scholarly journals Arsenic removal from arsenic-contaminated water by biological arsenite oxidation and chemical ferrous iron oxidation using a down-flow hanging sponge reactor

2017 ◽  
Vol 17 (5) ◽  
pp. 1249-1259 ◽  
Author(s):  
Nao Kamei-Ishikawa ◽  
Nami Segawa ◽  
Daisuke Yamazaki ◽  
Ayumi Ito ◽  
Teruyuki Umita
Keyword(s):  
Arsenic Removal ◽  
Low Cost ◽  
Iron Hydroxide ◽  
Iron Oxidation ◽  
Quality Standards ◽  
Small Scale ◽  
Contaminated Water ◽  
Water Quality Standards ◽  
Ferrous Iron Oxidation ◽  
Arsenite Oxidizing Bacteria

The down-flow hanging sponge (DHS) reactor was used for continuous As removal treatment of As-contaminated water. The treatment scheme was: (1) As(III) in contaminated water is oxidized by arsenite-oxidizing bacteria fixed in the sponges in the reactor; (2) Fe(II) naturally existing in the water is oxidized by dissolved oxygen; (3) Fe(III) is precipitated as iron hydroxide and As(V) is co-precipitated with the iron hydroxide; and finally (4) the co-precipitates are fixed in the sponges. This system could remove As from As-contaminated water on a small scale and at low cost. The results showed that, after using the DHS reactor, As and Fe concentrations in the treated water were lower than water quality standards for drinking water when Fe(II) concentration in the influent was lower than 10 mg/L and the Fe/As ratio was higher than 6.67–8.42, with dependence on the Fe concentration. Additionally, even if Fe concentration is higher than 10 mg/L, the treatment system is still applicable if the pH of the influent is higher than 7 or the retention time is longer than 2 h.

Subsurface iron and arsenic removal: low-cost technology for community-based water supply in Bangladesh

2010 ◽  
Vol 62 (11) ◽  
pp. 2702-2709 ◽  
Author(s):  
D. van Halem ◽  
S. G. J. Heijman ◽  
R. Johnston ◽  
I. M. Huq ◽  
S. K. Ghosh ◽  
...  
Keyword(s):  
Arsenic Removal ◽  
Low Cost ◽  
Iron Hydroxide ◽  
Oxidation Zone ◽  
Small Scale ◽  
Arsenic Adsorption ◽  
Community Based ◽  
Competing Anions ◽  
Tube Well

The principle of subsurface or in situ iron and arsenic removal is that aerated water is periodically injected into an anoxic aquifer through a tube well, displacing groundwater containing Fe(II). An oxidation zone is created around the tube well where Fe(II) is oxidised. The freshly formed iron hydroxide surfaces provide new sorption sites for soluble Fe(II) and arsenic. The system's efficiency is determined based on the ratio between abstracted volume with reduced iron/arsenic concentrations (V) and the injected volume (Vi). In the field study presented in this paper, the small-scale application of this technology was investigated in rural Bangladesh. It was found that at small injection volumes (<1 m3) iron removal was successful and became more effective with every successive cycle. For arsenic, however, the system did not prove to be very effective yet. Arsenic retardation was only limited and breakthrough of 10 μg/L (WHO guideline) was observed before V/Vi=1, which corresponds to arrival of groundwater at the well. Possible explanations for insufficient arsenic adsorption are the short contact times within the oxidation zone, and the presence of competing anions, like phosphate.

scholarly journals Analysis of the features and causes of the contamination in the Shandi River basin

2020 ◽  
Vol 199 ◽  
pp. 00007
Author(s):  
Hong Shi ◽  
Yongbo Zhang ◽  
Li Tang
Keyword(s):  
Surface Water ◽  
River Basin ◽  
Pollution Index ◽  
Quality Standards ◽  
Shanxi Province ◽  
Contaminated Water ◽  
Water Quality Standards ◽  
Volatile Phenols ◽  
Sampling Points

This study examined the contamination of the surface water in the Shandi River basin in Yangquan, Shanxi province. A total of 11 sampling points (numbered S1-S2, S3-S4, S5–S11) were selected from the upstream to the downstream of the river, and 19 indexes were selected for inspection to identify the causes and features of contaminated water in the basin. The Nemerow Pollution Index was applied to evaluate the quality of the surface water and the overall extent of contamination in the basin. The result revealed that the content of Cl-, As, Cr6+, CN-, and volatile phenols met the grade III water quality standards in China, and the remaining indexes exceeded the standards by varying degrees. The five sources of contamination in the basin negatively affect the environment. The presence of contaminants at the sampling points was in the following order, from highest to lowest: SO42-= Mn = NH3-N> Fe2+= Hg >Fe3+> Cd > Zn = F->COD>NO3 -= NO2-. The severity of the comprehensive contamination indexes decreased in the order of S6 > S9 > S7 > S11 > S10 > S3 > S8 > S5 >S4.

scholarly journals Water Quality Index Assessment ofGroundwater in Todaraisingh Tehsil of Rajasthan State, India-A Greener Approach

2010 ◽  
Vol 7 (s1) ◽  
pp. S428-S432 ◽  
Author(s):  
Ashok Kumar Yadav ◽  
Parveen Khan ◽  
Sanjay K. Sharma
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Statistical Analysis ◽  
Groundwater Quality ◽  
Water Quality Index ◽  
Quality Index ◽  
Quality Standards ◽  
Water Sources ◽  
Contaminated Water ◽  
Water Quality Standards

This study deals with the statistical analysis and study of water quality index to assess hardness of groundwater in Todaraisingh tehsil of Tonk district of Rajasthan state. The study has been carried out to examine its suitability for drinking, irrigation and industrial purpose. The presence of problematic salts contains in groundwater due to local pollutants and affected the groundwater quality adversely. The estimated values were compared with drinking water quality standards prescribed by B.I.S. It was found that drinking water is severely polluted with hardness causing salts. This study reveals that people dependent on water sources of the study area are prone to health hazards of contaminated water and quality managements to hardness urgently needed.

Microbial Production of Schwertmannite: Development from Microbial Fundamentals to Marketable Products

2017 ◽  
Vol 262 ◽  
pp. 568-572 ◽  
Author(s):  
Susan Reichel ◽  
Eberhard Janneck ◽  
Diana Burghardt ◽  
Stefan Peiffer ◽  
Gunter Kießig ◽  
...  
Keyword(s):  
Mine Water ◽  
Ferrous Iron ◽  
Iron Hydroxide ◽  
Iron Oxidation ◽  
Research Work ◽  
Industrial Effluents ◽  
Open Pit ◽  
Organic Polymer ◽  
Water Treatment Process ◽  
Ferrous Iron Oxidation

Pumped groundwater in the lignite open-cast mines in Lusatia, Germany, contains a high level of ferrous iron (up to 1000 mg/L) at an initial pH of about 5. In recent R&D projects G.E.O.S. developed an innovative water treatment process for ferrous iron oxidation using the autochthonous microbial consortium in the mine water. The pilot plant is operated in the Nochten open-pit mine in cooperation with the LEAG and produces 5 – 10 t of schwertmannite per year. Extensive research work was carried out in parallel to utilize the produced schwertmannite. Pigment production proved to be technically feasible but difficult due to economic and market constraints. However, the high affinity of schwertmannite to oxy-anions provides the suitability for utilization as adsorbent to remove arsenate, antimonate, chromate, molybdate, vanadate or phosphate from mine water or industrial effluents. In the R&D project SURFTRAPII two kinds of filter-stable sorption materials were developed 1) by compacting schwertmannite or 2) by adhesive curing using an organic polymer, respectively. The produced filter-stable adsorbents were tested under technical conditions in cooperation with potential end users to remove arsenate, molybdate and phosphate from mine and industrial water and to concentrate valuable metals. The results showed a better performance of the material compared to other commercially available iron hydroxide adsorbents.

Arsenic removal from contaminated water by the Soyatal Formation, Zimapán Mining District, Mexico – a potential low-cost low-tech remediation system

2001 ◽  
Vol 1 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Lois K. Ongley ◽  
Ma. Aurora Armienta ◽  
Katherine Heggeman ◽  
Alison S. Lathrop ◽  
Helen Mango ◽  
...  
Keyword(s):  
Arsenic Removal ◽  
Low Cost ◽  
Contaminated Water ◽  
Mining District

scholarly journals Bacteriophage inactivation as a function of ferrous iron oxidation

2019 ◽  
Vol 5 (7) ◽  
pp. 1309-1317 ◽  
Author(s):  
Joe Heffron ◽  
Brad McDermid ◽  
Brooke K. Mayer
Keyword(s):  
Ferrous Iron ◽  
Low Cost ◽  
Iron Oxidation ◽  
Ferrous Iron Oxidation ◽  
Iron Based

Iron-based disinfection has been promoted as a potential low-cost, low-byproduct means of virus mitigation.

Recovery of Metals and Stabilization of Arsenic from (Bio-)Leaching Operations by Engineered Biological Processes

2013 ◽  
Vol 825 ◽  
pp. 536-539
Author(s):  
Paula Gonzales Contreras ◽  
Martijn Olde Weghuis ◽  
Jan Weijma ◽  
Cees N.J. Buisman
Keyword(s):  
Arsenic Removal ◽  
Iron Oxidation ◽  
Cost Effective ◽  
Chemical Precipitation ◽  
Arsenic Content ◽  
Biological Processes ◽  
Structural Water ◽  
Large Size ◽  
Ferrous Iron Oxidation ◽  
High Concentrations

This paper focuses on the application of biotechnological stabilization of arsenic from (bio-) leaching operations. One of the latest applications of the Thioteq technology is arsenic immobilization. The Thioteq-scorodite biorecovery reactor is an aerobic system to immobilise arsenic in bio-scorodite crystals. In this patented process, biological arsenite oxidation, biological ferrous iron oxidation and crystallisation reactions are simultaneously taking place. Bio-scorodite crystals can be easily harvested by sedimentation due to their relative large size of up to 160 μm. This biogenic material is classified as non-hazardous due to its very low arsenic leaching rates. Furthermore, bioscorodite crystals resemble the colour, crystal morphology, iron and arsenic content, structural water of the mineral scorodite. The operational costs related to scorodite bio-crystallization can be reduced at least 50% compared to chemical precipitation because the use of biological reactions to induce the crystallization of scorodite and the good stability properties of the produced crystals. The Thioteq-scorodite process is a reliable cost effective solution to arsenic removal and immobilization by using biological processes. The stabilization of arsenic in the form of biologically produced scorodite is an attractive technology for the compact and safe immobilization of arsenic from medium to high concentrations of arsenic in acidic process streams.

Parameters Affecting Dye Adsorption - Using Graphene Coated Sand (GSC)

2018 ◽  
Vol 4 (02) ◽  
Author(s):  
Seroor Atalah Khaleefa Alia ◽  
Dr. Mohammed Ibrahimb ◽  
Hussein Ali Hussein
Keyword(s):  
Heavy Metals ◽  
Contact Time ◽  
Organic Dyes ◽  
Low Cost ◽  
Dye Adsorption ◽  
Contaminated Water ◽  
Maximum Adsorption Capacity ◽  
Engineering Designs ◽  
Heavy Metals Ions ◽  
Coated Sand

Adsorption is most commonly applied process for the removal of pollutants such as dyes and heavy metals ions from wastewater. The present work talks about preparing graphenic material attached sand grains called graphene sand composite (GSC) by using ordinary sugar as a carbon source. Physical morphology and chemical composition of GSC was examined by using (FTIR, SEM, EDAX and XRD). Efficiency of GSC in the adsorption of organic dyes from water was investigated using reactive green dye with different parameters such as (ph, temperature, contact time and dose). Adsorption isotherm was also studied and the results showed that the maximum adsorption capacity of dye is 28.98 mg/g. This fast, low-cost process can be used to manufacture commercial filters to treat contaminated water using appropriate engineering designs.

Occurrence of 1,4-dioxane and MTBE in drinking water sources in Japan

2006 ◽  
Vol 6 (2) ◽  
pp. 47-53 ◽  
Author(s):  
D. Simazaki ◽  
M. Asami ◽  
T. Nishimura ◽  
S. Kunikane ◽  
T. Aizawa ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Water Samples ◽  
Quality Standards ◽  
Raw Water ◽  
Water Quality Standards ◽  
Butyl Ether ◽  
Water Treatment Plants ◽  
Standard Value ◽  
Surface Water Samples

Nationwide surveys of 1,4-dioxane and methyl-t-butyl ether (MTBE) levels in raw water used for the drinking water supply were conducted at 91 water treatment plants in Japan in 2001 and 2002, prior to the revision of the drinking water quality standards. 1,4-dioxane was widely and continuously detected in raw water samples and its occurrence was more frequent and its concentrations higher in groundwater than in surface water. However, its maximum concentration in raw water was much lower than its new standard value (50 μg/L), which was determined as a level of 10−5 excessive cancer risk to humans. Trace levels of MTBE were also detected in several surface water samples.

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