References

Asuero AG (2007) Buffer capacity of a polyprotic acid: first derivative of the buffer capacity and pKa values of single and overlapping equilibria. Critical Reviews in Analytical Chemistry 37, 269–301.
| CrossRef | CAS |

Busato JG, Zandonadi DB, Dobbss LB, Façanha RA, Canellas LP (2010) Humic substances isolated from residues of sugar cane industry as root growth promoter. Scientia Agricola 67, 206–212.
| CrossRef | CAS |

Buschmann J, Kappeler A, Lindauer U, Kistler D, Berg M, Sigg L (2006) Arsenite and arsenate binding to dissolved humic acids: influence of pH, type of humic acid, and aluminum. Environmental Science & Technology 40, 6015–6020.
| CrossRef | CAS |

Chakravarty AK, Das DK (1997) Arsenic pollution and its environmental significance. Journal of Interacadamecia 1, 262–276.

Chen Y, Schnitzer M (1976) Viscosity measurements of soil humic substances. Soil Science Society of America Journal 40, 866–872.
| CAS |

Datta A, Sanyal SK, Saha S (2001) A study on natural and synthetic humic acids and their complexing ability towards cadmium. Plant and Soil 235, 115–125.
| CrossRef | CAS |

Gebreyowhannes YB (2009) Effect of silica and pH on arsenic removal by iron-oxide coated sand. MSc Thesis, UNESCO-IHE Institute for Water Education, Delft, The Netherlands.

Ghosh K, Schnitzer M (1980) Macromolecular structures of humic substances. Soil Science 129, 266–275.
| CAS |

Goh KH, Lim TT (2010) Influences of co-existing species on the sorption of toxic oxyanions from aqueous solution by nanocrystalline Mg/Al layered double hydroxide. Journal of Hazardous Materials 180, 401–408.
| CrossRef | CAS |

Grafe M, Eick MJ, Grossl PR, Saunders AM (2002) Adsorption of arsenate and arsenite on ferrihydrite in the presence and absence of dissolved organic carbon. Journal of Environmental Quality 31, 1115–1123.
| CrossRef | CAS |

Grossl PR, Eick M, Sparks DL, Goldberg S, Ainsworth CC (1997) Arsenate and chromate retention mechanisms on goethite. 2. Kinetic evaluation using a pressure-jump relaxation technique. Environmental Science & Technology 31, 321–326.
| CrossRef | CAS |

Hansen EH, Schnitzer M (1969) Zn-dust distillation and fusion of a soil humic and fulvic acid. Soil Science Society of America Proceedings 33, 29–36.
| CrossRef | CAS |

Huq SMI, Joardar JC, Parvin S, Correll R, Naidu R (2006) Arsenic contamination in food-chain: transfer of arsenic into food materials through groundwater irrigation. Journal of Health, Population, and Nutrition 24, 305–316.

ICAR (2005) Final Report: integrated management practices including phytoremediation for mitigating arsenic examination in soil–water–plant system. Ad hoc scheme being executed by Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, West Bengal; Principal Investigator – SK Sanyal.

Kononova MM (1961) ‘Soil organic matter—its nature, its role in soil formation and soil fertility.’ (Pergamon: New York)

Lin HT, Wang MC, Li GC (2004) Complexation of arsenate with humic substance in water extract of compost. Chemosphere 56, 1105–1112.
| CrossRef | CAS |

Manning BA, Goldberg S (1996) Modeling competitive adsorption of arsenate with phosphate and molybdate on oxide minerals. Soil Science Society of America Journal 60, 121–131.
| CrossRef | CAS |

Martin M, Celi L, Barberis E, Violante A, Kozak LM, Huang PM (2009) Effect of humic acid coating on arsenic adsorption on ferrihydrite-kaolinite mixed systems. Canadian Journal of Soil Science 89, 421–434.
| CrossRef | CAS |

Mukhopadhyay D, Sanyal SK (2004) Complexation and release isotherm of arsenic in arsenic-humic/fulvic equilibrium study. Australian Journal of Soil Research 42, 815–824.
| CrossRef | CAS |

Page AL (Ed.) (1982) ‘Methods of soil analysis, Part 2.’ 2nd edn. Agronomy Monograph 9. (American Society of Agronomy: Madison, WI)

Perminova IV, Hatfield K (2005) Design of quinonoid-enriched humic materials with enhanced redox properties. Environmental Science & Technology 39, 8518–8524.
| CrossRef | CAS |

Peters J, Combs S, Hoskins B, Jarman J, Kovar J, Watson M, Wolf A, Wolf N (Eds) (2003) ‘Recommended methods of manure analysis.’ (Cooperative Extension Publishing Operations: Madison, WI)

Relan PS, Girdhar KK, Khanna SS (1984) Molecular configuration of compost’s humic acid by viscometric studies. Plant and Soil 81, 203–208.
| CrossRef | CAS |

Saada A, Breeze D, Crouzet C, Cornu S, Baranger P (2003) Adsorption of arsenic (V) on kaolinite and on kaolinite–humic acid complexes—role of humic acid nitrogen groups. Chemosphere 51, 757–763.
| CrossRef | CAS |

Sanyal SK (2001) Colloid chemical properties of soil humic substances – a relook. Journal of the Indian Society of Soil Science 49, 537–569.
| CAS |

Sanyal SK, Nasar SKT (2002) Arsenic contamination of groundwater in West Bengal (India): build-up in soil-crop system. In ‘Analysis and practice in water resources engineering for disaster mitigation’. Vol. 1. Indian Association of Hydrologists. pp. 216–222. (New Age International Publishers: New Delhi)

Schnitzer M, Khan SU (1972) ‘Humic substances in the environment.’ (Marcel Dekker: New York)

Schnitzer M, Skinner SIM (1966) Organo-metallic interactions in soils: 5. Stability constants of Cu²⁺, Fe²⁺ and Zn²⁺-fulvic acid complexes. Soil Science 102, 361–365.
| CrossRef | CAS |

Shaw DJ (1970) Charged interfaces. In ‘Introduction to colloid and surface chemistry.’ Ch. 7. pp. 147–166. (Butterworths: London)

Sinha B, Bhattacharya K (2011) Retention and release isotherm in arsenic-humic/fulvic equilibrium study. Biology and Fertility of Soils 47, 815–822.
| CrossRef | CAS |

Šmejkalová D, Piccolo A (2008) Host-guest interactions between 2,4-dichlorophenol and humic substances as evaluated by 1H NMR relaxation and diffusion ordered spectroscopy. Environmental Science & Technology 42, 8440–8445.
| CrossRef |

Sparks DL, Page AL, Helmke PA, Loeppert PN, Soltanpour RH, Tabatabai M, Johnston CT, Sumner ME (1996) ‘Methods of soil analysis. Part 3. Chemical methods.’ (Ed. DL Sparks) pp. 811–818. (Soil Science Society of America, Inc., American Society of Agronomy, Inc.: Madison, WI)

Stevenson FJ (1994) ‘Humus chemistry—genesis, composition, reactions.’ (Wiley: New York)

Stokes RH, Mills R (1965) The B-coefficient. In ‘Viscosity of electrolytes and related properties.’ pp. 33–45. (Pergamon: New York)

Sturrock PE (1968) Is a weak acid monoprotic? A new look at titration curves. Journal of Chemical Education 45, 258–258.
| CrossRef | CAS |

Tadanier CJ, Schreiber ME, Roller JW (2005) Arsenic mobilization through microbially mediated deflocculation of ferrihydrite. Environmental Science & Technology 39, 3061–3068.
| CrossRef | CAS |

Thanabalasingam P, Pickering WF (1986) Arsenic sorption by humic acids. Environmental Pollution (Series B) 12, 233–246.
| CAS |

Wander MM (2004) Soil organic matter fractions and their relevance to soil function. In ‘Soil organic matter in sustainable agriculture’. (Eds F Magdoff, R Weil) pp. 67–102. (CRC Press: Boca Raton, FL)

Weng L, Van Riemsdijk WH, Hiemstra T (2009) Effects of fulvic and humic acids on arsenate adsorption to Goethite: rxperiments and modelling. Environmental Science & Technology 43, 7198–7204.
| CrossRef | CAS |

Yee MM, Miyajima T, Takisawa N (2009) Study of ionic surfactants binding to humic acid and fulvic acid by potentiometric titration and dynamic light scattering. Colloids and Surfaces A: Physicochemical and Engineering Aspects 347, 128–132.
| CrossRef | CAS |

Young SW, Bache BW, Linehan DJ (1982) The potentiometric measurement of stability constants of soil polycarboxylate-Cu²⁺ chelates. Soil Science 33, 467–475.
| CrossRef | CAS |