Treatment of high arsenic content wastewater by membrane filtration

Globally, arsenic introduced into the biosphere by human activities has greatly surpassed arsenic from natural sources, the supply of the element from these two sources being approximately 60 and 40%, respectively. However, numerous regions of the world have elevated concentrations of arsenic from natural sources. Arsenopyrite may contain up to 6000 μg∙g−1 of arsenic and the weathering of such geological materials can increase the levels of arsenic in groundwater. Long-term consumption of groundwater containing elevated concentrations of arsenic has caused natural chronic arsenic intoxication in local populations in Taiwan, Mexico, Chile, Argentina, and other countries. An endemic disease commonly called blackfoot disease, which is also caused by arsenic in drinking water, was documented in Taiwan in 1963. For more than 80 years local populations had consumed well water with arsenic concentrations as high as 1829 μg∙L−1. The widespread geographical distribution of minerals with high arsenic content suggests that many new regions with natural arsenic contamination will be identified in the near future.Key words: arsenic, natural, cycling, chronic, contamination.

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Health aspects of burning coal with a high arsenic content

Environmental Research ◽

10.1016/0013-9351(77)90019-6 ◽

1977 ◽

Vol 13 (3) ◽

pp. 386-395 ◽

Cited By ~ 29

Author(s):

Vladimír Bencko ◽

Karel Symon ◽

Vladimír Chládek ◽

Jaroslav Pihrt

Keyword(s):

Arsenic Content ◽

Burning Coal ◽

High Arsenic

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Bioprecipitation of Arsenic Sulphide at Low pH

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.71-73.581 ◽

2009 ◽

Vol 71-73 ◽

pp. 581-584 ◽

Cited By ~ 3

Author(s):

F. Battaglia-Brunet ◽

Dominique H.R. Morin ◽

S. Coulon ◽

Catherine Joulian

Keyword(s):

Bacterial Population ◽

Removal Rate ◽

Bacterial Consortium ◽

Low Ph ◽

Operating Conditions ◽

Arsenic Content ◽

Molecular Fingerprints ◽

Ph Values ◽

Reducing Activity ◽

High Arsenic

A process for the precipitation of trivalent arsenic sulphide in sulphate-reducing condition at low pH would be very attractive due to the high arsenic content (60%) in the final precipitate. A bacterial consortium able to reduce sulphate at pH 4.5 served to inoculate column bioreactors that were continuously fed with As(V) or As(III), glycerol and/or hydrogen, at pH values between 2 and 5. The diversity, functionality and evolution of the consortium colonizing the bioreactors were characterized by means of biomolecular tools, in relation with operating parameters (pH, As, sulphide, acetate). The highest As removal rate obtained during these experiments was close to 3 mg.l-1.h-1 using As(V) as the initial arsenic form, while precipitation rates were improved using As(III). When glycerol was replaced by hydrogen in a bioreactor containing a mature biofilm, sulphate-reducing activity increased roughly. Organisms related to Desulfosporosinus were the only sulphate-reducing bacterium (SRB) detected in the bioreactor. arrA genes, involved in As(V) dissimilatory reduction, were also detected and suggested that As(V) was reduced by a Desulfosporosinus-like organism. Molecular fingerprints evidenced an evolution of the bacterial population structure according to changes in operating conditions.

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Investigation of Novel Opuntia Ficus-indica Mucilage Nanofiber Membrane Filtration for Water Systems

MRS Proceedings ◽

10.1557/opl.2015.582 ◽

2015 ◽

Vol 1745 ◽

Cited By ~ 3

Author(s):

Sylvia W. Thomas ◽

Manopriya Devisetty ◽

Hruday Chand Katakam ◽

Samuel Perez ◽

Fei Guo ◽

...

Keyword(s):

Polyvinyl Alcohol ◽

Membrane Filtration ◽

Toxic Substance ◽

Water Systems ◽

Arsenic Content ◽

Atomic Fluorescence Spectrometry ◽

Natural Material ◽

Nanofiber Membrane ◽

Opuntia Ficus Indica ◽

Nanofiber Membranes

ABSTRACTNanofiltration technology is being investigated as a cost-eﬀective and environmentally acceptable mechanism of sustaining industrial and public water systems. Nanofiber membranes are part of the family of filtration devices being used to remove inorganics and organics from water systems. This study investigates the use of the natural material, Opuntia ficus-indica (Ofi) cactus mucilage, as a tool for nanofiber membrane filtration. Mucilage is a natural, non-toxic, bio-compatible, biodegradable, inexpensive and abundant material. Mucilage is a clear colorless substance comprised of proteins, mono-saccharides, and polysaccharides. It also contains organic species, which give it the capacity to interact with metals, cations and biological substances promoting flocculation for removing arsenic, bacteria, E. coli, and other particulates from drinking water. This natural material has the potential to be used as a sustainable method for water filtration and contaminant sensing. Therefore, mucilage nanofiber membranes were electrospun with volume ratios of polyvinyl alcohol (PVA) and polystyrene (PS) to mucilage comparing the interaction of non-polar solvents. Atomic Fluorescence Spectrometry (AFS) from PSAnalytical was used to evaluate electrospun nanofiber membranes made from volume ratios ranging from 30:70 to 70:30 of mucilage: polyvinyl alcohol, mucilage: polystyrene-D-limonene, and mucilage: polystyrene–toluene in different proportions. The mucilage nanofiber membranes were used as filtration devices for 50 ppb arsenic solutions. Arsenic, being a toxic substance, acts as a deadly poison in water systems and has plagued societal preservation for centuries. The total arsenic content in the samples were measured before and after treatment. Comparative tests were also performed using 1) coated and non-coated GVWP 0.22 µm and 0.45 µm filters from Millipore and 2) columnar flow through Pasteur glass pipets filled with 0.5 g of pre-washed sand from Fisher Scientific and 0.01 g of mucilage nanofibers. Results show mucilage: polystyrene nanofiber membrane filters were capable of removing arsenic from test solutions, in terms of the percentage of arsenic removed. These data elucidate that mucilage nanofiber membranes have the potential to serve as the basis for the next generation of economically sustainable filtration devices that make use of a natural non-toxic material for sustainable water systems.

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Bacteriological and Physicochemical Analysis of Drinking Water in Tokha, Kathmandu, Nepal

Med Phoenix ◽

10.3126/medphoenix.v1i1.17881 ◽

2017 ◽

Vol 1 (1) ◽

pp. 15-18

Author(s):

Amrullah Shidiki ◽

Dipak Bhargava ◽

Ravi Shankar Gupta ◽

Akhtar Alam Ansari ◽

Bijay Raj Pandit

Keyword(s):

Drinking Water ◽

Water Samples ◽

Membrane Filtration ◽

Agar Plate ◽

World Health ◽

Total Hardness ◽

Arsenic Content ◽

National Agency ◽

Ammonia Content ◽

Guideline Value

Background: This study reports the comparative studies and microbial risk assessment of different water samples used for drinking water. The results obtained were compared with WHO and EPA standards for drinking and recreational water.Methods: Physicochemical and bacteriological analysis of water samples were carried out from source, taps, well and stone spouts used for drinking purpose in Tokha (Saraswati and Chandeswari Village Development Committee). Total viable count was carried out by pour plate technique. Total coli form and fecal coli form were performed by membrane filtration technique. The results obtained were compared with World Health Organization (WHO), National Agency for Food and Drug Administration and Control (NAFDAC) and Nepal Standard of Drinking Water Quality (NSDWQ) standards for drinking water.Results: The pH, total hardness, chloride, nitrate and arsenic content of samples were found within permissible guideline value however well sample was found to exceed Nepal standard values for calcium hardness and ammonia content. The total viable counts for all the water samples were high exceeding the limit for water (1.0×102 cfu/ ml). All the water samples were found to contain coli forms and fecal organisms in numbers greater than the required WHO/FAO standards for water. The fecal coli form colonies on M-endo agar plate ranged between 143 and 152 and total coli form from 110 to 248 per 100 ml water also exceed the standard limit for water. The Isolated organisms were identified to be E.coli, Klebsiella spp. And Citrobacter spp.MED PhoenixVolume (1), Issue (1) July 2016, page: 15-18

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