Mika Sillanpää

Coherent quantum state storage and transfer between two phase qubits via a resonant cavity.

As with classical information processing, a quantum information processor requires bits (qubits) that can be independently addressed and read out, long-term memory elements to store arbitrary quantum states, and the ability to transfer quantum information through a coherent communication bus accessible to a large number of qubits. Superconducting qubits made with scalable microfabrication techniques are a promising candidate for the realization of a large-scale quantum information processor. Although these systems have successfully passed tests of coherent coupling for up to four qubits, communication of individual quantum states between superconducting qubits via a quantum bus has not yet been realized. Here, we perform an experiment demonstrating the ability to coherently transfer quantum states between two superconducting Josephson phase qubits through a quantum bus. This quantum bus is a resonant cavity formed by an open-ended superconducting transmission line of length 7 mm. After preparing an initial quantum state with the first qubit, this quantum information is transferred and stored as a nonclassical photon state of the resonant cavity, then retrieved later by the second qubit connected to the opposite end of the cavity. Beyond simple state transfer, these results suggest that a high-quality-factor superconducting cavity could also function as a useful short-term memory element. The basic architecture presented here can be expanded, offering the possibility for the coherent interaction of a large number of superconducting qubits.

Natural organic matter removal by coagulation during drinking water treatment: A review

Natural organic matter (NOM) is found in all surface, ground and soil waters. An increase in the amount of NOM has been observed over the past 10-20 years in raw water supplies in several areas, which has a significant effect on drinking water treatment. The presence of NOM causes many problems in drinking water and drinking water treatment processes, including (i) negative effect on water quality by causing colour, taste and odor problems, (ii) increased coagulant and disinfectant doses (which in turn results in increased sludge volumes and production of harmful disinfection by-products), (iii) promoted biological growth in distribution system, and (iv) increased levels of complexed heavy metals and adsorbed organic pollutants. NOM can be removed from drinking water by several treatment options, of which the most common and economically feasible processes are considered to be coagulation and flocculation followed by sedimentation/flotation and sand filtration. Most of the NOM can be removed by coagulation, although, the hydrophobic fraction and high molar mass compounds of NOM are removed more efficiently than hydrophilic fraction and the low molar mass compounds. Thus, enhanced and/or optimized coagulation, as well as new process alternatives for the better removal of NOM by coagulation process has been suggested. In the present work, an overview of the recent research dealing with coagulation and flocculation in the removal of NOM from drinking water is presented.

Heterogeneous water phase catalysis as an environmental application: a review.

Catalytic water phase processes as an environmental application is a relatively novel subject with tremendous potential in the near future. This review of 120 references presents the wide scale of heterogeneous water phase applications studied mainly within past five years. Both oxidation and hydrogenation processes are included as well as TiO2 assisted photocatalysis. According to the references, heterogeneous catalysis is developing rapidly. New bimetallic catalysts and supports with higher surface area have improved catalytic efficiency in both oxidation and hydrogenation processes. It also seems that study on use of some waste materials such as red mud as catalyst is a very progressive field. On the whole, the chemical aspects are pretty well known, but the catalyst durability, and in many cases activity as well, has to be improved.

Electrokinetic soil remediation - critical overview

In recent years, there has been increasing interest in finding new and innovative solutions for the efficient removal of contaminants from soils to solve groundwater, as well as soil, pollution. The objective of this review is to examine several alternative soil-remediating technologies, with respect to heavy metal remediation, pointing out their strengths and drawbacks and placing an emphasis on electrokinetic soil remediation technology. In addition, the review presents detailed theoretical aspects, design and operational considerations of electrokinetic soil-remediation variables, which are most important in efficient process application, as well as the advantages over other technologies and obstacles to overcome. The review discusses possibilities of removing selected heavy metal contaminants from clay and sandy soils, both saturated and unsaturated. It also gives selected efficiency rates for heavy metal removal, the dependence of these rates on soil variables, and operational conditions, as well as a cost-benefit analysis. Finally, several emerging in situ electrokinetic soil remediation technologies, such as Lasagna, Elektro-Klean, electrobioremediation, etc., are reviewed, and their advantages, disadvantages and possibilities in full-scale commercial applications are examined.

Water purification using magnetic assistance: a review.

Water is a major source for survival on this planet. Its conservation is therefore a priority. With the increase in demand, the supply needs to meet specific standards. Several purification techniques have been adopted to meet the standards. Magnetic separation is one purification technique that has been adapted from ore mining industries to anti-scale treatment of pipe lines to seeding magnetic flocculent. No reviews have come up in recent years on the water purification technique using magnetic assistance. The present article brings out a series of information on this water purification technique and explains different aspects of magnetism and magnetic materials for water purification.

Removal of natural organic matter from drinking water by advanced oxidation processes

Over the past 10-20years the amount of the natural organic matter (NOM) has been increased in raw water supplies on several areas. The presence of NOM causes many problems in drinking water treatment processes, including: (i) negative effect on water quality by colour, taste and odor problems, (ii) increased coagulant and disinfectant dose requirements (which in turn results increased sludge and potential harmful disinfection by-product formation), (iii) promoted biological growth in distribution system, and (iv) increased levels of complexed heavy metals and adsorbed organic pollutants. Thus, more efficient methods for the removal of NOM have emerged. Among these are advanced oxidation processes (AOPs). These include O(3)/H(2)O(2), O(3)/UV, UV/H(2)O(2), TiO(2)/UV, H(2)O(2)/catalyst, Fenton and photo-Fenton prosesses as well as ultrasound. In the present work, an overview of the recent research studies dealing with AOP methods for the removal of NOM and related compounds from drinking water is presented.

Applications of chitin- and chitosan-derivatives for the detoxification of water and wastewater--a short review.

Chitin and chitosan-derivatives have gained wide attention as effective biosorbents due to low cost and high contents of amino and hydroxyl functional groups which show significant adsorption potential for the removal of various aquatic pollutants. In this review, an extensive list of chitin- and chitosan-derivatives from vast literature has been compiled and their adsorption capacities for various aquatic pollutants as available in the literature are presented. This paper will give an overview of the principal results obtained during the treatment of water and wastewater utilizing chitin and chitosan-derivatives for the removal of: (a) metal cations and metal anions; (b) radionuclides; (c) different classes of dyes; (d) phenol and substituted phenols; (e) different anions and other miscellaneous pollutants. The review provides a summary of recent information obtained using batch studies and deals with the various adsorption mechanisms involved. It is evident from the literature survey that chitin- and chitosan-derivatives have shown good potential for the removal of various aquatic pollutants. However, still there is a need to find out the practical utility of such developed adsorbents on commercial scale.

An overview of the methods used in the characterisation of natural organic matter (NOM) in relation to drinking water treatment.

Natural organic matter (NOM) is found in all surface, ground and soil waters. During recent decades, reports worldwide show a continuing increase in the color and NOM of the surface water, which has an adverse affect on drinking water purification. For several practical and hygienic reasons, the presence of NOM is undesirable in drinking water. Various technologies have been proposed for NOM removal with varying degrees of success. The properties and amount of NOM, however, can significantly affect the process efficiency. In order to improve and optimise these processes, the characterisation and quantification of NOM at different purification and treatment processes stages is important. It is also important to be able to understand and predict the reactivity of NOM or its fractions in different steps of the treatment. Methods used in the characterisation of NOM include resin adsorption, size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) spectroscopy, and fluorescence spectroscopy. The amount of NOM in water has been predicted with parameters including UV-Vis, total organic carbon (TOC), and specific UV-absorbance (SUVA). Recently, methods by which NOM structures can be more precisely determined have been developed; pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), multidimensional NMR techniques, and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The present review focuses on the methods used for characterisation and quantification of NOM in relation to drinking water treatment.

As(V) adsorption on maghemite nanoparticles.

In this study a novel adsorbent, maghemite nanoparticles (gamma-Fe(2)O(3)), is used for As(V) removal. Maghemite nanoparticles are an exceptional adsorbent material due to its magnetic properties and a good adsorption capacity. The aims of the study were to investigate the suitability of maghemite nanoparticles for As(V) adsorption and to compare properties of different maghemites and their As(V) adsorption efficiency. Maghemite nanoparticles were characterized by XRD, XPS, TEM, VSM, BET and Zeta potential analyzers. Size of the particles varied from 3.8 to 18.4 nm. Adsorption experiments were carried out with three different kinds of maghemite nanoparticles: (i) commercially available, (ii) homemade with mechanochemical method and (iii) homemade with sol-gel process. All three different kinds of maghemite nanoparticles were successful in removing As(V) from water, one of them reached as high adsorption capacity as 50mg/g.

Increased biogas production at wastewater treatment plants through co-digestion of sewage sludge with grease trap sludge from a meat processing plant

The feasibility of co-digesting grease trap sludge from a meat-processing plant and sewage sludge was studied in batch and reactor experiments at 35 degrees C. Grease trap sludge had high methane production potential (918 m(3)/tVS(added)), but methane production started slowly. When mixed with sewage sludge, methane production started immediately and the potential increased with increasing grease trap sludge content. Semi-continuous co-digestion of the two materials was found feasible up to grease trap sludge addition of 46% of feed volatile solids (hydraulic retention time 16d; maximum organic loading rate 3.46 kgVS/m(3)d). Methane production was significantly higher and no effect on the characteristics of the digested material was noticed as compared to digesting sewage sludge alone. At higher grease trap sludge additions (55% and 71% of feed volatile solids), degradation was not complete and methane production either remained the same or decreased.