and butyric acid are important organic chemicals. These compounds can be found in many side streams and plant effluents. Recovery costs of carboxylic acids are high when they are removed from dilute solution. Conventional processes for the recovery of carboxylic acids from aqueous solutions are classical distillation or extractive distillation, azeotropic distillation or liquid-liquid extraction. The literature part of this Master’s of Science Thesis comprises possible extractants in liquid-liquid extraction of carboxylic acids from aqueous solutions and methods for their regeneration form the extract. The experimental part of this Thesis investigates liquid-liquid extraction of carboxylic acids from aqueous solutions. The aim of this work was to find a suitable extractant for liquid-liquid extraction and suitable process conditions to recover carboxylic acids from aqueous solutions. Also, back extraction of carboxylic acids and their thermal decomposition in relation to distillation of were. Experiments showed that there is more than one possible extractant for liquid-liquid extraction of carboxylic acids. Results also showed that it is possible to separate carboxylic acids and regenerate all the used extractants by vacuum distillation at suitable temperature.

EDTA- and DTPA-functionalized silica gel and chitosan adsorbents for the removal of heavy metals from aqueous solutions

Adsorbents functionalized with chelating agents are effective in removal of heavy metals from aqueous solutions. Important properties of such adsorbents are high binding affinity as well as regenerability. In this study, aminopolycarboxylic acid, EDTA and DTPA, were immobilized on the surface of silica gel, chitosan, and their hybrid materials to achieve chelating adsorbents for heavy metals such as Co(II), Ni(II), Cd(II), and Pb(II). New knowledge about the adsorption properties of EDTA- and DTPA-functionalizedadsorbents was obtained. Experimental work showed the effectiveness, regenerability, and stability of the studied adsorbents. Both advantages and disadvantages of the adsorbents were evaluated. For example, the EDTA-functionalized chitosan-silica hybrid materials combined the benefits of the silica gel and chitosan while at the same time diminishing their observed drawbacks. Modeling of adsorption kinetics and isotherms is an important step in design process. Therefore, several kinetic and isotherm models were introduced and applied in this work. Important aspects such as effect of error function, data range, initial guess values, and linearization were discussed and investigated. The selection of the most suitable model was conducted by comparing the experimental and simulated data as well as evaluating the correspondence between the theory behind the model and properties of the adsorbent. In addition, modeling of two-component data was conducted using various extended isotherms. Modeling results for both one- and twocomponent systems supported each other. Finally, application testing of EDTA- and DTPA-functionalized adsorbents was conducted. The most important result was the applicability of DTPA-functionalized silica gel and chitosan in the capturing of Co(II) from its aqueous EDTA-chelate. Moreover, these adsorbents were efficient in various solution matrices. In addition, separation of Ni(II) from Co(II) and Ni(II) and Pb(II) from Co(II) and Cd(II) was observed in two- and multimetal systems. Lastly, prior to their analysis, EDTA- and DTPA-functionalized silica gels were successfully used to preconcentrate metal ions from both pure and salty waters