Izabela Michalak

State of the art for the biosorption process--a review.

In recent years, biosorption process has become an economic and eco-friendly alternative treatment technology in the water and wastewater industry. In this light, a number of biosorbents were developed and are successfully employed for treating various pollutants including metals, dyes, phenols, fluoride, and pharmaceuticals in solutions (aqueous/oil). However, still there are few technical barriers in the biosorption process that impede its commercialization and thus to overcome these problems there has been a steadily growing interest in this research field. This resulted in large numbers of publications and patents each year. This review reports the state of the art in biosorption research. In this review, we provide a compendium of know-how in laboratory methodology, mathematical modeling of equilibrium and kinetics, identification of the biosorption mechanism. Various mathematical models of biosorption were discussed: the process in packed-bed column arrangement, as well as by suspended biomass. Particular attention was paid to patents in biosorption and pilot-scale systems. In addition, we provided future aspects in biosorption research.

Algae as production systems of bioactive compounds

Algal extracts are gaining increasing interest due to their unique composition and possibilities of wide industrial applications. Various extraction techniques are used for conversion of algal biomass into extracts. Recently, attention of scientists has been paid to novel methods, such as enzyme‐assisted extraction, microwave‐assisted extraction, pressurized liquid extraction, supercritical fluid extraction, and ultrasound‐assisted extraction, which enable the extraction of biologically active compounds without their degradation. In this review, the properties of biologically active compounds extracted from the biomass of algae reported in the literature are presented in a structured way. Algal extracts contain compounds such as carbohydrates, proteins, minerals, oil, fats, polyunsaturated fatty acids as well as bioactive compounds such as antioxidants (polyphenols, tocopherols [vitamin E], vitamin C, mycosporine‐like amino acids), and pigments, such as carotenoids (carotene xanthophyll), chlorophylls, and phycobilins (phycocyanin, phycoerythrin), which possess antibacterial, antiviral, antifungal, antioxidative, anti‐inflammatory, and antitumor properties. Finally, we assemble a list of applications of algal extracts in different developing branches of agriculture (biostimulants, bioregulators, feed additives) and in pharmaceutical industry.

Algal extracts: Technology and advances

A number of studies on the development of a variety of extraction techniques to produce algal extracts have been reported. At present, attention is paid to the production of algal extracts without resorting to toxic organic solvents or aggressive extraction conditions that could deteriorate biologically active compounds found in algal cells. In this review, we present a critical overview of novel techniques to extract biologically active compounds from algae without their degradation. We compare the advantages and disadvantages of classic and novel extraction techniques such as supercritical fluid extraction, microwave‐assisted extraction, ultrasound‐assisted extraction, enzyme‐assisted extraction, pressurized liquid extraction. Additionally, we review the different biomass pretreatment methods. Products derived from algae are safe to plants, animals, and human. Therefore, they can be used in modern agriculture (biostimulants, bioregulators, feed additives) and in food, cosmetic, and pharmaceutical industries.

Hair analysis in health assessment

BACKGROUND Hair analysis is used for estimation of the nutritional status of individuals. In the present work, a systematic review on the relation between the mineral composition of hair and the physical or mental disorders is discussed. Detailed information of examined populations, methods of sample preparations and analytical techniques are presented. METHODS A systematic literature search in four electronic databases Scopus, PubMed, Web of Science and Medline (from 1997 to 2012/01/31) for English language articles was performed. In addition, a reference list and manual search was undertaken. RESULTS The following number of studies was included: 66. Most of the authors reported that there exists a correlation between deficiency or excess of some elements in hair and occurrence of some diseases, such as: autism, cancer, hypertension, myocardial infarction, kidney disease and diabetes mellitus. However, not all results were consistent. CONCLUSIONS Most of the authors concluded that the profile of hair mineral imbalance might be useful as a diagnostic tool for the early diagnosis of many diseases. However, it seems that there is a need to standardize sample preparation procedures, in particular washing and mineralization methods.

Inter-relationship between elements in human hair: the effect of gender.

The aim of the present work was to examine the inter-relationship between elements in human hair depending on gender. In the whole population, the following groups of correlated elements were identified: alkaline earth metals (Ba, Ca, Mg, Sr), major microelements (Cu, Mn, Si, Zn) and La, Ti. In the subpopulation of males, the (Ag, Al, As, Fe) group was additionally included, whereas in the group of females (Ag, Al, Fe, Zr) was included. The group of alkali metals (Li, Na, K) and P was particularly visible in the group of males. In the group of females correlations among (Al, Co, Fe, K, Ti) were stronger than in males. In both sexes correlations between Mo, B and V (in females additionally Bi was present) and Bi-Co were found. Only in hair of males (Cd, Fe, Mn) and (Cu, Na, P) were detected, and the group of (As, Co, Cr, Fe, K, Ti) was detected only in females.

Effect of macroalgae enriched with microelements on egg quality parameters and mineral content of eggs, eggshell, blood, feathers and droppings

This study presents results obtained from feeding experiment on laying hens, which were fed with the diet supplemented with two marine macroalgae: Enteromorpha prolifera and Cladophora sp., enriched with microelements [Cu(II), Zn(II), Co(II), Mn(II), Cr(III)]. The applicability of the preparation was tested on five experimental groups of laying hens and one control group. In the control group, microelements were supplemented in the inorganic form, whereas in experimental groups, Cu, Zn, Co, Mn and Cr were replaced by macroalgae enriched with a given microelement ion. During feeding experiment, weight of laying hens, weight of eggs, eggshell thickness and mineral content of blood, feathers, droppings, eggs content (separately yolk and egg white) and eggshell were measured. Also egg number was counted and microclimate (temperature and relative humidity) was monitored. Supplementing bio-metallic feed additives to the diet of laying hens resulted in higher microelement transfer to eggs and enhanced the colour of yolk. It was also found that the presence of Enteromorpha prolifera and Cladophora sp. in laying hens diet influenced advantageously eggs weight, eggshell thickness as well as body weight of hens. On the basis of these results, it could be concluded that Enteromorpha prolifera and Cladophora sp. enriched with microelement ions could be potentially used as mineral feed additives in laying hens feeding.

Interactions of metal cations with anionic groups on the cell wall of the macroalga Vaucheria sp.

The aim of this article was to investigate the interactions of metal cations in aqueous solutions with the biomass of the freshwater macroalga Vaucheria sp. This problem is important when elaborating new applications of biosorption, e.g. the production of mineral feed additives for livestock from the biomass of algae enriched with microelement ions. Potentiometric titration was applied as a quick and cheap screening test to search for new efficient biosorbents. It revealed a variety of functional groups capable of cation exchange on the macroalgal surface, including carboxyl, phosphate, hydroxyl or amino groups. Fourier transform infrared spectroscopy on natural and chromium‐loaded Vaucheria sp. confirmed that carboxyl groups played a dominant role in the biosorption. The study also showed that Ca(II), Na(I), K(I), and Mg(II) ions were released from the biomass after biosorption of Cu(II), Mn(II), Zn(II), and Co(II) ions, indicating that ion exchange was a key mechanism in the biosorption of metal ions by Vaucheria sp. biomass. It was noticed that the mass of the microelement cations bound by the macroalga was proportional to the total mass of light metal ions [Na(I), K(I), Ca(II), and Mg(II)] released from the biomass.

Using ICP-OES and SEM-EDX in biosorption studies

AbstractWe have compared the analytical results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and by scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) in order to explore the mechanism of metal ions biosorption by biomass using two independent methods. The marine macroalga Enteromorpha sp. was enriched with Cu(II), Mn(II), Zn(II), and Co(II) ions via biosorption, and the biosorption capacity of alga determined from the solution and biomass composition before and after biosorption process was compared. The first technique was used to analyze the composition of the natural and metal-loaded biomass, and additionally the composition of the solution before and after biosorption. The second technique was used to obtain a picture of the surface of natural and metal ion-loaded macroalgae, to map the elements on the cell wall of dry biomass, and to determine their concentration before and after biosorption. ICP-OES showed a better precision and lower detection limit than EDX, but SEM-EDX gave more information regarding the sample composition of Enteromorpha sp. Both techniques confirmed that biosorption is a surface phenomenon, in which alkali and alkaline earth metal ions were exchanged by metal ions from aqueous solution. FigureThe advantages and disadvantages of ICP-OES and SEM-EDX techniques

The effect of dietary habits on mineral composition of human scalp hair.

In the present work, hair mineral analysis of 117 individuals was carried out. The subjects were asked to fill a questionnaire concerning their dietary habits. The content of minerals in hair was determined by ICP-OES (macroelements) and ICP-MS technique (micro-, toxic and other trace elements). The results were elaborated statistically by Statisticaver. 8.0. It was found that consuming highly processed food causes increased levels of e.g. Na and P in hair, intake of slimming preparation resulted in increased content of Al, Cr, Ti, taking in laxative agents caused lower level of Pb (this element was probably eliminated by other excretory routes). Individuals which declared the use of analgesic agents had more Si in their hair. Drinking coffee was related with higher level of Al, Ni, S and Ti and lower Pb in hair. Drinking tea caused reduction in the level of Hg. These results show that hair mineral content reflects exposure of elements from the diet.

Exposure to metals from orthodontic appliances by hair mineral analysis

The aim of the present work was to investigate the exposure of patients to metals released from orthodontic appliances in situ. The paper reports the results of biocompatibility studies of orthodontic appliances by an in vivo method using hair sampled from the group of patients (N = 28) and a control group (N = 18). The mean content of metals (Ni, Cr, Mn, Fe) in hair that were hypothesized to be systemically absorbed from stainless steel, was provided. The highest difference between the groups was found for Ni (39% higher level in hair of patients), Mn (18%), Fe (4.1%), Cr (2.5%), as calculated by a new dimensionless metal release coefficient (α). The second coefficient defined in the present work (β) corresponded to the difference in the mean content of elements between the groups. The coefficient was the highest for Fe, subsequently Ni, Mn and Cr. None of the differences was statistically significant. For each group and a given element, ranges between 10th and 90th percentile were determined. The upper value of the range differed the mostly between the groups for Ni (82.5%) showing that stainless steel of orthodontic appliance can be the source of exposure to this element. The difference was also identified for Mn (26.5%). For Cr and Fe, the lower value of the range was elevated. It was noted that 22% of patients undergoing orthodontic treatment had elevated levels of Ni in hair. A correlation matrix between the content of the elements in hair was calculated. Statistically significant correlations were found between Cr and Fe, showing similar sources of exposure. Multiple regression analysis showed the dependence of Ni content (dependent variable) on the level of Co and Mg (synergism) and V (antagonism).