A Holistic Process Model for Evaluating Alternative Biosolids Technologies and Operational Methodologies to Improve Performance and Sustainable Decision-making at High Purity Oxygen Wastewater Treatment Plants

Authors

Manuel E. Moncholi, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Civil Engineering

First Advisor's Name

Berrin Tansel

First Advisor's Committee Title

committee chair

Second Advisor's Name

Yelena Katsenovich

Second Advisor's Committee Title

committee member

Third Advisor's Name

Shonali Laha

Third Advisor's Committee Title

committee member

Fourth Advisor's Name

Helena Solo-Gabriele

Fourth Advisor's Committee Title

committee member

Fifth Advisor's Name

Michael Sukop

Fifth Advisor's Committee Title

committee member

Keywords

biosolids, wastewater, anaerobic digestion, process model, sludge thickening, sludge dewatering

Date of Defense

10-30-2018

Abstract

In the span of the last decade the regulatory, public and commercial sentiments in Florida towards wastewater biological sludges, termed biosolids, have resulted in more restrictive land application rules, public cynicism about quality and agricultural benefits, and defensive posturing and marketing to appease public opinion. To determine and recommend the most cost effective and sustainable combination of biosolids treatment technologies to achieve Class B biosolids at the MDWASD facilities, the author created a holistic process model that is novel in the realm of wastewater treatment.

The research methodology focused on the analyses of historical data, analyses of pilot-testing data, development of a biosolids process evaluation framework consisting of a holistic process model, model calibration using historical and pilot data, and technical evaluations carried out by the author. The process evaluation framework was applied to existing and alternative biosolids treatment processes to formulate a sustainable path forward for biosolids processing efforts at the South District and Central District Wastewater Treatment Plants in Miami-Dade (SDWWTP and CDWWTP). This research has contributed to significant advancements in the field of biosolids treatment, operations and management which are highlighted below:

• Developed a framework to evaluate biosolids treatment options for wastewater treatment facilities, comparing both existing and proposed technologies;
• Identified the most effective means of sludge thickening, anaerobic digestion and digested sludge dewatering ensuring Class B biosolids treatment while reducing biosolids production and hauling quantities at a lower capital and operational expenditure when existing equipment reaches end of useful life;
• Evaluated alternative struvite control methods to achieve higher dewatered sludge solids concentrations and improved struvite management;
• Identified the shortcomings of the traditionally used design and operating parameters provided in textbooks and provided necessary corrections and justifications.

The data analyses and holistic modeling efforts conducted during this study identified alternative biosolids treatment technologies and operational modifications for SDWWTP and CDWWTP. These recommendations were the replacement of existing gravity thickening with thickening centrifuges, retrofitting sludge stabilization from traditional primary-secondary anaerobic mesophilic digestion to single-stage anaerobic mesophilic digestion, and upgrading dewatering centrifuges to new highly-automated and more energy efficient units.

Identifier

FIDC007673

Recommended Citation

Moncholi, Manuel E., "A Holistic Process Model for Evaluating Alternative Biosolids Technologies and Operational Methodologies to Improve Performance and Sustainable Decision-making at High Purity Oxygen Wastewater Treatment Plants" (2018). FIU Electronic Theses and Dissertations. 4010.
https://digitalcommons.fiu.edu/etd/4010