Iron Behavior in the Ozonation and Filtration of Groundwater

In Finnish groundwater, the main substances that require treatment are iron and manganese. In addition to this, groundwaters are soft and acidic. Iron removal is usually relatively effective by oxidizing dissolved iron into an insoluble form, either by aeration or chemical oxidization and removing the formed precipitate by sand filtration. Sometimes, if the untreated water contains high amounts of organic matter, problems may arise for iron removal. In Finland, it is quite common that groundwater contains high levels of both iron and natural organic matter, mainly as humic substances. The groundwater of the Kukkala intake plant in Liminka has been found to be problematic, due to its high level of natural organic matter. This research studied the removal of iron from this water by means of oxidation with ozone and filtration. While the oxidation of iron by ozone was rapid, the precipitate particles formed were small, and thus could not be removed by sand and anthracite filtration, and the iron residue in the treated water was more than 2 mgL^?1. And while the filtration was able to remove iron well without the feed of ozone, the iron residue in the treated water was only 0.30 mgL^?1. In this case, iron was led to the filter in a bivalent dissolved form. So, the result of iron removal was the best when the sand/anthracite filter functioned largely as an adsorption filter.     

A Microprocessor Controlled System For Photoelectrochemical Measurements

ABSTRACT

An automatic system for measuring photocurrent of electrodes as a function of excitation wavelength and electrode potential is described. Applications to a chemically modified transparent Sn0₂ electrode and an oxide-covered tantalum electrode are shown.     

Optimisation model for integration of cooling and heating systems in large industrial plants

Large industrial plants have often hundreds of heating and cooling heat exchangers. A common situation is that cooling demands of the processes are satisfied without any deeper analysis of the overall impact of the cooling systems on the plant’s economy or the environment. If cooling water is available it is used as much as needed and then pumped back to the river, some degrees warmer.An optimisation model was developed for integration of cooling and heating systems to tackle the problem. An industrial cooling system is a complex energy system comprising different options of producing cooling, distribution pipelines for cold media and cooling storages. Integration of power generation and heating systems to the cooling systems was included in the model. An illustrative example is presented in the paper. 10 process streams with cooling demand and 10 streams with heating demand were chosen, situated at different locations at the plant site. The optimal matches between the streams were found together with the sizes of the heat exchangers and the demands of hot and cold utilities. The costs of pipelines and the pumping costs of the streams are included in the model. The model can be used in the design of greenfield and retrofit investments and in versatile what-if analyses of the plant design or operation.     

A new table for work with a microscope, a solution to ergonomic problems

Microscope workers are exposed to continuous static muscular work and an increased risk of musculoskeletal disorders in the neck, shoulder and upper extremities. In a Finnish research centre, microscope workers reported pain in the shoulder, neck, lower back and upper back. As a consequence, a programme to solve the ergonomic problems of microscope work was initiated and led to the construction of a new table for microscopes. Ten experienced male microscope workers were chosen as subjects to carry out an experimental study in which the new table and an old one, an ordinary non-adjustable laboratory table, were compared in a standardized microscope task. The dependent variable was the electromyographic activity measured from muscles in the neck–shoulder region. The new table allowed the microscope to be used with the head in an upright position, the forearms supported and with less flexion of the upper arm. Surface electromyographic measurements also confirmed that the changes were ergonomic improvements.     

Low-Power Application-Specific Processor for FFT Computations

In this paper, a processor architecture tailored for radix-4 and mixed-radix FFT computations is described. The processor has native support for power-of-two transform sizes. Several optimizations have been used to improve the energy-efficiency of the processor and experiments show that a programmable solution can possess energy-efficiency comparable to fixed-function ASICs.     

What goes down must come up? Trends of industrial electricity use in the North-West of Russia

This article uses decomposition method to analyse industrial electricity consumption in North-Western Russia, namely in Archangelsk oblast, the Republic of Karelia and Murmansk oblast. The case sectors, forestry and electricity, have in most cases developed similarly in the chosen regions during 1990–2001. The decomposition analysis shows that the reduction of economic activity has reduced electricity consumption in all three regions but that it is not always the main factor reducing consumption. The changes in energy efficiency increased consumption in the forestry sector in all regions while in the electricity sector it led to a reduction. The changes in the structures of the regional economies increased electricity consumption in electricity industry which gained importance due to developments in the manufacturing industry. In Murmansk, forestry sector has almost disappeared during the observation period. This was the main observed electricity consumption reduction caused by structural changes. Many of the developments can be better understood against the general knowledge of transition factors.     

The Effect of Ozonation on the Size Fractions of Manganese

Manganese is a commonly found substance in groundwater in Finland. As a powerful oxidant, ozone can be used for the oxidizing of manganese even without raising the pH. The SFS (Finnish Standards Association) standard has set the accepted limit for soluble manganese to 0.45 μm. However, some research papers have used the limit of 30 kD (kilodalton) for soluble manganese. This research concentrates on the size fractions of manganese in four samples of untreated groundwater and in four samples of ozonized groundwater when treated with 0.45 μm, 0.20 μm, 100 kD, 30 kD, and 10 kD filters. In all tests, nearly all manganese contained in raw water penetrated all filters. There were slight variations in the flocculation of manganese in ozonized groundwater; nevertheless, hardly any reduction in manganese levels took place beyond 100 kD. After ozonation, there were two water samples which surpassed the manganese limit of 50 μgl^?1 set for domestic water when the filtration was 0.20 μm and another two samples when the filtration was 100 kD.     

Design Methodology for Offloading Software Executions to FPGA

Field programmable gate array (FPGA) is a flexible solution for offloading part of the computations from a processor. In particular, it can be used to accelerate an execution of a computationally heavy part of the software application, e.g., in DSP, where small kernels are repeated often. Since an application code for a processor is a software, a design methodology is needed to convert the code into a hardware implementation, applicable to the FPGA. In this paper, we propose a design method, which uses the Transport Triggered Architecture (TTA) processor template and the TTA-based Co-design Environment toolset to automate the design process. With software as a starting point, we generate a RTL implementation of an application-specific TTA processor together with the hardware/software interfaces required to offload computations from the system main processor. To exemplify how the integration of the customized TTA with a new platform could look like, we describe a process of developing required interfaces from a scratch. Finally, we present how to take advantage of the scalability of the TTA processor to target platform and application-specific requirements.