New methodology for hazardous waste classification using fuzzy set theory Part II. Intelligent decision support system

Evolutionary Game Analysis of Government and Residents' Participation in Waste Separation Based on Cumulative Prospect Theory

Government and residents' participation in waste separation is a complex non-cooperative game process, and the evolutionary game can explain the behavior of participating subjects well. Considering that the traditional evolutionary game cannot satisfactorily explain the irrational psychology and risk preference factors of the participating issues, this study combines the prospect theory and evolutionary game, uses the prospect value function to supplement and improve the parameters of the evolutionary game payment matrix, and analyzes the evolutionary stabilization strategy. To verify the theoretical results, simulation experiments and impact analysis were conducted, and meaningful results were obtained: There are two stable evolutionary strategies in the system, namely higher participation benefits for residents and lower participation costs and opportunity costs, and reasonable direct benefit distribution coefficients all help to increase the participation rate of waste separation. This study can provide some scientific suggestions for the government to design and build a waste-separation system.

A new method for ranking potential hazards and risks from wastes

A quantitative approach for assessing hazards facilitates decision making on hazardous waste management practices. In this study, a scoring approach was developed to evaluate the physical, human health, environmental and amenity hazard aspects and risks (in case of exposure) of waste streams. The approach was based on the 15 hazard properties (HPs) defined in European Commission Waste Framework Directive 2008/98/EC and their related Globally Harmonised System of Classification and Labelling of Chemicals (GHS) hazard statement codes (H-codes). Additionally, amenity and other hazards including space requirement, odour, dust, vermin, visual impact, radioactivity and physical injury were considered. A score of 0-3 was assigned to each of the H-codes or amenity and other hazards. The scoring approach consisted of: 1) determining the waste composition; 2) searching H-codes based on waste composition and assigning H-codes to the associated HPs; 3) calculating the hazard score for each of the four hazard aspects; and 4) calculating the total score for each waste. Two methods were used to calculate the total hazard score for 29 hazardous wastes. The wastes were ranked over a hazard spectrum to indicate the potential degree of hazard. The new hazard scoring approach can be used for prioritising efforts in managing wastes.

A model for screening and prioritizing consumer nanoproduct risks: A case study from South Africa

The potential risks of the increasing variety and volume of engineered nanomaterials (ENMs) entering into the ecosystem remain poorly quantified. In recent years, information essential to evaluate the ecological risks of ENMs has increased. However, the data are highly fragmented, limited, or severely lacking. This limits the usefulness of the information to support holistic screening and prioritization of potentially harmful ENMs. To screen and prioritize ENMs risks, we adopted a two-phased approach. First, a holistic framework model was developed to integrate a diverse set of factors aimed to assess the potential hazard, exposure, and in turn, risk to the ecosystem of ENMs from a given consumer nanoproduct. Secondly, using published literature we created a database of consumer nanoproduct categories, and types based on embedded ENMs type. The database consisted of eight consumer product categories, eleven different types of ENMs, and twenty-three nanoproduct types. The model results indicates the largest quantities of ENMs were released from sunscreens, textiles, cosmetics and paints with dominant ENMs quantities in descending order (based on quantity) as nTiO₂>nZnO>nSiO₂>nAg, and nFe₂O₃. In addition, according to the results from this study, nAg from washing machine were found to likely the highest risk to the environment. Overall, our model-derived results based on the case study illustrated: (i) the holistic framework's ability to screen, prioritize, rank, and compare ENMs potential exposure and risks among different nanoproducts categories and types, (ii) the derived risk estimations could support nanowastes classification with likelihood of non-uniformity of nanowastes classes even from the same nanoproduct category (e.g. cosmetics), and (iii) the lack of a mass-based criteria specific for EMNs impedes realistic exposure and risk evaluation in the ecological systems.

The evaluation of an analytical protocol for the determination of substances in waste for hazard classification

The classification of waste as hazardous could soon be assessed in Europe using largely the hazard properties of its constituents, according to the the Classification, Labelling and Packaging (CLP) regulation. Comprehensive knowledge of the component constituents of a given waste will therefore be necessary. An analytical protocol for determining waste composition is proposed, which includes using inductively coupled plasma (ICP) screening methods to identify major elements and gas chromatography/mass spectrometry (GC-MS) screening techniques to measure organic compounds. The method includes a gross or indicator measure of 'pools' of higher molecular weight organic substances that are taken to be less bioactive and less hazardous, and of unresolved 'mass' during the chromatography of volatile and semi-volatile compounds. The concentration of some elements and specific compounds that are linked to specific hazard properties and are subject to specific regulation (examples include: heavy metals, chromium(VI), cyanides, organo-halogens, and PCBs) are determined by classical quantitative analysis. To check the consistency of the analysis, the sum of the concentrations (including unresolved 'pools') should give a mass balance between 90% and 110%. Thirty-two laboratory samples comprising different industrial wastes (liquids and solids) were tested by two routine service laboratories, to give circa 7000 parameter results. Despite discrepancies in some parameters, a satisfactory sum of estimated or measured concentrations (analytical balance) of 90% was reached for 20 samples (63% of the overall total) during this first test exercise, with identified reasons for most of the unsatisfactory results. Regular use of this protocol (which is now included in the French legislation) has enabled service laboratories to reach a 90% mass balance for nearly all the solid samples tested, and most of liquid samples (difficulties were caused in some samples from polymers in solution and vegetable oil). The protocol is submitted to French and European normalization bodies (AFNOR and CEN) and further improvements are awaited.

On the replacement of empirical parameters in multimedia mass balance models with QSPR data

Official OECD recommendations give the highest priority to application of purely empirical phys/chem data (partition coefficients, environmental half-live times etc.) in multimedia mass balance modeling of environmental overall persistence and long-range transport for potentially hazardous chemicals. We have demonstrated that the replacement of the empirical data with those predicted by employing Quantitative Structure-Property Relationships (QSPR) technique did not significantly decrease the performance of The Tool 2.0--the OECD multimedia mass balance model. To prove this, we compared each other the output results (overall persistence -P(OV); characteristic traveling distance -CTD and transport efficiency TE) obtained from 6 of multimedia models. The models utilized combinations of experimentally determined and QSPR-predicted values of the partition coefficients and half-live times. For predicting phys/chem data, we utilized 2 QSPRs developed in our laboratory and the EPI Suite package (US EPA). We did not observe any statistically significant (p<0.05) differences between the models. This conclusion is important, because it leads to reducing time and costs of laboratory studies required during the risk assessment procedure. Moreover, regarding the obtained results, we proposed to replace the single-threshold approaches established by majority of international regulations to screen substances for persistence, bioaccumulation and long-range transport potential with the approaches taking into account uncertainty of the results and/or probability of passing a given threshold.

Nanowastes and the environment: Potential new waste management paradigm

Recent exponential growth in the development of nanomaterials (NMs) and nanoproducts is premised on the provision of novel benefits to the society-through the exploitation of their unique industrial and biomedical applications like medical imaging, fabrics in textiles, tissue engineering, nanocomposites, bioremediation, and biomedicine. These NMs and nanoproducts have increased in quantity and volume from few kilograms to thousands of tonnes over the last fifteen to twenty years, and their uncontrolled release into the environment is anticipated to grow dramatically in future. However, their potential impacts to the biological systems are unknown. Among the key present challenges in the waste management sector include the emergence of nanowastes; however, the effectiveness and the capability of the current systems to handle them are yet to be established. Because of limited studies on nanowastes management, in this paper, three-fold objectives are pursued, namely; (i) to raise concerns related to the alarming increases of uncontrolled releases of NMs into the environment through nanowastes, (ii) examine the unique challenges nanowastes pose to the waste management systems-both from technological and legislative perspectives, and (iii) summarize results of the first nanowastes classification formalism in order to elucidate the potential challenges of waste streams containing nanoscale dimension materials to the present waste management paradigm. Finally, the article closes by summarizing several proactive steps of enhancing effective long-term and responsible management of nanowastes.

Nanotechnology risk assessment from a waste management perspective: Are the current tools adequate?

The burgeoning nanotechnology industry is rapidly generating new forms of waste streams generically referred herein as nanowastes. However, little is known about the fate and behavior of these waste streams and their impacts thereof in different ecological systems despite their increasingly widespread dispersion into the environment through production, distribution, handling, and nanomaterials (NMs) incorporation into bulk products processes. In this paper, risk assessment of nanotechnology from a waste management perspective was examined to elucidate potential new forms of challenges nanowastes may likely pose to the current legislative and waste management systems. This was through the identification of several knowledge gaps that merit urgent attention in order to increase our collective understanding of managing nanowastes safely, responsibly, and sustainably. The paper presents the identified gaps and consequently proposes a qualitative risk assessment of nanowastes to address some of the current challenges. The applicability of the proposed model is illustrated through several examples. In addition, the first nanowastes classification protocol presented in this article show that a given nanomaterial may result in generating nanowaste streams of different forms with variant hazard levels ranging from benign to extremely being hazardous waste streams — a dramatic phenomenon from the conventional waste streams due to macroscale chemicals. The study shows that it is in the early days to draw broad generic classification of different nanowastes, and each stream may require their risk profile be assessed on a case-by-case basis. We conclude by presenting several recommendations on what needs to be done in dealing with nanowastes as means of avoiding unintended long-term consequences of nanotechnology.