In situ arsenic removal in an alkaline clastic aquifer

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.

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A contribution to solve the arsenic problem in groundwater of Ganges Delta by in-situ treatment

Water Science & Technology ◽

10.2166/wst.2008.751 ◽

2008 ◽

Vol 58 (10) ◽

pp. 2009-2015 ◽

Cited By ~ 5

Author(s):

U. Rott ◽

H. Kauffmann

Keyword(s):

Arsenic Removal ◽

Low Cost ◽

Treatment Plant ◽

Cost Effective ◽

Treatment Technology ◽

Manganese Removal ◽

Arsenic In Groundwater ◽

Cost Effective Treatment ◽

Removal Of Arsenic

Arsenic in groundwater is a huge problem in numerous regions of the world. Many people are exposed to high arsenic concentrations and consequently risk getting ill or even die as a result of arsenic poisoning. There are several efficient technologies for the removal of arsenic but often these methods have disadvantages, e.g. high costs for installation and/or operation, the need for chemicals or the production of arsenic contaminated filter sludge. These disadvantages can make the application difficult, especially in poor regions. Under suitable ancillary conditions the subterranean (in-situ) treatment, which is often used for iron and manganese removal from groundwater, can also be applied for the removal of arsenic and can be a cost-effective treatment technology. A field trial was carried out with a low-cost in-situ treatment plant in West Bengal/India which is described in this paper, in order to investigate whether this treatment technology is also applicable under the boundary conditions there. As for the in-situ treatment technology besides oxygen no additives are required and no arsenic contaminated filter sludge is produced this technology could be a suitable method for arsenic removal especially in poor regions.

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In-situ modification, regeneration, and application of keratin biopolymer for arsenic removal

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2014.06.023 ◽

2014 ◽

Vol 278 ◽

pp. 360-371 ◽

Cited By ~ 38

Author(s):

Muhammad A. Khosa ◽

Aman Ullah

Keyword(s):

Arsenic Removal ◽

In Situ Modification

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Arsenic Removal via Cellulose-Based Organic/Inorganic Hybrid Materials from Drinking Water

Materials Science Forum ◽

10.4028/www.scientific.net/msf.730-732.563 ◽

2012 ◽

Vol 730-732 ◽

pp. 563-568

Author(s):

Catarina Martins ◽

Rui F. Duarte ◽

Maria C.F. Magalhães ◽

Dmitry Evtuguin

Keyword(s):

Aqueous Solutions ◽

Hybrid Materials ◽

Arsenic Removal ◽

Sol Gel ◽

Arsenic Concentration ◽

Cellulose Fiber ◽

Silica Network ◽

Bleached Pulp ◽

Removal Of Arsenic

Cellulose/silica derived hybrids materials (CSH), functionalized with aluminium, calcium, and propylammonium ions, were tested for their possible use in the removal of arsenic from aqueous solutions with controlled compositions to levels lower than 10 μg As/L. CSH were synthesized by sol-gel method using bleached pulp, as source of cellulose fiber, and tetraethoxysilane (TEOS) as main silica precursor. The silica network, made in situ, contained various anchored cations such as propylammonium (CSH-PA), aluminium (CSH-Al) and, calcium (CSH-Ca). Thin films or mesoparticles of silica were deposited on cellulose fibers as shown by SEM and XRD. These hybrid materials were immersed in controlled ionic strength aqueous solutions with arsenic concentrations lower than 0.2 mg As/L. The best performance was shown by CSH-PA that was able to remove a maximum of 20 % of the total arsenic concentration.

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