# Sustainable Environment ResearchLatest Publications

259
(FIVE YEARS 212)

## H-INDEX

24
(FIVE YEARS 21)

2468-2039, 2468-2039

2022 ◽
Vol 32 (1) ◽
Author(s):
Yu-Fong Huang ◽
Szu-Ling Chou ◽
Shang-Lien Lo
Keyword(s):

AbstractRecycling of waste printed circuit boards (PCBs) has attracted increasing attention because of its high annually produced amount and high content of gold. In this study, gold recovery from waste PCBs was carried out by using the processes including microwave pyrolysis, acid leaching, solvent extraction and oxidative precipitation. The leaching efficiency of copper was approximately 95% when using a lixiviant composed of sulfuric acid and hydrogen peroxide, and the leaching efficiencies of gold were approximately 59, 95 and 95% by using thiourea, thiosulfate and aqua regia, respectively. The gold ions contained in the leachate previously produced by the leaching processes were not satisfactorily extracted by using organic solvents including di-(2-ethylhexyl)phosphoric acid, tributyl phosphate, dibutyl carbitol and trioctylamine, so the leachate was decided to bypass solvent extraction and directly apply to the oxidative precipitation process. By using the oxidants of hydrogen peroxide and perchloric acid, the precipitation efficiencies of gold were approximately 95 and 99%, and the final recovery rates were approximately 90 and 93%, respectively. The high recovery rates of gold can be attributable to the use of microwave pyrolysis that prevents the loss of gold caused by shredding and grinding processes. In addition, perchloric acid can provide higher selectivity for gold recovery than hydrogen peroxide. The maximum processing capacity of microwave pyrolysis of waste PCBs would be approximately 1.23 kg. The gold recovered from 1 t of waste PCBs can be sold for approximately USD 10,000, and thus the return on investment can be as high as approximately 1400%.

2022 ◽
Vol 32 (1) ◽
Author(s):
Saroj Kumar Chapagain ◽
Geetha Mohan ◽
Andi Besse Rimba ◽
Carolyn Payus ◽
...
Keyword(s):

AbstractAn adequate water supply is essential for the continued and sustainable growth of the Balinese economy. In addition to mounting water demand, Bali’s water supply has been constrained by high levels of water pollution. Despite being paid great attention, Bali’s earlier efforts to control water pollution yet to prove effective, mainly owing to their reliance on traditional methods and regulations that focus on water pollution being linked to discrete sets of economic activity (e.g., processing industries, livestock farming, and hotels). However, an economy of a region/country comprises a set of sectoral activities, which are interconnected through supply chains; thus, water pollution could be well explained by examining the entire sectoral economic activities and their environmental performance. Therefore, determining the structural relationships between water pollution and economic activity serves as an important basis for more effective forms of pollution control for the Balinese economy. In this study, accordingly, we employed an environmentally extended input–output model to establish the links between water pollution and the production processes of the entire economy. Using biochemical oxygen demand (BOD) as a proxy for water quality in our analysis, we estimated that 246.9 kt of BOD were produced from Bali’s economic activity in 2007. Further, we identified the chief BOD-emitting sectors and found that intermediate demand and household demand were the major causes of BOD discharge in the economy. We also accounted for the indirect role of each sector in total BOD emissions. Moreover, we categorized the sectors into four groups based on their direct and indirect BOD emission characteristics and offered appropriate policy measures for each group. Managing demand (i.e., lowering household consumption and exports) and shifting input suppliers (i.e., from polluters to non-polluters) are effective measures to control pollution for Categories I and II, respectively; clean production and abatement is advised for Category III; and a hybrid approach (i.e., demand management and abatement technology) is recommended for Category IV.

2022 ◽
Vol 32 (1) ◽
Author(s):
Hellna Tehubijuluw ◽
Riki Subagyo ◽
Yuly Kusumawati ◽
Didik Prasetyoko

2022 ◽
Vol 32 (1) ◽
Author(s):
Carla S. Fermanelli ◽
Liliana B. Pierella ◽
Clara Saux
Keyword(s):

AbstractThe purpose of this work was to transform a regional biowaste into value-added chemicals and products through a modest thermo-catalytic pyrolysis process. ZSM-11 (Zeolite Socony Mobile-11) zeolites modified by nickel (Ni) incorporation (1–8 wt%) were synthesized and characterized by means of X-Ray Diffraction, Inductively Coupled Plasma Atomic Emission Spectroscopy, Infrared Fourier Transform Spectroscopy, UV–Vis Diffuse Reflectance Spectra and Temperature Programmed Reduction. Results demonstrated that Ni was mainly incorporated as oxide. These porous materials were evaluated as heterogeneous catalysts to improve biooil composition. In this sense, higher hydrocarbon yields, and quality chemicals were obtained and oxygenates were diminished. The deactivation of the most active material was studied over six cycles of reaction. In order to achieve the circular bioeconomy postulates, the obtained biochar (usually considered a residue) was further transformed through a physicochemical activation. The obtained activated biochars were extensively characterized.

2022 ◽
Vol 32 (1) ◽
Author(s):
Kanika Dulta ◽
Gözde Koşarsoy Ağçeli ◽
Parveen Chauhan ◽
Rohit Jasrotia ◽
P. K. Chauhan ◽
...
Keyword(s):

AbstractRhizome extract of Bergenia ciliata was used as a bio-functional reducing material for the green synthesis of copper oxide nanoparticles (CuO NPs). CuO NPs were characterized using ultraviolet–visible spectroscopy, Fourier transforms infrared spectroscopy, X-ray diffraction (XRD), dynamic light scattering, scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). XRD analysis revealed the monoclinic phase of synthesized CuO NPs with an average particle size of 20 nm. Spherical shaped nanoscale CuO particles were observed by EDX and SEM confirming the Cu and O presence in the synthesized NPs. CuO NPs showed antibacterial effects against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi. The antioxidant effect was measured and IC50 values for 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl and Ferric reducing antioxidant power assays were found to be 91.2, 72.4 and 109 μg mL− 1 respectively. Under sunlight, the CuO NPs reported extraordinary photocatalytic activity against Methylene Blue and Methyl Red degradation with efficiencies of 92–85%. CuO NPs have excellent potential application for the photocatalytic degradation of organic pollutants and in the development of antibacterial materials. This study offers new insights in the field of inexpensive and green synthesis-based antimicrobial effective CuO photocatalysts from B. ciliata to remove harmful dyes from industrial-based waters with high degradation efficiency, which is environmentally friendly.

2022 ◽
Vol 32 (1) ◽
Author(s):
Kahui Lim ◽
Harold Leverenz ◽
Samantha Barnum
Keyword(s):

AbstractClogging and odor is strongly associated with ureolytic biomineralization in waterless and low-flow urinal drainage systems in high usage settings. These blockages continue to hinder widespread waterless and low-flow urinal adoption due to subsequent high maintenance requirements and hygiene concerns. Through field observations, hypothesis testing, and multiple regression analysis, this study attempts to characterize, for the first time, the ureolytic activity of the biomineralization found in alternative technologies located at 9 State-owned restrooms. Multiple regression analysis (n = 55, df = 4, R2 = 0.665) suggests that intrasystem sampling location ($$\hat{\upbeta}$$ β ̂ = 1.23, p < 0.001), annual users per rest area ($$\hat{\upbeta}$$ β ̂ = 0.5, p = 0.004), and the volatile solids to total solids mass fraction ($$\hat{\upbeta}$$ β ̂ = 0.59, p = 0.003), are statistically significant influencers of the ureolytic activity of biomineral samples (p < 0.05). Conversely, ureC gene abundance (p = 0.551), urinal type (p = 0.521) and sampling season (p = 0.956) are not significant predictors of biomineral ureolytic activity. We conclude that high concentrations of the urease alpha subunit, ureC, which can be interpreted as proxy measure of a strong, potentially ureolytic community, does not necessarily mean that the gene is being expressed. Future studies should assess ureC transcriptional activity to measure gene expression rather than gene abundance to assess the relationship between environmental conditions, their role in transcription, and urease activities. In sum, this study presents a method to characterize biomineral ureolysis. This study establishes baseline values for future ureolytic inhibition treatment studies that seek to improve the usability of urine collection and related source separation technologies.

2021 ◽
Vol 31 (1) ◽
Author(s):
Tirukkovalluri Siva Rao ◽
Kapuganti Venkata Divya Lakshmi ◽
Gorli Divya ◽
Genji Jaishree ◽
...
Keyword(s):

AbstractThe present study discusses the synthesis of Nb doped TiO2/reduced graphene oxide (rGO) intercalated nanocomposites via sol-gel route at a lower temperature by using different loading amounts of graphene oxide (GO) (1 to 10 wt%). The synthesized composite materials were further characterized by copious instruments such as X-ray Diffractometer, UV-Vis Diffuse Reflectance Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Brunauer-Emmett-Teller surface area analysis, Raman and Fourier Transform-Infrared Spectroscopy. The experimental results stated that the Nb doped TiO2 nanoparticles uniformly distributed on the surface of rGO with an interfacial linking bond between TiO2 and rGO. Later, the photocatalytic degradation of Rhodamine B (RhB) dye using produced materials under visible light irradiation was examined. These results revealed that Nb doped TiO2/rGO nanocomposites exhibited better photocatalytic performance than Nb doped TiO2 for the removal of RhB dye. However, among all, the nanocomposite having 5 wt% of GO content achieves the highest degradation efficiency for RhB dye approximately 98% under visible light exposure. Altogether, the unique properties such as electron accepting and transporting properties of GO in the nanocomposite is caused to enhance photocatalytic activity by minimizing the charge carrier’s recombination rate.

2021 ◽
Vol 31 (1) ◽
Author(s):
Samantha Macchi ◽
Zane Alsebai ◽
Fumiya Watanabe ◽
Arooba Ilyas ◽
Shiraz Atif ◽
...
Keyword(s):

2021 ◽
Vol 31 (1) ◽
Author(s):
Leyla Y. Jaramillo ◽
Mauricio Vásquez-Rendón ◽
Sergio Upegui ◽
Manuel Romero-Sáez
Keyword(s):

AbstractThe annual worldwide production of coffee exceeds 10 million tons, and more than 90% of this production is waste, including the husk. On the other hand, plastic consumption increases every year, and sustainable alternatives are necessary to decrease it. This work arises to solve these two problems, and seeks to produce products at an industrial level from polyethylene/coffee husk eco-composites. Both Low Density Polyethylene and High Density Polyethylene were used, and the amounts of coffee husk added as filler were 20 and 40 wt%. The composites were characterized by different morphological, thermal and mechanical techniques. Scanning Electron Microscopy images showed husk particles embedded in the polymer matrix, but with some gaps between the polymer and the filler, because no compatibilizer agent was used. The addition of large amounts of natural filler negatively affected the tensile strength and elongation at break, but increases eco-composites crystallinity, and hence, their Young modulus and hardness. The industrial applicability of the eco-composites was verified through the production of five different consumer products by extrusion and injection processes, using mixtures with 40 wt% coffee husks. All products were obtained without significant defects. If only 3.25 wt% of the polyethylene products produced each year in Colombia did so with the eco-composites developed in this work, all the coffee husk produced in the country would be used, and the emission of about 5.390 million m3 of greenhouse gases would be avoided.

2021 ◽
Vol 31 (1) ◽
Author(s):
Giacomo Boldrini ◽
Caterina Sgarlata ◽
Isabella Lancellotti ◽
Luisa Barbieri ◽
Marco Giorgetti ◽
...
Keyword(s):

AbstractThe treatment of tannery wastewaters is a complex task due to the complexity of the waste: a mixture of several pollutants, both anionic and cationic as well as organic macromolecules which are very hard to treat for disposal all together. Geopolymers are a class of inorganic binders obtained by alkali activation of aluminosilicate powders at room temperature. Such activation process leads to a cement like matrix that drastically decreases mobility of several components via entrapment. This process taking place in the matrix can be hypothesized to be the in-situ formation of zeolite structures. In this work we use a metakaolin based geopolymer to tackle the problem directly in an actual industrial environment. To obtain a geopolymer, the metakaolin was mixed with 10 wt% of wastewater added with sodium hydroxide and sodium silicate as activating solutions. This process allowed a rapid consolidation at room temperature, the average compressive strength was between 14 and 43 MPa. Leaching tests performed at different aging times confirm a high immobilization efficiency close to 100%. In particular, only the 0.008 and 2.31% of Chromium and Chlorides respectively are released in the leaching test after 7 months of aging.