Investigation into combined ozone and biological treatment of pulp bleaching effluent : a thesis submitted in partial fulfillment of the requirements for the degree of Master of Technology in Environmental Engineering at Massey University

An investigation into combined ozone and biological treatment of pulp bleaching plant effluent was conducted. Treatment efficiencies were evaluated in terms of color, COD and BOD 5 removal. The effectiveness of ozone oxidation and subsequent biological treatment of pulp bleaching effluent were examined separately and the overall color, COD and BOD 5 removal through the two-stage combined treatment were determined. Ozone pretreatment was carried out in a vertical column batch reactor under a constant ozone flowrate 5 L/min condition. Changes of color. COD and BOD 5 in pulp bleaching effluent during ozonation process were recorded. The subsequent biological treatment was investigated in two lagoon systems. One was an anaerobic-aerobic lagoon system and the other was an aerated lagoon system. The separate contribution made by each zone of the anaerobic-aerobic lagoon to the overall effluent treatment was evaluated. To assess the effect of the ozone pretreatment on the followed biological treatment, the ozonated bleaching effluent and the non-ozonated raw bleaching effluent were parallelly operated in identical biological systems. Comparison of results obtained from treatment of the ozonated and non-ozonated effluent identified the improvement of a two-stage combined treatment over a biological treatment alone. Results obtained from ozone treatment of two batches of Eo and mixed (Eo and DC) bleaching effluent indicate that ozone was most effective in color removal (up to 74% measured at pH 7), followed by BOD 5 increase (up to 39%) and lesser effective in COD removal (up to 19% only). A color removal formula was developed to model color removal kinetics. The mathematical formula succinctly describes the color removal performance and offers an alternative option to study color removal kinetics during ozone treatment of pulp bleaching effluent. Because of the ozone pretreatment, the effectiveness of the subsequent biological treatment for COD and BOD 5 removal was improved. However, when the followed biological system included an anaerobic zone, a considerable color increase (98%) in the ozonated effluent was observed during the treatment. If the followed biological treatment was carried out under an aerobic condition only, the color increase in the ozonated effluent was very small (21%). This observation suggests that biological treatment of ozonated effluent should avoid involving an anaerobic condition, otherwise the color removal achieved during the ozone treatment would be lost in the subsequent biological stage. It would obviously be economically infeasible. The combined ozone oxidation and biological treatment regime improved the overall color removal (34-68%), COD removal (45-51%) and BOD 5 removal (82-95%) over a single stage biological treatment which only achieved up to 17% color removal, 30-35% COD removal and 64-92% BOD 5 removal. For removal of COD and BOD 5 , the combined ozone with anaerobic-aerobic lagoon treatment outperformed marginally the combined ozone with aerated lagoon system. However, for color removal, the efficiency of the combined ozone with aerated lagoon treatment was much higher (68%) than that of the combined ozone with anaerobic-aerobic lagoon treatment (43%). The anaerobic zone of the anaerobic-aerobic lagoon was identified as the main sources of color increase and limited the overall color removal for such a combined treatment. In summary, the combined ozone with aerated lagoon system was the better option for treatment of pulp bleaching plant effluent

Pair production of 125 GeV Higgs boson in the SM extension with color-octet scalars at the LHC

Although the Higgs boson mass and single production rate have been determined more or less precisely, its other properties may deviate significantly from its predictions in the standard model (SM) due to the uncertainty of Higgs data. In this work we study the Higgs pair production at the LHC in the Manohar-Wise model, which extends the SM by one family of color-octet and isospin-doublet scalars. We first scanned over the parameter space of the Manohar-Wise model considering exprimental constraints and performed fits in the model to the latest Higgs data by using the ATLAS and CMS data separately. Then we calculated the Higgs pair production rate and investigated the potential of its discovery at the LHC14. We conclude that: (i) Under current constrains including Higgs data after Run I of the LHC, the cross section of Higgs pair production in the Manohar-Wise model can be enhanced up to even $10^3$ times prediction in the SM. (ii) Moreover, the sizable enhancement comes from the contributions of the CP-odd color-octet scalar $S^A_I$. For lighter scalar $S^A_I$ and larger values of $|\lambda_I|$, the cross section of Higgs pair production can be much larger. (iii) After running again of LHC at 14 TeV, most of the parameter spaces in the Manohar-Wise model can be test. For an integrated luminosity of 100 fb$^{-1}$ at the LHC14, when the normalized ratio $R=10$, the process of Higgs pair production can be detected.Comment: 13 pages, 4 figure

Tuning Optical Properties of Transparent Conducting Barium Stannate by Dimensional Reduction

We report calculations of the electronic structure and optical properties of doped $n$-type perovskite BaSnO3 and layered perovskites. While doped BaSnO$_3$ retains its transparency for energies below the valence to conduction band onset, the doped layered compounds exhibit below band edge optical conductivity due to transitions from the lowest conduction band. This gives absorption in the visible for Ba2SnO4. Thus it is important to minimize this phase in transparent conducting oxide (TCO) films. Ba3Sn2O7 and Ba4Sn3O10 have strong transitions only in the red and infrared, respectively. Thus there may be opportunities for using these as wavelength filtering TCO

Analysis of Metabolic Factors Associated with Hyperuricemia in Diabetes Mellitus

After the occurrence of diabetes in patients, with the increase of the course of disease and the increase of the age of patients, the incidence of other combined diseases in patients is also increasing. Diabetes combined with hyperuricemia is a common clinical disease, and 40% of patients with diabetes will develop hyperuricemia and other complications, which not only makes the treatment of the disease more difficult, but also increases the burden of the hospital. Therefore, to analyze the metabolic factors related to hyperfatemia, and to provide a reference for the clinical exploration of active and effective treatment