Case study on the efficacy of a lanthanum-enriched clay (Phoslock®) in controlling eutrophication in Lake Het Groene Eiland (The Netherlands)

Lake Het Groene Eiland was created in the beginning of 2008 by construction of dikes for isolating it from the surrounding 220-ha water body. This so-called claustrum of 5 ha was treated using lanthanum-modified clay (Phoslock®) to control eutrophication and mitigate cyanobacterial nuisance. Cyanobacteria chlorophyll-a were significantly lower in the claustrum than those in the reference water body, where a massive bloom developed in summer, 2008. However, PO4-P and TP did not statistically differ in these two waters. TN and NO3-N were significantly lower in the claustrum, where dense submerged macrophytes beds developed. Lanthanum concentrations were elevated after the applications of the modified clay in the claustrum, but filterable lanthanum dropped rapidly below the Dutch standard of 10.1 μg l−1. During winter, dozens of Canada geese resided at the claustrum. Geese droppings contained an average of 2 mg PO4-P g−1 dry weight and 12 mg NH3-N g−1 dry weight and might present a growing source of nutrients to the water. Constructing the claustrum enabled unrestricted bathing in subsequent three summers, as no swimming bans had to be issued due to cyanobacteria blooms. However, the role of the modified clay in this positive outcome remains unclear, and longevity of the measures questionable.

School, a Miniature of Society: Life Stories about Well-being, Education and Career Plan of Young Iranians in Finland

This thesis examines the role of the Finnish education system in education and career plan of young Iranians with refugee background in Finland. Since the influential factors that affect their education and education plans are similar to other young immigrants in Finland, it indirectly involves the future education and career of many thousand potential fresh labour forces in Finland. The goal is to realise the influence of education system and school experiences on life, and education and career plan of the participants. The analysis of the data aims at answering: 1) How the participants evaluate their education in Finland through their life stories? And why do they so? 2) What is the place of the Finnish education system, including the schools, in the life stories of the participants? And why is it so? 3) How the participants justify their education and career choices in relation to Finnish schools? And why is it so? The new elements of this study are its uniqueness in Finland in terms of topic, target group, and researcher as an ethnic insider. Multiple theories on education and career of ethnic minorities influence the study. The theoretical standpoints are acculturation, transnational migration, and narrative explanations. The data is composed of narratives about participants’ lives with especial attention to their school experiences. It employs qualitative research methodology. Face to face interview by use of open-ended questionnaire and active interviewing, and participant observation are the main methods of collecting data. It applies narrative method for analysis and presenting the data. The main results confirm significant failures in education and education plan of the participants. The shortcomings of the education system and school played important role in the failures, mainly by inability to provide a place to belong, lack of professionalism in dealing with immigrant students and motivating them. Thus, there are lack of interest in higher education and related jobs, and interest in emigrating from Finland. However, individual agency and supportive role model produce interest in higher education. To conclude, since the participants and their social capital of family, relatives, and friends do not hold a strong position in controlling participants’ lives, the role of school is the most influential in producing interest in higher education and related career.   Key words: education, career, plan, young, Iranian, refugee, narrative, story, well-being, Finland, acculturation, belonging, transnational migration

School, a Miniature of Society: Life Stories about Well-being, Education and Career Plan of Young Iranians in Finland

This thesis examines the role of the Finnish education system in education and career plan of young Iranians with refugee background in Finland. Since the influential factors that affect their education and education plans are similar to other young immigrants in Finland, it indirectly involves the future education and career of many thousand potential fresh labour forces in Finland. The goal is to realise the influence of education system and school experiences on life, and education and career plan of the participants. The analysis of the data aims at answering: 1) How the participants evaluate their education in Finland through their life stories? And why do they so? 2) What is the place of the Finnish education system, including the schools, in the life stories of the participants? And why is it so? 3) How the participants justify their education and career choices in relation to Finnish schools? And why is it so? The new elements of this study are its uniqueness in Finland in terms of topic, target group, and researcher as an ethnic insider. Multiple theories on education and career of ethnic minorities influence the study. The theoretical standpoints are acculturation, transnational migration, and narrative explanations. The data is composed of narratives about participants’ lives with especial attention to their school experiences. It employs qualitative research methodology. Face to face interview by use of open-ended questionnaire and active interviewing, and participant observation are the main methods of collecting data. It applies narrative method for analysis and presenting the data. The main results confirm significant failures in education and education plan of the participants. The shortcomings of the education system and school played important role in the failures, mainly by inability to provide a place to belong, lack of professionalism in dealing with immigrant students and motivating them. Thus, there are lack of interest in higher education and related jobs, and interest in emigrating from Finland. However, individual agency and supportive role model produce interest in higher education. To conclude, since the participants and their social capital of family, relatives, and friends do not hold a strong position in controlling participants’ lives, the role of school is the most influential in producing interest in higher education and related career.   Key words: education, career, plan, young, Iranian, refugee, narrative, story, well-being, Finland, acculturation, belonging, transnational migration

Adsorption of dissociating aromatic compounds by activated carbon: Effects of ionization on the adsorption capacity

The adsorption of three dissociating aromatic compounds on an untreated commercially available activated carbon was investigated systematically. All adsorption experiments were carried out in pH-controlled aqueous solutions. The experimental isotherms were analyzed using the homogeneous Langmuir model. The effects of surface heterogeneity were investigated via the theory of localized physical adsorption, using the Langmuir equation as the local isotherm equation and assuming a Gaussian adsorption energy distribution. A new method of utilizing the extracted parameters from the homogeneous and heterogeneous models is presented. This new approach provided a better understanding of the change in monolayer capacity and other adsorption characteristics of a carbon/ solute system with pH

Research on the BET surface area and packing of molecules on the activated carbon

Adsorption of different aromatic compounds (two of them are electrolytes) onto an untreated activated carbon (F100) is investigated. The experimental isotherms are fitted into Langmuir homogenous and heterogeneous Model. Theoretical maximum adsorption capacities that are based on the BET surface area of the adsorbent cannot be close to the real value. The affinity and the heterogeneity of the adsorption system observed to be related to the pK(a) of the solutes. The maximum adsorption capacity (Q(max)) of activated carbon for each solute dependent on the molecular area as well as the type of functional group attached on the aromatic compound and also pH of solution. The arrangement of the molecules on the carbon surface is not face down. Furthermore, it is illustrated that the packing arrangement is most likely edge to face (sorbate-sorbent) with various tilt angles. For characterization of the carbon, the N-2 and CO2 adsorption were used. X-ray Photoelectron Spectroscopy (XPS) measurement was used to surface elemental analysis of activated carbon

Effects of acidic oxidation on the porosity of coal waste-derived chars

The effects of acidic oxidation and carbonisation temperature on the pore structures of chars from coal reject were studied in this work. The oxidation reactions were carried out by refluxing coal reject samples in nitric acid solutions under various conditions. Treated and untreated samples were then carbonised at 600 degrees C. Acid concentration, residence time and reaction temperature were varied to investigate their effects on the pore structure of the resulting chars. The porosity of the carbonised coal reject samples was significantly enhanced by acidic pre-treatment. It is found that an increase in the severity of pre-oxidation (mainly by increasing the acid concentration) enhanced the pore structure of the chars significantly. It was also found that the chemistry of the nitrogen containing functional groups, brought about by acid pre-treatments, was dependent on the carbonisation temperature rather than the pre-treatment conditions. (C) 1999 Elsevier Science Ltd. All rights reserved

Estimation of adsorption capacity for dissociating and non dissociating aromatic compounds on activated carbon with different models

The process of adsorption of two dissociating and two non-dissociating aromatic compounds from dilute aqueous solutions on an untreated commercially available activated carbon (B.D.H.) was investigated systematically. All adsorption experiments were carried out in pH controlled aqueous solutions. The experimental isotherms were fitted into four different models (Langmuir homogenous Models, Langmuir binary Model, Langmuir-Freundlich single model and Langmuir-Freundlich double model). Variation of the model parameters with the solution pH was studied and used to gain further insight into the adsorption process. The relationship between the model parameters and the solution pH and pK(a) was used to predict the adsorption capacity in molecular and ionic form of solutes in other solution. A relationship was sought to predict the effect of pH on the adsorption systems and for estimating the maximum adsorption capacity of carbon at any pH where the solute is ionized reasonably well. N-2 and CO2 adsorption were used to characterize the carbon. X-ray Photoelectron Spectroscopy (XPS) measurement was used for surface elemental analysis of the activated carbon

Adsorption of aromatic compounds by activated carbon: Effects of functional groups and molecular size

The adsorption of three aromatic compounds on to an untreated carbon was investigated. The solution pH was lowered in all experiments so that all the solutes were in their molecular forms. It was shown that the difference in the maximum adsorption of the solutes was mainly a result of the difference in the sizes of the molecules and their functional groups. Further-more, it was illustrated that the packing arrangement was most likely edge-to-face (sorbate-sorbent) with various tilt angles. On the other hand, the affinity and heterogeneity of the adsorption systems were apparently related to the pK(a) values of the solutes

Effects of the solute ionization on the adsorption of aromatic compounds from dilute aqueous solutions by activated carbon

Adsorption of four dissociating aromatic compounds and one nondissociating compound on a commercial activated carbon is investigated systematically. All adsorption experiments were carried out in pH-controlled aqueous solutions. The adsorption isotherms are fitted to the binary homogeneous Langmuir model, where the concentrations of the molecular and the ionic species in the liquid phase are expressed in terms of the sum of the two and the degree of solute ionization. Examination of the relationships between the solution pH, the degree of ionization of the solutes, and the model parameters is found to give new insights into the adsorption process. Furthermore, this is used to correlate the variation of the monolayer capacity with the solution pH

A novel lanthanum-modified bentonite, Phoslock, for phosphate removal from wastewaters

Phoslock (R), a lanthanum-modified bentonite, has been investigated for phosphate uptake from synthetic and real wastewaters in laboratory and field. In laboratory tests, equilibrium and kinetics were studied at various temperatures, ionic strength, and pHs. The investigation indicated that phosphate adsorption occurs through a chemisorption process. The activation energy of the adsorption process was calculated based on pseudo-second order rate constant. The maximum adsorption capacity of Phoslock was unaffected at pH 5-7, but decreased at higher pHs. The monovalent phosphate anion, H(2)PO(4)(-), had the greatest affinity for the adsorbent surface. Furthermore, it was also shown that the activation energy was lower at a higher solution pH attributed to the loss of adsorption sites at the higher pHs while it remained unaffected by the ionic strength of the solution. A field test also demonstrated that the Phoslock works well for phosphate uptake in polluted waters. (C) 2009 Elsevier B.V. All rights reserved