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US 2003/0196965 A1Published application
Process for recovery of nutrients from wastewater
AssigneeNone recorded
InventorKenneth Haggerty
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AssigneeNone recorded
InventorKenneth Haggerty
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The present invention relates to a process for treating a wastewater comprising an ammonium ion species and a phosphorus ion species. The process comprises the steps of: (i) treating the effluent in a first stage of the process to convert the phosphorus to a phosphorus-containing salt; (ii) treating the wastewater in a second stage of the process to convert the ammonium ion species to gaseous ammonia; (iii) removing the struvite and/or other phosphorous containing salts from the effluent; and (iv) removing the gaseous ammonia from the wastewater.
A process for treating a wastewater effluent comprising an ammonium ion species and a phosphorus species, the process comprising the steps of:
The process defined in any one of the preceding claims, wherein Step (i) comprises the steps of:
The process defined in any one of the preceding claims, wherein Step (iii) comprises allowing the phosphorus-containing salt to settle and thereafter decanting substantially phosphorous-free liquid.
The process defined in any previous claim, wherein Step (ii) comprises regulating the pH of the effluent to be greater than about 10.
8 The process defined in any previous claim, wherein Step (ii) comprises regulating the pH of the effluent to be in the range of from about 11 to about 13
The process defined in any previous claim, wherein Step (iv) comprises stripping the gaseous ammonia from the wastewater
The process defined in any previous claim, further comprising the step of recovering the ammonia.
The process defined in any previous claim, wherein the wastewater comprises urine.
The process defined in any previous claim, wherein the phosphorus-containing salt comprises struvite.
The process defined in any previous claim, wherein Step (iii) is conducted before Step (iv).
The process defined in any previous claim, wherein Step (iv) is conducted before Step (iii).
A process for pre-treatment of a fluid comprising urine, the process comprising the steps of:
Dependencies are inferred from the claim text.
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By removing specified dissolved compounds: by removing ammoniacal nitrogen
Using inorganic agents: using magnesium compounds and phosphoric acid for removing ammonia
Fertilisers based essentially on alkali or ammonium orthophosphates
Fertilisers from human or animal excrements
Term end not estimated
1. Field of the Invention
The present invention relates to a process for recovery of nutrients from a wastewater. As used through out this specification, the term “wastewater” is intended to any wastewater contain ammonia (also referred to in this specification as “ammonium species”) and phosphorus. Non-limiting examples of wastewaters which may be treated using the present process include water borne waste flow of human domestic, industrial, commercial or agricultural origin.
2. Description of the Prior Art
Embodiments of the present invention will be described with reference to the accompanying drawings, wherein like reference numerals denote like parts, and in which:
FIGS. 1-8 illustrate various graphs depicting various results from experimental work done in relation to a preferred embodiment of the present process.
In accordance with a preferred embodiment of the present process, the economical separation, collection, and removal of ammonia and phosphorous from a wastewater is facilitated by diverting the portion of the wastewater containing the majority of these species and treating it to effect removal of ammonia and phosphorus prior to dilution by mixing with other wastewater, if any, for final treatment.
Preferably, in process for treating a wastewater comprising an ammonium ion species and a phosphorus species, it is highly preferred that Steps (i) and (ii) are conducted substantially sequentially.
The phosphorus removal process relates to the fact that ammonia, magnesium and phosphate ions combine in the molar ratio of 1:1:1 to form a relatively insoluble salt called struvite (NH4MgPO4.6H2O) at a pH of about 8.4 or higher. The theoretical optimum pH being in the range between 10.0 and 10.7. In instances where magnesium concentration in the wastewater effluent is a limiting factor, a source of magnesium (e.g., MgCl2, MgO and the like, most preferably MgCl2) is added and mixed with the wastewater, the pH is raised to approximately 8.5 or greater and the resultant struvite crystals settle from the solution. The N and P in struvite is available to plants to meet their nutrient requirements. As the pH is increase the P may also combine with other species present in the wastewater (e.g. Ca++, or Fe++) to form insoluble salts