Benjamin S. Magbanua

Anaerobic codigestion of hog and poultry waste

Anaerobic batch tests were performed using hog and poultry wastes in various proportions. Treatments that received both wastes produced higher yields of biogas, up to 200 +/- 30 mL/g volatile solids (VS) destroyed, and methane, up to 130 +/- 20 mL/g VS destroyed, compared to either waste alone.

A technique for obtaining representative biokinetic parameter values from replicate sets of parameter estimates

The rational design and simulation of biotreatment systems requires sound mathematical models and reliable parameter estimates. Biodegradation kinetics are usually modeled using the Monod or Andrews equation, and model parameters are usually obtained by fitting an observed concentration-time profile to the model. Since the nature of the models and the method of parameter estimation result in correlation between the parameters, the question arose as to how to obtain a single set of Parameters Representing the Average μ-S response (referred to as PRAMUS values) from replicate sets of experimentally derived parameter estimates. The common approach of using the arithmetic mean parameter values was adequate only for data conforming to the Monod model, particularly when the variability among replicate parameter estimates was small. For the Andrews model, nonlinear regression was used to obtain PRAMUS values. The ability of the PRAMUS and mean parameter values to reproduce the average μ-S response and to simulate experimentally observed oxygen uptake was evaluated. On this basis, the use of PRAMUS values is recommended, particularly when dealing with systems modeled by the Andrews equation, with experimental data characterized by a high degree of experimental variability, and/or with process situations where high substrate concentrations are likely to be encountered, e.g. shock loads.

Wetlands for Wastewater Treatment.

This paper provides a review of the treatment technologies, which utilize natural processes or passive components in wastewater treatment. In particular, this paper primarily focuses on wetland systems and their applications in wastewater treatment (as an advanced treatment unit or decentralized system), nutrient and pollutant removal (single and multiple pollutants, and metals), and emerging pollutant removal (pharmaceuticals). A summary of studies involving the plant (vegetation) effects, wetland design and modeling, hybrid and innovative systems, storm water treatment and pathogen removal is also included.

A Critical Evaluation of Advanced Oxidation Processes for Emerging Contaminants Removal

Removing emerging contaminants from waste streams has become a topic of growing interest. The adverse effects of endocrine disrupting chemicals (EDCs) and pharmaceutical and personal care products (PPCPs) have been well documented, but much remains to be known about these contaminants and their removal. Their removal with traditional methods has not been entirely successful. However, adequate degradation can be achieved through the use of advanced oxidation processes (AOPs). Multiple factors must be considered when completing an in-depth comparison; therefore, process engineering, environmental, and economic and social parameters were included in a deeper analysis. This study presents a ranking system to numerically score the performance of various AOPs (e.g., Ozonation, UV irradiation, Photocatalysis, Fenton reaction, and integrated processes) in several categories of parameters under engineering, environmental, and socioeconomic components. From this preliminary assessment, it was noted that H2O2/O3 (Perozonation) presented the highest average ranking (3.45), with other processes showing comparable performance. TiO2 photocatalysis received the lowest ranking (2.11).

Modeling compartmentalized lagoon systems under cyclic operation

Abstract Aerated lagoon systems have been widely used for municipal wastewater treatment because of their simplicity and low maintenance costs, but many have subsequently required upgrading due to increased wastewater volume and stricter environmental regulations. To improve performance and increase capacity with minimal capital infusion, Hawkins (1997, United States Patent No. 5,624,563) developed a process wherein the lagoon basin is compartmentalized and selected compartments are cycled to separate and recycle biosolids. Simulation would be useful to assess the process and to evaluate alternative plant modification schemes. The hydraulic behavior of the system is complex, however, due to the interconnected and cyclic nature of the compartments and their operation. This paper describes the development of a hydraulic modeling approach for compartmentalized lagoon systems, and discusses its implementation using AQUASIM (EAWAG, Dubendorf, Switzerland). The modeling approach was implemented for a specific configuration and several operating conditions. Simulated tracer tests indicated that the oscillatory nature of the system makes its behavior difficult to simulate with commonly used non-ideal reactor models. Biotreatment simulations using Activated Sludge Model No. 1 suggest that conversion into a compartmentalized lagoon system could effectively upgrade the performance and capacity of a conventional aerated lagoon.