Mathematical modeling is a useful tool for the design, analysis and control of wastewater treatment systems. The activated sludge process is one of the most common processes used in wastewater treatment, and therefore is a particularly important candidate for the application of mathematical models. In the 1980s, a task group organized by the International Association on Water Quality (IAWQ) developed a conceptual model of the activated sludge process, which has become an industry-wide standard for the development of computer-based activated sludge models. A recent version of the IAWQ model incorporates 19 components, 17 processes, and numerous rate and stoichiometric coefficients. It is difficult and costly to quantify all of the necessary coefficients for any given application of the model; consequently, it is important to identify the most critical wastewater and biomass components and the relevant coefficients to be quantified for the most common uses of the model. It is also important to provide guidance to potential model users on the use of default and/or estimated values for the remaining parameters.

The design of wastewater treatment plants with redundancy to assure a quality end product may be in conflict with efforts to assure effectiveness. Redundancy of major system components is to assure compliance with regulations and protection of the environment and the health and safety of the public and treatment plant staff. However, the capital costs and maintenance associated with redundant equipment does not necessarily enhance facility performance. There are a number of forces driving the level of redundancy in plant designs. Federal and state compliance regulations and the design engineer's past experiences will influence the plant design. To some extent the plant staff may also provide input into the plant design and, therefore, contributes to the redundancy. This report determines alternative methods to address treatment plant redundancy, including examples of methods currently in place and, ideally, insight on the premises leading to these applications. A secondary objective is to identify the similarities and differences in redundancy requirements associated with federal and state regulatory agencies. This publication can also be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below

This book discusses the fundamental skills, techniques, and tools of auditing, and the characteristics of a good process safety management system. A variety of approaches are given so the reader can select the best methodology for a given audit. This book updates the original CCPS Auditing Guideline project since the implementation of OSHA PSM regulation, and is accompanied by an online download featuring checklists for both the audit program and the audit itself. This package offers a vital resource for process safety and process development personnel, as well as related professionals like insurers.

"Sanitation Safety Planning (SSP) is a step-by-step risk based approach to assist in the implementation of the 2006 WHO Guidelines for Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture. The approach can be applied to all sanitary systems to ensure the system is managed to meet health objectives. SSP assists users to: systematically identify and manage health risk along the sanitation chain; guide investment based on actual risks, to promote health benefits and minimize adverse health impacts; provide assurance to authorities and the public on the safety of sanitation-related products and services. The SSP manual is targeted at a variety of users at different levels including; health authorities and regulators, local authorities, wastewater utility managers, sanitation enterprises and farmers, community based organizations, farmers associations and NGOs. SSP brings together actors from different sectors to identify health risks in the sanitation system and agree on improvements and regular monitoring and underscores the leadership role of the health sector."--Publisher's description.