Systems ecological accounting for wastewater treatment engineering: Method,indicator and application

Wastewater treatment facility is vital for sustainable urban development. In the course of removing contaminants and discharging ready-for-reuse water, wastewater treatment consumes resources and triggers environmental emission during its lifetime. A comprehensive framework to analyze the embodied ecological elements as natural resources and environmental emissions of wastewater treatment is presented in this work. The systems method as a combination of process and input–output analyses is applied and a set of indicators are accordingly devised. Two representative ecological elements, i.e., greenhouse gases emissions and solar emergy of alternative wastewater treatment systems, i.e., a traditional activated sludge wastewater treatment plant and a constructed wetland have been taken into consideration. For each ecological element, five indicators have been calculated and compared to assess the impact on climate change and resources utilizing style of the case systems. The framework raised in this paper is fully supportive for optimal decision-making among different wastewater treatment technologies, and could be transplanted to be applied to systems ecological accounting for other production systems.     

江西省主要作物(稻、棉、油)生态经济系统综合分析评价

基于成本收益分析和能值分析理论,构建经济效益指标和生态经济效益指标,对江西省水稻(早稻和晚稻)、棉花、油菜种植系统的经济效益、生态经济综合效益进行分析和评价。经济效益方面,分析比较了单位面积作物成本构成,构建了净利润(Rev)和净利润率(Prof)两个经济效益指标;生态经济方面,分析比较了单位面积能值投入产出构成,构建了能值投入率、能值产出率、环境负载率、宏观经济能值等四个能值评价指标。计算结果表明江西省水稻、棉花和油菜等作物的生产成本占主导地位,价格因素是影响种植成本最重要的因素。水稻主要是以生产物资费用为主,而棉花和油菜以人工费用为主。从产值和收益来看,Rev大小为棉花>晚稻>早稻>油菜,Prof大小为晚稻>棉花>早稻>油菜。水稻、棉花和油菜种植系统对自然更新资源的依靠程度较低,系统的维系主要依赖于外部购买能值的投入,其构成与生产成本构成是一致的。水稻、棉花和油菜等作物的种植系统能值投入率比较高,大小为棉花>早稻>晚稻>油菜,能值产出率:油菜>棉花>晚稻>早稻,造成生态环境压力为晚稻>早稻>油菜>棉花,宏观经济能值大小为油菜>棉花>晚稻>早稻。结果表明,江西省水稻、棉花、油菜种植系统是高度开放的系统,主要依赖购买能值,但是系统产出率不高,其环境压力也不大。研究结果可为深入认识江西水稻、棉花和油菜等主要作物种植系统提供一个新的视角,并为种植业可持续发展提供一定的参考价值。     

基于能值理论的循环复合农业生态系统发展评价——以福建省福清星源循环农业产业示范基地为例

循环农业是当前农业可持续发展理念的具体运作模式。对能值分析方法优化,使其更适合循环复合生态系统的应用上进行优化,并以福建省福清星源循环农业产业示范基地为例验证,评价复合生态系统的可持续发展程度和经济效益。结果表明改进的能值分析方法对循环复合农业生态系统的可持续发展评价更科学,复合系统的可持续发展指数比单纯的生猪养殖提高23.44%—33.86%,在4种组合的循环模式中以"生猪养殖-沼气工程-有机肥生产-种植业"循环复合生态系统整体效益最佳,其可持续发展指数最高,环境负载率最低,净能值产出率仅略低于"生猪养殖-沼气工程-种植业"复合系统。     

Sustainability evaluation of e-waste treatment based on emergy analysis and the LCA method: A case study of a trial project in Macau

Electrical and electronic waste (e-waste) has become one of the fastest growing waste streams in the world, and many countries have established e-waste treatment enterprises to solve their e-waste problems. Because of the potential environmental pollution from e-waste, evaluating the overall sustainability of e-waste enterprises is critical to both nations and cities, although a great challenge academically. In this study, a combined approach of emergy analysis and life cycle assessment (LCA) was undertaken, to quantitatively investigate the effectiveness of an e-waste treatment trial project in Macau. In the emergy analysis, we also introduced two new indices (emergy recovery and technical efficiency) in order to evaluate the technical level of e-waste treatment in Macau. The research results show that the trial project has low competitive ability, due to high input emergy and low economic benefits. The emergy environmental efficiency analysis and LCA analysis together indicated that the trial project will indeed produce a low impact on the local environment, and because of the recovery of some resources in the e-waste treatment process, can even generate some environmental benefits. The analysis on the emergy recovery efficiency and technical efficiency shows that trial project has a relatively higher emergy recovery rate (52.78%) and technical level (72.36%) than the e-waste treatment enterprises in mainland China. However, based on both the emergy sustainability index (ESI) and the emergy–LCA sustainability index, it was found that the e-waste treatment trial project is not sustainable over the long term, due to low economic efficiency. Compared to ESI, the emergy–LCA sustainability index is more intuitive and easier to understand. Relevant results and data from this study could provide decision support to enterprise managers and government sectors, so that they could implement appropriate policies on e-waste treatment, to promote sustainable development and improved e-waste processing technologies.     

污水处理综合系统环境经济效益评估

污水处理、处理水处理和污泥处理是污水处理综合系统的3个基本单元.本文运用能值分析和新构建的能值指标评估了处理水回用与排放、污泥填埋与堆肥对系统整体性能的影响.该系统的价值包括环境收益和产品输出两方面.前者可通过污水处理前后的环境服务差值计算.由于系统内部物质和能量的转化数据难以获知,产品价值通过新提出的替代价值核算.结果表明： “污水处理+处理水回用+污泥填埋”的竞争力最高,“污水处理+处理水回用+蚯蚓堆肥”的可持续性能最高;处理水回用和蚯蚓堆肥均有助于提高系统可持续性;处理水回用与否应综合考虑处理水水质和当地条件;污泥蚯蚓堆肥的资源化效率还有待提高;改进的能值指标更适宜于污水处理综合系统效益评估.     

Feasibility of using constructed treatment wetlands for municipal wastewater treatment in the Bogotá Savannah,Colombia

The main water bodies in the Bogotá Savannah have been seriously polluted due to the mismanagement of domestic, agricultural, and industrial wastewater. While there are a number of wastewater treatment facilities in the region, most do not function properly. There is a great need for inexpensive and sustainable wastewater treatment systems that are not technologically sophisticated and that do not require intensive management. The main goal of this study was to quantify the performance and sustainability of treatment wetlands and existing wastewater treatment systems in this region. Using data from the literature, a treatment wetland model was developed, which focused on pollutant removal. The modeled performance was compared to a system of waste stabilization ponds and a sequencing batch reactor. The three systems were subject to cost analysis and an emergy evaluation, leading to the assessment of indicators of cost-benefit for comparison. The economic analysis suggested that the net annual cost of the treatment wetland was US$ 14,672, compared to US$ 14,201 for the stabilization ponds and US$ 54,887 for the batch reactor. The emergy evaluations show that the ponds have the lowest annual emergy flow (6.65 + 16 sej/yr), followed by the constructed wetland (2.88E+17 sej/yr) and the batch reactor (8.86E+17 sej/yr). These results were combined to estimate treatment ratios (contaminants removed per lifetime cost, and contaminants removed per total emergy), cost ratios (cost per volume of water, annual cost per capita, and construction cost per capita), and emergy ratios (treatment yield, renewable emergy, lifetime emprice, construction emprice, non-renewable emergy, empower density, environmental loading, total emergy per volume of water, and emergy per capita).     

Emergy analysis for the environmental sustainability of an inshore fish farming system

The emergy concept was used to evaluate the environmental sustainability of the rearing process of Gilthead Sea Bream (Sparus aurata) in an inshore fish farming system in Gulf of La Spezia (Italy, Northwestern Mediterranean). Emergy is defined as the available energy of one kind previously used up directly and indirectly to make a product or service. The indices for the examined fish farm calculated from the emergy evaluation were compared with those of three other systems producing fishes: two intensive fish farming systems producing, respectively, salmons (Salmo salar) and tilapia (Tilapia mariae), the third system producing again S. aurata but in a semi-natural extensive manner. The emergy evaluation showed that the rearing of fishes in a sheltered area of Mediterranean Sea imposes a large stress on the environment. The greatest contributions to the emergy needed for production were due to fingerlings purchased and goods and services provided that are two external, non-renewable inputs to the system. The strong dependence of external contributions and the relative inability at exploiting local natural resources affect strongly the level of environmental sustainability of the productive process.     

两种典型养鸡模式的能值分析

畜禽养殖的有机化过程被认为是实现养殖业持续发展与保障食品安全的重要途径.运用能值分析方法对两种典型养鸡模式——家庭有机饲养和林地散养进行了系统分析,并结合Castellini等人对意大利所做的同类研究(工业规模化笼养和草地散养)进行了横向对比.结果表明,林地散养生产系统的能值产出率为1.11,与家庭有机饲养系统相近,而在环境负载率和可持续发展能力方面的表现,均差于家庭有机饲养生产系统,说明林地散养模式尽管通过提高系统生产空间,理论上接近畜禽养殖的有机化理念,但由于大量的禽舍建筑、医药及其饲料等方面的外部资源输入,反而使得系统的环境负载率提高,可持续性大大下降.与意大利的结果比较发现,我国两个养殖系统的社会经济成本高、对外部不可再生资源的依赖程度较高,有机化目标并没有很好的实现.因此,我国现有的有机化畜禽养殖方式和外部制度都有待进一步改进和创新.     

Emergy and economic evaluations of four fruit production systems on reclaimed wetlands surrounding the Pearl River Estuary,China

Emergy and economic methods were used to evaluate and compare a traditional tropical fruit cultivation system, for bananas, and three newly introduced fruit cultivation systems, for papaya, guava and wampee, on reclaimed wetlands of the Pearl River Estuary, China. The goal of this study was to apply ecological engineering principles to fruit production system designs to maximize total emergy benefits and sustainability. The evaluations considered input structure, production efficiency, environmental impacts, economic viability and sustainability. The market effects on emergy exchange were assessed both for purchasing the inputs to production and for selling the fruit. These market effects were also considered in the evaluation of sustainability by using the Emergy Index for Sustainable Development (EISD), which was evaluated with and without taking the change in natural capital (i.e., soil organic matter) into consideration. The results showed that all three of the newly introduced systems are much more sustainable than the traditional banana production system. The guava production system had the highest value of the Emergy Sustainability Index (ESI = 0.40). The high price of wampee gave it the highest economic yield/cost ratio (4.87) and EISD (0.73). Emergy and economic evaluations are complementary methods, with emergy analysis shedding more light on environmental support and impacts of the production systems not considered in the market value, and economic analysis focusing on the effects of markets on fruit production. The Emergy Exchange Ratio (EER) was proposed as a bridge between emergy and economic evaluations for specific systems and/or processes.     

基于生态能量视角的我国小水电可持续性分析

我国的小水电开发经历了以解决农村地区用电短缺到当前以促进节能减排、清洁能源建设为目的的转变。运用生态能量分析的方法之一——能值分析方法,选取贵州省安龙县红岩二级水电站为案例,对其建设与运行的可持续性进行了系统分析,并与国内外大水电的相关指标进行了平行对比。结果表明:该水电站2010年电力产出的能值转换率为1.03×105sej/J,其可再生性比例为52.01%,在能值产出率、环境负载率和可持续能力等方面的表现均好于大水电。但其能值交换率为0.58,表明2010年水电上网价格偏低。小水电的不稳定运行也使其系统能值指标呈现波动变化,当实际发电量为设计发电量的50%时,水电的能值转换率接近于湄公河上大坝生产水电的能值转换率,可持续性指标的值从6.12急剧降到3.01。系统评估水电资源,作好流域小水电总体开发规划,保证小水电系统稳定运行是提高其可持续性的关键之一。     

基于能值分析的我国小水电生态影响研究

如何系统定量地评价小水电开发过程所引起的景观变化、河流局部断流等生态影响,是平息争议、进行合理规划与开发小水电前提之一。运用能值分析方法,以贵州省赤水市观音岩水电站为例,将小水电建设、运行的资源投入,以及河道中水流的时空改变所导致生态服务功能的损失纳入核算体系,对其生态影响进行综合定量评估。从2010年的实际结果来看,由于河流断流,导致水坝下游生态系统服务功能的能值损失为2.77×1018sej,占到了系统建设运行总投入的44.84%,其中重点保护鱼种在影响河段的生境破坏是最大的能值损失。若不考虑下游生态系统服务功能损失,系统的环境负载率为1.92,可持续性指标为1.22;而考虑下游生态影响之后,系统环境负载率增大至4.26,可持续性指标减小为0.34。研究表明,小水电的开发必须遵循适度开发、规划优先,保障河流最基本的生态需水底线,是协调小水电开发和河流健康矛盾、追求小水电持续发展的刚性要求。     

H. T. 奥德姆与中国的能值研究

简要论述了由霍华德.汤姆.奥德姆创立的能值理论与方法在中国的传播并综述了多年以来中国的能值研究进展。能值理论与方法在中国的传播始于1990年霍华德·汤姆·奥德姆第二次访华.在此期间,即1990年8月1日至1990年8月21日他访问了台北、广州、北京和沈阳,并作了多个学术报告,如“自组织与系统生态学”和“能值分析与环境评价”等。从此以后,我国的广州、北京、南京和沈阳、佛山等多座城市的大学和科研机构先后开展了10多年的能值研究,能值理论应用于多个领域,包括国家、省、市、自然保护区等生态经济系统的能值评估、农业生态系统、城市生态系统、环境与资源、废水处理、生态工程和工业的能值评价。用中文或英文发表关于能值的学术论文60多篇,由霍华德.汤姆.奥德姆所著的3本关于能值的书被翻译为中文,能值概念、理论和方法被10多部中文书刊引用,2本关于能值的中文专著已发表。能值分析的研究工作已得到国家自然科学基金资助,其中有些课题已结题,有些课题正在进行中。能值理论与方法已被许多中国生态学家所接受,但在应用过程中仍存在许多问题。     

能值生态足迹模型的改进——以海南为例

通过对比总结现有能值生态足迹模型研究成果,从能值密度、能值生态承载力、能值生态指标分类和整合等方面分析了模型存在的问题,在此基础上,构建了消费端和供给端构建足迹账户体系,并提出能值生态足迹和能值生态承载力模型的改进和优化。利用改进模型,实证分析了2000—2016年海南生态经济系统的变化特征。结果表明:(1)能源账户和生物产品账户足迹大幅增加。污染账户和建设用地账户足迹状态稳定。(2)生产承载力随着技术进步不断提高,而环境承载力随着人类对环境资源的占用强度增加不断下降。(3)海南生态环境整体表现为生态盈余,但污染账户、能源账户盈余缩减,2011年能源账户开始出现生态赤字。通过足迹账户的构建,能够更清晰地追踪各账户和各类土地能值生态足迹、能值生态承载力以及能值生态盈余/赤字产生的变化,能值生态足迹模型改进之后能够更客观反映区域生态经济系统状况,为地区有针对性开展环境管理和保护提供依据。     

城市可持续发展能力的能值评价新指标

能值理论、方法克服了传统能量与经济分析方法的诸多缺憾,为城市可持续发展的研究提供了全新的视角。但作为一种新兴的理论,其评价指标,尤其是针对城市可持续发展能力的综合评价指标尚不完善。从生态经济效益及环境影响的全面表达角度,剖析了国际现行可持续发展能值指标(ESI)的不足之处,并在此基础上拓展构建了新的可持续发展能值指标(EISD)。以珠江三角洲中山市1996～2000年的发展动态为例进行了案例研究。结果表明,新拓展的可持续发展能值指标．在系统效益评价中考虑了系统能值产出的实际经济效果,在环境影响评价中同时考虑了系统的消耗影响和排放影响,可以更全面明晰的评价城市系统的可持续发展能力、状态及其成因,为系统的优化指明方向。     

Improved emergy indices for the evaluation of industrial systems incorporating waste management

Emergy analysis is able to account for ecosystems’ contribution to industrial activity. Accordingly, it is an ecologically conscious tool useful for assessing the environmental impact and sustainability of industrial systems. The emergy-based approach requires proper system boundary definitions and uses several standard indices. In this article some perspectives on the deficiencies of three standard emergy indicators - environmental loading ratio (ELR), emergy yield ratio (EYR) and emergy index of sustainability (EIS) - when applied to industrial systems involving waste management are put forward and suggestions for overcoming them given. In addition, in order to account for the impact of waste emissions on the environment, a simple impact amplification factor is proposed for inclusion in the improved emergy indicators. To demonstrate their usefulness and highlight their superiority over standard indices, the improved emergy indicators are used to evaluate the interaction between a commercial polyethylene production process incorporating waste management and its surrounding environment.     

黄土高原典型流域种植业发展模式的能值分析

为客观评估和比较退耕还林后黄土高原典型小流域不同种植业发展模式的稳定性和可持续性,本研究通过能值分析方法,定量分析了粮食和果树兼作、粮食生产为主和果树种植为主3种典型流域种植业系统的能值投入和产出情况,建立能值分析指标体系,在自然资源压力、社会和经济发展水平方面进行比较,进而对3种模式的系统可持续性进行评估.结果表明: 黄土高原典型流域不同类型种植业系统外部辅助能值均占总能值投入的75%以上,且其中不可更新能值所占比例远大于可更新能值,由此造成了能值自给率低而环境承载率高的特点;流域粮食种植业生产具有高投入、低产出的特点,而水果种植和粮果兼作具有高投入、高产出的特点,3种模式能值密度均达到全国农业经济系统平均水平2倍以上,其中,粮食生产为主的模式净能值产出率最低而粮果兼作型最高;流域种植业能值可持续发展指数均<1,能值/环境可持续指标均远低于全国农业系统平均水平,可持续发展能力较低,以粮食和果树兼作的模式可持续发展指数最高.3种模式比较发现,粮果兼作发展模式在流域种植业发展中具有相对较好的发展能力和较高的系统稳定性,能值生产效率适中且可持续性最高,因此黄土高原地区以流域为单元的农业发展应该更加偏向于考虑多产业综合的复合结构生产方式.     

顺德产业生态系统能值动态分析

虽然当前的产业生态学研究多集中于生产线、企业和产业生态园尺度,但城市无疑是产业系统基本组合单元,城市区域尺度的产业生态学研究是产业生态学研究尺度上推的必经阶段。我国产业生态系统及城市化进程的空间分布不均,以顺德等为代表的东南沿海市(县)产业生态系统的发展历程对中西部地区有拉动和借鉴的双重作用。以能值理论方法为基础,结合环境经济学和区域经济学方法,从系统开放性、本土性、闭路循环性和经济性4个方面,投入和产出端2个角度,对顺德市产业生态系统改革开放22a的发展动态进行分析研究。结果发现,22a系统能值总用量增加15.65倍,能值密度增加16.31倍,人均能值使用强度增加9.70倍,外部不可更新资源用量增加16.32倍。能值废弃率在20世纪80年代不断上升而在90年代迅速下降,但环境负载率则表现为无规律的波动状态。20世纪90年代,系统能值出口率上升至1978年的4.10倍,但能值交换率小于1。结果表明,改革开放22a,顺德产业生态系统自组织能力明显提高,土地资源利用率不断提高,但系统对周边负熵资源,尤其是不可更新资源的依赖性不断提高,人力资源生产力水平提高相对较慢。20世纪90年代污染物处理产业发展迅速,但在系统资料消耗端的绿色化方面则无显明进展。系统对不可更新资源的利用效率不高,产出商品在市场交换中处于表面繁荣背景下的生态经济不利地位。系统已到了向知识密集型发展道路转变的拐点域。能值理论方法与环境经济学和区域经济学分析的整合可以满足产业生态系统分析评价要求,针对产业生态系统特点,进行多尺度、多方面联立评价,实现系统发展现状、动态与动因的整合分析,对产业生态系统优化点的发现与优化方向的确定有直接的意义。     

山西省农业生态经济系统能值分析

采用能值分析方法对2005年山西省农业生态经济系统的投入产出状况、运行效率和环境负荷进行了系统分析.结果表明：2005年,山西省农业生态系统仍处于主要依赖人力有机能和环境资源的传统农业阶段;研究区系统能值投资率（EIR）为1.07,能值产出率（EYR）为0.99,环境负载率（ELR）为6.55;在农业结构调整方面,畜牧业取得了长足发展,而小杂粮、蔬菜和干鲜果的能值产出仍较小,远未成为优势产业;研究区农业生态系统整体的回报效率较低,承受的压力较大.山西省今后应继续转移农业剩余劳动力、控制人口增长,同时加大农业科技辅助能值投入、提高环境资源的利用效率,使系统能值的投入产出向高水平发展.     

武夷山自然保护区生态旅游系统能值分析

能值理论与分析方法已经被广泛应用于对人类社会和自然界研究的各个层面.将武夷山国家自然保护区视为生态旅游系统,运用能值理论及其分析方法对其进行讨论和研究.由于传统的能值方法未能完全反映生态旅游系统的一切价值,研究中将条件价值法(CVM)与能值分析相结合,试图能够完整的体现出生态旅游系统的全部价值.在此认识的基础上提出了理想能值交换率等概念.并且将对该系统的研究结果与类似系统进行了横向比较.研究结果表明:(1)武夷山自然保护区生态旅游系统能值密度为7.31×1011sej/m2,低于福建省的16.02×1011sej/m2;而人均能值量为2.80×1016sej/m2,高于福建省人均能值5.75×1015sej/m2;净能值产出率为3.60,略高于广西恭城月柿生态农业旅游经济系统的2.79;武夷山自然保护区生态旅游系统理想能值交换率为0.70.(2)武夷山自然保护区自然环境条件良好,发展潜力较大;社区经济欠发达,居民生活水平较低;系统生产效率低,与外界贸易失衡,生态旅游处于探索阶段.     

舟山市东极大黄鱼养殖系统能值评估

以能值理论为基础,选择浙江省舟山市东极大黄鱼养殖系统为研究对象,在定量分析大黄鱼养殖系统的物流和能流基础上,通过建立能值评价指标体系,综合评价了东极大黄鱼养殖系统对环境的影响及其可持续性.结果表明:东极大黄鱼养殖系统的太阳能值转换率TR为1.46× 106 sej/J,环境承载力ELR为91.10,能值投入的生产效率PEEl为6.91× 10-7,能值持续性指数ESI为0.011.东极大黄鱼养殖系统虽然生产效率较高,但是过分依赖于外部购买资源,并且系统对环境的压力较大,环境的持续性也较差.另外,与广东珠江口3个不同鱼种养殖系统的有关指标进行了对比,提出了大黄鱼养殖系统的可持续性发展建议.