1992-06-01_REVISION - M1988112 (2)

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-Degusse Corporation `2- Introduction Depuesa has gained considerable experience over the last 1S yarn in the treatment of wastewater coutal.aiap cyanide uaiag peroxygen compounds, especially hydrogsa peroxide. A large number of customers use Deyursa's procesass in the detoxification of waatewnter ariainq from a variety o£ Sadustriea, includiAg gold mining companies. la several countries. This report coataiAa the results of testwork pesforlned on a pond eolutioA sample received in Allendale oa May 7, 1992. Before describiaq the work performed on this sample, a brief summary of the chemistry sill be given to provide a hackgsound for discussing the experimental results in detail. Aetoxilication with H.O, The male advantage of H.O. lA the treatment of wastdsvater is that it ie a "clear" chemical, Sn the seaee that no subrtaucas are intrerduoed with the oxidieiag agont hat might impair the quality of the water. Tha reaction betty ea Cx- and H,O. takes place lA a slAgle atop, without the rmation of toxic iatermediatos. The product ox the rsaCtioni is cynnete, xhich aubeequ•At1Y hydrolyses alowiy to yivk emrponium sad carbonate ions. pxidation of CN-: CN` + H=O= ---> OCIP- t HBO Hydrolysis of OClY': OCN- + 2H+ + H,O ---> C0~ + NH~y', or depending oA the pH. Although ammonia (iaH,) le toxic to fish at conceatrstflona above nbout 1 ppm, iL• is almosC eAtissl present in t~ha !ar i•ss toxic catiionic (amm+oAium) tosm at ~he natural p1# oi' open waterways. Zf excess H.O, la present Sa treated wast~awatarr it rapidly a•camposea to water and oxygen, anQ there re, prsaents no •nviroArpa¢itnl threat: 2H~0~ ---> 2 H,O + O, In addition, H,O, does not contribute to the anlt coataat of water, uni.ike moat other cyanide treatment chemicals. ItyflrogOL: peroxide can ba shipped safely at high concentrations (up to lot by weight H,O,) and stored ~or lor.6 periods without appreciable lass of activity, c~hich m kes ri,o, as Sdeal choice !or remote locations and for emn gency