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The treatment of hazardous LCD is a complicated coupled process, which contains a large number of impurity metals, especially Fe(III), increased the difficulty of In(III) recovery. Moreover, the defects of the traditional extraction process, such as extractant ageing quickly, difficulty to back-extraction, and easy emulsification, seriously restricted the efficient and environmentally friendly recovery of In. Therefore, a novel adsorbent (D2EHPA/SiO 2 –P) was synthesized for the separation and recovery of In(III), and a new recovery process was developed to eliminate the defects of traditional In recovery process in this study. D2EHPA/SiO 2 –P exhibited excellent adsorption selectivity and kinetics for In(III), and the adsorption equilibrium was obtained within 3 min. The adsorption process of In(III) conformed to the pseudo-second-order and Langmuir model. In(III) on D2EHPA/SiO 2 –P was desorbed by 3 M HCl solution, and D2EHPA/SiO 2 –P still had high adsorption and desorption efficiency for In(III) after 5 times of adsorption-desorption cycle experiments. The adsorption mechanism study found that the O–H bond on the D2EHPA participated in the substitution reaction and bonded with In(III) as the adsorption site during the adsorption process. The bond order value of In–O bond was the lowest in the D2EHPA adsorbed In(III) during the desorption process, indicating that In–O bond was easy to break and desorption form D2EHPA. Finally, in the 0.1M H 2 SO 4 system, a new process of using H 2 C 2 O 4 to reduce Fe(III) in advance, and then using D2EHPA/SiO 2 –P to adsorb In(III) was designed to recover In(III) without producing toxic gas, which realized the separation of In(III) and Fe(III). Our findings showed that the developed recovery process was both efficient and environmentally friendly, which had the potential for industrial application of In recovery from hazardous LCD. [Display omitted] • A silica-based adsorbent was successfully synthesized to separate and recover In(III). • A new process was designed to recover In(III) without producing toxic gas. • D2EHPA/SiO 2 –P showed excellent adsorption selectivity and kinetics towards In(III). • Adsorbent had good desorption and reusability proved by 5 adsorption-desorption cycles. • O–H bond in D2EHPA was involved in the binding and substitution reaction of In(III). [ABSTRACT FROM AUTHOR]

The liquid crystal display (LCD) industry has undergone drastic growth over the past decade. Considering that the lifetime of an LCD device is approximately ten years, a huge end LCD waste glass (ELWG) is being produced from end-of-life LCD devices. The recycling of ELWG derived from LCD device produced before 2011 is limited by the presence of toxic components such as As, Sb and Ba. In this work, the potential of recycling ELWG was examined to be used in the glass wool industry. 17 glass batches using four different simulated ELWGs (mixtures corresponding to LCD glasses produced in 2006, 2008, 2009, and 2010) were prepared and melted. ELWG was introduced up to 20% of the total glass. Two fixed viscosity points (T m , T w) corresponding to 102 and 103 dPas, and the liquidus temperature (T L) were determined in the melt state, and leaching tests of the glass powder in an acidic solution based on the toxicity characteristic leaching procedure (TCLP) were also carried out. As the ELWG content was increased, the T m , T w , and T L values did not show a linear relationship with the ELWG content, but some fluctuation in the values was observed. The T m value showed a larger deviation of 28–36 °C from that of the original glass than the T w (6–14 °C) and T L (2–16 °C) values. As and Sb were not detected in the leaching tests, and the Ba concentration (1.232–2.279 mg/L) was much lower than the TCLP regulatory level (100 mg/L). The observed T W -T L values suggested that the replacement of 20% or more of the total glass by ELWG is possible. Additionally, the economic and environmental effects of the recycling process were discussed. Image 1 • Recycling of end LCD waste glasses (ELWG) in glass wool was examined. • Source of B 2 O 3 such as penta-borax was replaced by ELWG. • Introduction of ELWG had very little influence on the fibreizing condition. • In extraction fluid As and Sb were not detected and Ba concentration was very low. • Replacement of more than 20% of the glass wool by ELWG was suggested. [ABSTRACT FROM AUTHOR]

The present study is the first report on the bioleaching of indium (In) from discarded liquid crystal displays (LCDs) using adapted Acidithiobacillus thiooxidans . The adaptation of bacteria to the LCDs powder began with 1% (w/v) and continued up to 4% (w/v). Response surface methodology (RSM) was used to evaluate the effects of initial pH, pulp density, and initial sulfur concentration and optimize their values in order to maximize In and Sr recovery. Under optimum conditions of an initial pH of 2.6, pulp density of 1.6% (w/v) and initial sulfur concentration of 8.6 (g/l), 100% of In and 10% of Sr were recovered. The rate-controlling step in this process was determined using the shrinking core model, which suggests that both diffusion and chemical reaction play an important role in the overall bioleaching process. Scanning electron microscopy (SEM) analysis demonstrated the effectiveness of bacterial activity in bioleaching. In addition, the results confirmed that bioleaching was more effective than chemical leaching. The bioleaching from discarded LCDs by A. thiooxidans is a promising technology that can decrease the environmental hazard of this waste. The bioleaching results of present study supplied a method for large-scale industrial purposes. [ABSTRACT FROM AUTHOR]

This papers details a simple, sustainable approach for the recovery and concentrating of indium from waste scrap LCD panels. After manual dismantling, the glass fraction of the panel was pulverized through a mechanical treatment, Indium from crushed glass was then mobilized in an acidic solution such as HCl:HNO 3 lixiviant followed by an ultrasonic wave. Indium was successfully adsorbed by three macro porous polystyrene-divinylbenzene resins (Lewatit TP 208, Lewatit TP 260 and Amberlite IRA 743) and the influence of pH, weight of resin, contact time, temperature and type of resin on the efficiency of sorption process were investigated and the optimum condition was found. Theoretical calculations, indicated the In(III) phase formed through the leaching process was InCl 3 (aq). The adsorbed In(III) onto the resins was effectively desorbed in acidic medium to prepare concentrated indium solution. For the kinetic study, the adsorption onto Lewatit TP 208, Lewatit TP 260 and Amberlite IRA 743 could be fitted to pseudo second-order. [ABSTRACT FROM AUTHOR]

In this study, real thin-film transistor liquid-crystal display wastewater with an initial chemical oxygen demand (COD) concentration of 1348.00 ppm was treated using chitosan-coated bentonite (CCB). Characterization analysis of the CCB adsorbent was performed using Brunauer-Emmett-Teller surface area analysis, scanning electron microscopy, and Fourier-transform infrared spectrometer. The effect of parameters such as contact time, CCB dosage, pH and temperature on the COD removal was examined. Results show that increasing the contact time and CCB dosage increases COD removal efficiency while no considerable change was observed in removal efficiency with varying temperature and pH. Adsorption experiments showed that the removal of COD using CCB best fits the Langmuir isotherm ( R 2 ≥ 0.9821) while kinetic data was best described by the pseudo-second order equation ( R 2 ≥ 0.9980), which implies that chemisorption is the rate-determining step. Thermodynamic studies revealed that adsorption of COD onto CCB was spontaneous, exothermic (ΔH° = 5.95 kJ/mol) and decreased randomness in the system (ΔS° = -0.88 J/mol·K). Optimization studies using response surface methodology with central composite design was performed to determine the operating parameters that would yield the maximum COD removal. It was determined that the optimum conditions of 20.32 h, 0.8 g CCB, pH 4.0, and 30 °C would yield a maximum removal of COD of 73.34%. [ABSTRACT FROM AUTHOR]

Recycling Sn from waste liquid crystal display (LCD) is crucial to alleviate resource shortage and prevent environmental pollution. However, the disposal of waste LCD is a complex coupling process affected by multi-factors. The lack of mature harmless and resource-based treatment process restricts the development of industrialization. Therefore, an environmentally sound process focusing on resource recovery was proposed to recover Sn efficiently and remove toxic substances from waste LCD in this study. The reaction mechanism and leaching kinetics were discussed assisted by mechanical activation, and the statistical and mathematical method (Box-Behnken Design (BBD) model) was adopted to optimize the leaching process. The results showed that the mechanical activation could improve the physical and chemical properties of ITO glass. The essence of the leaching reaction mechanism was that the H+ in H 2 SO 4 combined with O2− in the lattice of In 2 O 3 to form OH−, resulting in Sn–O bond broking and Sn4+ entering the aqueous solution. Furthermore, the Zeta potential results showed that the Zeta potential of SiO 2 particles less than 0.035 mm was close to zero near pH 2, resulting in agglomeration between SiO 2 particles under the action of Coulomb force. The leaching kinetics was well expressed by the shrinking core model. The BBD model showed satisfactory correlation between the predicted and actual results, and the particle size was the most critical factor affecting the leaching efficiency. The maximum leaching efficiency was 87.6% which was obtained under the following optimal condition: 6 mol/L H 2 SO 4 , 108 min, 88 °C, and 0.035 mm ITO glass powder. Our findings demonstrated that the developed recovery process was both efficient and environmentally sound, which had the potential in the industrialization of waste LCD recycling system. [Display omitted] • An eco-friendly process with experimental analysis and prediction model was proposed. • The process maximally recovered tin while treating hazardous liquid crystal display. • The shrinking core model was applied for the assessment of leaching kinetics. • Prediction model clarified the interaction and optimization of experiment parameters. • Besides the high efficiency the process proved to sustainability and practicality. [ABSTRACT FROM AUTHOR]

The contradiction of energy, resource and environment from waste liquid crystal display (LCD) panels is becoming more and more prominent because it contain both harmful liquid crystals and valuable metal indium. However, scarce researches have considered how to separate liquid crystals and recycle indium from waste LCD panels by an environment-friendly process. In this work, an integrated technological process to recycle energy and valuable resource from LCD panels is proposed. Firstly, a stripping product enriched liquid crystals and indium is gained by a mechanical stripping separation. Then, based on a series of pyrolysis separation, vacuum chlorinated separation and substitution reaction, concentration of indium is increased to 36 wt % in final product from 0.02 wt % in waste LCD panels. Several highlights were summarized as follows: (i) Feasibility, principle and reaction mechanism was studied to understand this integrated process. (ii) For pyrolysis process, separation rate of liquid crystals approached 82.06% under optimized parameters by response surface methodology. For vacuum chlorinated process, recovery rate of indium can reach 97.16%. This technological process is quite significant in accordance with the “Reduce, Reuse and Recycle Principle” for solid waste and further provides a new opportunity for sustainable development of LCD markets. [ABSTRACT FROM AUTHOR]

More than three quarters of global indium consumption is used for the manufacture of liquid crystal displays (LCDs). These devices contain indium at concentrations that appear to be too low to be economically valorized by standard hydro- or pyrometallurgical methods under current market conditions. Because indium is a metal critical to many electronics and clean energy technologies, developing commercially viable processes for recovery indium from such end of life products is expected to offer societal benefit. While LCD screens contain indium at low levels, the surface confinement of indium in these devices makes abrasion an intriguing option for concentrating indium to industrially relevant levels. To that end, attrition scrubbing is investigated and shown capable of producing a concentrate upgraded in indium concentration by a factor of 10 with greater than 90% recovery of indium. The same process leaves the LCD glass cleaned of semiconductor elements that are viewed as impurities to the glass recycling sector. Relative economics of such a pretreatment process relative to direct chemical processing routes are presented. [ABSTRACT FROM AUTHOR]

The need to increase the sustainability of the construction industry is leading to the search for alternative sources of raw materials. Liquid crystal display (LCD) screens have been used for many years and are also rapidly ageing as a result of fast development. Therefore, the use of waste from LCD screens is an interesting avenue for the construction industry. This paper presents a very practical study of the use of old LCD screen of ground material to replace various fine aggregates. Fifteen concrete mixes of different strength levels and with different amounts of LCD powder were prepared. These are C20, C25, and C35 grade concretes, all of which contain LCD powder in quantities ranging from 15% to 60%. Results of density, compressive strength, and tensile strength at 7 and 28 days after concreting. The results are correlated with the number of replacement components and are also correlated with each other. The data presented to improve our understanding of the practical application of LCD waste aggregate in concrete. The results show that the amount of LCD powder has a direct linear effect on the compressive strength and also a direct lognormal effect on the tensile strength of concrete. [ABSTRACT FROM AUTHOR]

Indium is a critical raw material with economic importance and high supply risk. In the present study, we recovered indium by means of cementation from a leaching solution of waste liquid crystal display panels. Cementation with zinc powder was optimized through the investigation of the effects of different variables (zinc concentration, pH, cementation time) on cementation efficiency and purity of the solid product. Almost all the indium present in the leaching solution passed to the solid phase when cementation was performed with a low (2–5 g/L), a medium (15–20 g/L) and a high (100 g/L) concentration of zinc, at pH 3. At pH 2, a complete cementation was obtained only with the highest concentration of zinc. Moreover, the highest purity of the indium product (62% indium percentage in the solid product, calculated in the 4-metal system indium-aluminum-calcium-iron) was achieved after a cementation of 10 min, whereas the presence of impurities increased with time. An empirical model successfully fitted the experimental data and suggested that the highest purity of the cemented product was expected at pH 2. A quantification of the environmental impact of the process for indium recovery from end-of-life liquid crystal display panels was also carried out through a life cycle analysis approach, and it outlined that relevant benefits to the environment were obtained thanks to the recovery of indium from waste electric and electronic equipment. The results obtained in the present study are promising since this is the first time that cementation was applied to a leaching solution of waste liquid crystal display panels. In this paper we found that indium cementation took place also with low concentrations of zinc at pH 3, allowing important reagent saving. Investigations in progress are aimed at increasing the purity of indium and at improving the environmental sustainability of the process. The approach presented here is considered extremely useful in the frame of urban mining strategies. It can help ensure progress towards sustainable societies, encourage industrial innovation of the recycling companies and the implementation of cleaner processes. [ABSTRACT FROM AUTHOR]

The widespread usage of liquid crystal display (LCD) has led to a large quantity of waste LCD panels, causing serious harm to environment and human health due to toxic substances they contain. Existing literature on this topic mainly deals with recovery of indium and glass from waste LCD panels while the recycling of organics is often neglected. Organics in waste LCD panels are generally treated by incineration and pyrolysis while both can bring about secondary pollution. In this study, the hydrothermal method, an efficient and environment-friendly way, was adopted to treat waste LCD panels with aim of recycling waste organics. Quality and quantity of liquid product (acetic acid) were determined by gas chromatography mass spectrometry and high performance liquid chromatography. Investigated factors included reaction time, temperature, pH value and oxidant supply. The highest yield of acetic acid was 44.91% under the following conditions: a temperature of 300 °C, a reaction time of 5 min, 3 mL of water, and a pH of 10. Additionally, the mechanism of acetic acid production was analyzed. [ABSTRACT FROM AUTHOR]

Alkali free alumino-borosilicate display glasses that serve as the window in a TFT-LCD (hereafter LCD) device not only have few impurities but also high homogeneity to guarantee the quality of the display. These characteristics of LCD glasses enable the possibility of recycling LCD glass cullet as a raw material for commercial soda lime silicate glasses from the perspectives of the raw material costs and the energy saving. In the present work, several batches containing LCD cullet for two commercial model glasses were prepared and melted in the laboratory. According to several properties of the melts and the glasses, there was no serious change in the properties with up to 9 wt% replacement of the flint glass and 11 wt% replacement of the low iron flat glass by the LCD cullet. Currently, LCD cullet is being used successfully in a number of industrial plants for the production of flint glass in Korea. Two-thirds of flint bottle glasses contain B2O3 component derived from LCD cullet. [ABSTRACT FROM AUTHOR]

Many facets of our civilization's contemporary life are related to the use of electrical and electronic equipment (EEE). EEE replacement is becoming more common as the need for high-performance EEE grows and technical advancement accelerates. As a result, a massive quantity of electronic waste (e-waste) is generated. One way of recycling e-waste is through pyrolysis, which is a thermochemical method used to recover polymers and concentrate metals into a solid residue. Additionally, this technique may be modified or integrated with other technologies to reduce the number of organic halides produced by harmful brominated flame retardants (BFRs), often used as additives in these materials. This article provides a comprehensive review in the context of pyrolysis of e-waste and its sustainability. The structure and components of the five significant types of e-waste, including printed circuit boards (PCBs), lithium-ion batteries (LIBs), tantalum capacitors (TCs), light-emitting diodes (LEDs), and liquid crystal displays (LCDs), are first discussed. Then five methods of e-waste pyrolysis, including vacuum pyrolysis, catalytic pyrolysis, co-pyrolysis, microwave pyrolysis, and plasma pyrolysis, have been carefully studied and the merits and demerits of each method are presented. In the following, the sustainability of the pyrolysis process is examined from three perspectives: economic, environmental, and social. In the end, ongoing challenges of e-waste pyrolysis and recommendations for future directions are also addressed. E-waste pyrolysis is still not completely industrialized. However, it can be said that it is a sustainable method, and the suitability of this method has been proven on the laboratory scale. It is hoped that we will see the industrialization of this method in industrialized and developing countries in the future. [Display omitted] • Five methods of e-waste pyrolysis and their sustainability are discussed. • Pyrolysis of PCBs, LIBs, TCs, LCDs, and LEDs are investigated. • Catalytic pyrolysis increases oil quality and reduces halogenated pollutants. • The prospects and challenges of e-pyrolysis have been scrutinized. [ABSTRACT FROM AUTHOR]

Abstract: Liquid Crystal Display (LCD) technology has evolved and developed over the past decades to replace Cathode Ray Tube (CRT) display technology as the market leader. This is evident, with global market figures for liquid crystal displays surpassing $75 Billion in 2008. Current End-of-Life (EoL) disposal for LCD screens is typically landfill or incineration, this form of disposal restricts the ability to recover potentially reusable materials from waste LCD screens e.g. steel, aluminium, copper etc. Thus to conserve raw materials and to protect the environment it is essential to replace the traditional flow of products from manufacturer to landfill with a recycle and recover approach. While the recycling methods for CRTs are well established, however those of LCDs are as yet in their infancy. However to reduce consumption of natural resources and reduce quantities of waste going to landfill, recycling process must be encouraged and developed. This paper aims to address the challenges facing EoL treatment of LCD units by analysing LCD build types, structures and component material to establish traits which may make EoL treatment less of a challenge. Analysing this data will lay the foundation to developing a balanced recovery system meeting the needs of economic viability and environmental conservation in future work. [Copyright &y& Elsevier]

Abstract: The waste electrical and electronic equipment (WEEE) directives are designed to deal with the rapidly increasing waste stream comprised of electrical and electronic equipment. Recycling electrical and electronic equipment reduces the quantity of waste going to final disposal. The demand for thin film transistor liquid crystal display (TFT-LCD) panels, commonly used in everyday electronic products, is increasing. Conventionally adopted treatments of TFT-LCD waste glass cannot meet WEEE directives. This study adopts the following operating conditions in fabricating glass–ceramics: sintering temperature of 800–950°C; sintering time of 6h; and, temperature increase rate of 5°C/min. The glass–ceramic samples then underwent a series of tests, including the Vickers hardness, water absorption and porosity tests, to determine product quality. The Vickers hardness was 12.1GPa when fired at 900°C for 6h, and density was 2.4g/cm3 and water absorption was 0%. Thus, TFT-LCD waste glass can be regarded as a good glass–ceramic material. [Copyright &y& Elsevier]

The possibility of vitrifying the fly ash generated from municipal solid-waste incinerators and the immobilisation effect of toxic elements were investigated using several batches of fly ash and two kinds of common waste glass (waste glass from end liquid crystal display device and soda lime silicate waste glass). Fly ash could be vitrified by melting at 1300 °C prior to the introduction of a minimum of 30 wt% waste glass to each batch. Leaching tests were performed using the TCLP (Toxicity Characteristic Leaching Procedure) for three types of glass to identify the concentrations of five harmful elements (Pb, Ba, As, Cd, Cr) in the extraction fluid and a surface analysis using SIMS (Secondary Ion Mass Spectrometry) was performed to reveal the elemental distribution of the glass. The results confirmed that the regulatory levels (Pb < 5, Ba<100, As<5, Cd < 1 and Cr < 5 ppm) set by the US EPA (Environmental Protection Agency) were satisfied, while the elemental distribution on the glass surface, before and after TCLP, differed only in the amount of Cr. Two melt properties (σ: electrical conductivity, η: viscosity) at around 1300 °C were examined for simulated glass melts assuming the application of CCIM (Cold-Crucible Induction Melting) technology and discussed in terms of their constraint values (σ: 0.1–1.0 S/cm, η: 10–100 dPas) for CCIM and the effect of their composition. To obtain the desired both melt properties, it is suggested that the present glasses should contain 2–4 wt% Na 2 O. Additionally, the economic and environmental effects of the waste glass recycling on fly ash vitrification were discussed from the view point of energy saving and CO 2 reduction. [Display omitted] • Fly ash is completely vitrified with only common waste glasses. • Leaching tests and surface analysis indicate excellent chemical durability. • Some fly ash batches are suitable for cold crucible induction melting. • Use of waste glass lowers melting temperature of fly ash batch. [ABSTRACT FROM AUTHOR]

Abstract: In order to fulfill the current WEEE directives, the traditional approach to manage thin film transistor-liquid crystal display (TFT-LCD) waste glass is inadequate. It is a serious opportunity to achieve resource conservation, reduction, stabilization and safety of management of TFT-LCD in the near future. To assist in achieving these goals, this study investigated the sintering characteristics and material properties of TFT-LCD waste glass, which can be pulverized and ground and subsequently blended with clay, at various substitution levels (0–40%) and finally fired from 800°C to 1000°C to make eco-brick. The brick thus produced was analyzed to determine variations in weight losses on ignition, 24-h absorption, bulk density, shrinkage, compressive strength and microstructure changes. The results for specific gravity, water adsorption, and compressive strength revealed that bricks made from mixtures containing TFT-LCD waste glass met the general requirements for bricks. The advantages of less water absorption, less weight loss on ignition, and a gain in compressive strength in the clay-TFT-LCD waste glass bricks should encourage the use of TFT-LCD waste glass as a brick additive. [Copyright &y& Elsevier]

Abstract: The effectiveness of supercritical water oxidation (SCWO) process for the simultaneous recovery of chromium and destruction of organics from liquid crystal display (LCD) manufacturing process wastewater was investigated. The experiments were performed in an isothermal continuous-flow tubular reactor and H2O2 was used as an oxidant. The reaction temperatures ranged from 400 to 605°C and the residence times ranged from 15 to 31s at a fixed pressure of 25MPa. The effect of temperature, oxidant concentration and residence time on chromium recovery and chemical oxygen demand (COD) conversion was investigated. The results of this study demonstrated that the SCWO process recovered chromium and decreased chemical oxygen demand up to 99.3% and 99.9%, respectively. The analyses showed that chromium are recovered as chromium oxide (α-HCrO2 and Cr2O3). The SCWO process is an effective technique for simultaneously recovering chromium and for the destruction of hazardous organics in the LCD manufacturing process wastewater. Our study showed that there are two consequent reactions, chromium recovery reaction (hydrolysis) followed by the organic decomposition reaction (oxidation). The recovery of chromium can be achieved without major organic decomposition. [Copyright &y& Elsevier]

Abstract: Final impact results from an industry-wide environmental life-cycle assessment of cathode ray tube (CRT) and liquid crystal display (LCD) computer monitors are presented for 20 environmental impact categories. Considering the entire life cycle of each monitor, water eutrophication and aquatic ecotoxicity impacts for the baseline analysis were greater for the LCD while all other impact categories (e.g., resource use, energy, ozone depletion, landfill space use, human health toxicity) were greater for the CRT. Energy inputs from CRT glass manufacturing, for which there was some uncertainty in the data, drive many of the CRT impacts. Modifying the glass energy data based on comparison to secondary data resulted in nine of the 20 impact categories having greater relative life-cycle impacts for the LCD than the CRT. When comparing the manufacturing stages of each monitor type in the baseline scenario, the LCD has greater relative burdens on the environment in eight categories. Energy, global warming, and human health toxicity impacts are also presented in greater detail, showing contributions from each life-cycle stage. This study''s results can allow industry to focus on frit manufacturing, PWB manufacturingimprovements can be made. [Copyright &y& Elsevier]

The market competition associated with the programmed obsolescence of electronic products, causes an increase in the amount of waste. In this context, the Product-Service Systems correspond to a sustainable business alternative, since their systemic character considers the processes from the conception of the proposal to the post-use destination. Thus arises the need to use models and techniques of environmental management that consider the entire life cycle of products, services and processes. In view of this, this work aims to propose the Life Cycle Analysis of an electronic product based on the concepts of the Product-Service System. The methodology adopted is composed of three stages: i) systematic review of the literature, ii) construction of a model that interrelates the Product-Service System and the Life Cycle Analysis and, iii) analysis of the model proposed on the product Liquid Crystal Display (LCD) screen of a discarded cell phone, where SIMAPRO® software was used. These steps allowed the analysis of the incineration process of 1 kg of waste from the LCD screen of cell phones, so that the results prove the impacts caused by this process: terrestrial ecotoxicity (99.8%), human toxicity (potentially carcinogenic material) (75.2%) and depletion of mineral resources (33.3%). In addition, the results highlight the materials that cause the most damage to the soil in the long term and point out Cadmium (63%) and Zinc (24%) as the toxic elements with the highest representation in the incineration of the LCD screen of cell phones. The results obtained corroborate the results of the literature, exposing the environmental and social impacts caused by these residues. • Scheduled obsolescence causes an increase in waste disposal to the environment. • Electronic equipment waste is toxic when improperly disposed. • Product-Service System aims at solutions for the reduction of electronic waste. • Life cycle analysis assesses the environmental impacts from the product. [ABSTRACT FROM AUTHOR]

In the present study, organic matter and indium were fully recycled from discarded LCD panels by microwave extraction - nitrogen pyrolysis - vacuum reduction. Triphenyl phosphate, an environmentally friendly halogen-free flame retardant, was extracted from the polarizing film using microwave extraction technology. The extraction rate under optimized conditions (acetone, 55 °C, 20 min, 1:50) was 95.89%. After the microwave extraction process, the polarizing film was treated with nitrogen pyrolysis. Uncondensed pyrolysis gas/oil (mainly acetic acid) was used to prepare an environmentally friendly snow melting agent. In addition, 26.42 wt% of the pyrolytic carbon residue was obtained under the optimized conditions (350 °C, 2 °C·min−1, 0.05 L min−1, 120 min), which could be used as a reductant to recycle indium from waste LCD panels. In the vacuum reduction process, the indium conversion rate could reach 99.92% without the addition of reductant. The reaction dynamics results show that the reduction process of pyrolytic carbon and In 2 O 3 is initially controlled by a chemical reaction, followed by a mixed control that transitions to a diffusion control. Moreover, the results of the contrast experiment show that the conversion efficiency of pyrolytic carbon to indium was comparable to that of activated carbon, and both were better than that of coke. This study can be used as a practical reference for the recycling of major components of LCD panels. [Display omitted] [ABSTRACT FROM AUTHOR]

Tetramethylammonium Hydroxide (TMAH) is widely used as a developer in the thin-film transistor liquid crystal display (TFT-LCD) industry, which is a corrosive alkaline and neuronal toxic compound. In this study, the performances of combined hydrolysis acidification-aerobic and anaerobic batch reactors for synthetic TMAH wastewater treatment were evaluated. It also investigated the real TMAH wastewater treatment in the anaerobic batch reactor. The batch tests focused on the removal efficiencies and intermediate products of TMAH biodegradation during different processes. Furthermore, microbial community structures were identified. The long-term monitoring of 380 days results demonstrated that TMAH degraded can be stably achieved by hydrolysis acidification-aerobic and anaerobic processes, and the total organic carbon removal efficiencies were both higher than 91%. The pretreatment by hydrolysis acidification process could avoid the inhibition of high concentration TMAH on subsequent aerobic treatment. Main intermediate products during the hydrolysis acidification-aerobic and anaerobic treatments included trimethylamine, dimethylamine, monomethylamine, which can be degraded easily by biotreatment. Consequently, nearly 70% organic nitrogen in the influent TMAH transferred to ammonium or nitrate, while the mineralization of intermediates caused methane and carbon dioxide generation. The study also proposed TMAH degradation pathways by different processes based on the intermediate's identification. Analysis of 16s rRNA gene sequencing revealed that mixed microbe contributed in TMAH degradation. At the phylum level, proteobacteria and bacteroidetes were abundant in all the reactors. Besides, patescibateria , cloacimonetes and acidobacteria were dominant in anaerobic reactors as well. This study suggests that traditional combined or single activated sludge processes could be used for TMAH-containing wastewater treatment. Especially, anaerobic process may be favored over other processes. Image 1 • Hydrolytic acidification-aerobic and anaerobic processes can degrade TMAH completely. • TOC removal rate was above 95% in the real TMAH wastewater by anaerobic process. • NH 4 + and NO 3 − were the main product in hydrolytic acidification-aerobic process. • Proteobacteria and bacteroidetes were abundant in all reactors. [ABSTRACT FROM AUTHOR]

For the first time, simultaneous iodide recovery and boron removal from thin-film transistor liquid crystal display wastewater were achieved using forward osmosis because iodide is a precious material and boron is toxic with 1 mg/L discharge standard in Taiwan. Cellulose triacetate and thin-film composite with aquaporin flat sheet membranes were tested for different feed solution, pH levels, and draw solution concentrations. The results indicated that the thin-film composite membrane had high boron and iodide rejections (98.4% and 98.3%, respectively) at a pH of 11; however, with a feed boron concentration of 600 mg/L, 9.8 mg/L boron was still present in the draw solution. Cationic surfactant cetyltrimethylammonium bromide was used to enhance the iodide recovery and boron removal efficiencies. Both efficiencies increased to 99.9% with 0.5 mM cetyltrimethylammonium bromide, and only 0.64 mg/L boron was present in the draw solution. In addition, negligible flux reduction was observed for forward osmosis process in the presence of cetyltrimethylammonium bromide. A membrane distillation system was used to concentrate and purify the MgCl 2 draw solution. Thus, the hybrid forward osmosis-membrane distillation process can be applied for iodide recovery and boron removal in the thin-film transistor liquid crystal display industry. • Iodide recovery and boron removal were achieved from the TFT-LCD wastewater. • Surfactant CTAB was used to enhance the iodide recovery and boron removal. • The removals were increased to 99.9% with 0.64 mg/L boron in the DS by 0.5 mM CTAB. • FO-MD can be used for iodide recovery and boron removal in the TFT-LCD industry. [ABSTRACT FROM AUTHOR]

Recovering indium from liquid crystal display (LCD) screen waste is important from a sustainability point of view for several reasons: the environmentally hazardous metals are not landfilled, the recovery process involves lower CO 2 emissions than primary production, and supply from secondary sources matches the continuously increasing demand of indium. In this study, two alternative process routes for recycling the critical metal, indium, from LCD panel waste were studied and compared using laboratory and bench-scale experiments. The first process was a conventional hydrometallurgical process that involves manual dismantling, hammer mill crushing of the glass, cross-current sulfuric acid leaching of the metals, and liquid-liquid extraction separation of indium. Using this process, over 99% pure indium solution can be produced with a recovery yield of over 70%. The second process is novel because it includes (manual) scraping of the indium tin oxide (ITO) layer from the glass panels, followed by sulfuric acid leaching of the metals. The yield of indium was over 80%, and the purity of the resulting solution was over 99%. The solutions obtained from either of the suggested processes were sufficiently pure for cementing indium in high purity. The novel process appears much more straightforward and economically more feasible because the polarizing filter need not be removed and the liquid-liquid extraction purification step is excluded. Moreover, less amount of leaching acid is required. • Two alternative processes for recovering In from LCD waste were demonstrated. • In the novel process ITO is scraped from the glass and leached with H 2 SO 4. • Yields in the processes were over 70% and 80% (conventional and novel). • Purities from both processes were over 99%. • The novel process appears economically more feasible than the conventional. [ABSTRACT FROM AUTHOR]