The demand for rare earth elements (REEs) is likely to outweigh supply. As such, every effort should be taken to salvage REEs from waste streams and other sources of discharge. In this study, PHREEQC geochemical modelling code coupled to parameter estimation software (PEST) was used to simulate the adsorption of REEs onto generalised sorption sites representing natural bentonite. Experimental observations and bentonite characterisation were used to calibrate the model. A total of 83–99.9%, 57–99.5%, 29–99% and 1–85% adsorption efficiencies were observed at 2, 5, 10 and 50 mg L⁻¹ initial concentration, respectively. The adsorption efficiency (> 99%) of REEs at pH 6 was not affected by the presence of anions and cations at different concentrations. Thus, PHREEQC modelling coupled to PEST can be used to simulate the adsorption of elements using limited data. This study indicated that natural bentonite is a suitable and competent adsorbent for the recovery of REEs from wastewater.

Pharmaceutically active compounds (PhACs), Diclofenac (DFC), Ibuprofen (IBU), and Paracetamol (PRC) are anti-inflammatory drugs commonly detected in wastewater. These micropollutants (pharmaceuticals) are not completely removed in conventional wastewater treatment plants. Therefore, alternative treatment methods are needed. In this context, the removal of three pharmaceuticals was investigated by the immobilized TiO₂ method on activated carbon. Emphasis was given on the effect of pH (3–5-7 and 9) and catalyst loading (0.025–0.05–0.075–0.1 and 0.125 g/L). Tube reactor with UV lamp (254 nm) system was used in the study. Concentration of PhACs was analyzed by LCMS/MS. Characterization of AC/TiO₂ composite was analyzed by XRD, Raman, and SEM. At the end of the study, the highest removal efficiencies were obtained for IBU and PRC at acidic pH while for DFC at neutral pH. It was determined that the removal efficiency increased as the dose of the catalyst increased for all three pharmaceuticals. The kinetic studies were fitted using the first order Langmuir–Hinshelwood model, obtaining a high accuracy based on R² value.

In 2020, the world gained dramatic experience of the development of the 2019 coronavirus disease pandemic (COVID-19) caused by severe acute respiratory syndrome 2 (SARS-CoV-2). Recent researches notice an increasing prevalence of anxiety and circadian rhythm disorders during COVID-19 pandemic. The aim of the study was describing clinical features of circadian rhythm disorders and the level of anxiety in persons who have had COVID-19. We have conducted a cohort retrospective study that included 278 patients who were divided into 2 study groups according to medical history: group 1 includes patients with a history of COVID-19; group 2 consists of patients who did not have clinically confirmed COVID-19 and are therefore considered not to have had this disease. To objectify circadian rhythm disorders, they were verified in accordance with the criteria of the International Classification of Sleep Disorders-3. The level of anxiety was assessed by the State-Trait Anxiety Inventory. The most common circadian rhythm disorders were sleep phase shifts. We found that COVID-19 in the anamnesis caused a greater predisposition of patients to the development of circadian rhythm disorders, in particular delayed sleep phase disorder. In addition, it was found that after COVID-19 patients have increased levels of both trait and state anxiety. In our study, it was the first time that relationships between post-COVID-19 anxiety and circadian rhythm disorders had been indicated. Circadian rhythm disorders are associated with increased trait and state anxiety, which may indicate additional ways to correct post-COVID mental disorders and their comorbidity with sleep disorders.

This paper presents a study on orange II sodium salt (OII) degradation based on iron nanoparticles supported by kaolinite clays. The effects of nanoscale iron and initial dye concentration, as well as hydrogen peroxide dosage in a Fenton process, on the degradation of OII were studied. These nanoparticles were synthesized by green methods using coffee bean extract as a natural antioxidant for this process. Aqueous iron chloride was mixed with coffee extract, which is rich in antioxidants, and these antioxidants are responsible for the reduction of metal compounds into nanoparticles. The composite iron nanoparticle-kaolinite composite was synthesized from an aqueous FeCl₃ and kaolinite solution with the added coffee bean extract. The results showed that OII removal efficiency increased with the amount of iron nanoparticles (n-Fe) alone and with the amount iron-supported-kaolinite composite. By increasing the amount of composite, the adsorptive surface area increases as well as the number of active sites, which determine the higher removal efficiency. Regarding H₂O₂ dosage, dye removal was more efficient at lower quantities: 62% removal efficiency with addition of 10 mL H₂O₂, while for the test conducted with 20 mL H₂O₂, removal efficiency was 47%. A possible reason for this behavior can be the n-Fe/ H₂O₂ ratio, which influences the production of degradation products and hinders the degradation. HIGHLIGHTS: • Green synthesized metallic iron nanoparticles (n-Fe) using coffee bean extract as a natural oxidant were used for the removal of Orange II • In order to improve the degradation process, a clay-nanoscale iron composite was used, as well as Fenton oxidation using added H₂O₂. As a support material for the composite, kaolinite was used. The results showed that both reduction and adsorption processes are involved in the dye removal process. Applying Langmuir and Freundlich isothermal models shows monolayer coverage • By comparing the efficiency of the composite alone with the efficiency of the composite with the Fenton process, better results were obtained for the second case which shows the importance of the H₂O₂/Fe system in the degradation process. Also, we may state that the best results were obtained by using n-Fe only • Since the amount of n-Fe present in the composite is low (0.01 g), further experiments should be held concerning the ratios between n-Fe and clay in the composite. Experiments using wastewater containing dyes from a real industrial process should also be done as well, to confirm the activity of this material containing nanoscale iron made using green synthesis in a real wastewater environment, with all the associated ions and compounds.

Laponite nanoparticles have been proposed for soil densification to reduce the negative impacts of seismic hazards. However, the effects of laponite on the aquatic ecosystem are lacking. In this study, different concentrations (0.1, 0.2, 0.3, 0.4, and 0.5%) of laponite were used to investigate the growth and total chlorophyll content of microalgae: Chlorella sp. This study examined the potential toxic effects of laponite on the growth characteristics of freshwater green algae Chlorella sp. isolated from northern Ontario. The experiments were carried out in a 500-ml glass flask with 300 ml working volume and placed under white fluorescent lights for 16 h: 8 h day-night cultivation cycle in a constant orbital shaker. The results revealed that the lower concentration of laponite can enhance microalgae growth, while the higher laponite concentration had a growth inhibitory effect. The total chlorophyll content increased by 33% at 0.1% treatment group than that of the control group. Based on the SEM images, aggregation of microalgae was significantly noticeable at the lower concentration of laponite (0.1% treatment) whereas, in the higher laponite concentration (0.4 and 0.5% treatment), algal cells were embedded in laponite gel and also noticed some physical impairment.

In this paper, Web of Science (a database) is used to retrieve related literature in the field of heavy metal pollution in desert. CiteSpace is used to make a quantitative and qualitative evaluation on the literature in the field on the basis of a brief analysis on the research status, research focus, and evolution process in the field. Through CiteSpace visual analysis, a comparative analysis is given on related literature in terms of annual number of published papers, author groups, and their countries and regions, journals, publishing institutions, highly cited papers, research focuses, and burst terms, so as to explore the research status and future development trend of the field on a global scale. The results are shown as follows: (1) The literature in the field was originally published in 2000; the number of published papers increased steadily. The literature was mostly published on high-quality journals, the USA topped in terms of the number of published papers, and the research results achieved by developed countries had a greater influence. Chinese Acad Sci topped with the highest centrality and most published papers, which have made outstanding contributions to the field and occupy a leading position in the field. However, the fact is that there lacks communication and cooperation among research institutions. The most influential journal is Science of the Total Environment. (2) The hot research words in the field are as follows: heavy metal, soil, pollution, lead, desert, cadmium, and microelement. (3) In the field, burst terms have transformed from atmospheric deposition, biomonitoring, and phytoremediation to trace element, stream sediment, street dust, and water quality, and finally transformed to river and sediment. New words keep emerging in the research, and more and more attention is paid to the issue of heavy metal pollution in river sediment, which will be a future research hotspot in the field.

The increasing discrepancy between a regional economy and transportation imposes higher requirements for their coordinated development. This paper utilized the coupling coordination degree (CCD) model and entropy method (EM) to quantitatively study the coupling coordination state between regional economy and transportation and its spatial distribution of 30 provinces in China from 2004 to 2017. The results show the following: (1) The comprehensive level of regional economy and transportation development in China has shown a growing trend, and the development of regional economy is faster than that of the transportation. (2) The CCD between regional economy and transportation in China is changing from incoordination to high-level coordination. The imbalance of CCD levels among the regions studied varies significantly. The CCD in the eastern regions is slightly higher than that in the central, western, and northeast regions. (3) In the region with a higher CCD, the discrepancy between the development of regional economy and transportation is higher than that in other regions. Moreover, suggestions are provided to promote the coordinated development from a regional perspective. This study provides references to policymakers to help them properly plan and design transportation systems while considering the regional economy, thus stimulating the coordinated and sustainable development between regional economy and transportation.

More than 150 lakes on different peninsulas and islands are situated in the Larsemann Hills. The Larsemann Hills is an ice-free area and are located halfway between the Vestfold Hills and the Amery Ice Shelf on the southeastern coast of Prydz Bay, Princess Elizabeth Land, and East Antarctica. During 34th Indian Scientific Expedition to Antarctica (ISEA) from 2014 to 2015, twenty lake water samples in triplicates were collected from the Broknes & Grovnes peninsula. Coliform and fecal coliform bacteria were analyzed in these samples. Out of twenty, eleven lake water samples were found to be contaminated with coliform bacteria. However, fecal coliform bacteria were absent in all the lake water samples. Coliforms are found in the lakes of Broknes peninsula (P2 Lake & P3 Lake) and Grovnes peninsula (L1C NG, L1D NG, L1E NG, L7 NG, L7A NG, L7B NG, L2 SG, L4 SG & L5 SG). Antarctic lakes water is being polluted due to anthropogenic activities caused by various research activities and tourism. The present study confirms the presence of coliform bacteria in the lakes of East Antarctica which indicates an alarming situation and needs to be investigated further.

In recent years, the prospective use of algae as an alternate fuel source for petroleum-based fuels has increased drastically. It has been researched extensively and proven that it can be used as a sustainable feedstock for producing green energy considering environmental safety. This article focused on the economically viable algal feedstock for the production of lipid content for its use as a feedstock for biodiesel production. For this purpose, the algal species Scenedesmus obliquus and Chlorella vulgaris were selected, and it was grown under lab and open ambient conditions with two Blue green Medium (BG-11) and Bold Basal medium (BBM). Upon the yield, it was noticed that the BG-11 medium gave optimum lipid yield for both species. Hence, it was determined that through this medium higher lipid yield can be expected, and based on the GC-MS result it was notified that it can be a viable source of alternate fuel.

In recent years, palm oil production has grown rapidly as a result of rising demand. Oil palm plantations have been established on thousands of acres to meet this demand. The objective of this study is to assess the suitability of oil palm production as driven by soil, climate, and land use. The land suitability assessment (LSA) method was adopted in this study. We use geospatial techniques of overlay mapping as a suitable land suitability assessment method, in which the evaluation criteria are recorded as superimposed layers. A land suitability map is produced by integrating these layers into a single layer. The method is also applied to delineate available areas for growing oil palm in Peninsular Malaysia. The findings revealed that suitable soil areas for oil palm production are extensively found in the selected regions of Peninsular Malaysia, in states like Selangor and some parts of Kedah, Kelantan, and Terengganu with clay loam and sandy loam soil properties, while in the southern region like Melaka, moderate suitability for oil palm production was found due to the domination of clay soil in the area. Highly suitable areas were estimated (mean annual water deficit <150 mm) to be 3688254.00 ha (29.54%) of the total land area; suitable areas (mean annual water deficit <250 mm) were 6540669.00 ha (52.38%); moderately suitable areas were (mean annual water deficit <400 mm) 2227500.00 ha (17.84%), and unsuitable areas (mean annual water deficit >400mm) for oil palm production as a result of poor water availability was 31104.00ha (0.25%). The Land Use Land Cover Map of Peninsular Malaysia revealed the suitable areas to cover an average of 10885001.46 ha (82.45%), water bodies 1239505.58 ha (9.39%), built-up areas (unsuitable areas) 1051544.34 ha (7.96%), and bare surface areas are also not suitable areas for oil palm production at 26509.73 ha (0.20%). This study recommends that oil palm plantations be expanded into areas with highly suitable soils and climates.