| 1. |
- Irunde, R., et al.
(författare)
-
Developing innovations for adsorptive removal of arsenic from drinking water sources in north mara gold mining area, Tanzania
- 2016
-
Ingår i: Arsenic Research and Global Sustainability - Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. - : CRC Press/Balkema. - 9781138029415 ; , s. 559-560
-
Konferensbidrag (refereegranskat)abstract
- Arsenic (As) contamination in drinking water have been reported to occur in areas where mining are practiced such as North Mara, lake Victoria basin in Mwanza, Geita and Rukwa. The removal of As requires methods such as ion-exchange, reverse osmosis, electrodialysis, contact precipitation, acti-vated alumina, bone charcoal and activated clay. The use of ion-exchange, reverse osmosis and electrodi-alysis are expensive to be implemented in Tanzania. In order to safeguard the drinking water supplies, it is important to explore the low-cost and efficient locally available adsorbents such as activated alumina, bone char and clay for the removal of As for drinking water consumption.
|
|
| 2. |
- Ligate, F. J., et al.
(författare)
-
Occurrence of arsenic in groundwater, soil and sediments in Tanzania
- 2016
-
Ingår i: Arsenic Research and Global Sustainability - Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. - : CRC Press/Balkema. - 9781138029415 ; , s. 88-89
-
Konferensbidrag (refereegranskat)abstract
- Tanzania is among the sub-Sahara African countries where most of the rural populations use ground water for drinking and other household activities. The presence of elevated concentrations of arsenic in some parts of Tanzania is possibly related to both geogenic and anthropogenic sources. From its origin in the bed-rock, inorganic As enters into soil where its concentration depends on the parent rock, climate, forms of As, redox conditions of the soils as well as anthropogenic activities. The interactions of water with rocks and sediments together with environmental deposition have resulted into high concentration in groundwater. Microbial activities in soil and sediments may produce the methylated form of As which are volatile in nature and can re-enter the atmosphere and ultimately be re converted back to inorganic forms. Exposure to elevated concentration of arsenic causes arsenicosis. Further investigations are needed in order to come up with a comprehensive report concerning the occurrence and distribution of As in Tanzania.
|
|
| 3. |
- Ijumulana, J., et al.
(författare)
-
Arsenic occurrence in groundwater sources of Lake Victoria basin in Tanzania
- 2016
-
Ingår i: Arsenic Research and Global Sustainability - Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. - : CRC Press/Balkema. - 9781138029415 ; , s. 86-87
-
Konferensbidrag (refereegranskat)abstract
- Increasing naturally occurring toxic substances are becoming threat to many safer groundwater sources worldwide. Their detection, scale of occurrence and removal procedures requires sophisticated tools. This study employs geostatistical methods to study the extent of arsenic occurrence over Lake Victoria basin in Tanzania. Water samples are randomly taken at village level from available drinking water source, tested at water quality laboratory to quantify levels of As concentrations. The study further uses fuzzy logics to identify areas with no, low, moderate and high As concentrations based on the World Health Organization (WHO) guidelines and Tanzania Bureau of Standards (TBS) standards of 0.01 mg/L and 0.05 mg/L As respectively. The result of this study is vital to understanding severity of As contamination and prediction of potential human health effects dwelling within these regions.
|
|
| 4. |
- Maity, J. P., et al.
(författare)
-
Hydrogeochemical reconnaissance of arsenic cycling and possible environmental risk in hydrothermal systems of Taiwan
- 2017
-
Ingår i: Groundwater for Sustainable Development. - : Elsevier. - 2352-801X. ; 5, s. 1-13
-
Tidskriftsartikel (refereegranskat)abstract
- Hydrothermal activity creates geo-hydro-chemical interactions between hot water/fluid and the host rocks, which changes the hydro-chemical composition of the geothermal water/fluid and enriches trace elements. Existence of arsenic (As) is reported from different hydrothermal systems as well as several region in groundwater system at elevated concentration globally, compared to 10 μg/L WHO (World health Organization) guideline. The distribution of dissolved major and minor elements, including arsenic (As) was studied in hydrothermal systems of Taiwan. For the first time in Taiwan As(V) and As(III) species were researched from the three principal geological settings of Taiwan. Aim was to understand the cycling, fate and transport and potential impact of As on the surficial hydrological systems. Water samples were collected from sixteen hydrothermal springs of 3 different geological settings. Three groups of hydrothermal spring water samples could be distinguished: (i) strongly acidic (pH<3), sulfate-enriched waters of H-SO4-type (Yangmingshan, and Taipu, Beitou), (ii) slightly alkaline waters (pH: 8–8.95) (Jiben, Antung and Kung-Tzu-Ling), and (iii) circum-neutral waters (pH 6.47–7.41) of Na-HCO3/Na-Cl-HCO3-type (Wulai, Hongye, Rueisuei, Chung-Lun and Biolai). The waters are enriched with alkali and alkali earth metals compared to drinking water. Similarly, the water of most of the geothermal springs were found to be enriched with As (highest concentration at Beitou: 1.456 mg/L) with As(III) being the principal As species. Arsenic concentrations of hydrothermal spring waters in igneous rock terrains exhibit highest concentrations (0.69±0.71 mg/L) followed by those of sedimentary (0.16±0.14 mg/L) and metamorphic (0.06±0.02 mg/L) terrains. The discharged geothermal springs water contaminate the surface and groundwater (including drinking and irrigation water resources), where significant levels of arsenic and other toxic element have detected and hence being a significant risk for human health and environmental.
|
|
| 5. |
- Maity, J. P., et al.
(författare)
-
Investigation of arsenic contamination from geothermal water in different geological settings of Taiwan : Hydrogeochemical and microbial signatures
- 2016
-
Ingår i: Arsenic Research and Global Sustainability - Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. - : CRC Press/Balkema. - 9781138029415 ; , s. 84-85
-
Konferensbidrag (refereegranskat)abstract
- The dissemination of dissolved elements, including arsenic (As(V)/As(III)) and microbial diversity was studied in hydrothermal systems of Taiwan considering three different principal geological settings such as Igneous rock terrains, Metamorphic terrains and Sedimentary terrains to understand the cycling, fate and transport and potential impact of As on hydrological systems. The results were indicated as strongly acidic (pH< 3), sulfate-enriched waters of H-SO4-type in igneous-sedimentary rock terrains, slightly alkaline waters (pH: 8–8.95) in metamorphic terrains, and circum-neutral waters (pH 6.47–7.41) of Na-HCO3/Na-Cl-HCO3-type in metamorphic-sedimentary terrains. The geothermal waters were enriched with As in igneous terrains (Beitou: 1.46 mg/L) as compared to sedimentary (0.16 ± 0.14 mg/L) or metamorphic (0.06 ± 0.02 mg/L) terrains. The 16S rRNA gene sequence of bacterial diversity indicates prevalence of mesophilic sulfur- and thiosulfate-oxidizing bacterium in Taipu (igneous rock terrains). The discharge from geothermal springs with significant levels of As and other toxic element contaminate the surface and groundwater of environment.
|
|
| 6. |
- Maity, J. P., et al.
(författare)
-
Removal of fluoride from water through bacterial-surfactin mediated novel hydroxyapatite nanoparticle and its efficiency assessment : Adsorption isotherm, adsorption kinetic and adsorption Thermodynamics
- 2018
-
Ingår i: Environmental Nanotechnology, Monitoring and Management. - : Elsevier. - 2215-1532. ; 9, s. 18-28
-
Tidskriftsartikel (refereegranskat)abstract
- Fluoride contamination in water due to natural and anthropogenic activities has been documented as serious problems worldwide commanding a major threat to the environment. Present study focuses to synthesis bacterial-surfactin (Bacillus subtilis) mediated nano-hydroxyapatite (HAp), novel adsorbents for defluoridation. HAp particle size and morphology were controlled by varying temperature of 90–150 °C and pH of 7–11, respectively. The TEM and SEM micrographs reveal that the short-rod particle is observed 20–30 nm at 90 °C and pH 11. The ratio between the length (nm) and width (nm) of nanoparticle are decreased from 4.17 to 1.65 with increasing pH (7–11). The selected area diffraction (SAD) of particles are indicated uniform rod-like monocrystals. The XRD and FTIR observations were indicated the synthesized HAp nanoparticles were well-crystallized with purity phase and high quality. The study reflected that the fluoride removal from contaminated water by HAp was increased significantly (R2 = 99) with the increasing adsorbent concentration, temperature and time, with two-step adsorption process as the first portion a rapid adsorption occurs during first 90 min after which equilibrium is slowly achieved. The adsorption process is closer to Freundlich isotherm (R2 > 98) than to Langmuir isotherm (R2 ≈ 92), indicating HAp as a good adsorbent (n > 3). Above 97% of fluoride removal were noticed at a HAp dose of 0.06 g/10 mL. The adsorption kinetics more fit with pseudo-second-order (R2= 99) in compare to pseudo-first-order (R2 ≈ 91). The slope and intercept of Arrhenius equation indicated the activation/adsorption energy (Ea) of 3.199 kJ/mol and frequency factor (A) of 1.78 1/s. Adsorption thermodynamic parameters (free energy (ΔG < 0), enthalpy (ΔH > 0) and entropy (ΔS > 0)) indicates the spontaneous and endothermic reactions of the adsorption process. Thus, newly synthesized HAp nanoparticles exhibit as a good adsorbent for fluoride removal, theoretically and experimentally being applicable for environmental pollution control.
|
|
| 7. |
-
Arsenic Research and Global Sustainability: Proceedings of the Sixth International Congress on Arsenic in the Environment (As2016), June 19-23, 2016, Stockholm, Sweden
- 2016
-
Proceedings (redaktörskap) (refereegranskat)abstract
- The Congress "Arsenic in the Environment" offers an international, multi- and interdisciplinary discussion platform for research and innovation aimed towards a holistic solution to the problem posed by the environmental toxin arsenic, with considerable societal impact. The congress has focused on cutting edge and breakthrough research in physical, chemical, toxicological, medical, agricultural and other specific issues on arsenic across a broader environmental realm. The Congress "Arsenic in the Environment" was first organized in Mexico City (As2006) followed by As2008 in Valencia, Spain, As2010 in Tainan, Taiwan, As2012 in Cairns, Australia and As2014 in Buenos Aires, Argentina. The 6th International Congress As2016 was held June 19-23, 2016 in Stockholm, Sweden and was entitled Arsenic Research and Global Sustainability.
|
|
| 8. |
|
|
| 9. |
- Bundschuh, Jochen, et al.
(författare)
-
Editor's preface
- 2017
-
Ingår i: Geothermal, Wind and Solar Energy Applications in Agriculture and Aquaculture. - : Informa UK Limited. ; , s. xxxix-xl
-
Bokkapitel (refereegranskat)
|
|
| 10. |
- Bundschuh, Jochen, et al.
(författare)
-
Geothermal, wind and solar energy applications in agriculture and aquaculture
- 2017
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- The agri-food chain consumes about one third of the world's energy production with about 12% of it for crop production and nearly 80% for processing, distribution, retail, preparation and cooking. The agri-food chain also accounts for 80-90% of total global freshwater use where 70% alone is for irrigation. Additionally, on a global scale, freshwater production consumes nearly 15% of the entire energy production. It can therefore be argued that making agriculture and the agri-food supply chain independent from fossil fuel use has a huge potential to contribute to global food security and climate protection not only for the next decades but also for the coming century. Provision of secure, accessible and environmentally sustainable supplies of water, energy and food must thus be a priority. One of the major objectives of the world's scientists, farmers, decisions makers and industrialists is to overcome the present dependence on fossil fuels in the agro-food sector. This dependency increases the volatility of food prices and affects economic access to sustenance. This book provides a critical review of recent developments in solar, wind and geothermal energy applications in agriculture and the agro-food sector such as processing, distribution, retail, preparation and cooking.
|
|
| 11. |
- Herath, I., et al.
(författare)
-
Geochemical processes for mobilization of arsenic in groundwater
- 2016
-
Ingår i: Arsenic Research and Global Sustainability - Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. - : CRC Press/Balkema. - 9781138029415 ; , s. 23-24
-
Konferensbidrag (refereegranskat)abstract
- This paper presents an overview of natural geochemical processes that can mobilize arsenic (As) from aquifer sediments into groundwater. The primary source of As in groundwater is pre-dominantly natural (geogenic), and can be mobilized via complicated biogeochemical interactions within various aquifer solids and water. Oxidation of sulfide minerals such as arsenopyrite, As-substituted pyrite and other sulfide minerals are susceptible to oxidation in near surface environment, and release significant quantities of As from sediments. Reductive dissolution of As-bearing Fe(III) oxides/hydroxides 2and sulfide oxidation are the most common and significant geochemical triggers that tend to release As from aquifer sediments into groundwater. Hence, strengthening direct action and implementation of the best practices to target the safe groundwater sources for installing safe drinking water wells are an urgent necessity for sustainable As mitigation on a global scale.
|
|
| 12. |
- Herath, I., et al.
(författare)
-
Sulfur-arsenic interactions and formation of thioarsenic complexes in the environment
- 2018
-
Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 210-211
-
Konferensbidrag (refereegranskat)abstract
- Thiolated arsenic compounds are the sulfur analogous substructures of oxo-arsenicals as the arsinoyl (As=O) is substituted by an arsinothioyl (As=S) group. Relatively brief history of thioarsenic research, mostly in the current decade has endeavored to understand their consequences in the natural environment. However, thioarsenic related aspects have by far not attached much research concern on global scale compared to other arsenic species. This paper provides a critical overview on formation mechanisms of thioarsenicals and their chemistry aiming to direct future research towards thioasenic mitigation strategies. Sulfur-arsenite/arsenate interactions and dissolution of arsenic sulfide minerals are the main mechanisms that involve in the formation of different thioarsenic species in the natural environment. The formation and chemical analysis of thioarsenicals in soil and sediments are highly unknown. Future research needs to be more inclined towards in determining the molecular structure of unknown thioarsenic complexes in various environmental suites.
|
|
| 13. |
- Khan, E. U., et al.
(författare)
-
Biogas energy polygeneration integrated with air-gap membrane distillation (AGMD) as arsenic mitigation option in rural Bangladesh
- 2016
-
Ingår i: Arsenic Research and Global Sustainability - Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. - : CRC Press/Balkema. - 9781138029415 ; , s. 554-556
-
Konferensbidrag (refereegranskat)abstract
- Sustainable energy and drinking water access have been seen as major challenges for rural households in Bangladesh despite of governmental and non-governmental organizations have been made extensive efforts. This study contemplates a universal approach towards tackling both of these issues via biogas based polygeneration integrated with membrane distillation employed at the village level. The specific technologies chosen for the key energy conversion steps are as follows: plug-flow digester (co-digestion and mesophilic condition); internal combustion engine; and air-gap membrane distillation. The proposed techno-economic results show that daily electricity demand can be met with such a system while simultaneously providing 0.4 m3cooking fuel and 2–3 L pure drinking water. Cost analysis illustrates that the approach is highly favorable compare to other available system. The payback time of such system is between 2 and 2.5 years.
|
|
| 14. |
-
Membrane technologies for water treatment : Removal of toxic trace elements with emphasis on arsenic, fluoride and uranium
- 2016
-
Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Focuses on the application of membrane technologies in removing toxic metals\metalloids from water. Particular attention is devoted to the removal of arsenic, uranium, and fluoride. These compounds are all existing in the earth's crust at levels between two and five thousands micrograms per kg (parts per million) on average and these compounds can be considered highly toxic to humans, who are exposed to them primarily from air, food and water. In order to comply with the new maximum contaminant level, numerous studies have been undertaken to improve established treatments or to develop novel treatment technologies for removing toxic metals from contaminated surface and groundwater. Among the technologies available, applicable for water treatment, membrane technology has been identified as a promising technology to remove such toxic metals from water. The book describes both pressure driven (traditional processes, such as Nanofiltration, Reverse Osmosis, Ultrafiltration,etc) and more advanced membrane processes (such as forward osmosis, membrane distillation, and membrane bio-reactors) employed in the application of interest. Key aspect of this book is to provide information on both the basics of membrane technologies and on the results depending on the type of technology employed.
|
|
| 15. |
- Schneider, J., et al.
(författare)
-
Arbuscular mycorrhizal fungi-assisted phytoremediation of a lead-contaminated site
- 2016
-
Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 572, s. 86-97
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge of the behavior of plant species associated with arbuscular mycorrhizal fungi (AMF) and the ability of such plants to grow on metal-contaminated soils is important to phytoremediation. Here, we evaluate the occurrence and diversity of AMF and plant species as well as their interactions in soil contaminated with lead (Pb) from the recycling of automotive batteries. The experimental area was divided into three locations: a non-contaminated native area, a coarse rejects deposition area, and an area receiving particulate material from the chimneys during the Pb melting process. Thirty-nine AMF species from six families and 10 genera were identified. The Acaulospora and Glomus genera exhibited the highest occurrences both in the bulk (10 and 6) and in the rhizosphere soils (9 and 6). All of the herbaceous species presented mycorrhizal colonization. The highest Pb concentrations (mg kg− 1) in roots and shoots, respectively, were observed in Vetiveria zizanoides (15,433 and 934), Pteris vitata (9343 and 865), Pteridim aquilinun (1433 and 733), and Ricinus communis (1106 and 625). The diversity of AMF seems to be related to the area heterogeneity; the structure communities of AMF are correlated with the soil Pb concentration. We found that plant diversity was significantly correlated with AMF diversity (r = 0.645; P > 0.05) in areas with high Pb soil concentrations. A better understanding of AMF communities in the presence of Pb stress may shed light on the interactions between fungi and metals taking place in contaminated sites. Such knowledge can aid in developing soil phytoremediation techniques such as phytostabilization.
|
|
| 16. |
- Schneider, J., et al.
(författare)
-
Potential of different AM fungi (native from As-contaminated and uncontaminated soils) for supporting Leucaena leucocephala growth in As-contaminated soil
- 2017
-
Ingår i: Environmental Pollution. - : Elsevier Ltd. - 0269-7491 .- 1873-6424. ; 224, s. 125-135
-
Tidskriftsartikel (refereegranskat)abstract
- Arbuscular mycorrhizal (AM) fungi inoculation is considered a potential biotechnological tool for an eco-friendly remediation of hazardous contaminants. However, the mechanisms explaining how AM fungi attenuate the phytotoxicity of metal(oid)s, in particular arsenic (As), are still not fully understood. The influence of As on plant growth and the antioxidant system was studied in Leucaena leucocephala plants inoculated with different isolates of AM fungi and exposed to increasing concentrations of As (0, 35, and 75 mg dm−3) in a Typic Quartzipsamment soil. The study was conducted under greenhouse conditions using isolates of AM fungi selected from uncontaminated soils (Acaulospora morrowiae, Rhizophagus clarus, Gigaspora albida; and a mixed inoculum derived from combining these isolates, named AMF Mix) as well as a mix of three isolates from an As-contaminated soil (A. morrowiae, R. clarus, and Paraglomus occultum). After 21 weeks, the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were determined in the shoots in addition to measuring plant height and mineral contents. In general, AM fungi have shown multiple beneficial effects on L. leucocephala growth. Although the activity of most of the stress-related enzymes increased in plants associated with AM fungi, the percentage increase caused by adding As to the soil was even greater for non-mycorrhizal plants when compared to AM-fungi inoculated ones, which highlights the phytoprotective effect provided by the AM symbiosis. The highest P/As ratio observed in AM-fungi plants, compared to non-mycorrhizal ones, can be considered a good indicator that the AM fungi alter the pattern of As(V) uptake from As-contaminated soil. Our results underline the role of AM fungi in increasing the tolerance of L. leucocephala to As stress and emphasize the potential of the symbiosis L. leucocephala-R. clarus for As-phytostabilization at moderately As-contaminated soils.
|
|
| 17. |
- Zhu, Y. -G, et al.
(författare)
-
Editors’ foreword
- 2018
-
Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - : CRC Press/Balkema. ; , s. xlv-xlvi
-
Konferensbidrag (refereegranskat)
|
|
