The socially optimal recycling rate: Evidence from Japan

This paper estimates the average social cost of municipal waste management as a function of the recycling rate. Social costs include all municipal costs and revenues, costs to recycling households to prepare materials estimated with an original method, external disposal costs, and external recycling benefits. Results suggest average social costs are minimized with recycling rates well below observed and mandated levels in Japan. Cost-minimizing municipalities are estimated to recycle less than the optimal rate. These results are robust to changes in the components of social costs, indicating that Japan and perhaps other developed countries may be setting inefficiently high recycling goals.     

Optimal pollution in the presence of adjustment costs

This paper explores optimal pollution control when pollution is considered a stock and costs of treating pollution are a function both of the level and rate of change of pollution control. It is shown that even if the long run optimum stock of pollution is below the initial level adjustment costs may imply an optimally increasing stock of pollution in the short run. The results obtained are contrasted with those which emerge when adjustment costs are absent and when damages are taken to be a function of the flow of pollution; the appropriate tax rates of polluting discharges are examined.     

当代城市生活垃圾处理技术现状与展望——兼论中国城市生活垃圾对策视点的调整

以探究全球城市生活垃圾治理技术实践 ,展示人类面向 2 1世纪解决城市生活垃圾问题的新视点 ,并对我国垃圾对策视点的调整及垃圾产业化提出建议     

Adjustment costs from environmental change

The paper is concerned with the case whereby the distribution of a firm's productivity shocks changes without the knowledge of the firm. Over time the firm learns about the nature and extent of the change in the distribution of the shock and adjusts, incurring adjustment costs in the process. The long-run loss in profits (±) due to the shift in the distribution we term the equilibrium response. The transitory loss in profits, incurred while the firm is learning about the distribution shift, is termed the adjustment cost. The theory is then applied to the problem of measuring adjustment costs in the face of imperfectly observed climate change in agriculture. The empirical part of the paper involves estimating a restricted profit function for agricultural land in a five-state region of the Midwest US as a function of prices, land characteristics, actual weather realizations and expected weather. We then simulate the effect of an unobserved climate shock, where learning about the climate shock is by observing the weather and updating prior knowledge using Bayes Rule. We find adjustment costs to climate change are 1.4% of annual land rents.     

Fissioning minimizes ranging costs in spider monkeys: a multiple-level approach

The adjustment to deal with intragroup food competition is probably the most plausible explanation of high levels of fission–fusion dynamics. However, studies did not always support expected relations between food availability, ranging costs, and subgroup size. We used several levels of analysis differing in the time and spatial scale in order to investigate this explanation in spider monkeys. In our study, subgroups were larger when food availability was higher across most levels of analyses used. We also found a fine-scale adjustment: compared to the food patch previously visited, spider monkeys traveled to larger patches just after fusions. This was not without an immediate travel cost: the interpatch distance and travel time after a fusion were longer than that before the fusion. This rapid adjustment shows the flexibility that fission–fusion dynamics can offer. Spider monkeys are in large subgroups only when food conditions are favorable, as evidenced by the fact that at all the other time-scale levels larger subgroups did not experience greater ranging costs than smaller subgroups. Our results indicate that on the whole spider monkeys successfully minimize ranging costs by fission and fusion of subgroups.     

Mining of the forest and the time path of the price of timber

The paper analyzes the effect of transportation (site specific) costs and the effect of mining (depletion) of the forest on the time path of the price and of the net price of timber in two forestry models. The models differ in that one has zero costs and the other has positive costs. The analyses yield the standard mining theory results for certain cases. They also yield extentions of these results for cases with growth of the harvested trees and/or regeneration on the harvested land. The paper concludes, as one would expect, that the theory of the mine is useful in analyzing the time path of the price of timber.     

Nonseparability and the voluntary approach to externality problems

Ronald Coase asserted that voluntary two-party bargaining with zero transaction costs results in an optimal resource allocation, which is invariant with respect to the liability rule. It has been argued that nonseparabilities destroy the validity of Coase's theorem. In this paper it is shown that this criticism is based on implausible assumptions about the externality-receivers adjustment to the externality level.     

Restoring Natural Resources with Destination-Driven Costs

Economics typically assumes that injured natural resources are restored along a fixed path of increasing marginal costs. By contrast, many restoration efforts—such as cleaning a contaminated aquifer or replacing the sand on an oil-tarnished beach—are characterized bydestination-driven costs, which depend mainly on final quality, not the prerestoration quality. Given the resulting nonconvexities in cost, the optimal level of restoration may be a discontinuous and nonmonotonic function of post-injury quality. Regulatory rules should reflect these patterns, as should liability rules, since restoration plans and costs determine the expected cost of putting a resource at risk.     

Analytische Schnellerkennungsmethoden: Bewertung abzulagernder Abfälle und Kontrolle von Deponien

Rapid test methods have been developed to classify waste. These procedures includes rapid elution and analytical determination methods for the detection of such elements as copper, nickel and zinc. Test kits for matter analysis (with a time requirement of about 30 minutes) have been modified with regard to the matrix waste. A comparison between such rapid testing methods and standard procedures using real samples leads to a similar waste classification. The reduction in time and costs via rapid assay methods allows multiple determinations of wastes to consequently increase the reliability of results from heterogeneous samples. The simple and rapid employment of these tests also makes an “on-site” performance possible.     

Optimal management of renewable resources with growing demand and stock externalities

In an equilibrium framework, optimal management of renewable resources in the presence of growing demand or externalities leads to steady states that differ from those characterized by rate of interest equals rate of change in growth plus rate of change in prices. Measures to reach an optimum with externalities other than direct controls are found to be critically mediated by the costs of harvesting.     

A decision framework for estimating the cost of marine plastic pollution interventions

Marine plastic pollution has emerged as one of the most pressing environmental challenges of our time. Although there has been a surge in global investment for implementing interventions to mitigate plastic pollution, there has been little attention given to the cost of these interventions. We developed a decision support framework to identify the economic, social, and ecological costs and benefits of plastic pollution interventions for different sectors and stakeholders. We calculated net cost as a function of six cost and benefit categories with the following equation: cost of implementing an intervention (direct, indirect, and nonmonetary costs) minus recovered costs and benefits (monetary and nonmonetary) produced by the interventions. We applied our framework to two quantitative case studies (a solid waste management plan and a trash interceptor) and four comparative case studies, evaluating the costs of beach cleanups and waste-to-energy plants in various contexts, to identify factors that influence the costs of plastic pollution interventions. The socioeconomic context of implementation, the spatial scale of implementation, and the time scale of evaluation all influence costs and the distribution of costs across stakeholders. Our framework provides an approach to estimate and compare the costs of a range of interventions across sociopolitical and economic contexts.     

Chromium recovery from solid leather waste by chemical treatment and optimisation by response surface methodology

The leather industry uses conventional tanning methods which cause environmental pollution due mainly to the presence of chromium. This study suggests a treatment for solid leather waste containing chromium as an ecological alternative to the pollution generated by tanneries. The study uses an original approach to the optimisation of chromium recovery by mathematical and statistical treatment of the experimental data. Several factors that influence recovery, such as temperature, concentration, time and solid/liquid ratio through acid and basic hydrolysis were analysed with the aid of experimental design. Tanning liquor was obtained by adjusting pH, alkalinity and concentration when hydrolysis finished. An appropriate response surface model was constructed using alkaline hydrolysis experiments with sodium hydroxide, leading to conditions for maximum recovery of Cr₂O₃. The optimal NaOH concentration (1.58%), temperature (63.7 °C), time (3 h) and solid/liquid ratio (1/70 g·mL^?1) were established. The results indicate that sodium hydroxide as an hydrolysis agent is a highly efficient means of recovering chromium from solid leather waste in order to produce tanning liquor.     

Industrial ecosystems — some conditions for success

SUMMARY

The development of Industrial Ecology (IE) is based on the philosophy that the two systems, the industrial system and the ecosystem operate through different principles of system development and on the philosophy that IE can serve to reduce the conflict between the two systems as it learns from the model of an ecosystem. In an IE, following the roundput analogy of a natural ecosystem, the industrial actors co-operate by utilising each other's waste material and energy flows and try and reduce the system virgin material and energy input as well as the waste and emission output. In a successful IE, a business-environment win-win might be possible because the raw material and energy costs, waste management costs, costs resulting from environmental legislation, as well as the image costs of the companies in the system and of the system as a whole, can be reduced. In this paper, the IE analogy includes the four basic principles of system development of ecosystems; roundput, diversity, locality and gradual change. The principles are understood as a potential direction in which Regional Industrial Ecosystem Management (RIEM) can be developed.     

The feasibility of processing lead-based paint abatement wastes through primary and secondary lead smelters

This study was undertaken to determine the feasibility of processing soil and lead-based paint (LBP) abatement waste through primary and secondary lead smelting facilities. The main objectives were to determine the compatibility of soil and LBP abatement waste with lead smelting circuits; the costs associated with transporting and processing the abatement waste through a smelter; and a review of major environmental laws or regulations which may impact the lead smelting industry's ability to carry out this process. While not all categories of LBP wastes are suited for reclamation through lead smelters, sufficient classes are to make the effort worthwhile. Specifically, lead paint chips, dusts, heatgun sludge, soils and certain blasting abrasives appear metallurgically compatible with the lead smelting circuits. Additionally, there do not appear to be any current regulatory statutes that forbid the process from being carried out, so long as certain permit modifications are obtained. Finally, the estimated smelting costs seem to compare favourably with current treatment and disposal fees at approved landfills. However, despite the promise of these initial findings, a great deal of work remains to be done if the concept of processing lead paint wastes through lead smelters for reclamation is to become a reality.     

Implikationen der landwirtschaftlichen Klärschlammverwertung Status quo und Perspektiven

Goal and Scope

At all times animal as well as human excrements have been used as organic fertilizers. Disposing of municipal sewage sludge on arable farmland means saving mineral fertilizer to conserve the exhaustible resource phosphorus; one can consider this kind of recycling management as a contribution to a sustainable regional development. However, the use of sludge implies a significant release of pollutants. Hence, in Germany as well as internationally, this is a controversial issue and therefore it needs to be re-evaluated under consideration of regional circumstances.

Methods

A material flow management framework is used to first analyse toxic, fertilizing and legal aspects of the ‘sludge metabolism’ in Schleswig-Holstein, including involved participants. Then, the treatment of waste water as well as potential and actual recycling of domestic sewage sludge are regionally compared. The study is based on a survey of the municipal waste water treatment plants which serve more than 10.000 people including population equivalence; these plants cover about 94% of the sewage sludge in Schleswig-Holstein.

Results and Conclusions

After taking the phosphorus of manure into account, the modelled potentials of recycling on the scale of districts do not correspond with the actual use of sludge in agriculture. The disposal firms recycle the sludge where they can get the highest profit. By minimizing transaction costs, lager recycling distances can be compensated. The potential of phosphorus recycling is limited. The calculated state-wide amount is not more than 10% of the total phosphorus demand of the arable land, so the benefit is less important for the national economy. On the other hand, there is a significant discharge of pollutants mainly into the soil, where apart from copper and cadmium, the charge through sewage sludge is higher than through mineral fertilizer and manure. In addition, the risk of pollutants with endocrine disrupters is difficult to estimate.

Outlook

In respect of the net ecological effects, thermal utilization of sewage sludge, e.g. in clinker works, coal-fired power stations or waste incineration plants, combined with previous or additional phosphorus recovery from cinder, meets the criteria of sustainable material flows more than its use on arable land. Even though these disposal options are still more expensive, law induced adjustment of the waste market and more strict land application regulations will reduce their price differences. This will make a middle-term change from the agricultural use to a thermal recycling of sewage sludge possible to avoid soil impacts and fulfil the requirements of a sustainable development.     

Environmental policy with collective waste disposal

Centralized collection and disposal is an integral component of waste management strategies for many solid and liquid wastes, and carbon capture and storage is currently being considered for gaseous waste. In this paper we show how collective waste disposal systems introduce essential changes in the design of optimal environmental policy. Absent collective disposal, an optimal environmental policy imposes relatively stringent regulations on polluters in regions where local environmental damage functions are “high”; however, under collective waste disposal, the optimal environmental policy level increases monotonically over distance from the disposal site, and this is true irrespective of the degree of spatial heterogeneity in local environmental damage functions. We characterize the optimal spatial pattern of environmental policy levels under collective waste disposal and identify optimal membership size for waste disposal networks comprised of homogeneous producers.     

The economic implications of recycling exhaustible natural resources: The case for crude oil

Regardless of whether the bulk of decision-making in an economy is done by a central unit or by decentralized smaller units, the government can act to propose guidelines to individual agents. This is of particular importance when the activities of the latter cause aggregative or social problems which are not directly acted upon by the smaller agents. The purpose of this paper is to set up a model by which a central authority can make choices in the presence of two pressing social problems, namely, a diminishing domestic supply of an exhaustible resource and the contamination of the environment through discharged waste materials.The model itself takes the form of an integer-linear programming problem which runs through discrete time to a finite horizon. Besides the traditional modes of “virgin” exploration and production and/or importation from abroad, society is also given the choice of recycling. Society will choose combinations of the above three to minimize the costs of satisfying fixed (projected) oil product demands in the future. The costs include those for increasing exploration for virgin refineries; for collection, refining and transportation for refineries and for the cost to society of discharges of waste-oil into the environment. The constraints include process flow restrictions, import quotas, capacity limits and discharge restrictions as well as fixed demands.An effort was made to keep the model as general as possible. Although no numerical solution is obtained in this paper, we feel that the policy implications of some presumed solution (possible through the use of a well-known algorithm for mixed variable problems) are worth examining. They revolve around the model itself, citing the potential attractiveness of recycling as the other two alternatives become increasingly expensive, and as development of alternatives to oil progresses at an alarmingly slow rate. Also mentioned are problems relating to the potential demands for recycled versus virgin oil products, balance-of-trade problems, and the mutability of social and economic institutions in the crisis of economic adjustment that much of the world is now facing.     

A note on environmental risk and the rate of discount: Comment

The sign of the adjustment to the riskless discount rate for environmental risk depends on whether the price of avoiding the consequences of the externality is seen as reducing expected net benefits or increasing expected costs. The conclusion is that the risk adjustment is positive when the externality is defined as reducing expected net benefits.     

多目标优化方法在城市污水厂汇水区污染源总量控制规划中的应用

在城市污水处理厂汇水区实行污染源总量控制,应该避免与城市污水处理厂重复治理.针对这个问题,提出难降解有机物控制的多目标准则指标,建立了多目标优化模型.     

Treatment technologies for aqueous perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA)

Fluorochemicals (FCs) are oxidatively recalcitrant, environmentally persistent, and resistant to most conventional treatment technologies. FCs have unique physiochemical properties derived from fluorine which is the most electronegative element. Perfluorooctanesulfonate (PFOS), and perfluorooctanoate (PFOA) have been detected globally in the hydrosphere, atmosphere and biosphere. Reducing treatment technologies such as reverses osmosis, nano-filtration and activated carbon can remove FCs from water. However, incineration of the concentrated waste is required for complete FC destruction. Recently, a number of alternative technologies for FC decomposition have been reported. The FC degradation technologies span a wide range of chemical processes including direct photolysis, photocatalytic oxidation, photochemical oxidation, photochemical reduction, thermally-induced reduction, and sonochemical pyrolysis. This paper reviews these FC degradation technologies in terms of kinetics, mechanism, energetic cost, and applicability. The optimal PFOS/PFOA treatment method is strongly dependent upon the FC concentration, background organic and metal concentration, and available degradation time.