Estudi per a la construcció de l'EDAR mitjançant filtres verds de la Nou de Gaià (Tarragonès)

El tractament de les aigües en nuclis menors de 2000 habitants es troba pendent de completar per part de l’Agència Catalana de l’Aigua més concretament al corresponent Pla de Sanejament d’Aigües Residuals Urbanes (PSARU). El nucli de La Nou de Gaià (al Tarragonès) es troba pendent de la construcció de la corresponent instal·lació de sanejament, projectada al 2007. Alternativament a les depuradores tradicionals basades en l’ús de formigó (o materials alternatius) i en la despesa elèctrica per assegurar una aeració i una evacuació dels fangs generats, existeixen tecnologies “toves”. Aquestes tecnologies, també conegudes com a “verdes”, es basen en imitar els sistemes naturals maximitzant el seu potencial d’autodepuració. A grans trets existeixen dos formes de depurar les aigües de forma ecològica”: llacunatges (existeix una capa d’aigua lliure) i filtres verds. El present estudi es basa en l’aplicació de filtres verds de morfologia vertical i flux subsuperficial, plantat amb canyes dels generes Scirpus o Phragmites. El resultat han estat 4 bases de 35*35 per a tractar un cabal de 150 m3/d i una població equivalent de 1272.

Treatment of oily wastewater by ultrafiltration: The effect of different operating and solution conditions

In many industries, such as petroleum production, and the petrochemical, metal, food and cosmetics industries, wastewaters containing an emulsion of oil in water are often produced. The emulsions consist of water (up to 90%), oils (mineral, animal, vegetable and synthetic), surfactants and other contaminates. In view of its toxic nature and its deleterious effects on the surrounding environment (soil, water) such wastewater needs to be treated before release into natural water ways. Membrane-based processes have successfully been applied in industrial applications and are considered as possible candidates for the treatment of oily wastewaters. Easy operation, lower cost, and in some cases, the ability to reduce contaminants below existing pollution limits are the main advantages of these systems. The main drawback of membranes is flux decline due tofouling and concentration polarisation. The complexity of oil-containing systems demands complementary studies on issues related to the mitigation of fouling and concentration polarisation in membranebased ultrafiltration. In this thesis the effect of different operating conditions (factors) on ultrafiltration of oily water is studied. Important factors are normally correlated and, therefore, their effect should be studied simultaneously. This work uses a novel approach to study different operating conditions, like pressure, flow velocity, and temperature, and solution properties, like oil concentration (cutting oil, diesel, kerosene), pH, and salt concentration (CaCl2 and NaCl)) in the ultrafiltration of oily water, simultaneously and in a systematic way using an experimental design approach. A hypothesis is developed to describe the interaction between the oil drops, salt and the membrane surface. The optimum conditions for ultrafiltration and the contribution of each factor in the ultrafiltration of oily water are evaluated. It is found that the effect on permeate flux of the various factors studied strongly depended on the type of oil, the type of membrane and the amount of salts. The thesis demonstrates that a system containing oil is very complex, and that fouling and flux decline can be observed even at very low pressures. This means that only the weak form of the critical flux exists for such systems. The cleaning of the fouled membranes and the influence of different parameters (flow velocity, temperature, time, pressure, and chemical concentration (SDS, NaOH)) were evaluated in this study. It was observed that fouling, and consequently cleaning, behaved differently for the studied membranes. Of the membranes studied, the membrane with the lowest propensity for fouling and the most easily cleaned was the regenerated cellulose membrane (C100H). In order to get more information about the interaction between the membrane and the components of the emulsion, a streaming potential study was performed on the membrane. The experiments were carried out at different pH and oil concentration. It was seen that oily water changed the surface charge of the membrane significantly. The surface charge and the streaming potential during different stages of filtration were measured and analysed being a new method for fouling of oil in this thesis. The surface charge varied in different stages of filtration. It was found that the surface charge of a cleaned membrane was not the same as initially; however, the permeability was equal to that of a virgin membrane. The effect of filtration mode was studied by performing the filtration in both cross-flow and deadend mode. The effect of salt on performance was considered in both studies. It was found that salt decreased the permeate flux even at low concentration. To test the effect of hydrophilicity change, the commercial membranes used in this thesis were modified by grafting (PNIPAAm) on their surfaces. A new technique (corona treatment) was used for this modification. The effect of modification on permeate flux and retention was evaluated. The modified membranes changed their pore size around 33oC resulting in different retention and permeability. The obtained results in this thesis can be applied to optimise the operation of a membrane plant under normal or shock conditions or to modify the process such that it becomes more efficient or effective.

Project «Water and Environment»: Improving educational practices in the aquatic environment

The project "Water and Environment"for the improvement of educational practices in the aquatic environment, is a research project led by four members of the Research Group of Physical Education at the University of Vic (GREF) experts in water activities. The aim is to train the technicians who teach swimming during school hours. The training is based on improving water treatment practices and competence to face a contradictory scene where clubs develop educational content and where schools transfer to clubs part of its educational activity to contribute significantly and positively to water activities fitting the educational curriculum.

Wet oxidation of recalcitrant lignin waters: Experimental and kinetic studies

The dissertation is based on four articles dealing with recalcitrant lignin water purification. Lignin, a complicated substance and recalcitrant to most treatment technologies, inhibits seriously pulp and paper industry waste management. Therefore, lignin is studied, using WO as a process method for its degradation. A special attention is paid to the improvement in biodegradability and the reduction of lignin content, since they have special importance for any following biological treatment. In most cases wet oxidation is not used as a complete ' mineralization method but as a pre treatment in order to eliminate toxic components and to reduce the high level of organics produced. The combination of wet oxidation with a biological treatment can be a good option due to its effectiveness and its relatively low technology cost. The literature part gives an overview of Advanced Oxidation Processes (AOPs). A hot oxidation process, wet oxidation (WO), is investigated in detail and is the AOP process used in the research. The background and main principles of wet oxidation, its industrial applications, the combination of wet oxidation with other water treatment technologies, principal reactions in WO, and key aspects of modelling and reaction kinetics are presented. There is also given a wood composition and lignin characterization (chemical composition, structure and origin), lignin containing waters, lignin degradation and reuse possibilities, and purification practices for lignin containing waters. The aim of the research was to investigate the effect of the operating conditions of WO, such as temperature, partial pressure of oxygen, pH and initial concentration of wastewater, on the efficiency, and to enhance the process and estimate optimal conditions for WO of recalcitrant lignin waters. Two different waters are studied (a lignin water model solution and debarking water from paper industry) to give as appropriate conditions as possible. Due to the great importance of re using and minimizing the residues of industries, further research is carried out using residual ash of an Estonian power plant as a catalyst in wet oxidation of lignin-containing water. Developing a kinetic model that includes in the prediction such parameters as TOC gives the opportunity to estimate the amount of emerging inorganic substances (degradation rate of waste) and not only the decrease of COD and BOD. The degradation target compound, lignin is included into the model through its COD value (CODligning). Such a kinetic model can be valuable in developing WO treatment processes for lignin containing waters, or other wastewaters containing one or more target compounds. In the first article, wet oxidation of "pure" lignin water was investigated as a model case with the aim of degrading lignin and enhancing water biodegradability. The experiments were performed at various temperatures (110 -190°C), partial oxygen pressures (0.5 -1.5 MPa) and pH (5, 9 and 12). The experiments showed that increasing the temperature notably improved the processes efficiency. 75% lignin reduction was detected at the lowest temperature tested and lignin removal improved to 100% at 190°C. The effect of temperature on the COD removal rate was lower, but clearly detectable. 53% of organics were oxidized at 190°C. The effect of pH occurred mostly on lignin removal. Increasing the pH enhanced the lignin removal efficiency from 60% to nearly 100%. A good biodegradability ratio (over 0.5) was generally achieved. The aim of the second article was to develop a mathematical model for "pure" lignin wet oxidation using lumped characteristics of water (COD, BOD, TOC) and lignin concentration. The model agreed well with the experimental data (R2 = 0.93 at pH 5 and 12) and concentration changes during wet oxidation followed adequately the experimental results. The model also showed correctly the trend of biodegradability (BOD/COD) changes. In the third article, the purpose of the research was to estimate optimal conditions for wet oxidation (WO) of debarking water from the paper industry. The WO experiments were' performed at various temperatures, partial oxygen pressures and pH. The experiments showed that lignin degradation and organics removal are affected remarkably by temperature and pH. 78-97% lignin reduction was detected at different WO conditions. Initial pH 12 caused faster removal of tannins/lignin content; but initial pH 5 was more effective for removal of total organics, represented by COD and TOC. Most of the decrease in organic substances concentrations occurred in the first 60 minutes. The aim of the fourth article was to compare the behaviour of two reaction kinetic models, based on experiments of wet oxidation of industrial debarking water under different conditions. The simpler model took into account only the changes in COD, BOD and TOC; the advanced model was similar to the model used in the second article. Comparing the results of the models, the second model was found to be more suitable for describing the kinetics of wet oxidation of debarking water. The significance of the reactions involved was compared on the basis of the model: for instance, lignin degraded first to other chemically oxidizable compounds rather than directly to biodegradable products. Catalytic wet oxidation of lignin containing waters is briefly presented at the end of the dissertation. Two completely different catalysts were used: a commercial Pt catalyst and waste power plant ash. CWO showed good performance using 1 g/L of residual ash gave lignin removal of 86% and COD removal of 39% at 150°C (a lower temperature and pressure than with WO). It was noted that the ash catalyst caused a remarkable removal rate for lignin degradation already during the pre heating for `zero' time, 58% of lignin was degraded. In general, wet oxidation is not recommended for use as a complete mineralization method, but as a pre treatment phase to eliminate toxic or difficultly biodegradable components and to reduce the high level of organics. Biological treatment is an appropriate post treatment method since easily biodegradable organic matter remains after the WO process. The combination of wet oxidation with subsequent biological treatment can be an effective option for the treatment of lignin containing waters.

Evaluation of the effect of the seed extract of Moringa oleifera Lam over the efficiency of organic filters in wastewater treatment of dairy cattle breeding

This study aimed to evaluate the effect of Moringa oleifera Lam extract on the removal of total solids (TS), total suspended solids (TSS) and chemical oxygen demand (COD), in different filter media for treating wastewater of dairy cattle breeding (DCW). The moringa seed extract was obtained by grinding 50 g of seeds in one liter of distilled water and, after passing the solution through a quantitative paper filter of 25 microns, 60 mL of the extract were added to wastewater from cattle breeding before the filtration process in organic filters made of thin coal, bamboo leaves, eucalyptus leaves, gliricidia branches and sawdust. This was followed by the completely randomized experimental design, adopting a factorial of 5 x 2. Aliquots of filtered effluent were collected and the total solids (TS) concentrations, total suspended solids (TSS) and chemical oxygen demand (COD) were determined. It was found that the increase in the efficiency of removal of COD and total solids can be attributed to the coagulating power of the moringa seed extract, wherein the filter medium with bamboo leaves presented the best performance, showing potential for use as alternative filter material in the primary treatment of DCW.

Electrocoagulation in the treatment of industrial waters and wastewaters

Chemical coagulation is commonly used in raw water and wastewater treatment plants for the destabilisation of pollutants so that they can be removed in the subsequent separation processes. The most commonly used coagulation chemicals are aluminium and iron metal salts. Electrocoagulation technology has also been proposed for the treatment of raw waters and wastewaters. With this technology, metal cations are produced on the electrodes via electrolysis and these cations form various hydroxides in the water depending on the water pH. In addition to this main reaction, several side reactions, such as hydrogen bubble formation and the reduction of metals on cathodes, also take place in the cell. In this research, the applications of electrocoagulation were investigated in raw water treatment and wastewater applications. The surface water used in this research contained high concentrations of natural organic matter (NOM). The effect of the main parameters – current density, initial pH, electric charge per volume, temperature and electrolysis cell construction – on NOM removal were investigated. In the wastewater treatment studies, the removal of malodorous sulphides and toxic compounds from the wastewaters and debarking effluents were studied. Also, the main parameters of the treatment, such as initial pH and current density, were investigated. Aluminium electrodes were selected for the raw water treatment, whereas wastewaters and debarking effluent were treated with iron electrodes. According to results of this study, aluminium is more suitable electrode material for electrocoagulation applications because it produces Al(III) species. Metal ions and hydroxides produced by iron electrodes are less effective in the destabilisation of pollutants because iron electrodes produce more soluble and less charged Fe(II) species. However, Fe(II) can be effective in some special applications, such as sulphide removal. The resulting metal concentration is the main parameter affecting destabilisation of pollutants. Current density, treatment time, temperature and electrolysis cell construction affect the dissolution of electrodes and hence also the removal of pollutants. However, it seems that these parameters have minimal significance in the destabilization of the pollutants besides this effect (in the studied range of parameters). Initial pH and final pH have an effect on the dissolution of electrodes, but they also define what aluminium or iron species are formed in the solution and have an effect on the ζ-potential of all charged species in the solution. According to the results of this study, destabilisation mechanisms of pollutants by electrocoagulation and chemical coagulation are similar. Optimum DOC removal and low residual aluminium can be obtained simultaneously with electrocoagulation, which may be a significant benefit of electrocoagulation in surface water treatment compared to chemical coagulation. Surface water treatment with electrocoagulation can produce high quality water, which could be used as potable water or fresh water for industrial applications. In wastewater treatment applications, electrocoagulation can be used to precipitate malodorous sulphides to prevent their release into air. Technology seems to be able to remove some toxic pollutants from wastewater and could be used as pretreatment prior to treatment at a biological wastewater treatment plant. However, a thorough economic and ecological comparison of chemical coagulation and electrocoagulation is recommended, because these methods seem to be similar in pollutant destabilisation mechanisms, metal consumption and removal efficiency in most applications.

Electro-Oxidation Treatment of Pulp and Paper Mill Circulating Waters and Wastewaters

Interest in water treatment by electrochemical methods has grown in recent years. Electrochemical oxidation has been applied particularly successfully to degrade different organic pollutants and disinfect drinking water. This study summarizes the effectiveness of the electrochemical oxidation technique in inactivating different primary biofilm forming paper mill bacteria as well as sulphide and organic material in pulp and paper mill wastewater in laboratory scale batch experiments. Three different electrodes, borondoped diamond (BDD), mixed metal oxide (MMO) and PbO2, were employed as anodes. The impact on inactivation efficiency of parameters such as current density and initial pH or chloride concentration of synthetic paper machine water was studied. The electrochemical behaviour of the electrodes was investigated by cyclic voltammetry with MMO, BDD and PbO2 electrodes in synthetic paper mill water as also with MMO and stainless steel electrodes with biocides. Some suggestions on the formation of different oxidants and oxidation mechanisms were also presented during the treatment. Aerobic paper mill bacteria species (Deinococcus geothermalis, Pseudoxanthomonas taiwanensis and Meiothermus silvanus) were inactivated effectively (>2 log) at MMO electrodes by current density of 50 mA/cm2 and the time taken three minutes. Increasing current density and initial chloride concentration of paper mill water increased the inactivation rate of Deinococcus geothermalis. The inactivation order of different bacteria species was Meiothermus silvanus > Pseudoxanthomonas taiwanensis > Deinococcus geothermalis. It was observed that inactivation was mainly due to the electrochemically generated chlorine/hypochlorite from chloride present in the water and also residual disinfection by chlorine/hypochlorite occurred. In real paper mill effluent treatment sulphide oxidation was effective with all the different initial concentrations (almost 100% reduction, current density 42.9 mA/cm2) and also anaerobic bacteria inactivation was observed (almost 90% reduction by chloride concentration of 164 mg/L and current density of 42.9 mA/cm2 in five minutes). Organic material removal was not as effective when comparing with other tested techniques, probably due to the relatively low treatment times. Cyclic voltammograms in synthetic paper mill water with stainless steel electrode showed that H2O2 could be degraded to radicals during the cathodic runs. This emphasises strong potential of combined electrochemical treatment with this biocide in bacteria inactivation in paper mill environments.

Treatment of Fe-containing Acid Mine Waters in Fixed Bed Adsorption Column with Calcite Side-Stone

The acid mining drainage is considered the most significant environmental pollution problem around the world for the extensive formation acidic leachates containing heavy metals. Adsorption is widely used methods in water treatment due to it easy operation and the availability of a wide variety of commercial adsorbent (low cost). The primary goal of this thesis was to investigate the efficiency of neutralizing agents, CaCO3 and CaSiO3, and metal adsorption materials with unmodified limestone from Company Nordkalk Oy. In addition to this, the side materials of limestone mining were tested for iron adsorption from acidic model solution. This study was executed at Lappeenranta University of Technology, Finland. The work utilised fixed-bed adsorption column as the main equipment and large fluidized column. Atomic absorption spectroscopy (AAS) and x-ray diffraction (XRD) was used to determine ferric removal and the composition of material respectively. The results suggest a high potential for the studied materials to be used a low cost adsorbents in acid mine drainage treatment. From the two studied adsorbents, the FS material was more suitable than the Gotland material. Based on the findings, it is recommended that further studies might include detailed analysis of Gotland materials.

Lämpötilan vaikutus oksaalihapon hapetukseen pulssitetulla koronapurkauksella

Tutkimuksen tarkoituksena oli kartoittaa lämpötilan vaikutusta veden orgaanisten haitta-aineiden hapetuksessa PCD-menetelmällä. Kokeita tehtiin näytteiden eri alkulämpötiloilla. Malliyhdisteenä kokeissa käytettiin oksaalihappoa. Teoriaosuudessa käsiteltiin pulssittaista koronapurkausta ilmiönä. Lisäksi tarkasteltiin, kuinka PCD-menetelmällä muodostuu hapettimia neste-kaasufaasissa. Syntyvistä hapettimista keskityttiin otsoniin ja hydroksyyliradikaaliin. Kokeellisessa osuudessa esiteltiin käytetty PCD-laitteisto. Esittelyn jälkeen siirryttiin hapetuskokeiden kuvaamiseen ja analyysin suorittamiseen titrauksella. Lopuksi koottiin tulokset. Tutkimuksissa prosessin hapetustehon havaittiin heikentyvän lämpötilan noustessa tutkitulla lämpötila-alueella, mikä voi selittyä kaasufaasissa muodostuvan otsonin heikentyvällä liukoisuudella. Tuloksia voidaan pitää viitteellisinä, ja selkeän mallin muodostamiseksi tarvitaan jatkotutkimuksia laajemmalla lämpötila-alueella tarkasti toistettavilla koejärjestelyillä.

Formation of nitrates in water in presence of formate and oxalate treated with pulsed corona discharge (PCD)

Tavallisten hapetusmenetelmien sijasta kehittyneitä hapetusmenetelmiä (AOP) on kehitetty yhä enemmän, jotta hapetusprosessista tulisi kannattavampi, tehokkaampi, ympäristöystävällisempi ja sitä voitaisiin hyödyntää laajalti eri paikoissa. Uusi teknologia, joka käyttää otsonia ja hydroksyyliradikaalia sähköimpulssien kanssa, on yksi mahdollinen tehokkaampi vedenkäsittelymentelmä. Kyseistä menetelmää kutsutaa pulsed corona discharge (PCD) -menetelmäksi, joka käyttää prosessissa muodostuvia otsonia ja hydroksyyliradikaalia hapettavina tekijöinä. Tässä työssä tutkittiin nitraatin muodostumista vedessä, kun vettä käsiteltiin PCD-laitteessa ja, kun oksalaatti- ja formaatti-ioneja oli sekoittuneina veteen. Nitraatteja muodostuu PCD–laitteessa veteen, kun ilman typpi reagoi hapettimina toimivien otsonin ja hydroksyyliradikaalin kanssa. Aiemmissa tutkimuksissa nitraatin muodostumisen on todistettu parantuvan, kun karboksyylihapot muurahais- ja oksaalihappo ovat sekoittuneina veteen. Tässä tutkimuksessa tarkoituksena oli tutkia, miten formaatti- ja oksalaatti-ionien, joiden pitoisuudet olivat 0 ppm, 50 ppm ja 100 ppm, läsnäolo vedessä vaikuttaa nitraatin muodostumiseen. PCD-kokeista saadut näytteet analysoitiin ionikromatografilla. Kyseisessä tutkimuksessa nitraatin muodostuminen oli samansuuruista jokaisessa kokeessa hapetusajan kasvaessa samalla, kun otettujen näytteiden pH-arvot laskivat. Tuloksena voitiin pitää sitä, ettei formaatti- tai oksalaatti-ioneilla ollut vaikutusta nitraatti-ionien muodostumiseen.

Dialysis water treated by reverse osmosis decreases the levels of C-reactive protein in uremic patients

Atherosclerosis is a major complication of chronic renal failure. Microinflammation is involved in atherogenesis and is associated with uremia and dialysis. The role of dialysate water contamination in inducing inflammation has been debated. Our aim was to study inflammatory markers in patients on chronic dialysis, before and 3 to 6 months after switching the water purification system from deionization to reverse osmosis. Patients had demographic, clinical and nutritional information collected and blood drawn for determination of albumin, ferritin, C-reactive protein (CRP), interleukin-6, and tumor necrosis factor-alpha in both situations. Acceptable levels of water purity were less than 200 colony-forming units of bacteria and less than 1 ng/ml of endotoxin. Sixteen patients died. They had higher median CRP (26.6 vs 11.2 mg/dl, P = 0.007) and lower median albumin levels (3.1 vs 3.9 g/l, P < 0.05) compared to the 31 survivors. Eight patients were excluded because of obvious inflammatory conditions. From the 23 remaining patients (mean age ± SD: 51.3 ± 13.9 years), 18 had a decrease in CRP after the water treatment system was changed. Overall, median CRP was lower with reverse osmosis than with deionization (13.2 vs 4.5 mg/l, P = 0.022, N = 23). There was no difference in albumin, cytokines, subjective global evaluation, or clinical and biochemical parameters. In conclusion, uremic patients presented a clinically significant reduction in CRP levels when dialysate water purification system switched from deionization to reverse osmosis. It is possible that better water treatments induce less inflammation and eventually less atherosclerosis in hemodialysis patients.

Suljetun jätetäytön kaatopaikkavesien käsittelyvaihtoehtojen vertailu

Hajoaminen kaatopaikalla tapahtuu fysikaalisten, kemiallisten ja biologisten prosessien avulla. Nämä prosessit voivat kestää vuosista jopa vuosikymmeniin. Näiden prosessien kehittymistä ajan saatossa kuvataan jätetäytön eri hajoamisvaiheiden avulla. Kaatopaikan eri toiminnoista syntyvät vesivirrat ovat laadultaan ja määrältään hyvin erilaisia. Suotovesi syntyy jätetäytön läpi suotautuvasta vedestä ja on yleisesti ottaen suurin kaatopaikkavesien kuormituksen aiheuttaja. Suotoveden sisältämien pitoisuuksien tiedetään laskevan kun jätteen loppusijoitus on lopetettu ja kun jätetäyttö on suljettu pintarakentein. Mitä pidemmälle jätetäytön hajoaminen on edennyt, sitä pienemmät suotoveden pitoisuudet ovat. Hyvä käytäntö on erottaa erityyppiset kaatopaikkavedet toisistaan ja käsitellä ne niiden vaatimalla tavalla. Diplomityön tarkoitus on löytää ympäristöystävällisin ja taloudellisin keino suljetun jätetäytön suotovesien sekä muiden vähintään yhtä laimeiden kaatopaikkavesien käsittelemiseksi. Vertailtavia käsittelymenetelmiä ovat kunnallisella jätevedenpuhdistamolla ja juurakkopuhdistamolla käsittely. Työn tulos on, että eri tyyppisillä juurakkopuhdistamoilla voidaan tehokkaasti käsitellä kaatopaikkavesiä. Empiirisen osan tarkastelu osoittaa, että hyvin pienien haitta-aine- ja ravinnepitoisuuksien käsittelyssä juurakkopuhdistamo on ympäristöystävällisempi sekä taloudellisempi kunnalliseen jätevedenpuhdistamoon verrattuna.

Water chemistry management for future large experimental facilities

The thesis focuses on the water chemistry of the experimental test facilities and their reference VVER reactors. The main objective of the thesis is to provide recommendations for water chemistry management for laboratory facilities (VEERA, PACTEL) simulating the VVERs and for the large future facilities of the Lappeenranta University of Technology. In the beginning, the concept of nuclear power generation and the applicability of the nuclear power usage is discussed. Next, different water chemistry and water purification systems in primary and secondary circuits currently used at the power plant have been outlined. Also the construction geometry and design of test facilities PACTEL and VEERA, as well as the operation principles of their main equipment has been described. Finally, the appropriate water chemistry and water treatment system have been proposed for the existing and future experimental facilities of LUT.

Kohti vesiensuojelun aikaa; veden laadun muutokset eteläisimmällä Saimaalla

Työn tarkoituksena on ollut tutkia vesianalytiikan kehitystä Suomessa, arvioida rutiini-analytiikan luotettavuutta, selvittää eteläisimmän Saimaan jätevesikuormituksen kehitys ja siihen vaikuttaneet tekijät, laatia aikasarjat eräiden tutkimusalueen keskeisten veden laadun seurantapaikkojen veden laadun kehityksestä ja esittää keinoja veden laadun kehityksen kuvaa¬miseksi tiivistämällä suuri havaintomateriaali yksinkertaisiksi tunnusluvuiksi. Työssä käsiteltä¬vä aikajakso alkaa 1900-luvun alusta ja päättyy vuoteen 1998. Tutkimus on osa laajempaa ko¬konaisuutta. Tutkimusalue käsittää Vuoksen vesistön keskusjärven, Saimaan, eteläisimmät osat eli Pien-Saimaan, Suur-Saimaan, Vuoksen niskan ja Haapaveden altaat sekä vesistön purku¬-uoman, Vuoksen virran (ks. kuvat 5.1. ja 5.2.). Veden laatu alueen luonnontilaisilla alueilla on luokiteltavissa osin oligotrofiseksi, osin lievästi dysoligotrofiseksi. Sadan viimeisen vuoden aikana teollinen toiminta on muuttanut sitä voimakkaasti. Vesiensuojeluun on eteläisimmän Saimaan alueella investoitu yli 1,5 miljardia markka viimeisten noin 30 vuoden aikana. Investointien tuloksena kuormitus on laskenut oleellisesti 1960-luvun maksimikuormituksesta. Jätevesien purkuvesistön veden laatu on tänä aikana myös merkittävästi parantunut. Tämä on osoitettu veden laadun seurantatuloksista tehtyjen erilaisten tarkastelujen avulla (aikasarjadiagrammit, tilasto tarkastelut, indeksilukuluokitukset, PCA- ja PLS- ja DPLS- monimuuttujamallinnukset). Nykyisin veden laatu on lähes koko tutkimusalu¬eella vähintään tyydyttävä. Fysikaalis-kemiallisen veden laadun seurannan historia on Suomessa kansainvälisesti ja kansallisesti pitkä, ja Saimaalta voidaan veden laadun kehitystä arvioida luotettavasti 40 vuoden ajalta. Tutkimusmetodiikat vesitutkimusten pioneerimaissa ovat olleet samankaltaisia ja niiden perusteella on laadittu myös eurooppalaisen vedenlaadunseurannan suositukset. Vaikka tulevai¬suudessa vesistöä ja sen tilan kehitystä on tarkasteltava ekologisena kokonaisuutena, ei tätä voida tehdä ilman nykyisen kaltaista monitorointia. Teollisuuden jätevesikuormitus on laskenut neljännesvuosisadan aikana hyvin merkittä¬västi tavalla, joka vielä kymmenkunta vuotta sitten tuntui saavuttamattomalta. Saimaan. kuten muunkin Suomen metsäteollisuuden taso onkin kansainvälisesti korkea ja täyttää jo nyt kuormi¬tuksen suhteen lähes 2000-luvun alun BAT-tekniikan vaatimukset. Veden laatu ei kuitenkaan ole kuormitetuilla alueilla kaikkialla vielä hyvä, joten vesiensuojeluun on edelleen panostettava, kun tavoitteena on vesien hyvä ekologinen tila. Vesistöstä käsin tarkasteltuna hitaasti hajoavan orgaanisen aineen määrän vähentäminen vedestä on oltava seuraavana tavoitteena. Tätä tukee myös BAT-tekniikan tarkastelu.

Solutions to water problems in the bottom of the pyramid market

Solving the water crisis in the developing world is a critical issue. Four billion people in the globe, so called the Base of the Pyramid (BoP) population suffer from inadequate access to safe drinking water, while millions die daily from waterborne diseases and lack of clean water. The BoP people desperately need to obtain a satisfactory access to safe water sources. In order to address the issue, this research has been carried out. To provide holistic consideration to the matter, comprehensive exploration of various causes of the water crisis and its impacts in developing countries were discussed. Then, various viable and relevant solutions to the problem have been thoroughly scrutinized, including scientific, rational, practical and speculative approaches, examination of existing methods, technologies and products at the BoP water market. The role of clean water to the sustainable development was specifically featured. The paper also has studied social and economic factors, actors and circumstances which affect the market development of clean water technologies in the BoP. Possibilities and potentials of successful business between foreign water enterprises and BoP consumers were considered, while primary obstacles are deliberated on, with suggestion of the ways to tackle them. Technologies and products which are needed by the poor must be affordable, sustainable and of an appropriate quality. The crucial question of technology transfer was soundly discussed with pointing out main hindrances on the way of its implementation between the developed and developing world. The means to overcome these barriers were properly observed as well. To explore to some extent the possibility and feasibility of technology transfer from Finland to the BoP sector, 3 case study analyses have been implemented. Personal discussions in form of interviews were conducted at Kemira, Outotec and Fenno Water, Finnish water treatment and supply enterprises. The results of the interviews shed light on the specific practical matters, actual obstacles and potential solutions of the technology transfer from Finland to low-income countries.