Alternative water sources and wastewater management pdf
File Name: alternative water sources and wastewater management .zip
- Reclaimed Water as an Alternative Water Source for Crop Irrigation
- EC On-Site Alternative Water Reuse
- Wastewater treatment
- Contributions of recycled wastewater to clean water and sanitation Sustainable Development Goals
Please purchase via www. Binding: Hardback. Owing to climate change related uncertainties and anticipated population growth, different parts of the developing and the developed world particularly urban areas are experiencing water shortages or flooding and security of fit-for-purpose supplies is becoming a major issue. The emphasis on decentralized alternative water supply systems has increased considerably. Most of the information on such systems is either scattered or focuses on large scale reuse with little consideration given to decentralized small to medium scale systems.
Reclaimed Water as an Alternative Water Source for Crop Irrigation
Yet, the current constraints in this system and the immensity of urbanisation in the country begs and compels planners, engineers and systems thinkers to rethink what best can work as a sustainable wastewater system. With particular reference to the ever-expanding Harare metropolitan region, this article provides an evaluative analysis on the potentiality, risks and strategies that can be adopted by Harare and its satellites in addressing the problems of the conventional wastewater management system.
The suggested framework of operation is a decentralised domestic wastewater collection and treatment system which however has its own multifarious risks. Using systems dynamics conceptualisation of the potentiality, opportunities, risks and strategies, the paper seeks to model the path and outcomes of this decentralised domestic wastewater collection and treatment system and also suggests a number of policy measures and strategies that the city of Harare and its satellites can adopt.
Developing countries are burdened with a multiplicity of problems, and wastewater management is increasingly becoming a priority issue.
The management of wastewater system in developing countries is exacerbated by accelerating urbanisation, inadequate management and disposal of wastewater and the implementation of sophisticated treatment technologies that are highly centralised Libralato et al.
The current wastewater management systems are riddled with a plethora of irregularities that calls for a paradigm shift from the current centralised system to the decentralisation in wastewater treatment management. The principal reason for this has been that the provision of centralised systems is not technically, economically or environmentally feasible as De Gisi et al.
Decentralised systems also offer an alternative approach to providing water, wastewater and storm water services to urban areas Nhapi a , b , c ; Libralato et al.
In recent times, the concept of integrating water and wastewater systems through separate collection and treatment of various water and waste streams and recovery of valuable water, nutrients and energy has been proposed. Furthermore, innovative decentralised systems are being planned and implemented for new and future urban development either as separate facilities or in combination with a centralised system Diaper et al.
Wilsenach : 4 observes that a general critique against classical civil engineering projects is that they have not dealt with transport, drinking water, energy and wastewater in an integrated way.
These were all designed as linear systems, without consideration of the cyclic character of most natural systems De Gisi et al. In urban water management there is a need for a change to improve the sustainability of the systems. This has been a wakeup call from proponents such as Cook et al.
Rather, a new approach has to be embraced that should include the integration of social, economic, and environmental aspects with practices such as rainwater management, water conservation, wastewater reuse, rational energy management incorporating the use of alternative sources , nutrient recovery, and sorting at source De Gisi et al.
This present paper is an attempted evaluation and analysis of the decentralised wastewater treatment and management systems, putting into picture potentialities, opportunities, risks and strategies. It is a study that emanates from the fact that the conventional centralised wastewater management systems have failed to produce sustainable outcomes in terms of social, economic and environmental concerns.
This work reviews some existing technologies applied in decentralised wastewater treatment and disposal in developing countries such as the septic tank, imhoff tank, and soil infiltration device, to name these few ibid. Technologies that are potentially sound and beneficial for wastewater treatment are also explored.
Emphasis is placed on faecal sludge management, which is grossly inadequate, and in some cases totally lacking in rural, peri-urban and some urban areas of developing countries.
To demonstrate this, we use documentary and discourse analysis. First, the paper starts by providing an analytical framework, and then proceeds to provide a comparative analysis of the centralised and decentralised systems. The rationale for adoption of decentralised wastewater management system is also explained.
Second, the legislative and policy framework for wastewater treatment and management in Zimbabwe is explained, which is then followed by an outline of the current situation in Harare as well as reflections on systems dynamics in the City. Third, the paper ends by a discussion, practical implications, policy options and conclusion. This section provides a conceptual reflection of the decentralised wastewater treatment and management systems. The aim of this section is to describe and explain the key features or characteristics of the decentralised wastewater management concept.
Decentralised wastewater system is when raw wastewater is simply treated next to the source point of generation according to Omenka through a range of simple technologies. Office of Water United States Environmental Protection Agency : 3 defines decentralised wastewater systems as consisting of a wide range of onsite and cluster treatment systems that process household and commercial sewage.
The Rocky Mountain Institute defines decentralised systems as an alternative to conventional, centralised systems. In addition, the decentralised concept can be explained as an organisational paradigm for wastewater management De Gisi et al. Some systems in arid regions promote evaporation or wastewater uptake by plants. However, decentralised wastewater treatment is not without its share of challenges resulting from choice of inappropriate technology, improper siting of infrastructure, in adherence to correct design concepts and lack of proper maintenance Omenka ; Libralato et al.
These bring about negative public health and environmental impacts including groundwater nitrate contamination, eutrophication of surface water bodies and contribution to global warming through the emission of green house gases. In developing countries such as Zimbabwe, onsite systems are generally used in high income and low density areas where the collection of infrastructure discourages sewered systems.
The wastewater management systems in Latin America are also centralised systems that are contributing to environmental problems Noyola As such, the municipal wastewater treatment systems in Latin America are currently unsustainable because they are characterised by high water consumption, especially for transporting wastes out of cities Suriyachan et al.
The mixing of industrial waste streams further complicates resource recovery and reuse than if process streams would be kept separate. On this note, De Gisi et al. Cook et al. With, generally, little awareness of environmental consequences, little institutional attention for recovery of resources, and with only degradable organics potentially removed from wastewater effluent or sludge, the remaining resources are either distributed into surface waters or into sludge. As such, wastewater collection and treatment contribute to environmental pollution.
Most of the technologies used for centralised treatment of wastewater are expensive investment and maintenance and require well-trained staff Nhapi a , b , c. For these and other reasons, an intermediate or decentralised approach to wastewater management is urgently needed aiming at resource conservation and reducing environmental impacts of current approaches Cook et al. Massoud et al. Developing countries lack both the funding to construct centralised facilities and the technical expertise to manage and operate them.
The decentralised system is therefore not only a long-term solution for small communities but is more reliable and cost effective. Such an approach allows for flexibility in management, and simple as well as complex technologies are available.
While there are many impediments and challenges towards wastewater management in developing countries, these can be overcome by suitable planning and policy implementation. Understanding the receiving environment is crucial for technology selection and should be accomplished by conducting a comprehensive site evaluation process.
Centralised management of the decentralised wastewater treatment systems is essential to ensure they are inspected and maintained regularly Nhapi a , b , c. In light of this argument by Nhapi a , b , c , Libralato et al. Bernal and Restrepo : 9—12 have pointed out that environmental pollution, water scarcity, population growth, innovation, and technological developments are drivers that encourage rethinking the current approach to urban water management. In this sense, decentralisation encourages us to think of urban water management in a holistic way, integrating all sectors, drinking water, wastewater, and storm water to get the most benefit out of them, thereby reducing costs, improving environmental management, expanding service coverage, and considering social and environmental benefits that are not visible with the current perspective De Gisi et al.
Centralised wastewater treatment systems are costly when compared to the decentralised systems. According to a study carried out by United Nations for South-East Asia it emerge that the decentralised system is more economical than the centralised system because treatment facilities for decentralised treatment facilities can be built in an incremental way and requires less initial capital investment than centralised treatment that requires millions of dollars.
The above-mentioned should be accompanied by a reform of policies and guidelines that govern urban development plans and water management plans in cities in developing countries.
The incorporation of decentralisation as a viable option for wastewater management in urban areas and the regulation of reusing practices such as defining quality criteria are necessary actions to articulate the conceptual framework with the actions that occur in reality. In addition to the benefits, the key issues of each one of the identified economic, social, and environmental categories should be discussed. These include, among others, the cost of collecting and treating wastewater, acceptance and social awareness, and environmental protection, all of which must be considered in implementing decentralisation in urban areas in developing countries Nhapi a , b , c.
According to the context of each case, the level of decentralisation may be a critical issue to achieving sustainability of a wastewater management system. In short, wastewater treatment can be decentralised thereby reducing plumbing and pumping costs, possibility of safe reuse of water for gardening open spaces and can be integrated as part of the landscape.
The Decentralised wastewater treatment system was introduced in the Philippines as a way of responding to the problems caused by the conventional system that was in place UNEP A new effective system was therefore necessary to prevent further environmental pollution and threats to public health. For the implementation of the decentralized wastewater system in Philippines, the following were required: biogas reactor, settling unit, anaerobic baffled reactor, anaerobic filter and indicator pond ibid.
The same project was also implemented in the Vietnam, where there was training of staff in the Operations and Maintenance of the system. The same impacts of reduced environmental pollution and reduced threats to public health were recorded UNEP Gauss points out that decentralized wastewater treatment systems have been implemented in Central and South America as well as Latin America. The method that was implemented is the constructed wetlands system in Cities such as Masaya Nicaragua , Lima Peru , and Pereira Colombo and in countries such as Brazil.
Recently, the Melbourne Metropolitan sewerage strategy for Melbourne aims to provide sustainable sewerage services in the city to The strategy aims to decongest the existing centralised sewerage system for Melbourne through the adoption of decentralised and on-site wastewater systems.
The options include secondary and tertiary treatment systems that incorporate re-use of water for non-portable uses, urine separation, black and greywater separation and composting toilets Brown et al.
De Gisi et al. The method is based on biological processes that separate urine and faeces resulting in the formation of Terra Preta soils that are eventually used in agriculture. The common technologies currently in use include septic tanks, pit latrines, composting toilets, urine diversion and pour flush. Each strategy and technology comes with its pros and cons and basically fall under two categories namely wet and dry technologies. From the Latin American, Central American and South American Cases, major lessons were drawn about the decentralized wastewater management system.
The lessons include the following:. Low operation and maintenance costs of the system De Gisi et al. Robustness and good contaminant removal Guo et al. Low environmental impact Gauss Gauss also argues that decentralized wastewater management systems require an experienced sanitary engineer and community participation is key in the selection of preferred technology. In Southern Africa, countries show different patterns with regards to centralized and decentralized wastewater systems.
For example, Kenya uses conventional wastewater treatment systems which are inadequate and non-functional due to higher costs of operation and maintenance Benard and Omondi There are also weak institutions mandated with wastewater management. The conventional systems are capital intensive, requiring large sums of shilling which the majority of the local governments do not afford.
Windhoek is also one of the Cities in Southern Africa that has shown meaningful progress with regards to the implementation and management of decentralized systems Moyo In Malawi and Mozambique De Gisi et al. In Zimbabwe, there are cases of decentralised wastewater management system mainly in the rural areas where pit latrines are commonly used.
According to Nhapi a , b , c , cases of such a system are in places such as Gweru, Redcliff, Nemanwa and Mupandawana. In Gweru, the decentralized wastewater system started in In the town of Redcliff, there is evidence of decentralised wastewater treatment and management system as evidenced by the reuse of wastewater for agriculture.
Septic tanks are a common wet technology that is used in areas with large plot sizes. The following technologies are used in Redcliff: duckweed pond systems, constructed wetlands and aquaculture. In Mupandawana and Nemanwa, the use and availability of duckweed pond systems provides an opportunity for the implementation of decentralized wastewater treatment and management systems Nhapi a , b , c.
In Zimbabwe, the effective implementation of decentralised wastewater management systems is affected by unavailability of data on basic design of the technologies. The framework and national strategy for wastewater management is governed by several pieces of legislation that are the responsibility of different Government Ministries and Agencies.
These regulations generally set for the basic framework for wastewater management in Zimbabwe Thebe and Mangore
EC On-Site Alternative Water Reuse
Yet, the current constraints in this system and the immensity of urbanisation in the country begs and compels planners, engineers and systems thinkers to rethink what best can work as a sustainable wastewater system. With particular reference to the ever-expanding Harare metropolitan region, this article provides an evaluative analysis on the potentiality, risks and strategies that can be adopted by Harare and its satellites in addressing the problems of the conventional wastewater management system. The suggested framework of operation is a decentralised domestic wastewater collection and treatment system which however has its own multifarious risks. Using systems dynamics conceptualisation of the potentiality, opportunities, risks and strategies, the paper seeks to model the path and outcomes of this decentralised domestic wastewater collection and treatment system and also suggests a number of policy measures and strategies that the city of Harare and its satellites can adopt. Developing countries are burdened with a multiplicity of problems, and wastewater management is increasingly becoming a priority issue. The management of wastewater system in developing countries is exacerbated by accelerating urbanisation, inadequate management and disposal of wastewater and the implementation of sophisticated treatment technologies that are highly centralised Libralato et al.
Treated wastewater from domestic, agricultural, and industrial sources could prove invaluable in meeting the growing global demand for freshwater and other critical resources, a report from UN-Water finds. Released on World Water Day, the United Nations World Water Development Report Wastewater: The Untapped Source pages, PDF argues for a paradigm shift in wastewater management from "treatment and disposal" to "reuse, recycle, and resource recovery," which it touts as a reliable alternative to freshwater supplies that are under stress from a growing global population. According to the report, two-thirds of the world's population currently lives in areas that experience water scarcity for at least one month a year, even as large volumes of untreated wastewater are released into the environment or reused for agricultural irrigation, polluting water sources and contaminating crops. In , , deaths in low- and middle-income countries were linked to contaminated water and inadequate sanitation services. Improving the supply and quality of water as well as sanitation services, the report argues, would significantly help reduce health risks and contribute to progress toward the United Nations ' Sustainable Development Goals. Coordinated by the UN World Water Assessment Programme of UNESCO , the study also finds that wastewater can provide a cost-efficient and sustainable source of energy, nutrients such as phosphorus and nitrates, and organic matter — with potential benefits for human and environmental health, food and energy security, and climate change mitigation.
Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. As demand for water increases, water managers and planners need to look widely for ways to improve water management and augment water supplies. The Committee on Ground Water Recharge concludes that artificial recharge can be one option in an integrated strategy to optimize total water resource management, and it believes that with pretreatment, soil-aquifer treatment, and posttreatment as appropriate for the source and site, impaired-quality water can be used as a source for artificial recharge of ground water aquifers. Artificial recharge using source waters of impaired quality is a sound option where recharge in intended to control saltwater intrusion, reduce land subsidence, maintain stream baseflows, or similar in-ground functions. It is particularly well suited for nonpotable purposes, such as landscape irrigation, because health risks are minimal and public acceptance is high. Where the recharged water is to be used for potable purposes, the health risks and uncertainties are greater.
Please purchase via www. Binding: Hardback. Owing to climate change related uncertainties and anticipated population growth, different parts of the developing and the developed world particularly urban areas are experiencing water shortages or flooding and security of fit-for-purpose supplies is becoming a major issue.
Bob Boulware. Bob Boulware pdf. Summary: Publisher's Note: Products purchased from Third Party sellers are not guaranteed by the publisher for quality, authenticity, or access to any online entitlements included with the product. The definitive guide to alternative water sources and wastewater solutionsThis timely volume discusses alternative water sources and waste disposal methods that are appropriate when traditional means and methods do not exist or are inadequate.
Contributions of recycled wastewater to clean water and sanitation Sustainable Development Goals
Wastewater treatment , also called sewage treatment , the removal of impurities from wastewater, or sewage, before it reaches aquifers or natural bodies of water such as rivers , lakes , estuaries , and oceans. Since pure water is not found in nature i. In broad terms, water is said to be polluted when it contains enough impurities to make it unfit for a particular use, such as drinking, swimming, or fishing. Although water quality is affected by natural conditions, the word pollution usually implies human activity as the source of contamination.
Federal agencies may have water uses that can be met with alternative water sources. Alternative waters are sustainable sources of water, not supplied from fresh surface water or groundwater, that offset the demand for freshwater. Alternative water can serve as a vital water supply to federal agencies in support of water resilience by providing diverse water sources. The remainder of this BMP describes alternative water sources and considerations to account for when planning for implementation. Rainwater harvesting is the collection of rainwater from rooftops or other covered surfaces to divert and store for later use. Harvested rainwater is commonly used for non-potable applications, often to irrigate landscaping. Other common uses include wash applications, cooling tower make-up, and dust suppression.
Alternative Water Sources and Wastewater Management presents a variety The definitive guide to alternative Summary PDF. Annotate. Table of Contents.
On-site alternative water reuse intentionally captures, treats, and utilizes stormwater, graywater, and wastewater for reuse at the building site. Stormwater includes precipitation such as rainfall and snowmelt. Graywater also spelled gray water, greywater and grey water refers to untreated water from bathroom sinks, laundry, and bathing and does not include water contaminated with toilet waste, food and grease content from kitchen sinks, or dishwasher soap residue. Implementing on-site alternative water reuse starts with water conservation and includes identifying and evaluating opportunities to substitute or supplement potable water use with on-site alternative water sources based on the water quality and treatment requirements of the intended end-uses, and the feasibility of capturing and delivering alternative water sources to those end-uses see Indoor Water Conservation. Harvest and filter rainwater from rooftops to supplement or replace landscape irrigation and toilet and urinal flushing see Emergency Water Supply and Storage and Site and Stormwater Management. Capture graywater from fixtures and appliances by designating separate drain lines, storage units, and pumps to deliver graywater to desired locations.
Дэвид подмигнул крошечной Сьюзан на своем мониторе. - Шестьдесят четыре буквы. Юлий Цезарь всегда с нами. Мидж развела руками. - О чем .
Именно. Танкадо рассудил, что, если он погибнет, деньги ему не понадобятся, - так почему бы не вручить миру маленький прощальный подарок. Оба замолчали. Сьюзан глубоко дышала, словно пытаясь вобрать в себя ужасную правду. Энсей Танкадо создал не поддающийся взлому код. Он держит нас в заложниках.
Стратмор мгновенно взвесил все варианты. Если он позволит Хейлу вывести Сьюзан из шифровалки и уехать, у него не будет никаких гарантий. Они уедут, потом остановятся где-нибудь в лесу.