The Chesapeake Bay watershed has seen an increase in population, nutrient loading, and stringent effluent limits; therefore, cost-effective technologies must be explored and implemented to intensify the treatment of regional wastewater. This work describes the bioaugmentation and retention of anammox (AMX) granules in a continuous adsorption/bio-oxidation (A/B) mainstream deammonification pilot-scale process treating domestic wastewater. The AMX granules were collected from the underflow of a sidestream DEMON® process. The bioaugmentation rate was based on several factors including full-scale sidestream DEMON® wasting rate and sidestream vs mainstream AMX activity. The retention of bioaugmented AMX granules required a novel settling column at the end of the deammonification step. The settling column was designed to provide a surface overflow rate (SOR) that allowed dense AMX granules to settle into the underflow and less dense floccular biomass to outselect into the overflow. B-Stage was operated to out-select nitrite oxidizing bacteria (NOB) by maintaining an ammonia residual (>2 mg NH4-N/L), a relatively high dissolved oxygen (DO) (>1.5 mg O2/L) concentration, an aggressive solids retention time (SRT) for NOB washout, and intermittent aeration for transient anoxia. AMX activity was not detected in the mainstream at any time. The settling column AMX retention quantification suggested but did not confirm AMX were maintained in the mainstream. NOB were not suppressed during this study and no nitrite accumulation was present in the mainstream process. It was theorized that AMX granules were successfully settled into the settling column underflow and accumulated in the intermittently mixed sidestream biological phosphorus reactor (SBPR) where they disintegrated. This work also describes optimization of carbon addition to an anoxic partial denitrification anammox (PdN/A) moving bed biofilm reactor (MBBR) testing glycerol, acetate, and methanol as carbon sources to maximize total inorganic nitrogen (TIN) removal through the anammox pathway and to minimize effluent TIN. A carbon feeding strategy was developed and was evaluated by the extent of partial denitrification vs full denitrification (partial denitrification efficiency, PdN efficiency). All three carbon sources were capable of high TIN removal, low effluent TIN, and moderate to high PdN efficiency. Average TIN removal for glycerol was 10.0 ± 3.6 mg TIN/L, for acetate it was 8.7 ± 2.9 mg TIN/L, and for methanol it was 11.5 ± 5.6 mg TIN/L. Average effluent TIN for glycerol was 6.0 ± 4.0 mg TIN/L, for acetate it was 5.0 ± 1.1 mg TIN/L, and for methanol it was 4.3 ± 1.5 mg TIN/L. Average PdN efficiency for glycerol was 91.0 ± 9.0%, for acetate it was 88.0 ± 7.7%, and for methanol it was 74.0 ± 8.5%. When PdN efficiency was factored into the cost of each carbon source, methanol was 5.83% cheaper than glycerol per mass TIN removed and 59.0% cheaper than acetate per mass TIN-N removed. / Master of Science / The Chesapeake Bay watershed has seen an increase in population, nutrient loading, and stringent effluent limits; therefore, cost-effective technologies must be explored and implemented to intensify the treatment of regional wastewater. This work involves removing nitrogen from wastewater in a pilot sized modeled from a real wastewater treatment plant. The removal of nitrogen from wastewater can become costly. This cost is due to aeration and chemical demands to remove the nitrogen. This masters work uses a type of microorganism that can remove nitrogen without the need for aeration or chemicals through anaerobic ammonia oxidation (AMX bacteria). A specific environment has been created for AMX bacteria during this study to ensure they perform nitrogen removal optimally. Often times, communities of bacteria can help remove nitrogen more effectively when they work together. Therefore, communities of bacteria were encouraged to grow during this study. We were able to see that nitrogen removal was indeed occurring at high rates and producing high effluent water quality. We used several different metrics to prove this nitrogen removal technology worked well. This research was important because it showed the capabilities of a highly intensified process of successful nitrogen removal at a pilot-scale facility. It is the hope that these findings can be improved upon and implemented at full-scale facilities. These full-scale facilities would be able to achieve low levels of nitrogen in their effluent while saving millions of dollars on operational costs.

One of the major water quality issues affecting waterways is eutrophication. Controlling the input of nutrients from municipal wastewater treatment plants (WTP’s) is a significant step in reducing eutrophication. Tertiary wastewater treatment for water quality improvement in particular Biological Nutrient Removal (BNR) is often expensive to construct with high maintenance costs. Constructed wetlands (CWs) offer an alternative wastewater treatment and have been used successfully worldwide to treat various types of wastewater. This study investigated the effectiveness of the Oxley Creek horizontal subsurface flow (SSF) CW for tertiary municipal wastewater treatment and the suitability of four native macrophyte species, Baumea articulata, Carex fascicularis, Philydrum lanuginosum and Schoenoplectus mucronatus. The investigation consisted of four main components: 1) Plants: monitoring plant establishment, growth, impact of cropping, gravel size, nutrient content and storage for the four macrophyte species trialed; 2) Water quality - effluent treatment: monitoring water quality and quantity entering and leaving the wetland to determine wastewater treatment; 3) Organic matter: accumulation of organic carbon within the wetland cells for the different gravel sizes (5mm and 20mm) and 4) Mass balance: combining nutrient storage by macrophytes with wastewater nutrient removal to determine proportion of nutrient removal by plant uptake. The Oxley horizontal SSF CW is situated at the Oxley Creek WTP in Brisbane (South- East), Queensland, Australia which has a sub-tropical climate. The experimental design involved four different substrate treatments: Cell A new 5mm gravel, Cells B and C old 20mm gravel and Cell D old 5mm gravel. Cells B, C and D had been operational since 1995 whereas Cell A had been in use since 2000. The wetland received secondary treated effluent direct from the Oxley Creek WTP at an average flow rate of 8L/min with a median hydraulic loading rate (HLR) of 0.12m/day and a hydraulic retention time (HRT) of 2 to 3 days. Each cell consisted of three gravel sections (Section 1 to 3) separated by 1m wide open water sections. Gravel Sections 2 and 3 were planted out with the four macrophyte species in October 2000, Section 1 remained unplanted. Plant health and leaf height was monitored to assess plant establishment and growth. Investigations into plant establishment and growth demonstrated that Carex was most suitable. Carex achieved the highest maximum leaf height and was not affected by pests and disease unlike Schoenoplectus and Philydrum. Above ground biomass was cropped in May and August 2001, with biomass of cropped material measured on both occasions. Plant health and re-growth following cropping of above ground biomass in May and August 2001 demonstrated that cropping retarded regrowth of Schoenoplectus and Philydrum. Carex and Baumea recovered quickest following cropping, with Carex achieving leaf height prior to cropping within 6 months. Proportion of biomass contained above and below ground was measured by collecting biomass samples three times over 9 months and dividing into plant components (roots, rhizomes, leaves, flowers and stems). Investigations into the proportion of above and below ground components indicated that >80% of biomass is contained above ground. Therefore cropping above ground biomass would potentially remove a significant proportion of nutrient storage from the CW. The results indicated that the ideal time for cropping was in spring/summer when plants are flowering particularly for Philydrum, whose flowering stems comprised 40% of total plant biomass. Flowering stems of Philydrum could potentially have a commercial use as a cut flower. Nutrient content of the four species in each cell was measured for individual plant components when first planted and after three (summer) and six (autumn) months growth. This was combined with biomass data to quantify nutrient bioaccumulation (nitrogen and phosphorus) by the four species in each cell. In terms of ability to bioaccumulate nitrogen and phosphorus, measurements of nutrient content and storage indicated that all four species were suitable. Nutrient storage was highest for Baumea and Carex. However high nutrient content may make the macrophytes more susceptible to pest and disease attack as found in this study for Philydrum and Schoenoplectus. Nutrient storage was highest in Cell A (new 5mm gravel) as a result of higher biomass achieved in this cell. The cropping and nutrient storage experiments indicated that Carex was the most suitable species for use in SSF CWs. Carex achieved the highest nutrient storage and had the fastest regrowth following cropping. Organic carbon accumulation between gravel particles measured as the proportion of material lost at 500oC was determined for gravel samples collected from each section for all four cells at 10cm depth increments (0-10cm, 10-20cm and 20-30cm). Investigations into organic carbon accumulation within the gravel substrate showed that organic accumulation was higher in the planted sections particularly for cells that had previously been planted with Phragmites australis. Organic accumulation was highest in the top 20cm of the gravel, which can be attributed to litter fall and root material. The effect of gravel size on plant growth, biomass, root depth and organic accumulation was assessed throughout the study. Investigations indicated that gravel size did not appear to affect biomass, maximum root penetration, re-growth following cropping and organic accumulation. Water quality from the inlet and outlet of each cell was measured fortnightly over 12 months (May 2001 to May 2002). Water quantity (HLR) was measured weekly using tipping buckets located at the inlet and outlet of each cell. Water quality and quantity were combined to investigate the nutrient removal efficiency of the wetland. The Oxley wetland was highly effective in reduction of TSS (<2mg/L) and COD (<30mg/L). Principal TSS and COD removal mechanism was physical with the first gravel section acting as a filter removing the majority of particulate material. Average loading rates to the wetland were 7.1 kg/ha/d PO4-P, 14 kg/ha/d NH4-N and 5.4 kg/ha/d NOx-N. Average daily mass removal rates ranged from 7.3 kg/ha NH4-N in Cell D to 4.6 kg/ha in Cell C (i.e. 37%-22% removal efficiency respectively); 5.2 kg/ha NOx-N in Cell C to 1.3 kg/ha in Cell A (i.e. 75%-22% removal efficiency) and 0.8 kg/ha PO4-P in Cell A to 0.1 kg/ha in Cell C (i.e. 10%-1% removal efficiency). Removal efficiency was calculated on a loads basis. Insufficient retention times (2-3 days based on tracer study) and anaerobic conditions (<1mg/L) limited further nitrogen removal. Negligible phosphorus removal for all cells was attributed to short retention time and likelihood of phosphorus adsorption being close to capacity. Investigation into the proportion of nutrient removal attributed to plant uptake demonstrated that nutrient uptake and storage in plant biomass accounted for <12% TN and <5% TP. This research project has provided several useful outcomes that can assist in future guidelines for designing effective SSF CWs in the subtropics/tropics. Outcomes include the importance of maintaining an adequate water level during the initial establishment phase. Maximising effluent treatment by pre-treatment of wastewater prior to entering SSF CWs to enable ammonia to be converted to nitrate and ensuring adequate hydraulic retention time. Carex fascicularis was the most suitable species particularly where harvesting regimes are employed. Philydrum flowering stems could be used as a cut flower in the florist trade.

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Research was performed at a pilot-scale wastewater treatment plant operating an adsorption/bio-oxidation (A/B) process at 20C. The study compared B-Stage performance under DO Control, Ammonia Based Aeration Control (ABAC), and Ammonia vs. NOx (AvN) control. AvN in 1) fully-intermittent and 2) intermittently-aerated MLE configurations was compared to DO Control and ABAC, each with continuous aeration, in an MLE configuration. The study also examined operation of each aeration strategy with two different feed types: A-Stage effluent (ASE) and primary clarifier effluent (PCE). Operating modes were compared on the basis of nitrogen removal performance, COD utilization efficiency for denitrification, and alkalinity consumption. AvN was found to provide comparable nitrogen removal performance to DO Control and ABAC. The highest nitrogen removal performance was seen when operating DO Control (81.4 ± 1.2%) and ABAC (81.1 ± 1.2%) with PCE. High nitrogen removal efficiency (77.5 ± 6.1%) was seen when fully-intermittent AvN operation was fed ASE containing a high particulate COD fraction. A high effluent nitrite accumulation ratio (NAR = NO2-/(NO2-+NO3-)) was seen during this period (46 ± 15%) accompanied by the out-selection of Nitrospira. Feeding effluent from AvN control to an Anammox MBBR improved removal efficiency. Increased soluble COD loading resulted in greater nitrogen removal with strategies operating in an MLE configuration while particulate COD was found to be important for processes where removal was designed to occur in downstream reactors. Efficiency of COD for denitrification was found to vary based on the amount and type of influent COD; however AvN in an MLE configuration was found to use COD more efficiently than fully-intermittent AvN. In either configuration, AvN required less alkalinity addition than DO Control or ABAC. High sCOD concentrations in PCE led to increased nutrient removal as compared to ASE but increased heterotrophic growth and mixed liquor concentrations in the B-Stage making the A-Stage an attractive option for its ability to control the C/N ratio fed to BNR processes. / Master of Science

In conventional wastewater treatment plants, methanol, ethanol, and acetate are used as carbon source for the denitrification process in the biological nutrient removal. However, growing concern regarding economical costs and carbon footprints from the fossil-based production of these chemicals have forced the companies to look for other alternatives. VFAs have shown a great potential in replacing the conventionally used carbon sources. If implemented this will result in lower chemical cost and a drastic decrease in carbon footprint as well as striving WWTPs towards sustainable development. In this work denitrification has been analysed using different variations of VFAs such as fermented potato protein liquor, food waste and chicken manure VFA. This was done using a basic laboratory setup of a denitrification reactor which used basic stirring agitation and nitrogen purging to ensure anoxic conditions. Nutrients and excess sCOD were added to ensure the highest denitrification rates. The denitrifying biomass was collected at Gryaab AB in the form of k1-carriers making this process a MBBR. The most influential characteristic of the VFAs is the distribution of the acids in the VFA effluent. Butyric acid along with caproic acid showed the best potential for efficient denitrification. The possibility of concentration of VFA effluent showed a high potential when using a nanofiltration system. A C/N ratio of 4.5 conventionally used when methanol is added showed to be the most optimal condition for VFA addition. The combination of VFAs together with conventional used carbon sources showed the best potential in denitrification efficiency proving to be as good or even better than pure synthetic ones. VFAs effluents showed the best potential in removing the intermediate nitrite from the wastewater at high rates. Overall, VFAs shown a great potential for replacing conventionally used carbon sources, demonstrating the potential of substitution, which if implemented will result in lower carbon footprint and a strive towards sustainable development.