Water and Wastewater Management Projects in the Tropics
Over the last 30 years a significant number of water and sanitation projects have been implemented in developing countries and billions of dollars has been spendt. Projects have covered rural as well as urban water supply systems, wastewater collection, disposal and treatment systems, and have mainly been financed by international funding agencies such as international banks and international aid organisations. However, unfortunately it is a fact that the number of failures, or non-functioning, of the established systems, outnumbers the number of successes.
Reduction of Sludge Production in Wastewater Treatment Plants
The volume of sludge produced in a WWTP is only about 1% (dewatered sludge is 0.5‰) of the volume of influent wastewater to be treated. To manage WWTPs effectively and efficiently, it is absolutely necessary to extract waste sludge, including inert solids and excess biomass, in order to prevent their accumulation within the system.
Sludge Drying Overview - Treatment Methods and Applications
Sludge is a residual, semi-solid by-product left from industrial or refining processes. It is a separated solid suspended in a liquid, typically containing major quantities of interstitial water between its solid particles. This material can be dried to cut its volume and reduce most of the moisture content of the biosolids present in the sludge.
Helminth eggs are the infective agents for the types of worm diseases known globally as helminthiases. Although helminths are pluricellular animals their eggs are microscopic (around 20 to 80 μm for those that are important in the sanitary field) and are contained in variable amounts in wastewater, sludge and excreta. Helminth eggs infect humans through: (1) the ingestion of food crops polluted with wastewater sludge or excreta, (2) direct contact with polluted sludge or faecal material, and (3) the ingestion of polluted meat or fish.
Bio-toilets: Sustainable Solution to India’s Sanitation Challenge
Banka BioLoo Pvt Ltd, a firm committed to environmental betterment and social uplift, is supporting to eradicate the malaise of open defecation in India. By providing eco-friendly bio-toilets (or bioloos), the enterprise is helping meet the Millennium Development Goals (MDG-7) and actively supporting the government’s vision of an open defecation free society.
Removal Technologies in Wastewater Treatment
Since heavy metal ions are non-biodegradable, they can accumulate their amounts along the food chain. Therefore, it is critical necessary to remove or minimize the heavy metal ions in wastewater systematically. In this article, we mainly introduce three commonly used methods for heavy metal elimination: chemical precipitation, ion exchange, and adsorption.
Activated Sludge Process
Activated sludge (AS) is a process dealing with the treatment of sewage and industrial wastewaters and developed around 1912-1914. There is a large varity of design, however, in principle all AS consist of three main components: an aeration tank, which serves as bio reactor; a settling tank ("final clarifier") for seperation of AS solids and treated waste water; a return activated sludge (RAS) equipment to transfer settled AS from the clarifier to the influent of the aeration tank.
Faecal Sludge Management
It is estimated that literally billions of residents in urban and peri-urban areas of Africa, Asia, and Latin America are served by onsite sanitation systems (e.g. various types of latrines and septic tanks). Until recently, the management of faecal sludge from these onsite systems has been grossly neglected, partially as a result of them being considered temporary solutions until sewer-based systems could be implemented. However, the perception of onsite or decentralized sanitation technologies for urban areas is gradually changing, and is increasingly being considered as long-term, sustainable options in urban areas, especially in low- and middle-income countries that lack sewer infrastructures. This is the first book dedicated to faecal sludge management. It compiles the current state of knowledge of the rapidly evolving field of faecal sludge management, and presents an integrated approach that includes technology, management, and planning based on Sandecs 20 years of experience in the field.
Faecal Sludge Management: Systems Approach for Implementation and Operation addresses the organization of the entire faecal sludge management service chain, from the collection and transport of sludge, and the current state of knowledge of treatment options, to the final end use or disposal of treated sludge. The book also presents important factors to consider when evaluating and upscaling new treatment technology options. The book is designed for undergraduate and graduate students, and engineers and practitioners in the field who have some basic knowledge of environmental and/or wastewater engineering.
Process Control of Activated Sludge Plants by Microscopic Investigation
Process stability and final effluent quality largely depend upon the composition of the biomass in an activated sludge plant. Operational problems such as bulking and scum formation occur when the wrong micro-organisms are dominating the sludge population. Microscopic sludge investigation is therefore essential for process control and stable plant operation. The manual outlines the theoretical framework, extensively illustrated with full-colour micrographs.
Contents: - Microscopy - Microscopic sludge investigation - Characteristics of activated sludge flocs - Filamentous micro-organisms - Protozoa and metazoa - Conclusions of microscopic sludge investigation - The activated sludge process - Operational problems - Bulking sludge - Scum formation.
Organic Waste Recycling: Technology and Management – Third Edition
This book covers the principles and practices of technologies for the control of pollution originating from organic wastes (e.g. human faeces and urine, wastewater, solid wastes, animal manure and agro-industrial wastes) and the recycling of these organic wastes into valuable products such as fertilizer, biofuels, algal and fish protein and irrigated crops.
Each recycling technology is described with respect to: - Objectives - Benefits and limitations - Environmental requirements - Design criteria of the process - Use of the recycled products - Public health aspects. Organic Waste Recycling includes case studies, examples, exercises and questions. This book is intended as a text or reference book for third or fourth year undergraduate students interested in environmental science, engineering and management, and graduate students working in the environment-related disciplines. It also serves as a reference text for policy makers, planners and professionals working in the environment and sustainable development fields.