Training system for conceptual design and evaluation for wastewater treatment

Rising population, rapid urbanisation and growing industrialisation have severely stressed water quality and its availability in Malawi. In addition, financial and institutional problems and the expanding agro industry have aggravated this problem. The situation is worsened by depleting water resources and pollution from untreated sewage and industrial effluent. The increasing scarcity of clean water calls for the need for appropriate management of available water resources. There is also demand for a training system for conceptual design and evaluation for wastewater treatment in order to build the capacity for technical service providers and environmental practitioners in the country. It is predicted that Malawi will face a water stress situation by 2025. In the city of Blantyre, this situation is aggravated by the serious pollution threat from the grossly inadequate sewage treatment capacity. This capacity is only 23.5% of the wastewater being generated presently. In addition, limited or non-existent industrial effluent treatment has contributed to the severe water quality degradation. This situation poses a threat to the ecologically fragile and sensitive receiving water courses within the city. This water is used for domestic purposes further downstream. This manuscript outlines the legal and policy framework for wastewater treatment in Malawi. The manuscript also evaluates the existing wastewater treatment systems in Blantyre. This evaluation aims at determining if the effluent levels at the municipal plants conform to existing standards and guidelines and other associated policy and regulatory frameworks. The raw material at all the three municipal plants is sewage. The typical wastewater parameters are Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and Total Suspended Solids (TSS). The treatment target is BOD5, COD, and TSS reduction. Typical wastewater parameters at the wastewater treatment plant at MDW&S textile and garments factory are BOD5 and COD. The treatment target is to reduce BOD5 and COD. The manuscript further evaluates a design approach of the three municipal wastewater treatment plants in the city and the wastewater treatment plant at Mapeto David Whitehead & Sons (MDW&S) textile and garments factory. This evaluation utilises case-based design and case-based reasoning principles in the ED-WAVE tool to determine if there is potential for the tool in Blantyre. The manuscript finally evaluates the technology selection process for appropriate wastewater treatment systems for the city of Blantyre. The criteria for selection of appropriate wastewater treatment systems are discussed. Decision support tools and the decision tree making process for technology selection are also discussed. Based on the treatment targets and design criteria at the eight cases evaluated in this manuscript in reference to similar cases in the ED-WAVE tool, this work confirms the practical use of case-based design and case-based reasoning principles in the ED-WAVE tool in the design and evaluation of wastewater treatment 6 systems in sub-Sahara Africa, using Blantyre, Malawi, as the case study area. After encountering a new situation, already collected decision scenarios (cases) are invoked and modified in order to arrive at a particular design alternative. What is necessary, however, is to appropriately modify the case arrived at through the Case Study Manager in order to come up with a design appropriate to the local situation taking into account technical, socio-economic and environmental aspects. This work provides a training system for conceptual design and evaluation for wastewater treatment.

Tertiary Treatment and Re-use of Kraft Pulp Mill Effluent

The efficient use of materials and natural recourses, for ecological and economic reasons, has become more and more important in all industries. In the forest industries this means higher levels of closure in the material circulations of the mills. One possibility to reduce wastewater discharge is to re-use part of the 2nd clarifier effluent as process water. The main target of this thesis was to evaluate the technical suitability of several mechanical and chemical tertiary treatment methods for water re-use. Some of the tested methods seemed to have high potential for the removal of some specific constituents from the wastewater. Tertiary treatment is needed because higher levels of closure may cause problems with increasing amounts of non-process elements in different points of kraft pulp process. The aspect of sustainable development was taken into account by evaluating positive and negative environmental effects of the treatment processes. Environmental benefits can be gained by using some of the tertiary treatment methods tested. These methods should still be researched more for system optimization.

Iran's domestic and foreign policies

Iran has a reputation of being a problematic country. Right now, it is proceeding with its nuclear program despite the opposition of the West and neighboring countries and the massive sanctions inflicted upon it. The country is also struggling with domestic issues. Half of Iran’s population belongs to different ethnic or religious minorities. They have poor rights to express their culture in the country, which is a cause of dissatisfaction among non-Shiite and non-Persian citizens. After the Arab Spring, the situation in Iran is getting more topical than ever. In the Syrian conflict, the Shiite Iran is constantly giving support to al-Assad’s regime. These are all factors that have aggravated the already irritated relations between Iran and the West.

Study of Control Methods of a High-Frequency Cycloconverter for Domestic Induction Heating Appliances

A high-frequency cyclonverter acts as a direct ac-to-ac power converter circuit that does not require a diode bidge rectifier. Bridgeless topology makes it possible to remove forward voltage drop losses that are present in a diode bridge. In addition, the on-state losses can be reduced to 1.5 times the on-state resistance of switches in half-bridge operation of the cycloconverter. A high-frequency cycloconverter is reviewed and the charging effect of the dc-capacitors in ``back-to-back'' or synchronous mode operation operation is analyzed. In addition, a control method is introduced for regulating dc-voltage of the ac-side capacitors in synchronous operation mode. The controller regulates the dc-capacitors and prevents switches from reaching overvoltage level. This can be accomplished by variating phase-shift between the upper and the lower gate signals. By adding phase-shift between the gate signal pairs, the charge stored in the energy storage capacitors can be discharged through the resonant load and substantially, the output resonant current amplitude can be improved. The above goals are analyzed and illustrated with simulation. Theory is supported with practical measurements where the proposed control method is implemented in an FPGA device and tested with a high-frequency cycloconverter using super-junction power MOSFETs as switching devices.

Feeling vs. Being like a Domestic Goddess: Cookbooks and Lifestyle Choices

Tämä pro gradu -tutkielma tarkastelee, miten keittokirjat muovaavat pääasiassa naispuolista lukijakuntaansa. Tärkein kysymys, johon tutkielmassa on etsitty vastausta on, että onko naisilla, menneiden sukupolvien taisteltua vuosikymmeniä tasa-arvon puolesta, oikeus valita viettää aikaa keittiössä ja oikeasti nauttiakin siitä. Kahtena päälähteenä tutkielmassa on käytetty brittiläisen Nigella Lawsonin keittokirjoja How to Eat ja How to be a Domestic Goddess. Näiden kirjojen analysoinnin ja muiden lähteiden avulla tutkielmassa on käsitelty ruuanlaiton ja leipomisen nautittavuutta ja sitä onko se ylipäätään sallittua vai syntistä. Lawson on julkaissut urallaan sitten vuoden 1998 yhteensä yhdeksän keittokirjaa, joiden lisäksi kirjojen tueksi on tehty useita televisiosarjoja. How to Eat on yleispätevä opas hyvän ruuan nautintoihin ja periaatteisiin, How to be a Domestic Goddess taas sisältää lähinnä leivontareseptejä. Nämä kaksi kirjaa ovat Lawsonin ensimmäiset keittokirjat. Nigella Lawsonin keittokirjat eivät ole vain reseptikokelmia eivätkä reseptit vain aineisosalistoja ja valmistusohjeita. Lawsonin kirjoja voi lukea kirjallisuutena eikä vain reseptien takia. Lawson viittaa usein naisen asemaan ja yrittää vakuuttaa lukijoitaan ruuanlaiton ja leipomisen nautittavuudesta.

Optimization of PV and battery capacity for domestic purposes

The usage of PV batteries nowadays became more and more widely spread. Due to the fact that the efficiency of modern PV is rising every year the prevalence of this source of energy is increasing. As the source of the energy is sunlight, these batteries need to be complimented by storage capacitors which will store energy for future use. Nevertheless the less the calculation of demanded amount of energy according the load and capacity of a storage battery that will keep the end consumer in work during certain time still is not overviewed. In this thesis the overall system will be considered and there will be made economic calculations for configurations of such system that will depend from the load. Also the behavior of the system in different geographical and climate conditions that influence of the amount of energy produced will be overviewed.