Cost analysis of alternative methods for wastewater handling in small communities

Wastewater collection and treatment is quite important for sustainable management. It would be uneconomical and impractical to provide sewer systems and separate wastewater treatment plants (WWTP) for small communities. The decision process in wastewater planning is rather important in terms of comparing the alternatives considered. The two important points in the management of wastewater at rural areas not connected to a sewer system are to develop an optimized operation strategy and to make sure that the complete system is environmentally and economically sustainable. In some regions, package treatment could be an alternative solution. However, in cases where there is an existing large WWTP, a cluster system, where sewage generated by small communities could be transported via conveyors to a centralized WWTP, could be employed. In this study, the wastewater treatment and disposal problems in small communities were addressed and an alternative wastewater handling scenario was proposed. Additionally, three wastewater handling scenarios were compared. As a case study, Gebze villages were selected.     

Optimization of wastewater treatment alternative selection by hierarchy grey relational analysis

This paper describes an innovative systematic approach, namely hierarchy grey relational analysis for optimal selection of wastewater treatment alternatives, based on the application of analytic hierarchy process (AHP) and grey relational analysis (GRA). It can be applied for complicated multicriteria decision-making to obtain scientific and reasonable results. The effectiveness of this approach was verified through a real case study. Four wastewater treatment alternatives (A(2)/O, triple oxidation ditch, anaerobic single oxidation ditch and SBR) were evaluated and compared against multiple economic, technical and administrative performance criteria, including capital cost, operation and maintenance (O and M) cost, land area, removal of nitrogenous and phosphorous pollutants, sludge disposal effect, stability of plant operation, maturity of technology and professional skills required for O and M. The result illustrated that the anaerobic single oxidation ditch was the optimal scheme and would obtain the maximum general benefits for the wastewater treatment plant to be constructed.     

HOW CLIMATE UNCERTAINTY SHOULD BE INCLUDED IN GREAT LAKES MANAGEMENT: MODELING WORKSHOP RESULTS1

ABSTRACT: In two workshops, we evaluated decision analysis methods for comparing Lake Erie levels management alternatives under climate change uncertainty. In particular, we wanted to see how acceptable and effective those methods could be in a public planning setting. The methods evaluated included simulation modeling, scenario analysis, decision trees and structured group discussions. We evaluated the methods by interviewing the workshop participants before and after the workshops. The participants, who were experienced Great Lakes water resources managers, concluded that simulation modeling is user-friendly enough to enable scenario analysis even in workshop settings for large public planning studies. They felt that simulation modeling can improve not only understanding of the system, but also of the options for managing it. Scenario analysis revealed that the decision for the case study, Lake Erie water level regulation, could be altered by the likelihood of climate change. The participants also recommended that structured group discussions be used in public planning settings to elicit ideas and opinions. On the other hand, the participants were less optimistic about decision trees because they felt that the public might view subjective probabilities as difficult to understand and subject to manipulation.     

A MATHEMATICAL MODEL FOR OPTIMUM DESIGN AND CONTROL OF METROPOLITAN WASTEWATER MANAGEMENT SYSTEMS1

ABSTRACT: A comprehensive mathematical model (Urban Wastewater Management Model) has been developed to continuously simulate time-varying wastewater flows and qualities in complex metropolitan combined sewerage systems. The model serves three functions: (1) assessment of existing or planned system performance in relation to other wastewater discharges in either a metropolitan or river basin area; (2) determination of the optium operation or automatic control of existing or planned systems during rainstorms; and (3) determination of the most economically feasible combination of design alternatives for improving or expanding existing systems to meet specified performance criteria. The model provides an efficient engineering tool for evaluating and controlling pollutant discharges from combined sewerage systems (including treatment plants) to receiving waters, while considering the time and spacial variations of rainfall and dry-weather flows and qualities as well as economic constraints.     

Evaluation Criteria for Implementation of a Sustainable Sanitation and Wastewater Treatment System at Jiuzhaigou National Park, Sichuan Province, China

The administration of Jiuzhaigou National Park in Sichuan Province, China, is in the process of considering a range of upgrades to their sanitation and wastewater treatment systems. Their case history involves an ongoing series of engineering design flaws and management failures. The administration of the Park identified sustainability, environmental protection, and education goals for their sanitation and wastewater treatment system. To meet the goal of sustainability, environmental and economic concerns of the Park’s administration had to be balanced with socio-cultural needs. An advanced reconnaissance method was developed that identified reasons for previous failures, conducted stakeholder analysis and interviews, determined evaluation criteria, and introduced innovative alternatives with records of successful global implementations. This evaluation also helped the Park to better define their goals. To prevent future failures, the administration of the Park must commit to a balanced and thorough evaluation process for selection of a final alternative and institute effective long-term management and monitoring of systems. In addition, to meet goals and achieve energy efficient, cost-effective use of resources, the Park must shift their thinking from one of waste disposal to resource recovery. The method and criteria developed for this case study provides a framework to aid in the successful implementation of sanitation projects in both underdeveloped and developed areas of the world, incorporating socio-cultural values and resource recovery for a complex group of stakeholders.     

PERFORMANCE VARIATIONS OF COD AND NITROGEN REMOVAL BY VEGETATED SUBMERGED BED WETLANDS1

ABSTRACT: Vegetated submerged bed wetlands can supplement treatment of onsite wastewater systems. This study evaluated vegetation, media, and seasonal impacts on system performance in six meso scale rock plant filters with and without narrow leaf cattails (Typha augustifolia). Daily chemical oxygen demand (COD) reductions in planted cells averaged 85 percent and weekly total nitrogen (TN) reductions averaged 50 percent. Planted cells had 17 percent greater COD reduction and 76 percent greater TN reduction than unplanted cells, both significant differences. Media type affected COD reduction, particularly in unplanted cells. COD treatment in planted cells was highest for fine crushed limestone (87±13 percent) and least variable for coarse river gravel (85±11 percent). No significant difference in TN reduction was observed for different media types (48 to 51 percent range). Seasonal influences on treatment included a significant decrease during late fall and early spring and a significant increase with temperature. After a step increase in organic loading, treatment efficiency decreased sharply but returned to prior levels after an adaptation period of about one month. Planted cells not only exhibited higher treatment efficiency but also had a retarded organic matter breakthrough, appearing after three to seven times the period for a bromide tracer. This supports a hypothesis that retardation of contaminant movement through the treatment cells results in enhanced removal. These results support the use of rock plant filters, but demonstrate the need to account for performance variations in system design. (KEY TERMS: constructed wetlands; seasonal effects; subsurface flow; Typha augustifolia; onsite wastewater treatment; water quality.)     

The role of learning in sustainable communities of practice

This paper adds to the literature on skills for sustainable communities by examining the role and processes of learning in “communities of practice” that exist within a “grassroots association”. Interviews were conducted with participants in the communities of practice of a student group called Green Action, which engages with environmental issues in practical ways. The findings demonstrate how learning occurred in the communities of practice, how participants gained skills and knowledge for sustainable consumption, and how learning in the communities of practice appeared to help Green Action to sustain itself in the long-term. This paper could serve as a useful demonstration to others as to how to apply the theories and concepts from the literature on communities of practice when researching skills and knowledge for sustainable communities. It also has some value for grassroots associations themselves in understanding their own activities.     

Applying knowledge-based methods to design and implement an air quality workshop

In response to protection needs in class I wilderness areas, forest land managers of the USDA Forest Service must provide input to regulatory agencies regarding air pollutant impacts on air quality-related values. Regional workshops have been convened for land managers and scientists to discuss the aspects and extent of wilderness protection needs. Previous experience with a national workshop indicated that a document summarizing workshop discussions will have little operational utility. An alternative is to create a knowledge-based analytical system, in addition to the document, to aid land managers in assessing effects of air pollutants on wilderness. Knowledge-based methods were used to design and conduct regional workshops in the western United States. Extracting knowledge from a large number of workshop participants required careful planning of workshop discussions. Knowledge elicitation methods helped with this task. This knowledge-based approach appears to be effective for focusing group discussions and collecting knowledge from large groups of specialists.     

A MODEL FOR PLANNING AND LOCATION OF ON-SITE WASTE DISPOSAL SYSTEMS1

Abstract: A model that incorportaes performace data about data about several wastewater management systems is discussed. From these data the excepted behavior of an individual wastewater system or group of systems can be product of the performace probabilities of its individual components. The modeel can be used on a regional scale facilitating land use planning by allowing accurate estimates of performance for a prospective wastewater management system. At this scale it can allow the impact evaluation of new wastewater technology on land use in a region.     

轮毂行业涂装车间环境污染与防治

轮毂行业快速增长的同时,涂装车间作业排放的废气、废水、废渣、噪声,对环境造成了严重的污染。分析了轮毂行业涂装车间的环境污染状况,包括污染物的来源和种类,指出采用低污染材料、先进的生产设备,并优化生产工艺,是解决涂装“三废”问题的有效途径。     

“We can keep the fire burning”: building action competence through environmental justice education in Uganda and Germany

The global dimensions of climate change necessitate a response that takes national differences – social, economic, geographic, and cultural – into account. Action-oriented education has a key role to play in advancing citizen engagement in a culture of sustainability. This paper describes research conducted with one such education programme, Youth Leading Environmental Change (YLEC), which operates in six countries and engages university-aged youth in discussion and practice related to global sustainability, systems thinking, and environmental justice. YLEC aims to advance four key competencies; this paper focuses on the goal of action competence, which involves acquiring knowledge, reflecting on experience in the context of one’s values, envisioning alternative futures, and acting individually and collectively to advance those alternatives. The present article examines the impacts of YLEC on environmental action competence in two of the countries involved in this research: Uganda and Germany. In-depth interviews were conducted with participants in both countries to examine the development of action competence during and after the programme. Findings suggest that outcomes differed in each country, reflective of participants’ different lived experiences. YLEC effectively built on the conditions faced in each country to accompany youth to a higher level of awareness and action. These findings have implications for environmental education programmes striving to work with multiple nations and diverse participants.     

The Potential of Public Participation Geographic Information Systems in UK Environmental Planning: Appraisals by Active Publics

The paper draws on an empirical study of two workshops in which the issues that arise from the use of geographic information systems (GIS) as a planning tool in public participation settings were explored by local residents who take an active interest in local planning matters in their London borough. The paper demonstrates how issues concerned with the democratization of GIS and public participation GIS (PPGIS) informed the structure and conduct of the workshops and the qualitative analysis of the workshop discussions. Key themes raised by participants included: the potential of PPGIS as a means of extending knowledge networks; issues of data ownership and the responsiveness of data providers to public concerns; and the role that institutional norms and practices play in democratizing information availability and the transparency of the decision-making process. The paper concludes that the potential of PPGIS as a planning tool cannot be separated from public concerns about the legitimacy of the planning process or local government.     

Environmental impact studies: An interdisciplinary approach for assigning priorities

The cross-impact assessment process (CAP) is presented as a practical method for efficiently identifying a parsimonious set of critically important variables and associated relationships needed to conduct environmental impact studies. CAP was developed from the logic of a number of techniques that are collectively referred to as cross-impact analysis. The process is based on a series of structured workshops. The participants represent a variety of disciplines and individual members are selected because they have both the depth of understanding necessary to contribute specific knowledge on the environmental impact assessment problem and the breadth of view to integrate that knowledge with the information provided by other panelists. The results of the workshops are summarized in an importance index and presented in a cross-impact matrix. CAP is illustrated with an example from an Upper Mississippi River recreation impact study, but it can also be applied to any environmental impact assessment problem that can be characterized as a system of variables and relationships. CAP also provides an efficient and reasonably objective means for assigning priorities to environmental impact studies.     

含油污水回用处理新工艺研究

研究了一种处理回用含油污水的新工艺,二期炼油污水深度处理中试研究表明,以炼油企业二级处理达标排放污水为处理对象,在使用该工艺处理水量为0.5m3/h、水力停留时间为1.49h 以及污水中COD、氨氮、石油类的浓度变化分别为44.07～102.13 mg/L、28.37～50.01 mg/L、4.10～6.77 mg/L时,平均去除率分别达到94%、96.1%、91.9%,其排出水质符合循环水补充水的水质要求。对该工艺进行了5.5h抗冲击实验,结果表明其抗冲击能力优良。     

Observations on the workshop as a means of improving communication between holders of traditional and scientific knowledge

Traditional ecological knowledge (TEK) and the information and insights it offers to natural resource research and management have been given much attention in recent years. On the practical question of how TEK is accessed and used together with scientific knowledge, most work to date has examined documentation and methods of recording and disseminating information. Relatively little has been done regarding exchanges between scientific and traditional knowledge. This paper examines three workshop settings in which such exchanges were intended outcomes. The Barrow Symposium on Sea Ice, the Exxon Valdez Oil Spill Restoration Program Synthesis/Information Workshops, and the Alaska Beluga Whale Committee illuminate certain features of the preparation, format, and context of workshops or series of workshops and their eventual outcomes and influence. The examples show the importance of long-term relationships among participants and thorough preparation before the actual workshop. Further research should look more systematically at the factors that influence the success of a given workshop and the various ways in which participants perceive success.     

A system dynamics approach for regional environmental planning and management: a study for the Lake Erhai Basin

In recent years, water-quality deterioration associated with rapid socio-economic development in the Lake Erhai Basin, China, has acquired more and more attention from the public and the government. An effective planning for the basin's environmental management system is desired for sustainable regional development. In this study, an environmental system dynamics model, named ErhaiSD, is developed for supporting this planning task. The ErhaiSD consists of dynamic simulation models that explicitly consider information feedback that governs interactions in the system. Such models are capable of synthesizing component-level knowledge into system behaviour simulation at an integrated level. This capability is very useful in analyzing and recommending policy decisions. For the study case, interactions among a umber of system components within a time frame of 15 years are examined dynamically. Four planning alternatives are considered. The base run is based on an assumption that the existing pattern of human activities will prevail in the entire planning horizon, and the other alternatives are based on previous planning studies. The contributions of various nonpoint pollution sources to the lake's eutrophication problems, and the effects of industrial activities and wastewater treatment processes on pollution problems in the Xier River are analyzed through the developed modeling system. The exercise draws attention to the implications of different alternatives to the system's environmental and socio-economic objectives. The modeling results are directly useful for simulating and evaluating a variety of decision actions and their dynamic consequences, and answering questions such as 'What should I do?', 'What if I do?' and 'What are the expected consequences?'.     

炼油污水的深度处理

论述了炼油污水深度处理的常用技术--过滤、膜分离及化学氧化技术,对炼油污水深度处理进行了中试试验,并结合试验结果对动态砂滤系统、PAN膜处理系统和高级氧化系统处理炼油厂二级排放水的适用性进行了论证。结果表明,二级排放水经动态砂滤系统和NF纳滤系统处理后,COD、氨氮、SS、硫化物、酚、浊度、总铁等指标均达到循环水补水水质要求,可以回用于循环水场;经PAN膜制成的UF超滤和RO反渗透系统处理后,各种污染物指标和盐类指标都降至微量,且脱盐效果明显。     

Integrated Risk Framework for Onsite Wastewater Treatment Systems

Onsite wastewater treatment systems (OWTS) are becoming increasingly important for the treatment and dispersal of effluent in new urbanised developments that are not serviced by centralised wastewater collection and treatment systems. However, the current standards and guidelines adopted by many local authorities for assessing suitable site and soil conditions for OWTS are increasingly coming under scrutiny due to the public health and environmental impacts caused by poorly performing systems, in particular septic tank-soil adsorption systems. In order to achieve sustainable onsite wastewater treatment with minimal impacts on the environment and public health, more appropriate means of assessment are required. This paper highlights an integrated risk based approach for assessing the inherent hazards associated with OWTS in order to manage and mitigate the environmental and public health risks inherent with onsite wastewater treatment. In developing a sound and cohesive integrated risk framework for OWTS, several key issues must be recognised. These include the inclusion of relevant stakeholders throughout framework development, the integration of scientific knowledge, data and analysis with risk assessment and management ideals, and identification of the appropriate performance goals for successful management and mitigation of associated risks. These issues were addressed in the development of the risk framework to provide a generic approach to assessing risk from OWTS. The utilisation of the developed risk framework for achieving more appropriate assessment and management techniques for OWTS is presented in a case study for the Gold Coast region, Queensland State, Australia.     

Reduction of pathogen indicator organisms in dairy wastewater using an ecological treatment system

Ecological treatment systems can provide a sustainable, plant-based alternative to traditional wastewater treatment. One factor essential to the success of these systems is ensuring their ability to reduce coliform concentrations in wastewater. Wastewater is the primary source of fecal contamination in aquatic ecosystems, containing total and fecal coliforms on the order of 10(8)-10(10) and 10(7)-10(9) CFU L(-1), respectively. This study assessed the ability of an ecological treatment system to reduce concentrations of total coliforms and Escherichia coli from dairy wastewater. Low strength wastewater was pumped into the system during July of 2005 and high strength in September 2005. Wastewater passes through a series of anaerobic, aerobic, and clarifier reactors and wetland cells before exiting the system. Regardless of wastewater strength, average total coliform and E. coli concentrations were consistently reduced by at least 99% from influent to effluent, with the majority of the reduction (76%) occurring in the first two reactors. Relationships between internal concentrations of solids and coliforms indicated that increased reduction of solids may further reduce coliform concentrations. Although U.S. Environmental Protection Agency discharge requirements for E. coli were not always met, the substantial reductions achieved indicate that ecological treatment systems have the potential to successfully reduce coliforms in wastewater to meet discharge limits. The results from this study will be used to guide design and management of future ecological treatment systems, so that larger and more consistent coliform reductions can be achieved.     

Building the Capacity of Grassroots Conservation Organizations to Conduct Participatory Evaluation

Stakeholder participation has become a key factor in the success of grassroots conservation and natural resource management programs. Yet the majority of program evaluations are conducted by external consultants for the purposes of accountability, rather than program improvement. Too often, systematic evaluations of conservation programs are not conducted at all. The objective of this study was to build the capacity of a grassroots conservation organization to conduct participatory evaluation, involving project stakeholders in the design, implementation, and use of evaluation. The study applied a conceptual model for participatory evaluation to the Wildlife Clubs of Kenya (WCK), the largest grassroots conservation program for youth in Africa, involving more than one million youth since 1968. Seven trainings in participatory evaluation were conducted with WCK staff, teachers, and community members. The 120 participants, representing nine WCK regions with 800 clubs, showed a significant increase in attitudes and knowledge regarding evaluation, as reflected by mean test scores before and after training. To institutionalize evaluation at WCK, existing organizational practices were assessed and used as a foundation for developing an evaluation system. Based on club competitions, a new evaluation initiative was launched called the WCK Incentive Program. Participants in all seven workshops identified indicators and sources of evidence for this evaluation system, which now serves as a basis for rewarding outstanding performance in WCK. This study revealed the importance of incentives for evaluation, the need to build on existing structures to promote organizational learning, and the necessity for the conservation community to commit resources to capacity building in participatory evaluation.