A methodology to screen priority toxins in pollutant release inventories.

Pollutant release inventories are used for environmental policy making to reduce toxic pollutants, even though the quantity-based inventory analysis does not take into account the relative toxicity of pollutants. To overcome this limit, life cycle impact assessment (LCIA)-based inventory analysis was developed but still has a high uncertainty from modelling the site- and time-specific fates and transports of pollutants. Thus, this study develops a methodology to evaluate toxicity potentials based on the concentration of pollutants in the exposure to humans in order to circumvent the uncertainty and subsequently screen priority toxins in pollutant release inventories.

Nickel ferrite/MXene-coated carbon felt anodes for enhanced microbial fuel cell performance.

In recent years, the modification of electrode materials for enhancing the power generation of microbial fuel cells (MFCs) has attracted considerable attention. In this study, a conventional carbon felt (CF) electrode was modified by NiFeO (NiFeO@CF), MXene (MXene@CF), and NiFeO-MXene (NiFeO-MXene@CF) using facile dip-and-dry and hydrothermal methods. In these modified CF electrodes, the electrochemical performance considerably improved, while the highest power density (1385 mW/m), which was 5.

Unique selectivity and rapid uptake of molybdenum-disulfide-functionalized MXene nanocomposite for mercury adsorption.

A heterogeneous nanoadsorbent composed of two-dimensional TiCT MXene nanosheets (MX) functionalized with nanolayered molybdenum disulfide (MoS/MX-II) was synthesized by a facile hydrothermal treatment method and used to remove toxic mercuric ions (Hg). Mercury was adsorbed by the synergistic action of the sulfur (disulfide) and the oxygenated terminal groups of TiCT in the MoS-MX-II composite. Ultrasonication increased the surface area and interlayer distance of the TiCT nanosheets, which enhanced the removal capability of the composite.

Investigating the role of anodic potential in the biodegradation of carbamazepine in bioelectrochemical systems.

Anode potential is a critical factor in the biodegradation of organics in bioelectrochemical systems (BESs), but research on these systems with complex recalcitrant co-substrates at set anode potentials is scarce. In this study, carbamazepine (CBZ) biodegradation in a BES was examined over a wide range of set anode potentials (-200 to +600 mV vs Ag/AgCl). Current generation and current densities were improved with the increase in positive anode potentials.

Effect of rGO loading on FeO: A visible light assisted catalyst material for carbamazepine degradation.

Carbamazepine (CBZ), an anticonvulsant drug, is one of the most recalcitrant pharmaceuticals detected in wastewater. For the photocatalytic degradation of CBZ, visible light assisted heterogeneous Fenton-like hybrid composites were synthesized via a co-precipitation method by anchoring magnetite (FeO) with reduced graphene oxide (rGO). The rGO loading not only reduced the aggregation of FeO nanoparticles, but also increased the adsorption capacity of the hybrid composites.

Environmental effects of the technology transformation from hard-disk to solid-state drives from resource depletion and toxicity management perspectives.

Solid-state drives (SSDs) are used as data storage systems in various electronic devices in place of hard-disk drives (HDDs) due to their higher speed and durability and lower noise and power consumption. Although SSDs have these advantages, the environmental consequences of the technology transformation from HDD to SSD need to be examined from resource depletion and toxicity management perspectives because most electronic components and devices contain rare, precious, and toxic metals. Thus, the objective of this study was to assess and compare resource depletion and toxicity potentials from metals in an HDD and an SSD on a same capacity basis.

Potential resource and toxicity impacts from metals in waste electronic devices.

As a result of the continuous release of new electronic devices, existing electronic devices are quickly made obsolete and rapidly become electronic waste (e-waste). Because e-waste contains a variety of metals, information about those metals with the potential for substantial environmental impact should be provided to manufacturers, recyclers, and disposers to proactively reduce this impact. This study assesses the resource and toxicity (i.

Application of a combined three-stage system for reclamation of tunnel construction wastewater.

A combined three-stage system, (1) coagulation (2) zeocarbon filtration and (3) membrane filtration, a combination of microfiltration (MF) and reverse osmosis (RO), was investigated for reclamation of tunnel construction wastewater having a salinity of 10.8-12.9‰ and a concentration of suspended solids (SS) in the range of 264-1084 mg/L.

Casein hydrolytic peptides mediated green synthesis of antibacterial silver nanoparticles.

A green route based on the casein hydrolytic peptides (CHPs) has been established for the synthesis of highly stable and smaller sized (10±5nm) silver nanoparticles (AgNPs), without producing any type of toxic byproducts. The formation of AgNPs was triggered by the addition of an aqueous NaOH solution due to the catalytic properties of OH(-) and/or hydration of the functional groups of CHPs. The 99% transformation of Ag ions (9mM) in 20mL reaction mixture into identical AgNPs using substantially low concentration of CHPs (0.

Potential environmental impacts from the metals in incandescent, compact fluorescent lamp (CFL), and light-emitting diode (LED) bulbs.

Artificial lighting systems are transitioning from incandescent to compact fluorescent lamp (CFL) and light-emitting diode (LED) bulbs in response to the U.S. Energy Independence and Security Act and the EU Ecodesign Directive, which leads to energy savings and reduced greenhouse gas emissions.

Integrating toxicity reduction strategies for materials and components into product design: a case study on utility meters.

Using RIO Tronics utility meter products as an industrial case study, the numeric Fraunhofer Toxic Potential Indicator (TPI) assessment tool is used to determine high impact materials with the aim of reducing the content of inherently toxic substances in these products. However, because product redesign with alternative materials affects entire components, overall component toxicity potential must also be explored. To achieve this, material TPI scores are aggregated into component TPI scores by 2 methods: 1) the Sum-Weighted Component TPI method, which considers the mass of materials in the component to assign an overall score, and 2) the Max Component TPI method, which scores the component with the highest impact material.

Potentials of macroalgae as feedstocks for biorefinery.

Macroalgae, so-called seaweeds, have recently attracted attention as a possible feedstock for biorefinery. Since macroalgae contain various carbohydrates (which are distinctively different from those of terrestrial biomasses), thorough assessments of macroalgae-based refinery are essential to determine whether applying terrestrial-based technologies to macroalgae or developing completely new technologies is feasible. This comprehensive review was performed to show the potentials of macroalgae as biorefinery feedstocks.

Adsorption of a cationic dye, methylene blue, on to chitosan hydrogel beads generated by anionic surfactant gelation.

Chitosan hydrogel beads (CSB) formed by sodium dodecyl sulphate (SDS) gelation were used for the removal of a cationic dye, methylene blue (MB), from aqueous solutions. The adsorption capacity of chitosan beads (CB) formed by alkali gelation was low because of charge repulsions between the chitosan (CS) and the MB. The adsorption capacity of CSB (4 g/L SDS gelation) for MB (100 mg/L) was 129.

Priority screening of toxic chemicals and industry sectors in the U.S. toxics release inventory: a comparison of the life cycle impact-based and risk-based assessment tools developed by U.S. EPA.

Life Cycle Impact Assessment (LCIA) and Risk Assessment (RA) employ different approaches to evaluate toxic impact potential for their own general applications. LCIA is often used to evaluate toxicity potentials for corporate environmental management and RA is often used to evaluate a risk score for environmental policy in government. This study evaluates the cancer, non-cancer, and ecotoxicity potentials and risk scores of chemicals and industry sectors in the United States on the basis of the LCIA- and RA-based tools developed by U.

Environmental and risk screening for prioritizing pollution prevention opportunities in the U.S. printed wiring board manufacturing industry.

Modern manufacturing of printed wiring boards (PWBs) involves extensive use of various hazardous chemicals in different manufacturing steps such as board preparation, circuit design transfer, etching and plating processes. Two complementary environmental screening methods developed by the U.S.

Effect of the addition mode of carbon nanotubes for the production of chitosan hydrogel core-shell beads on adsorption of Congo red from aqueous solution.

The adsorption performance of chitosan (CS) hydrogel beads (CSBs) generated by sodium dodecyl sulfate (SDS) gelation with multi-walled carbon nanotube (CNT) impregnation was investigated for Congo red removal as a model anionic dye. CNT-impregnated CSBs were prepared by four different strategies for dispersing CNTs: (a) in CS solution (CSBN1), (b) in SDS solution (CSBN2), (c) in CS solution containing cetyltrimethylammonium bromide (CTAB) (CSBN3), and (d) in SDS solution for gelation with CTAB-containing CS solution (CSBN4). It was observed from FE-SEM study that depending on nature of CNT dispersion, CNTs were found on the outer surface of CSBN2 and CSBN4 only.

Potential environmental impacts of light-emitting diodes (LEDs): metallic resources, toxicity, and hazardous waste classification.

Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury-free. This study aimed to determine if LEDs engender other forms of environmental and human health impacts, and to characterize variation across different LEDs based on color and intensity. The objectives are as follows: (i) to use standardized leachability tests to examine whether LEDs are to be categorized as hazardous waste under existing United States federal and California state regulations; and (ii) to use material life cycle impact and hazard assessment methods to evaluate resource depletion and toxicity potentials of LEDs based on their metallic constituents.

Toxicity potentials from waste cellular phones, and a waste management policy integrating consumer, corporate, and government responsibilities.

Cellular phones have high environmental impact potentials because of their heavy metal content and current consumer attitudes toward purchasing new phones with higher functionality and neglecting to return waste phones into proper take-back systems. This study evaluates human health and ecological toxicity potentials from waste cellular phones; highlights consumer, corporate, and government responsibilities for effective waste management; and identifies key elements needed for an effective waste management strategy. The toxicity potentials are evaluated by using heavy metal content, respective characterization factors, and a pathway and impact model for heavy metals that considers end-of-life disposal in landfills or by incineration.

Quantity-based and toxicity-based evaluation of the U.S. Toxics Release Inventory.

The U.S. EPA Toxics Release Inventory (TRI) represents an extensive, publicly available dataset on toxics and, as such, has contributed to reducing the releases and disposal of toxic chemicals.

Human health and ecological toxicity potentials due to heavy metal content in waste electronic devices with flat panel displays.

Display devices such as cathode-ray tube (CRT) televisions and computer monitors are known to contain toxic substances and have consequently been banned from disposal in landfills in the State of California and elsewhere. New types of flat panel display (FPD) devices, millions of which are now purchased each year, also contain toxic substances, but have not previously been systematically studied and compared to assess the potential impact that could result from their ultimate disposal. In the current work, the focus is on the evaluation of end-of-life toxicity potential from the heavy metal content in select FPD devices with the intent to inform material selection and design-for-environment (DfE) decisions.

Urban water infrastructure optimization to reduce environmental impacts and costs.

Urban water planning and policy have been focusing on environmentally benign and economically viable water management. The objective of this study is to develop a mathematical model to integrate and optimize urban water infrastructures for supply-side planning and policy: freshwater resources and treated wastewater are allocated to various water demand categories in order to reduce contaminants in the influents supplied for drinking water, and to reduce consumption of the water resources imported from the regions beyond a city boundary. A case study is performed to validate the proposed model.

Environmental indicators for communication of life cycle impact assessment results and their applications.

Life cycle impact assessment (LCIA) is performed to quantitatively evaluate all environmental impacts from products, systems, processes and services. However, LCIA does not always provide valuable information for choosing among alternatives with different specifications, functionalities and lifetimes. The objectives of this study are (1) to propose environmental indicators to evaluate environmental efficiency and value qualitatively and quantitatively on the basis of analogies to financial and economic indicators, and (2) to present the application of the indicators.

Environmental impact minimization of a total wastewater treatment network system from a life cycle perspective.

Synthesis of distributed wastewater treatment plants (WTPs) has focused on cost reduction, but never on the reduction of environmental impacts. A mathematical optimization model was developed in this study to synthesize existing distributed and terminal WTPs into an environmentally friendly total wastewater treatment network system (TWTNS) from a life cycle perspective. Life cycle assessment (LCA) was performed to evaluate the environmental impacts of principal contributors in a TWTNS.

Cooperative water network system to reduce carbon footprint.

Much effort has been made in reducing the carbon footprint to mitigate climate change. However, water network synthesis has been focused on reducing the consumption and cost of freshwater within each industrial plant. The objective of this study is to illustrate the necessity of the cooperation of industrial plants to reduce the total carbon footprint of their water supply systems.