The membrane bioreactor (MBR) is becoming increasingly popular for wastewater treatment, mainly due to its capability of producing high quality effluent with a relatively small footprint. However, high plant maintenance and operating costs due to membrane fouling limit the wide spread application of MBRs. Membrane fouling generally depends on the interactions between the membrane and, the activated sludge mixed liquor, which in turn, are affected by the chosen operating conditions. The present research study aimed to explore the process performance and membrane fouling in the membrane enhanced biological phosphorus removal (MEBPR) process under different operating conditions by, (1) comparing two MEBPRs operated in parallel, one with constant inflow and another with a variable inflow, and by, (2) operating the MEBPRs with different solids retention times (SRT). On-line filtration experiments were conducted simultaneously in both MEBPR systems by using test membrane modules. From the transmembrane pressure (TMP) data of the test membrane modules, it was revealed that fouling propensities of the MEBPR mixed liquors were similar in both parallel reactors under the operating conditions applied, although the fouling propensity of the aerobic mixed liquors of both reactors increased when the SRT of the reactors was reduced. Routinely monitored reactor performance data suggest that an MEBPR process with a varying inflow (dynamic operating condition) performs similarly to an MEBPR process with steady operating conditions at SRTs of 10 days and 20 days. Mixed liquor characterization tests were conducted, including critical flux, capillary suction time (CST), time to filter (TTF) and, bound and soluble extracellular polymeric substances (EPS) were quantified, to evaluate their role on membrane fouling. The tests results suggest that the inflow variation in an MEBPR process did not make a significant difference in any of the measured parameters. With decreased SRT, an increase in the concentrations of EPS was observed, especially the bound protein, and the bound and soluble humic-like substances. This suggests that these components of activated sludge mixed liquors may be related to membrane fouling. No clear relationship was observed between membrane fouling and other measured parameters, including critical flux, normalized CST and normalized TTF.

Low plant available phosphorus limits legume growth and biological nitrogen fixation (BNF). This study examined, under controlled conditions, the relationship between soil phosphorus and alfalfa and soybean BNF on two contrasting low-P soils (Ontario and Nova Scotia) from organic dairy farms. Soluble P was applied up to 135 mg P kg-1. An optimum range of 45 to 90 mg kg-1 applied P increased soybean plant growth, nodulation, N and P uptake and BNF. Significant effects of soil type reflected greater N supplying ability and lower P sorption for the Ontario soil. Alfalfa response to soluble P application was not as apparent. In addition three potentially organically acceptable amendments (MSW compost, Crystal Green® struvite and partially solubilized rock phosphate) were evaluated as alternate sources of plant available P. Compost and struvite, applied at moderate rates, sufficiently supplied P to increase plant growth and BNF comparably to that found for soluble P fertilizer.

Despite many drawn parallels between carbon and phosphorus, the development of catena-phosphorus chemistry is superficially explored when compared to carbon. This lack of progression is especially highlighted for cationic phosphorus frameworks, as neutral and anionic phosphorus frameworks have been studied to a much greater extent. This stresses cationic catena-phosphorus frameworks as important molecules for an improved understanding of fundamental phosphorus chemistry. Recent advancements in synthetic methods demonstrate that phosphorus frameworks of this type are viable target molecules. Furthermore, the precedence of a variety of new cationic catena-phosphorus frameworks by such methods exemplify their versatility. Here, novel 1,3-diphosphino-2-phosphonium [R2P-PR2-PR2]+, 2-phosphino-1,3-diphosphonium [R3P-PR-PR3]+ and cyclo-triphosphinophosphonium [R2P(RP)3]+ cations have been isolated and characterized in order to study the insertion of phosphenium cations into the phosphorus-phosphorus bonds of catena-phosphines.

Utilizing food and yard waste (FYW) compost for plant production requires determination of application rates that support crop production, improve soil properties and avoid excessive nutrient build-up. An 88 day incubation experiment showed 12 t ha-1 FYW compost to contribute 3.6 kg M3P ha-1 and 0.3 kg mineral N ha-1, 24 t ha-1 supplied 15.1 kg M3P ha-1 and 0.7 kg N ha-1 and 36 t ha-1 gave 39.5 kg M3P ha-1 and 1.2 kg N ha-1 to Pugwash series coarse, loamy soil. A field study showed FYW compost yielded higher P concentrations in grain and stover but lower grain yields than fertilizer. In the residual year, compost treatment yields didn’t decrease and concentrations and amounts of P and N increased. This FYW compost applied to corn at 24 t ha-1 with an N fertilizer can yield similarly to fertilizers only, removing greater amounts of P in grain and stover.

A mass-balance modeling approach has been applied to gain an improved understanding of the relative contributions of phosphorus loading from various sources into a freshwater lake with cage-aquaculture in Ontario. All cage-aquaculture in Ontario is located within Lake Huron and Georgian Bay of the Great Lakes where concerns about potential environmental issues are constraining growth of the industry. Phosphorus is of particular concern for cage-aquaculture operations in Ontario since this nutrient may accelerate eutrophication of freshwater. Sound scientific information is needed for the Ministry of Environment lake managers to make defensible decisions to move the industry forward in a sustainable manner. Lake Wolsey is located on Manitoulin Island in Lake Huron, Ontario. The lake is connected to the North Channel by a small inlet where water exchanges periodically. A cage-aquaculture operation was established in 1986 and has an average annual production of approximately 250 metric tonnes of rainbow trout. We have estimated total phosphorus loadings from eight sources of inputs and three sinks from the lake. We then applied a sensitivity analysis to establish parameters that require empirical measurement and field validation. Results show non-point sources as the leading contributor of total phosphorus to Lake Wolsey (40%, 1120 kg) followed by the farm (32%, 915 kg), groundwater (11%, 305 kg), and dwellings (8%, 219 kg), internal phosphorus load from the hypoxic hypolimnion mid-lake (7%, 186 kg), precipitation (3%, 79 kg) and leaf litter (0.3%, 8 kg). Results of the sensitivity analysis show non point sources to be the most significant parameter in terms of total phosphorus loading, followed by the lake sedimentation, then the contribution by the aquaculture operation. This is followed by the exchange via the inlet, groundwater, dwellings, the internal phosphorus, sportfishing, precipitation and leaf litter. Information from this project will provide water quality managers with scientific information to aid in decisions pertaining to policy and regulatory approaches for water quality risk assessment and management of cage-aquaculture in Ontario. / Great Lakes Sustainablility Fund, Great Lakes Action Plan V, Ontario Sustainable Aquaculture Working Group

Abstract Methyldiphenylphosphonium cyclopentadienylide, C5H4PMePh2 (II), has been synthesized and characterized spectroscopically and crystallographically, and has been found to exhibit properties consistent with the zwitterionic structure IIb. New group 6 complexes, (η5-C5H4PMePh2)M(CO)3, have been synthesized and fully characterized. Comparisons of ν(CO) of these complexes with those of the isoelectronic (η6-C6H6)M(CO)3 and [(η5-C5H5)M(CO)3]- suggest that the electron donating ability of the ylide is between that of the cyclopentadienyl anion (Cp-) and benzene, but closer to Cp-. The electronic structures of II and of (η5- C5H4PMePh2)Cr(CO)3 have been investigated using ab initio methodologies. Thermal and photochemical substitutions of the CO ligands of (η5-C5H4PMePh2)M(CO)3 (M = Cr, Mo) by equimolar amounts of PMe3 and PPh3 were not observed, but the ylide is displaced photochemically from (η5-C5H4PMePh2)Mo(CO)3 by excess PMe3 to form fac- Mo(CO)3(PMe3)3 while (η5-C5H4PMePh2)Mo(CO)3 reacts with I2 to form [(η5- C5H4PMePh2)Mo(CO)3I]I. One electron oxidations of (η5-C5H4PMePh2)M(CO)3 (M = Cr, Mo, W) have been performed to give the cationic radicals [(η5-C5H4PMePh2)M(CO)3]+, which undergo dimerization to give dicationic metal-metal bonded dimers ((η5-C5H4PMePh2)M(CO)3)2 2+ in the solid state. These complexes have been fully characterized spectroscopically and crystallographically. It has been determined that the chromium dimer ((η5- C5H4PMePh2)Cr(CO)3)2 2+ undergoes dissociation extensively in solution to the persistent radical cation monomer (η5-C5H4PMePh2)Cr(CO)3 +, but that the heavier metal analogues iii ((η5-C5H4PMePh2)M(CO)3)2 2+ (M = Mo, W) dissociate very little, if at all. The Cr-Cr bond distance of the chromium complex is 3.3509(7) Å, which is the longest Cr-Cr bond distance known for a compound not containing some type of ligand bridging the metalmetal bond. The hitherto unknown indenyl-derived ylide, C9H6PMePh2, has been synthesized and characterized spectroscopically and crystallographically. The chromium tricarbonyl complex of this ligand, (η5-C9H6PMePh2)Cr(CO)3, has been synthesized and characterized spectroscopically and crystallographically. This complex is a mixture of two isomers exhibiting planar chirality generated upon coordination of the ligand. This complex represents the first structurally characterized phosphorus noncyclopentadienylide coordinated in an η5 manner. The spectroscopic and crystallographic behaviour of C9H6PMePh2 demonstrates that this ylide behaves much like the related cyclopentadienylides. / Thesis (Ph.D, Chemistry) -- Queen's University, 2007-09-07 11:46:39.391

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The availability of phosphorus from the anoxic hypolimnia of lakes to epilimnetic plankton was investigated by experimental studies on eight lakes in Ontario and Quebec. Availability was determined with a short-term bioassay based on the standardized retardation of planktonic uptake of phosphorus tracer in the presence of orthophosphate; availability was also estimated by SRP (soluble reactive phosphorus) analysis, since approximately 90% of SRP was available in anoxic waters. / Iron concentrations were high in some hypolimnia, but should become diluted after mixing with surface water. When iron concentrations after mixing exceeded 0.20 mg/L, aeration lowered availability and SRP. Therefore, samples from anoxic hypolimnia were kept anoxic. The fate of hypolimnetic phosphorus at turnover was studied by construction of a budget for SRP, total phosphorus, particulate iron containing phosphorus and particulate biological phosphorus at fall turnover in Lake Magog. Despite high concentrations of hypolimnetic iron, only 30% of the upwelling hypolimnetic phosphorus combined with iron after complete mixing, 30% was incorporated into biomass and 38% stayed potentially available as SRP. / In two lakes, hypolimnetic iron was undetectable hydrogen sulfide concentrations were high. H(,2)S interfered with the SRP analysis and poisoned plankton. After degassing, routine SRP analysis was possible, and availability was close to 100%. Iron and H(,2)S interference in the SRP analysis were circumvented by degassing or by maintaining anoxia. A simpler method, the analysis of TRP (total reactive phosphorus) after aeration, was developed which analyses SRP quantitatively in anoxic waters.

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