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[en] Highlights: • Pairing social and technical innovations improves organic collection programs. • Supportive infrastructure significantly increases household food waste diversion. • Norm communication increases separation behavior and reduces dropout. •Model predicting-fit best behavior-change tools is partially supported. • Norms are most effective on population perceiving low benefits and barriers. - Abstract: Cities around the world are under increasing political pressure to develop organics collection programs (OCP) to curb the flow of food waste into landfills, reduce the associated greenhouse gases, and generate compost or biogas. While OCPs tend to focus on infrastructure, they often overlook the linchpin role that household behavior change plays in the success of OCPs. The current research used a longitudinal field experiment (n=370) to test both the effectiveness of a new curbside OCP and new social innovations intended to stimulate pro-environmental changes in household behavior. The findings suggest greater participation levels occur by implementing both new supportive infrastructure (i.e., curbside carts and collection services), and innovations that target the social aspects of waste (i.e., communicating social norms of separation). The data also provide an opportunity to test new model for predicting the most efficacious behavior-change interventions based on population profiles. The results provide some support for the model; reducing barriers (i.e., curbside carts and collection) tends to help all population profiles, but norm communication increases participation more for the hypothesized profile than for other sub-groups.
[en] This paper aims at providing an overview of electrochemical oxidation processes used for treatment of landfill leachate. The typical characteristics of landfill leachate are briefly reviewed, and the reactor designs used for electro-oxidation of leachate are summarized. Electrochemical oxidation can significantly reduce concentrations of organic contaminants, ammonia, and color in leachate. Pretreatment methods, anode materials, pH, current density, chloride concentration, and other additional electrolytes can considerably influence performance. Although high energy consumption and potential chlorinated organics formation may limit its application, electrochemical oxidation is a promising and powerful technology for treatment of landfill leachate
[en] This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2010 and includes inspection and repair activities completed at the following seven CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 407: Roller Coaster RadSafe Area (TTR); (3) CAU 424: Area 3 Landfill Complexes (TTR); (4) CAU 426: Cactus Spring Waste Trenches (TTR); (5) CAU 453: Area 9 UXO Landfill (TTR); (6) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR); and (7) CAU 487: Thunderwell Site (TTR).
[en] This paper describes the feasibility of an aerobic system (rotating biological contactor, RBC) and a biological anaerobic system (upward-flow anaerobic sludge bed reactor) at small scale for the treatment of a landfill leachate. In the first phase of the aerobic system study, a cyclic-batch RBC system was used to select perforated acetate discs among three different acetate disc configurations. These discs were chosen on the basis of high COD removal (65%) and biological stability. In the second phase, the RBC system (using four stages) was operated continuously at different hydraulic retention times (HRT), at different rotational speeds, and with varying organic concentrations of the influent leachate (2500-9000 mg L-1). Forty percent of the total surface area of each perforated disc was submerged in the leachate. A COD removal of about 52% was obtained at an HRT of 24 h and a rotational speed of 6 rpm. For the anaerobic system, the reactor was evaluated with a volumetric organic load of 3273 g-COD m-3 day-1 at an HRT of 54, 44, 39, 24 and 17 h. At these conditions, the system reached COD removal efficiencies of 62%, 61%, 59%, 44% and 24%, respectively
[en] This study was designed to accomplish two objectives. The first was to provide to the US Air Force and the regulatory community quantitative procedures that they might want to consider using for addressing uncertainty and variability in exposure to better characterize potential health risk. Such methods could be used at sites where populations may now or in the future be faced with using groundwater contaminated with low concentrations of the chemical trichloroethylene (TCE). The second was to illustrate and explain the application of these procedures with respect to available data for TCE in ground water beneath an inactive landfill site that is undergoing remediation at Beale Air Force Base in California. The results from this illustration provide more detail than the more traditional conservative deterministic, screening-level calculations of risk, also computed for purposes of comparison. Application of the procedures described in this report can lead to more reasonable and equitable risk-acceptability criteria for potentially exposed populations at specific sites
[en] Traditional estimates of health risk are typically inflated, particularly if cancer is the dominant endpoint and there is fundamental uncertainty as to mechanism(s) of action. Risk is more realistically characterized if it accounts for joint uncertainty and interindividual variability after applying a unified probabilistic approach to the distributed parameters of all (linear as well as nonlinear) risk-extrapolation models involved. Such an approach was applied to characterize risks to potential future residents posed by trichloroethylene (TCE) in ground water at an inactive landfill site on Beale Air Force Base in California. Variability and uncertainty were addressed in exposure-route-specific estimates of applied dose, in pharmacokinetically based estimates of route-specific metabolized fractions of absorbed TCE, and in corresponding biologically effective doses estimated under a genotoxic/linear (MA(sub g)) vs. a cytotoxic/nonlinear (MA(sub c)) mechanistic assumption for TCE-induced cancer. Increased risk conditional on effective dose was estimated under MA(sub G) based on seven rodent-bioassay data sets, and under MA, based on mouse hepatotoxicity data. Mean and upper-bound estimates of combined risk calculated by the unified approach were and lt;10(sup -6) and and lt;10(sup -4), respectively, while corresponding estimates based on traditional deterministic methods were and gt;10(sup -5) and and gt;10(sup -4), respectively. It was estimated that no TCE-related harm is likely occur due any plausible residential exposure scenario involving the site. The unified approach illustrated is particularly suited to characterizing risks that involve uncertain and/or diverse mechanisms of action
[en] This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2008 and includes inspection and repair activities completed at the following ten CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR) CAU 404: Roller Coaster Lagoons and Trench (TTR) CAU 407: Roller Coaster RadSafe Area (TTR) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR) CAU 424: Area 3 Landfill Complexes (TTR) CAU 426: Cactus Spring Waste Trenches (TTR) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR) CAU 453: Area 9 UXO Landfill (TTR) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR) CAU 487: Thunderwell Site (TTR)
[en] Highlights: ► Critical assessment of the main commercially available MSW gasifiers. ► Detailed discussion of the basic features of gasification process. ► Description of configurations of gasification-based waste-to-energy units. ► Environmental performance analysis, on the basis of independent sources data. - Abstract: The paper proposes a critical assessment of municipal solid waste gasification today, starting from basic aspects of the process (process types and steps, operating and performance parameters) and arriving to a comparative analysis of the reactors (fixed bed, fluidized bed, entrained bed, vertical shaft, moving grate furnace, rotary kiln, plasma reactor) as well as of the possible plant configurations (heat gasifier and power gasifier) and the environmental performances of the main commercially available gasifiers for municipal solid wastes. The analysis indicates that gasification is a technically viable option for the solid waste conversion, including residual waste from separate collection of municipal solid waste. It is able to meet existing emission limits and can have a remarkable effect on reduction of landfill disposal option.