Encina Wastewater Authority’s Innovative Management Plan for Class A Biosolids Pellets

justin — Tue, 06 Jul 2010 18:00:04 +0000

The Encina Wastewater Authority (EWA) recently upgraded the biosolids and energy management facilities at the Encina Water Pollution Control Facility (EWPCF) in Carlsbad, California. Biosolids processing improvements included replacement of existing dewatering equipment with centrifuges and the installation of a triple-pass, rotary drum heat dryer system to produce Class A biosolids pellets for beneficial reuse. As an integral part of its expansion project, EWA prepared a Biosolids Management Plan (BMP) through a multifaceted process that included formulation of evaluation factors for the decision framework, surveys of potential endusers, evaluation of various reuse/disposal (R/D) options using economic and qualitative analyses, generation of a Financial Model, preparation of a Business Plan, and other related elements. This paper presents an overview of the BMP, focusing on the major planning elements, development process, and several unique features that make the approach used in the BMP a valuable tool for development of EWA’s biosolids distribution and marketing program. Source: WEFTEC 2009 Proceedings

Case Study – Fargo, North Dakota: Hydrogen Peroxide for Regeneration of Ferrous Chloride, an Innovative Approach to Hydrogen Sulfide Control

justin — Tue, 06 Jul 2010 17:56:42 +0000

Historically, ferrous chloride (FeCl2) injection has been utilized to successfully control odors and corrosion within the sanitary sewer collection system of Fargo, North Dakota. However, increased odor complaints prompted an evaluation of the odor conditions present in the sanitary sewer system. Study results indicated that the current FeCl2 dosing rate was insufficient to control odors. In response, a number of liquid phase odor control treatment alternatives were evaluated. Due to the existing FeCl2 injection program, iron regeneration and improved odor control were realized through the innovative use of hydrogen peroxide. A program was initiated to demonstrate the efficacy of the proposed treatment strategy on a full-scale level. In response to improved sulfide treatment, reduced FeCl2 injection rates, and economic benefits realized during the demonstration program, the City of Fargo elected to incorporate PRI-SC as part of their upcoming collection system improvements. Variable dosing strategies for FeCl2 and H2O2 were incorporated for efficient odor control. The injection rates will fluctuate based on diurnal and seasonal sulfide loadings to prevent overdosing and reduce overall chemical costs. Hydrogen peroxide injection will be utilized to regenerate spent FeCl2 at a new 151,410 m3/d (40 mgd) sanitary lift station located in north Fargo. The PRI-SC technology will serve to reduce odors and corrosion in the 750 mm (30 inch) diameter forcemain from the new lift station and at the forcemain discharge at the WWTF headworks. While PRI-SC was found to be beneficial for the City of Fargo, any liquid phase technology should be evaluated for effectiveness based on site specific conditions. Source: WEFTEC 2009 Proceedings

Sustainability Archive » Innovative Approach

Encina Wastewater Authority’s Innovative Management Plan for Class A Biosolids Pellets

Case Study – Fargo, North Dakota: Hydrogen Peroxide for Regeneration of Ferrous Chloride, an Innovative Approach to Hydrogen Sulfide Control