Effects of carbon dioxide addition on algae and treatment performance of high rate algal ponds : a thesis presented in partial fulfilment of the requirements of the degree of Master of Engineering in Environmental Engineering at Massey University

Waste stabilisation ponds have been used for treating a great variety of wastewaters around the world for many decades. More advanced systems combine anaerobic or advanced facultative ponds with high rate algal ponds (HRAP) followed by a number of algae settling ponds and maturation ponds to achieve enhanced and more reliable removal of wastewater pollutants, while yielding possibly valuable by-products such as biogas and algal biomass. In recent years a growing number of scientists and engineers have proposed the use of HRAP treating domestic wastewater for carbon dioxide (CO2) scrubbing from biogas and CO2 sequestration. The experiments presented in this thesis sought to determine if the treatment performance of HRAP is affected by the addition of CO2 and subsequent reduction of pond pH. Experiments with algae cultures grown on domestic wastewater in laboratory microcosms, outside mesocosms and outside pilot-scale HRAP were conducted. Carbon dioxide addition to algae wastewater cultures restricted the maximum pH level to ~8. Key wastewater quality parameters of CO2 added cultures, were compared to control cultures without CO2 addition. The wastewater quality parameters monitored include temperature, pH, and concentrations of total suspended solids (TSS), ammoniacal-nitrogen (NH4-N), dissolved reactive phosphorus (DRP), filtered biochemical oxygen demand (fBOD5) and the faecal indicator Escherichia coli (E. coli). Carbon dioxide addition to algae wastewater cultures was found to promote algal growth and increased the TSS concentrations. Over 8 day culture length CO2 addition in laboratory and outside batch experiments increased algal growth (indicated by TSS) by up to 76% and 53%, respectively. During semi-continuous outside experiments CO2 addition increased algal growth by ~20% in comparison to the control cultures. Despite enhancing algal growth (TSS), CO2 addition appeared to have little effect on algae cell morphology, species composition and zooplankton activity in the algae wastewater cultures. Monitoring of the key nutrients NH4-N and DRP in cultures with and without CO2 addition indicated that CO2 addition can lead to an increase or a decrease in nutrient removal. Under culture conditions which allowed the control cultures to achieve high day-time pH levels CO2 addition, and subsequent pH restriction, appeared to reduce overall nutrient removal. Only slight changes or an increase in nutrient removal as a result of CO2 addition were observed under culture conditions which allowed only for a moderate or small elevation of the control culture pH. However, the increases in algal biomass, observed in all CO2 added cultures indicate a greater potential for the reclamation of potentially valuable wastewater nutrients in the form of algal biomass. Monitoring of fBOD5 levels during several outside experiments showed that CO2 addition had no effect on the fBOD5 removal by the algae wastewater cultures under those conditions. During several outside batch experiments (of up to 8 day culture length) the removal of the faecal indicator bacteria E. coli was monitored. It was shown that CO2 addition reduced E. coli removal by 1.4 to 4.9 log units compared to control cultures. Basic modelling of carbon flows indicated that under New Zealand conditions the CO2 volumes required for the changes described above would be available from the biogas produced in a wastewater pond system treating wastewater with a volatile solids (VS) concentration of ~ 500 mg/L. In systems treating weaker wastewaters additional CO2 could be made available through the onsite combustion of biogas. In summary, the obtained results suggest that CO2 addition to a field-scale HRAP could increase algal biomass growth year-round and slightly enhance nutrient removal during winter, but might reduce nutrient removal during summer, and reduce E. coli removal year-round, while having no effect on fBOD5 removal. The reduction in nutrient treatment performance during summer, and especially the losses in E. coli removal resulting form CO2 addition may require more sophisticated downstream processing of the HRAP effluent, like increase retention times in maturation ponds. Such remedial measures have to be evaluated on a case by case basis, and are dependent on the given regulations and discharge regimes of the system. This study indicates that in general HRAP can be employed for biogas purification and provide a useful sink for CO2 rich waste streams. The beneficial effects of CO2 addition to HRAP do not appear to allow for any design or management changes within the system, while it was indicated that most detrimental effects of CO2 addition could be accommodated without major alternations, although in some cases significant remedial measures may be required for correcting the losses in disinfection and nutrient removal performance

Incentive Contracts in Team Sports - Theory and Practice

A comparison of incentive clauses of players’ contracts in German soccer and clauses used in the NFL and NBA shows considerable differences. Against the background of principle-agent theory we have a closer look at these incentive systems. In contrast to other industries it is easy to observe the employees’ effort in team sports. Therefore, it would be desirable to set incentives for players based on their individual effort. We show that there are reasons why incentive clauses in professional German soccer, the NBA and the NFL are not directly based on effort. We argue that there are two main reasons: Firstly, efficient incentives are complementarily provided by subjective and objective performance measures. Secondly, cooperation amongst team members is essential in team sports.sports, labor contracts, agency theory, incentives,

WHEAT DISEASE MANAGEMENT WITH FUNGICIDES: QOI-RESISTANT \u3ci\u3e PARASTAGONOSPORA NODORUM \u3c/i\u3e AND \u3ci\u3e ZYMOSEPTORIA TRITICI, \u3c/i\u3e APPLICATION TIMING FOR LEAF DISEASE MANAGEMENT, AND SPRAYER CONFIGURATIONS FOR FUSARIUM HEAD BLIGHT MANAGEMENT

Disease management in winter wheat can be improved by a properly implemented foliar fungicide program. The fungicide, application time, and application system should be selected based on the host, pathogens present, risk of fungicide resistance, and time of disease onset. These factors vary among environments and require region-specific research to determine appropriate practices. Trials were conducted to evaluate different aspects of fungicide applications for managing Fusarium head blight (FHB), caused by Fusarium graminearum, and the Septoria tritici leaf blotch complex, caused by Zymoseptoria tritici and Parastagonospora nodorum. A survey of P. nodorum isolates from Kentucky and Illinois and Z. tritici isolates from Kentucky showed that both pathogen populations included strains that were resistant to quinone outside inhibitor (QoI) fungicides. Trials were conducted to determine the optimal fungicide application time to manage the Septoria leaf blotch complex, and whether disease management programs benefited from adding a foliar fungicide. The effect that sprayer speed, nozzle type, and configuration had on coverage of wheat heads and FHB management was evaluated. Applying alternative fungicide chemistries to the QoI class at Feekes 9 along with an application at Feekes 10.51 made with an appropriate nozzle and application speed will provide a more effective fungicide program for winter wheat in Kentucky

Constraints on Moon's orbit 3.2 billion years ago from tidal bundle data

The angular momentum of the Earth-Moon system was initially dominated by Earth's rotation with a short solar day of around 4 hours duration. Since then, Earth gradually transferred angular momentum through tidal friction to the orbit of the Moon, resulting in an increasing orbital radius and a deceleration of Earth's rotation. Geologic observations of tidal deposits can be used to verify and constrain models of lunar orbital evolution. In this work we reexamine the oldest tidal record suitable for analysis from the Moodies Group, South Africa with an age of 3.22 billion years. Time frequency analysis of the series of thicknesses of the sandstone layers yields a periodicity at 15.0 layers, taking into account the possibility of missing laminae. Assuming a mixed tidal system, the duration of two neap-spring-neap cycles was 30.0 lunar days for dominant semidiurnal or 30.0 sidereal days for dominant diurnal tides. We derive the relationship between this observation and the past Earth-Moon distance and re-visit related published work. We find that the Earth-Moon distance 3.22 billion years ago was around 70% of today's value. The Archean solar day was around 13 hours long with around 700 solar days per year. The ratio of solar to lunar tide-raising torque controls the leakage of angular momentum from the Earth-Moon system, but deviation from the assumed ratio of 0.211 results in only moderate changes. A duration of a postulated 21-hour atmospheric resonance shorter than 200 million years would be consistent with our observation; it would significantly alter Earth-Moon distance