Treatment of sewage sludges
AssigneeRhodia UK Limited
InventorsStephanie Edmunds, Paul Douglas Gilbert, Robert Eric Talbot
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Abstract
The present invention provides a method of reducing the pathogen content of sewage sludge comprising (a) adding to the sludge an effective amount of a phosphorous-containing compound and (b) keeping the phosphorous-containing compound in contact with the sludge for a sufficient time to reduce the amount of pathogens present in the sludge by an amount equivalent to a logarithmic reduction of 2 or more.
Claims39
A method of treating sewage sludge to reduce the pathogen content of said sludge, the method comprising the steps of:
- (a) adding to the sludge an effective amount of a tetrakis(hydroxyorgano)phosphonium salt or compound of formula (I)
- [R′R″(CH2OH)2P+]nXn− (I)
- wherein:
- n is the valency of X;
- R′ and R″, which may be the same or different, are each an alkyl, hydroxyalkyl, alkenyl or aryl moiety and X is an anion;
- and
- (b) keeping the tetrakis(hydroxyorgano)phosphonium salt or compound in contact with the sludge for sufficient time to give rise to a finally treated sludge wherein the total reduction in the amount of pathogens present is by an amount equivalent to a logarithmic reduction of 2 or more compared to the amount of pathogens present in untreated sludge.
A method of treating sewage sludge to reduce the pathogen content of said sludge, the method comprising the steps of:
- (a) adding to the sludge an effective amount of an alkyl-substituted phosphine as shown in formula (II):
- (CH2OHR2)P (II)
- wherein:
- each R, which may be the same or different, is selected from a alkyl, hydroxyalkyl, alkenyl or aryl moiety;
- and
- (b) keeping the alkyl-substituted phosphine in contact with the sludge for sufficient time to give rise to a finally treated sludge wherein the total reduction in the amount of pathogens present is by an amount equivalent to a logarithmic reduction of 2 or more compared to the amount of pathogens present in untreated sludge.
Dependencies are inferred from the claim text.