Series:

WERF Research Report

2 total works

Cover of Producing Class A Biosolids With Low-Cost, Low-Technology Treatment Processes
Class A biosolids can be produced using low-cost, low-technology biosolids treatment processes including lagoon storage, air drying, and cake storage. This project reviewed the available literature and municipal agency data about these processes. This report presents design and operating guidelines distilled from the review process. It is designed for wastewater treatment plant (WWTP) managers, operators, and engineers who wish to discern whether these processes, used alone or in combination, might be practically applied at specific plants. This report also describes the U.S. regulatory environment in relation to producing Class A Biosolids and defining Class A processes. It also presents a list of recommended research needs. This report: Familiarizes WWTP managers, operators, and engineers with low-cost, low-technology biosolids treatment processes, likely pathogen kill mechanisms, and practices that have reduced pathogen densities to Class A levels at scales ranging from laboratory tests to large municipal biosolids treatment operations. Presents guidelines for producing Class A biosolids under a variety of conditions. Describes low-technology treatment processes within the Class A regulatory framework, identifies satisfactory end conditions for products created from low-tech treatment processes, and provides guidance in developing national or site-specific certification as processes equivalent to a process to further reduce pathogens (PFRP).

Cover of Developing Protocols for Measuring Biosolids Stability
The general goal of this project is to validate test protocols that are commonly used to assess the stability of various biosolids products, and to specify a standard for each test method. Toward this end, the project team conducted a literature review, surveyed selected practicing facilities, and conducted a sampling and analysis program. Information concerning stability-testing protocols and data for each biosolids-stabilization technology and testing method reviewed were collected and evaluated. The biosolids-stabilization technologies reviewed were aerobic and anaerobic digestion, alkaline stabilization, and composting; the testing methods reviewed were specific oxygen uptake rate, volatile solids reduction, additional volatile solids reduction, pH and changes in pH, and carbon dioxide evolution.The report recommends specific protocols for each testing method, and presents intrinsic precision data for each protocol. In addition, data is presented from facilities using each protocol, to serve as a basis for evaluating the collective degree of variability associated with each stabilization process. Collective variability results from sampling, feedstock, the stabilization process, and the intrinsic variability of each testing method. Using split sample testing, interlaboratory data (variability among different laboratories) are presented. Issues associated with variability, error sources, shortcomings, and numerical criteria values are discussed for each method.