The Effect of Thermal Hydrolysis Pretreatment on the Anaerobic Degradation of Nonylphenol and Short-Chain Nonylphenol Ethoxylates in Digested Biosolids

The presence of micropollutants can be a concern for land application of biosolids. Of particular interest are nonylphenol diethoxylate (NP2EO), nonylphenol monoethoxylate (NP1EO), and nonylphenol (NP), collectively referred to as NPE, which accumulate in anaerobically digested biosolids and are subject to regulation based on the environmental risks associated with them. Because biosolids are a valuable nutrient resource, it is essential that we understand how various treatment processes impact the fate of NPE in biosolids. Thermal hydrolysis (TH) coupled with mesophilic anaerobic digestion (MAD) is an advanced digestion process that destroys pathogens in biosolids and increases methane yields and volatile solids destruction. We investigated the impact of thermal hydrolysis pretreatment on the subsequent biodegradation of NPE in digested biosolids. Biosolids were treated with TH, anaerobic digestion, and aerobic digestion in laboratory-scale reactors, and NPE were analyzed in the influent and effluent of the digesters. NP2EO and NP1EO have been observed to degrade to the more estrogenic NP under anaerobic conditions; therefore, changes in the ratio of NP:NPE were of interest. The increase in NP:NPE following MAD was 56%; the average increase of this ratio in four sets of TH-MAD samples, however, was only 24.6 ± 3.1%. In addition, TH experiments performed in pure water verified that, during TH, the high temperature and pressure alone did not directly destroy NPE; TH experiments with NP added to sludge also showed that NP was not destroyed by the high temperature and pressure of TH when in a more complex sludge matrix. The post-aerobic digestion phases removed NPE, regardless of whether TH pretreatment occurred. This research indicates that changes in biosolids processing can have impacts beyond just gas production and solids destruction

Predictive Analytics for Quantifying the Long-Term Costs of Defects During Bridge Construction

SPR-4526During the lifecycle of a bridge, deterioration of the concrete deck originates from many sources, e.g., corrosion due to water infiltration in conjunction with chlorides from the use of de-icing salts. Such deterioration may be affected by any one of the following six actions relevant to a bridge from conception to demolition: design, construction, in-service conditions, maintenance, repair and rehabilitation, and replacement. Many researchers have studied the relationships between these sources and their consequences. However, the relationship between construction defects and inspection practices, and its impact on the deterioration process has not yet been identified. This project focuses on the development of predictive models to assess the impact that defects present during concrete bridge deck construction may have on the lifecycle performance of the bridge deck in terms of the chemical and environmental deterioration relevant to Indiana. Based on the relevant cost information from the Indiana Department of Transportation (INDOT), a methodology is developed here to determine the potential costs associated with this deterioration. Recommendations relevant to construction and inspection and data collection practices are discussed to improve future bridge construction and inspection practices. The models and methods developed in this work will enable INDOT to better predict the accelerated deterioration of a concrete deck when a construction defect has been identified and the associated additional cost

On Algebras Generated by Composition Operators

Let Δ be the open unit disk in the complex plane and let be the group of automorphisms of Δ onto Δ, define byThe Banach spaces Hp = Hp(Δ), 1 ≦ p &lt; ∞, are the Hardy spaces of functions analytic in Δ with their integral p means bounded,</jats:p

Unbounded composition operators on 𝐻²(𝐵₂)

Examples are given of holomorphic self-maps of the unit ball on C 2 {{\text {C}}^2} which induce unbounded composition operators on the Hardy space H 2 {H^2} . In particular, an example is given which is one-to-one on the closed ball. Also, a valence condition on the boundary of this ball is given which is sufficient for unboundedness of the induced composition operator.</p