# US 2014/0190898 A1 · Cactus Mucilage and Ferric Ions for the Removal of Arsenate (As(V)) from Water > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190898 A1 - Document ID: US20140190898A1 - Status: Published application - Kind: A1 - Application number: 14/206,404 - Filed: 2014-03-12 - Published: 2014-07-10 - Earliest claimed: 2011-09-14 - Assignees: University of South Florida - Inventors: Norma A. Alcantar; Dawn I. Fox - Web page: https://patentgrep.com/patent/US20140190898A1 ## CPC - C02F 1/5263: {using natural chemical compounds} - B01D 21/01: using flocculating agents (for purifying water C02F1/52; for liquid radioactive waste G21F9/10) - C02F 1/5245: {using basic salts, e.g. of aluminium and iron} - C02F 1/5272: {using specific organic precipitants} - C02F 1/56: Macromolecular compounds - A61K 36/33: Cactaceae (Cactus family), e.g. pricklypear or Cereus - C02F 1/286: {using natural organic sorbents or derivatives thereof} - C02F 1/5236: {using inorganic agents} - C02F 1/62: Heavy metal compounds - C02F 2101/103: {Arsenic compounds} - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) ## Abstract Potable drinking water is plagued with widespread arsenic contamination, particularly in developing communities. Ferric ions were introduced to interact with arsenate based on the strong affinity of arsenate for ferric hydroxides, followed by mucilage addition. The mucilage coagulated and flocculated the ferric-arsenate complex and formed visible flocs that settled at the bottom of the tubes. The system showed 75-96% arsenate removal in 1 hour, while longer retention times showed 100% removal. The role of the mucilage was demonstrated by untreated solutions showing no concentration difference and remaining stable for more than 15 days. This mucilage-based technology has the potential to be a relatively inexpensive, environmentally sustainable alternative to synthetic polymer flocculants for removing arsenic from drinking water. ## Claims ### Claim 1 A method of removing arsenic contamination from a sample of water, comprising: obtaining a sample of water, wherein the sample of water is contaminated with arsenic; dosing the sample of water with a ferric salt; allowing the ferric salt to interact with the arsenic; adding a gelling extract obtained from cactus to the sample of water, where the gelling extract is obtained by the steps further comprising: obtaining cactus pads; dicing and boiling the cactus pads; liquidizing the cactus pads and adding a base to neutralize the liquidized cactus pad; centrifuging the liquidized cactus pads and collecting the solid precipitate; adding sodium hexametaphosphate to the solid precipitate and mixing; filtering the solid precipitate; resuspending the solid precipitate and lowering the pH of the suspension; precipitating a mucilage precipitate from the suspension; resuspending the mucilage precipitate with water and adjusting the pH until the mucilage precipitate dissolves; and filtering the dissolved mucilage precipitate to form the gelling extract; mixing the sample of water and gelling extract; and allowing the sample of water to cure, wherein during the curing step arsenic precipitates out of the sample of water. ### Claim 2 (depends on 1) The method of claim 1, wherein the gelling extract is added at a final concentration of between about 50 and about 500 mg/L. ### Claim 3 (depends on 2) The method of claim 2, wherein the gelling extract is at a final concentration of between about 100 mg/L and about 200 mg/L. ### Claim 4 (depends on 2) The method of claim 2, wherein the gelling extract is at a final concentration of 100 mg/L. ### Claim 5 (depends on 1) The method of claim 1, wherein the ferric salt is ferric nitrate, ferric chloride, ferric sulfate, ferric carbonate, ferric gluconate, ferric oxalate, or saccharated ferric oxide. ### Claim 6 (depends on 5) The method of claim 5, wherein the ferric nitrate is at a final concentration of between about 6 mg/L and about 50 mg/L. ### Claim 7 (depends on 6) The method of claim 6, wherein the ferric nitrate is at a final concentration of between about 26 mg/L and about 50 mg/L. ### Claim 8 (depends on 7) The method of claim 7, wherein the ferric nitrate is at a final concentration of between about 40 mg/L and about 50 mg/L. ### Claim 9 (depends on 1) The method of claim 1, further comprising allowing the water and ferric salt and gelling mucilage extract to stand for at least 10 min prior to addition of gelling extract. ### Claim 10 (depends on 9) The method of claim 9, wherein the water and ferric salt and gelling mucilage extract to stand for about 1 hour. ### Claim 11 (depends on 9) The method of claim 9, wherein the water and ferric salt and gelling mucilage extract to stand for about 24 h. ### Claim 12 (depends on 1) The method of claim 1, further comprising filtering residual iron and mucilage from the sample of water further comprising: collecting the sample of water after precipitation of arsenic; and running the sample of water through filter cloth, filter paper, Büchner funnel, Rotary vacuum-drum filter, Screen filter, sand filter, fine mesh sieve, coffee filter, ceramic membrane size-exclusion filter, cellulose acetate membrane size-exclusion filter, polyvinylidene fluoride membrane size-exclusion filter, polyacrylonitrile membrane size-exclusion filter, polypropylene membrane size-exclusion filter, polysulfone membrane size-exclusion filter, polyethersulfone membrane size-exclusion filter, polyamide membrane size-exclusion filter, hollow fiber filter, or a combination thereof in sequence. ### Claim 13 (depends on 1) The method of claim 1, further comprising hydrolyzing the ferrous salt prior to addition to the sample of water. ### Claim 14 (depends on 13) The method of claim 13, wherein the ferrous salt is aged in water for at least 48 hours to hydrolyze the salt. ### Claim 15 A method of removing arsenic contamination from a sample of water, comprising: obtaining a sample of water, wherein the sample of water is contaminated with arsenic; dosing the sample of water with a hydrolyzed ferric salt, wherein the ferrous salt is aged in water for at least 48 hours to hydrolyze the salt; allowing the ferric salt to interact with the arsenic; adding a gelling extract obtained from cactus to the sample of water, where the gelling extract is obtained by the steps further comprising: obtaining cactus pads; dicing and boiling the cactus pads; liquidizing the cactus pads and adding a base to neutralize the liquidized cactus pad; centrifuging the liquidized cactus pads and collecting the solid precipitate; adding sodium hexametaphosphate to the solid precipitate and mixing; filtering the solid precipitate; resuspending the solid precipitate and lowering the pH of the suspension; precipitating a mucilage precipitate from the suspension; resuspending the mucilage precipitate with water and adjusting the pH until the mucilage precipitate dissolves; and filtering the dissolved mucilage precipitate to form the gelling extract; wherein the gelling extract is added at a final concentration of between about 50 and about 500 mg/L; mixing the sample of water and gelling extract; and allowing the sample of water to cure, wherein during the curing step arsenic precipitates out of the sample of water. ### Claim 16 (depends on 15) The method of claim 15, wherein the gelling extract is at a final concentration of 100 mg/L. ### Claim 17 (depends on 15) The method of claim 15, wherein the ferric salt is ferric nitrate, ferric chloride, ferric sulfate, ferric carbonate, ferric gluconate, ferric oxalate, or saccharated ferric oxide. ### Claim 18 (depends on 17) The method of claim 17, wherein the ferric nitrate is at a final concentration of between about 40 mg/L and about 50 mg/L. ### Claim 19 (depends on 15) The method of claim 15, further comprising allowing the water and ferric salt and gelling mucilage extract to stand for at least 10 min prior to addition of gelling extract. ### Claim 20 (depends on 19) The method of claim 19, wherein the water and ferric salt and gelling mucilage extract to stand for about 24 h. ### Claim 21 (depends on 15) The method of claim 15, further comprising filtering residual iron and mucilage from the sample of water further comprising: collecting the sample of water after precipitation of arsenic; and running the sample of water through filter cloth, filter cloth, filter paper, Büchner funnel, Rotary vacuum-drum filter, Screen filter, sand filter, fine mesh sieve, coffee filter, ceramic membrane size-exclusion filter, cellulose acetate membrane size-exclusion filter, polyvinylidene fluoride membrane size-exclusion filter, polyacrylonitrile membrane size-exclusion filter, polypropylene membrane size-exclusion filter, polysulfone membrane size-exclusion filter, polyethersulfone membrane size-exclusion filter, polyamide membrane size-exclusion filter, hollow fiber filter, or a combination thereof in sequence.