堆肥中腐熟污泥替代外源添加剂的研究

本文对用腐熟污泥替代木屑等外源添加剂高温好氧堆肥作了研究。通过腐熟污泥回流三次的堆肥结果显示,每次回流的堆肥温度都能在55℃以上保持5天以上,达到无害化的要求,含水率都能降到45％左右,污泥的有机物降解率相近,pH在6～9之间。需要注意的是腐熟污泥多次回流中重金属浓度有个增加的过程,达到峰值后逐渐下降。     

Mechanical recycling of EOL concrete into high-grade aggregates

Recycling End of Life (EOL) concrete into high-grade aggregate for new concrete is a challenging prospect for the building sector because of the competing constraints of low recycling process cost and high aggregate product quality. A further complicating factor is that, from the perspective of the environment, there is a strong societal drive to reduce bulk transport of building materials in urban environments, and to apply more in situ recycling technologies for Construction & Demolition Waste. The European C2CA project investigates a combination of smart demolition, grinding of the crushed concrete in an autogenous mill to increase the liberation of cement mortar from the surface of aggregates and a novel dry classification technology called ADR to remove the fines. The feasibility of this recycling process was examined in a demonstration project involving 20,000 tons of EOL concrete from two office towers in Groningen, the Netherlands. Results show that the +4 mm recycled aggregate compares favorably with natural aggregate in terms of workability and the compressive strength of the new concrete, showing 30% higher strength after 7 days.     

Urban Australians using recycled water for domestic non-potable use--an evaluation of the attributes price, saltiness, colour and odour using conjoint analysis

Recycled water use in urban areas is viewed as one part of the solution to Australia's water shortage. The effectiveness of policies designed to promote recycled water systems depends on the acceptance by the community of the price, colour, odour and salt content of the recycled water. In Australia and other countries, limited research has been conducted that investigates community attitudes to and willingness to pay for recycled water, especially in urban settings. Community acceptance of recycled water and the economic feasibility of such projects have not been widely evaluated, even though the long-term feasibility of many projects is dependent on such information. This paper examines the attitudes of an urban Australian community living at Mawson Lakes in South Australia, to using recycled water for non-potable domestic purposes. Conjoint analysis (CA) was used to evaluate participant's (n=136) preferences for various attributes of recycled water (colour, odour, salt content and price) for various uses (garden watering, toilet flushing and clothes washing). The analysis was used to estimate the respondent's willingness to pay (WTP) for quality increases for each of the attributes. Differences in WTP were investigated according to various demographic variables including income and education. Results indicate that for garden watering having 'low salt levels' is the most important attribute of recycled water, for clothes washing 'colourless' is the most important attribute, and for toilet flushing a 'low price' was the most important attribute. Respondents were willing to pay for increases in the quality of recycled water. The amount they were willing to pay varied depending on applied use and the attribute in question. Respondents were most willing to pay for an increase in quality of recycled water when used for clothes washing (willing to pay Australian dollars (A$) 0.07/cubic meter (m(3)) for removal of colour, A$0.065 per cubic meter for an increase in quality of recycled water from 'salty' to 'low salt,' and A$ 0.06/m(3) for removal of odour (1A$=0.75 US $ and 0.62 euro, August 24, 2005)). Segmentation of the price attribute by demographic sectors reveals that those in the higher income bracket, higher education sector, middle age group, and who are male, had a higher marginal valuation on price. The results of this study provide important information for recycled water retailers and water policy developers, helping achieve greater economic feasibility for future recycled water projects, to the satisfaction of the communities involved.     

Thermal treatments of industrial wastes in controlled atmospheres for the elimination of As, Hg, Cd, Se and the concentration of Pb, Cu and Zn

Thermal treatments of five different types of non-ferrous metallurgical wastes, under a controlled atmosphere, were carried out at temperatures lower than 800°C for the separation of their toxic compounds and the concentration of valuable metals in the treatments residues. The best results were obtained by the treatments in air or hydrogen, or both successively. Simple treatments, using air or hydrogen, of three samples allowed the elimination of more than 95% of their toxic elements and almost doubled their valuable metals concentration. For the rest of the samples, a combined treatment was necessary for their efficient decontamination. In this case, the valuable metals content in the treatment's residue was increased to a reasonable value. Most of the solids issuing from these treatments can be recycled in current non-ferrous metallurgical processes.     

Responses of community to the possible use of recycled water for washing machines: A case study in Sydney, Australia

Recycled water is a valuable resource that has potential to free up potable water supplies and recharge systems while improving the environment. Recycled water for washing machine could be one of the options as new end use of recycled water to alleviate the demand on existing and limited water supplies. This paper summarizes the findings of a research survey in Sydney, Australia to explore the attitudes and opinions of community towards the use of recycled water for different purposes, especially for the washing machine. The survey showed that 97% of the respondents were aware of the persisting water shortage problem while more than 60% of the respondents supported the use of recycled water for washing clothes. This paper exposes the basic concern of participants for using recycled water in washing machine. Health issue was found as the most concerns of the community. The survey also presents the further conditions to be considered for using recycled water for washing machine according to the participants’ opinions. Correlation between knowledge and attitudes of respondents was also found in this survey.     

Desalinated versus recycled water: public perceptions and profiles of the accepters

Many countries' water resources are limited in both quantity and quality. While engineering solutions can now safely produce recycled and desalinated water from non-potable sources at a relatively low cost, the general public is sceptical about adopting these alternative water sources. Social scientists, policy makers and technical experts need to better understand what is causing this lack of acceptance by the general population and how acceptance levels for recycled and desalinated water can be increased. This study is the first to conduct a comparative analysis of knowledge, perceptions, and acceptability, and determine segments of residents who are more open-minded than the general population toward the use of recycled and desalinated water. The Australian population once perceived desalinated water as environmentally unfriendly, and recycled water as a public health hazard. The general level of knowledge about these two concepts as potential water sources has historically been low. After nearly five years of serious drought, accompanied by severe water restrictions across most of the country, and subsequent media attention on solutions to water scarcity, Australians now show more acceptance of desalinated water for close-to-body uses, and less resistance to recycled water for garden watering and cleaning uses. The types of people likely to be strong accepters of the two alternative water sources are distinctly different groups, and can be reached through different media mixes. This finding has significant implications for policy makers and water practitioners.     

Study on recycled asphalt concrete for use in surface course in airport pavement

This research investigated the possibility of using recycled asphalt concrete as surface course in airport pavement. The basic properties of recycled asphalt binder after short- and long-term aging were firstly tested and compared with those of the virgin asphalt. Then, a series of laboratory tests were performed to evaluate the performance of recycled asphalt concrete (containing 40% and 70% RAP), in which the HMA mixture without RAP was used as a control. Furthermore, an experimental pavement consisting of three sections (corresponding to 0%, 40% and 70% RAP content) was constructed to verify the laboratory test results. These results indicated that the recycled asphalt could achieve the similar properties against long-term aging as virgin asphalt. Recycled asphalt concrete containing 40% RAP could be used as surface course in airport pavement as it exhibited similar performance as control mixture both from the laboratory and experimental pavement test results. On the contrary, recycled asphalt concrete containing 70% RAP was not recommended as its fatigue property was much poorer compared with that of virgin asphalt mixture.     

PVC-based composite material containing recycled non-metallic printed circuit board (PCB) powders

The study is directed to the use of non-metallic powders obtained from comminuted recycled paper-based printed circuit boards (PCBs) as an additive to polyvinyl chloride (PVC) substrate. The physical properties of the non-metallic PCB (NMPCB) powders were measured, and the morphological, mechanical and thermal properties of the NMPCB/PVC composite material were investigated. The results show that recycled NMPCB powders, when added below a threshold, tended to increase the tensile strength and bending strength of PVC. When 20 wt% NMPCB powders (relative to the substrate PVC) of an average diameter of 0.08 mm were added, the composite tensile strength and bending strength reached 22.6 MPa and 39.83 MPa, respectively, representing 107.2% and 123.1% improvement over pure PVC. The elongation at break of the composite material reached 151.94% of that of pure PVC, while the Vicat softening temperature of the composite material did not increase significantly compared to the pure PVC. The above results suggest that paper-based NMPCB powders, when used at appropriate amounts, can be effective for toughening PVC. Thus, this study suggests a new route for reusing paper-based NMPCB, which may have a significant beneficial environmental impact.     

Concrete block production from construction and demolition waste in Tanzania

In Tanzania, construction and demolition (C&D) waste is not recycled and knowledge on how it can be recycled especially into valuable products like building materials are still limited. This study aimed at investigating the possibility of recycling the C&D waste (mainly cementitious rubble) into building material in Tanzania. The building materials produced from C&D waste was concrete blocks. The concrete blocks were required to have a load bearing capacity that meets the building material standards and specifications. Eight C&D waste samples were collected from C&D building sites, transported to the recycling site, crushed, and screened (sieved) to get the required recycled aggregates. Natural aggregates were also used as control. The recycled aggregates were tested in the laboratory following the standard methods as specified in Tanzanian standards. The physical, mechanical and chemical characteristics were determined. The physical and mechanical results showed that recycled aggregates were weaker than natural aggregates. However, chemically they were close to natural aggregates and therefore suitable for use in new concrete block production. In the production process, each experiment utilized 100% recycled aggregates for both fine and coarse portions to replace natural aggregates. The Fuller's maximum density theory was used to determine the mix proportions of materials in which a method that specifies concrete mix by system of proportion or ratio was used. The concrete blocks production processes included batching, mixing (that was done manually to get homogeneous material), compacting and moulding by hand machine and curing in water. After 28 days of curing, the concrete blocks were tested in the laboratory on compressive strength, water absorption ratio and density. The results showed that the blocks produced with 100% recycled aggregates were weaker than those with natural aggregates. However, the results also showed that there is a possibility of recycling the C&D waste into building material because 85% of the tested concrete block specimens from recycled aggregates achieved a compressive strength of 7 N/mm², which is defined as the minimum required load bearing capacity in Tanzania. Therefore, the C&D waste could be a potential resource for building material production for sustainable construction in Tanzania rather than discarding it. Further work should focus on the economic feasibility of production of concrete blocks with recycled aggregates in Tanzania.     

Mangrove mapping in Ecuador: The impact of shrimp pond construction

A cooperative mangrove mapping project between the Ecuadorian Center for Remote Sensing (CLIRSEN) and the University of Delaware was begun in August 1982. The objectives of the project were to create historical maps of mangrove ecosystem extent and change, while transferring aerial photographic interpretation techniques to Ecuadorian personnel. The result of this cooperation was a series of three 125,000 scale maps of historical mangrove extent and change from 1966 to 1982 in the southern Gulf of Guayaquil. This multitemporal study showed a 16% decrease in mangrove extent and a 27% increase in shrimp pond development. If these rates of change prevail into the future, mangroves in Ecuador will reach parity with shrimp ponds in 1984 and completely disappear by mid-1990. Recognizing the significance of this loss to shellfish and fish production along the coast, Ecuadorian scientists at CLIRSEN have subsequently initiated a nationwide mangrove mapping program to create a historical base for future mangrove management strategies.     

Taxing virgin natural resources: Lessons from aggregates taxation in Europe

The objective of this review paper is to analyze the efficiency of environmentally motivated taxes on virgin raw materials. We analyze both the economic-theoretical foundations of virgin natural resource taxation, and the empirical experiences of aggregates taxes i.e., taxes on, for instance, gravel, rock, stone, etc. in three European countries. These include Sweden, Denmark and the United Kingdom. The theoretical analysis indicates that taxing natural resource output or use typically represents a ‘second-best’ policy alternative, which can be used when, for instance, the monitoring of non-point source emissions is difficult or efficient property rights regimes cannot be established. The empirical analysis shows that the European aggregate taxes have assisted in reducing virgin resource use in spite of the relatively low own-price responses. However, generators of recycled materials typically have few incentives to enhance their waste sorting activities in the presence of a tax on virgin materials. Unless additional policies to increase the supply of recycled materials are implemented, supply will not increase much even in the presence of high demand. Finally, although second-best taxes are sometimes motivated by the desire to keep administration costs low, they could come at the cost of improper incentives and of limited policy legitimacy.     

Supplier codes of conduct: Company authorization of subcontractors

Companies continue to build greater sustainability and transparency in their supply chains to increase their business value and to respond to greater stakeholder pressures and expectations to increase sustainability and transparency. As company supply chains have grown and expanded, which presents increased challenges for building greater transparency, it is possible that the use of subcontractors in supply chains has also increased. The amount and impact of subcontracting conducted in supply chains may be of greater concern to certain companies and/or sectors than others, and it may have an important impact on their sustainability efforts. This article assesses the extent to which supplier codes of conduct apply to the use of subcontractors and include a requirement for suppliers to obtain prior company approval or authorization before subcontractors conduct work. Based on a review of more than 50 supplier codes of conduct, the companies that are highlighted in this article for including this requirement are primarily in the apparel/footwear, food, pharmaceuticals, and/or retail sectors. The article asserts that supplier codes of conduct that include requirements for suppliers to protect and safeguard confidential business information could be strengthened to further protect the company's products, integrity, and reputation/brand and increase its competitiveness and resilience by also including a requirement of prior approval or authorization of a supplier's use of subcontractors.     

Assessing the potential of yield improvements, through process scrap reduction, for energy and CO2 abatement in the steel and aluminium sectors

Targets to cut 2050 CO₂ emissions in the steel and aluminium sectors by 50%, whilst demand is expected to double, cannot be met by energy efficiency measures alone, so options that reduce total demand for liquid metal production must also be considered. Such reductions could occur through reduced demand for final goods (for instance by life extension), reduced demand for material use in each product (for instance by lightweight design) or reduced demand for material to make existing products. The last option, improving the yield of manufacturing processes from liquid metal to final product, is attractive in being invisible to the final customer, but has had little attention to date. Accordingly this paper aims to provide an estimate of the potential to make existing products with less liquid metal production.Yield ratios have been measured for five case study products, through a series of detailed factory visits, along each supply chain. The results of these studies, presented on graphs of cumulative energy against yield, demonstrate how the embodied energy in final products may be up to 15 times greater than the energy required to make liquid metal, due to yield losses. A top-down evaluation of the global flows of steel and aluminium showed that 26% of liquid steel and 41% of liquid aluminium produced does not make it into final products, but is diverted as process scrap and recycled. Reducing scrap substitutes production by recycling and could reduce total energy use by 17% and 6% and total CO₂ emissions by 16% and 7% for the steel and aluminium industries respectively, using forming and fabrication energy values from the case studies. The abatement potential of process scrap elimination is similar in magnitude to worldwide implementation of best available standards of energy efficiency and demonstrates how decreasing the recycled content may sometimes result in emission reductions.Evidence from the case studies suggests that whilst most companies are aware of their own yield ratios, few, if any, are fully aware of cumulative losses along their whole supply chain. Addressing yield losses requires this awareness to motivate collaborative approaches to improvement.     

The contemporary European silver cycle

This paper examines the 1-year anthropogenic stocks and flows of silver as it progresses from extraction to final disposal on the European continent. The primary flows of silver include production, fabrication and manufacturing, use, and waste management. A substance flow analysis (SFA) was used to trace the flows and inventory data, and mass balance equations were used to determine the quantity of flows. The results reveal that Europe has a low level of silver mine production (1580 Mg Ag/year) and instead relies on silver imports and the recycling of scrap in production and fabrication. In the year 1997, Europe imported 1160 Mg Ag of ore concentrate and 2010 Mg Ag of refined silver, and recycled 2750 Mg Ag of new and old scrap. There is a net addition of 3320 Mg Ag/year into silver reservoirs at the use stage. This is the result of a greater amount of silver entering the system from manufacturing than is leaving the system into waste management. The waste flow with the highest content of silver is municipal solid waste, which contains 1180 Mg Ag/year. In total, 62% of all discarded silver is recycled and 38% is sent to landfills. The results of this study and other element and material flow analyses can help guide resource managers, environmental policy makers, and environmental scientists in their efforts to increase material recovery and recycling, address resource sustainability, and ameliorate environmental problems.     

含油污泥处理技术方案

阐述了含油污泥处理存在的难点,通过对现有技术的分析,针对某石化厂含油污泥的特点提出了"调质机械脱水、干化减量化、热裂解"3种技术的组合工艺。运行结果表明该工艺能够有效实现含油污泥的减量化和无害化,处理后的含油污泥石油类物质含量低于0.01%,符合SY/T 7301-2016《陆上石油天然气开采含油污泥资源化综合利用及污染控制技术要求》。处理后含油污泥浸出液中重金属含量符合GB5085.3-2007《危险废物鉴别标准浸出毒性鉴别》标准。处理约2 000m3含液率85%的含油污泥,回收油品量约100t。     

The effects of recovering fibre and fine materials on sludge dewatering properties at a deinked pulp mill

The manufacture of deinked pulp generates large amounts of waste for disposal. The yield loss in the production of recycled paper can be up to 25%. The use of landfills for waste disposal is very expensive and will be prohibited in Europe in the next few years. Thus, there is a great pressure to improve the material efficiency and to reduce the amount of waste that is produced at deinked pulp mills. However, the issue is complex because an improvement of the material efficiency at one process unit may deteriorate the performance of other stages. For example, the attempts to increase the fibre yield in the deinking processes can lead to poor sludge dewatering properties, resulting in that there are no added advantages for the mill anymore.This work aims to determine the limitations between the sludge dewatering properties and the improvements in material efficiency at a deinked pulp mill by investigating the dewatering properties of sludge samples that contained variable amounts of fine screening and flotation froth rejects. The results show that the deinked pulp mill material efficiency can be increased without weakening the sludge dewatering properties if the fibre content is not reduced below a certain limit. The material efficiency can be increased either by (1) recovering fibres at an acceptable quantity where the fibre content does not decrease below the limiting point or by (2) recovering fine materials simultaneously with fibres in a way that maintains the fibre content above a limiting point. The first method provides an opportunity for deinking mills to increase the yield, even though the increase is less than 2 percentage units. With the simultaneous recovery of fibres and fine materials using the second method, it would be possible to improve the material efficiency at the deinked pulp mill by approximately 5 percentage units without affecting the dewatering of the combined sludge.     

Modeling methods for managing raw material compositional uncertainty in alloy production

Operational uncertainties create disincentives for use of recycled materials in metal alloy production. One that greatly influences remelter batch optimization is variation in the raw material composition, particularly for secondary materials. Currently, to accommodate compositional variation, firms commonly set production targets well inside the window of compositional specification required for performance reasons. Window narrowing, while effective, does not make use of statistical sampling data, leading to sub-optimal usage of recycled materials. This paper explores the use of a chance-constrained optimization method, which allows explicit consideration of statistical information on composition. The framework and a case study of cast and wrought production with available scrap materials are presented. Results show that it is possible to increase the use of recycled material without compromising the likelihood of batch errors, when using this method compared to conventional window narrowing. This benefit of the chance-constrained method grows with increase in compositional uncertainty and is driven by scrap portfolio diversification.     

Future U.S. Water Consumption: The Role of Energy Production1

Elcock, Deborah, 2010. Future U.S. Water Consumption: The Role of Energy Production. Journal of the American Water Resources Association (JAWRA) 46(3):447-460. DOI: 10.1111/j.1752-1688.2009.00413.x Abstract: This study investigates how meeting domestic energy production targets for both fossil and renewable fuels may affect future water demand. It combines projections of energy production developed by the U.S. Department of Energy with estimates of water consumption on a per-unit basis (water-consumption coefficients) for coal, oil, gas, and biofuels production, to estimate and compare the domestic freshwater consumed. Although total domestic freshwater consumption is expected to increase by nearly 7% between 2005 and 2030, water consumed for energy production is expected to increase by nearly 70%, and water consumed for biofuels (biodiesel and ethanol) production is expected to increase by almost 250%. By 2030, water consumed in the production of biofuels is projected to account for nearly half of the total amount of water consumed in the production of all energy fuels. Most of this is for irrigation, and the West North Central Region is projected to consume most of this water in 2030. These findings identify an important potential future conflict between renewable energy production and water availability that warrants further investigation and action to ensure that future domestic energy demand can be met in an economically efficient and environmentally sustainable manner.     

制药行业药渣污泥干化工艺研究

通过对南阳市危废处置中心药渣污泥干化系统的研究,设计了一套有效的干化系统,使药渣污泥的含水率从75%～80%干化至含水率20%,为药渣污泥进一步减量化、无害化和资源化处理提供更多的可能。系统配套有效的尾气处理系统,使该项目废气排放指标达到《工业炉窑大气污染物排放标准》(GB9078-96)以及《恶臭污染物排放标准》(GB14554-93)中的相关要求。     

Leaching of pharmaceuticals and personal care products in turfgrass soils during recycled water irrigation

An important beneficial reuse of treated wastewater (recycled water) in arid and semiarid regions is landscape irrigation. However, the environmental fate, especially groundwater contamination potential, of trace contaminants such as pharmaceuticals and personal care products (PPCPs) is a significant concern that can hinder the acceptance and adoption of such reuses. In this study, we irrigated mature turfgrass plots with nonspiked tertiary treated wastewater for over 6 mo at 100 or 130% of the reference evapotranspiration rate (ETo) and collected leachate water at the 90-cm depth on a weekly basis. In the recycled water, all 14 target PPCPs were consistently found, and the mean levels of atenolol, gemfibrozil, meprobamate, carbamazepine, and sulfamethoxazole were above 100 ng L. However, only five compounds were detected in the leachate at trace levels. Trimethoprim and primidone were frequently found, whereas the detection of sulfamethoxazole, meprobamate and carbamazepine was less frequent (<50%). When detected, the overall mean concentration in the leachate was 10.2 ng L for trimethoprim, 7.1 ng L for primidone, and 2.9 to 12.4 ng L for carbamazepine, sulfamethoxazole, and meprobamate. The majority of the target PPCPs were completely removed. Given that the irrigation rates were higher than normal, this study clearly demonstrated the efficacy of turfgrass systems in attenuating PPCPs during recycled water irrigation. However, it is also apparent that some PPCPs are more susceptible to leaching than others, and these PPCPs thus merit further research attention.