Recycling nickel from spent catalyst of Phu My fertilizer plant as a precursor for exhaust gas treatment catalysts preparation

In this study, a very promising way of treating and recycling spent nickel catalysts of fertilizer plants in Vietnam was proposed. Firstly, nickel was recovered from spent catalyst using HNO₃—leaching process. Results show that nickel recovery of over 90% with a purity of over 90% can be achieved with HNO₃ 2.1–2.5 M at 100?°C in 75 min. The residue after leaching is not considered as a hazardous waste according to the Vietnamese regulations. Then, the leachate solution was used as a precursor to prepare a model catalyst for exhaust gas (CO, HC, NO_x) treatment. In comparison with the catalyst prepared from the commercial nickel nitrate solution, the catalyst synthesized from recovered nickel exhibits similar properties and activities. The influence of Ni loading of Ni/alumina catalyst as well as the modification of active phase by some metals addition (Mn, Ba, Ce) was also investigated. It is feasible to modify active phase by transition metals such as Mn, Ba, and Ce for complete oxidation of CO and HC at 270?°C and a reduction of NO_x below 350?°C at high volumetric flow condition (GHSV?=?110.000 h^?1).     

Thermodynamic analysis of fatty acid harvesting by novel carbon-based adsorbent

In this study, separation and concentration of fatty acids (FA) from the synthetic food processing wastewater containing low concentration of FA (250 mg/L) were investigated using expanded graphite (EG) as a novel adsorbent at different temperatures (298~318 K). The adsorption results were further analyzed to verify adsorption mechanisms and thermodynamics of FA onto EG. Results show that the adsorption of FA onto EG was explained well by the Langmuir model with the maximum adsorption capacity up to 8.01 g FA/g EG at 298 K, and considerably affected by temperature. The adsorption kinetics fitted with pseudo-second-order kinetic model and the adsorption mechanism analysis showed that the intraparticle diffusion was not the rate-limiting step, but the coalescence of FA droplets played the significant role for novel adsorption of FA onto EG. The calculated activation energy and thermodynamic parameters such as Gibbs free energy change (ΔG⁰), enthalpy change (ΔH⁰), and entropy change (ΔS⁰) indicated that the adsorption of FA onto EG was very feasible, was highly spontaneous, occurred physically, was exothermic in nature, and was stable in aquatic environmental changes. Overall, FA can be effectively harvested and concentrated from the food processing wastewater by EG even at low concentration.     

Occurrence of pharmaceutical and personal care products in Cau River,Vietnam

Environmental Science and Pollution Research - This study evaluated the occurrence of PPCPs in Cau River (Vietnam). Surface water and sediment samples were collected to determine PPCP...     

Development of adaptive neuro-fuzzy inference system model for predict trihalomethane formation potential in distribution network simulation test

Environmental Science and Pollution Research - Trihalomethanes (THMs), which is one of the major classes of DBP known to be highly cytotoxic and genotoxic, were formed and modeled under controlled...     

Arsenic-contaminated groundwater and its potential health risk: A case study in Long An and Tien Giang provinces of the Mekong Delta,Vietnam

Environmental Science and Pollution Research - The occurrence of arsenic (As) in groundwater (drilled well water) that were used for drinking, cooking, and personal hygiene and its risks to human...     

Analysis of winter thermal comfort conditions: street scenarios using ENVI-met model

Environmental Science and Pollution Research - Rapid migration to cities and the increasing demand for housing negatively affect living areas. Furthermore, uncontrolled population growth,...     

Formation,antimicrobial activity,and biomedical performance of plant-based nanoparticles: a review

Environmental Chemistry Letters - Because many engineered nanoparticles are toxic, there is a need for methods to fabricate safe nanoparticles such as plant-based nanoparticles. Indeed, plant...     

A survey of parabens in aquatic environments in Hanoi,Vietnam and its implications for human exposure and ecological risk

Environmental Science and Pollution Research - Seven parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), iso-propylparaben (iPrP), butylparaben (BuP), benzylparaben...     

Health risk assessment of soil trace elements using the Sequential Gaussian Simulation approach

Environmental Science and Pollution Research - In this study, the performance of the Sequential Gaussian Simulation (SGS) approach was studied with the aim of accurately determining local health...     

Energy crop as an environmentally sustainable reclamation option for post-mining sites: a life cycle assessment of cassava planting in Vietnam

Environmental Science and Pollution Research - Using post-mining areas for planting energy crops has emerged as a promising and sustainable reclamation solution due to its potential contributions...