Effects of fly ash addition on physical properties of porous clay-fly ash composites via polymeric replica technique

The porous composites of clay and fly ash have the potential to be used in many fields, such as catalyst support and gas adsorbents. In this study, various ratios of fly ash (1–2) with different percentage of suspension (50–70 wt%) were applied to produce porous clay-fly ash composites via polymeric replica technique. Fabrication process starts by mixing clay and fly ash in distilled water to form slurry. The process is followed by fully immersing polymer sponge in slurry. The excess slurry is then removed through squeezing. Finally, the sponge coated with slurry is sintered at 500 and 1250 °C for 1 h. It is found that the compressive strength of porous composites improves significantly (0.178–1.28 MPa) when the amount of clay-fly ash suspension mixture (50–70 wt%) increases. The compressive strength of porous composites is mainly attributed to the mullite, quartz and amorphous phase formations. These results are supported by X-ray diffraction analysis. On the other hand, increase in the amount of suspension reduces the apparent density (from 2.44 to 2.32 g/cm³) and porosity (from 97 to 85 %). The reduction in apparent density is believed to be caused by the presence of high fly ash content in porous composites. The melted fly ash cenospheres have closed the internal pores and increased density of samples. Higher suspension level not only reduces porosity, but also increases close pores of the porous composites. The results are justified through the observation from the structures of porous clay-fly ash composites.     

Life cycle assessment of biodiesel fuel production from waste cooking oil in Okayama City

A life cycle assessment (LCA) is performed to make clear of the actual environment impacts from conversation of waste cooking oil (WCO) to biodiesel fuel (BDF) in Okayama. A scenario analysis is carried out based on different participation rate of residents who separate WCO from general waste, corresponding to different BDF utilisation rate in transportation system. Sub scenarios complying with different gas emission standards regarding vehicles are designed as well. Afterwards, life cycle impact assessment is conducted to focus on global warming, acidification, and urban air pollution. Overall improvement of almost all kinds of life cycle inventories is significant when diesel is replaced with BDF, demonstrating that a shift from WCO-to-incineration to WCO-to-BDF is more beneficial. Under carbon neutral, compared to base scenario (S0), about 746.05 ton CO₂ emission will be reduced annually in the scenario with 100 % BDF utilisation in vehicles (S4). Meanwhile, total external cost in three environmental impacts (EI) sharply reduces by 51.90 %, showing much economic sustainability in S4. Moreover, the manufacturing cost for producing one litter WCO-to-BDF is 97.32 Yen. Sensitivity analysis shows that the gas emission standard regarding vehicles had much bigger effect on EI than BDF manufacturing process in this research.     

Current and future solid waste management system in Northern Viet Nam with focus on Ha Noi: climate change effects and landfill management

The contribution investigates the solid waste management system in Ha Noi under consideration of the interrelation between climate change effects and landfill management by means of a cause-and-effect-analysis as well as water balances using the HELP 3.95 model and gas emission data, followed by a Strength, Weakness, Opportunities, Threats (SWOT) analysis. Even landfills are sources of methane (CH₄) emissions they are also impacted by climate change. The main effects on landfill sites are the change of climatic conditions, namely the regional water balance, extreme precipitation and storm events. The results of the water balance model results show that a geomembrane surface sealing can reduce the leachate formation significantly, a fact that is also valid for the climate change scenario with higher precipitation. The risk of flooding and erosion at the landfill sites increases, which will require a customized water management. In parallel landfill gas offers the opportunity for recovery of Greenhouse Gases (GHG) and the generation of renewable energy. Some further management options are wind turbines, photovoltaic systems or biomass for biogas conversion, which was grown on closed landfill sites. The inclusion of climate friendly management options of closed landfills in a “Good Landfill Aftercare Practice” is recommended.     

Conversion of CCA-treated wood to ethanol: a method to reduce leaching of metals from disposed treated wood prior to disposal

The objective of this paper is to evaluate the feasibility of producing ethanol from CCA-treated wood that is highly leachable. Following the initial tests, CCA-treated wood was hydrolysed and fermented and the results showed not only that ethanol was produced during the fermentation process but that metals were taken up by the yeast. Toxicity characteristic leaching procedure tests of the hydrolysed wood leached less than 4 mg/L of As while minimal amounts of Cr and Cu remained in the hydrolysed wood which makes landfilling of hydrolysed wood acceptable and less hazardous. A slightly lower amount of ethanol from CCA-treated than untreated wood was produced (6 and 7 g/L, respectively). In general, it suggests that production of ethanol as a source of energy from a hazardous waste (CCA-treated wood) is feasible.     

PCBs,PBDEs and dioxin-related compounds in floor dust from an informal end-of-life vehicle recycling site in northern Vietnam: contamination levels and implications for human exposure

Floor dusts from Vietnamese end-of-life vehicle (ELV)-processing households were investigated to elucidate the contamination levels and exposure risk of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and dioxin-related compounds (DRCs). The concentrations were in order of PBDEs (260–11,000, median 280 ng/g overall) > PCBs (19–2200, median 140 ng/g) > dioxin-like PCBs (8.8–450, median 22 ng/g) ? polybrominated dibenzo-p-dioxin/dibenzofurans (PBDD/Fs, 2000–28,000, median 8500 pg/g) > polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs, 440–4100, median 1800 pg/g) > MoBPCDD/Fs (1.9–1200, median 250 pg/g). Concentrations of PCBs and DRCs were higher than those reported for Vietnamese urban houses, indicating ELV processing as a significant source of these contaminants. Higher concentrations of PCBs relative to PBDEs suggest the abundance of old electrical capacitors/transformers in ELVs. The PBDD/F and PCDD/F profiles were indicative of DecaBDE-containing materials and combustion sources, respectively. PBDFs, PCDFs and DL-PCBs were the most important dioxin-like toxic equivalent (TEQ) contributors. The estimated PCB and TEQ intake doses from dust ingestion approached or exceeded the reference doses for children living in some ELV-processing households, indicating potential health risk. More comprehensive risk assessment of the exposure to PCBs and DRCs is required for residents of informal ELV recycling sites.     

Survey on readability of online information for upgrading understandability of biomass energy technology

Waste management contributes to renewable energy such as biodiesel production from processes of various types of biomass including vegetable oils, animal fats, and waste of edible oil. Successful waste management effort is influenced by people concern about benefit of waste management including for renewable energy from biomass. It involves their understanding initiated by literacy on biomass energy. To help increase literacy on waste recycle and biomass energy technology, we study readability of online information regarding biomass energy in Indonesian language (Bahasa Indonesia). Indonesia is considered as one of biomass-rich country with a little utilization for energy. The readability is studied by combining two approaches: measurement by readability standard and survey on readability confirming measurement by the standard. This study focuses on the confirmation survey readability standard measured on biomass online information in Indonesian language. In the survey, 19 online text materials were read by respondents and they were asked to give their impression whether the texts are easy or difficult to understand. From this study, what factors influence understandability of text information are shown. The results could be a guidance for preparing text information to raise people concern on waste recycle and renewable energy in general.     

Municipal solid waste composition and food loss reduction in Kyoto City

For 35 years, Kyoto City has conducted detailed household waste composition surveys under the guidance of Kyoto University by dividing household waste into approximately 400 categories. In addition, the city has conducted detailed composition surveys of commercial waste generated by businesses. These surveys show that food loss accounts for approximately 40% of total waste, of which leftovers and untouched food account for about 40% in both households and business facilities. Consequently, the annual generation of household and commercial food loss is estimated at about 30,000 tons. Various efforts have been made to reduce waste, including food loss, but further reduction in environmental burden is needed. Thus, Kyoto City revised the ordinance for waste reduction, and in March 2015, formulated a new municipal waste management plan. The plan not only includes the 2Rs (reduce, reuse), but also, for the first time in Japan, sets quantitative targets for reducing food loss. Kyoto City must ensure that the necessary waste reduction measures are clearly explained to the residents and business operators. To ensure that this plan is successful, it is important to clarify concrete actions that residents and business operators should implement, along with their effects.     

Demonstrating Contaminant Degradation at an MGP Site With Metabolic Gas Flux and Radio Carbon Dating

Obtaining lines of evidence indicating that contamination in sediment environments is degrading and being transformed to less toxic forms is an important component of building support for a monitored natural recovery remedy for contaminated sediments. This project was a field demonstration of manufactured gas plant contaminant degradation in river sediments using metabolic gas flux and was performed in an urban area section of a river in northeastern Indiana. CO₂ sorbent traps were deployed to measure CO₂ flux from the river sediments. Sediment samples were collected and analyzed for polycyclic aromatic hydrocarbon (PAH) concentrations and for microbial community composition using molecular techniques. The results showed that the deployment was successful, measuring CO₂ flux at all sediment locations and demonstrating that microbial contaminant degrading activity was occurring in the sediments. Radio carbon dating showed a significant portion of the CO₂ being generated (approximately 19–27 percent) was the result of fossil fuel degradation. Molecular results showed that the microbial community consisted of phylotypes known to be associated with monocyclic aromatic and PAH degradation. ©2017 Wiley Periodicals, Inc.     

Towards an international standard: The ISO/DIS 18504 standard on sustainable remediation

Sustainable remediation is the elimination and/or control of unacceptable risks in a safe and timely manner while optimizing the environmental, social, and economic value of the work. Forthcoming International Organization for Standardization (ISO) Standard on Sustainable Remediation will allow countries without the capacity to develop their own guidance to benefit from work done over the past decade by various groups around the world. The ISO standard has progressed through the committee draft (ISO/CD 18504) and draft international standard (ISO/DIS 18504) stages. The risk‐based approach to managing the legacy of historically contaminated soil and groundwater has been incorporated into policy, legislation, and practice around the world. It helps determine the need for remediation and the end point of such remediation. Remediation begins with an options appraisal that short lists strategies that could deliver the required reduction in risk. A remediation strategy comprises one or more remediation technologies that will deliver the safe and timely elimination and/or control of unacceptable risks. The ISO standard will help assessors identify the most sustainable among the shortlisted, valid alternative remediation strategies. Practitioners presenting case studies claiming to constitute sustainable remediation should now report how they have aligned their work with the new standard. Indicators are used to compare alternative remediation strategies. The simplest metric that allows a characteristic to act as an indicator should be chosen. Weightings indicators can become a contested exercise and should only be undertaken where there is a clear desire for it by stakeholders and a clear need for it in identifying a preferred strategy. The simplest means of ranking alternative remediation strategies should be adopted.     

Optimization of Pellet Production from Agro-Industrial By-Products: Effect of Plasticizers on Properties of Pellets and Composite Pots

The present study aimed to optimize the pellets formulation (deoiled rice bran, potato peel powder and plasticizers) for the development of the injection molded pots. The maximum hardness and bulk density (desirable responses) were obtained for pellets having 100 g of deoiled rice bran, 100 g potato peel powder and 14 % of cashew nut shell liquid (CNSL) as well as 14 % of glycerol (GL) (on raw material basis). The optimized pellets and the pots developed from them were characterized for their physico-chemical, functional, rheological and morphological properties. Expansion ratio, pellet durability index and hardness of the pellets with 14 % CNSL were found to be 1.097, 98.647 % and 485.551 N, respectively. For pellets with 14 % GL expansion ratio, pellet durability index and hardness were found to be 1.150, 97.747 % and 462.949 N, respectively. The biodegradation analysis of the pots developed from optimized pellets with 14 % CNSL and GL degraded in 11 and 9 weeks, respectively. Porosity, puncture force, density and hardness of ‘AP’ pots were 27.473 %, 495.731 N, 1.549 g/ml and 542.641 N, respectively. However, for ‘BP’ pots, the porosity, puncture force, density and hardness were 32.548 %, 440.149 N, 1.191 g/ml and 507.841 N, respectively. Pots prepared from 14 % CNSL (AP) were better in physical and mechanical properties as compared to pots developed from glycerol.