A method of separating sludge which involves adding an insoluble mineral colloidal suspension into an industrial sludge to destabilize the industrial sludge and separating destabilized components of the industrial sludge. The insoluble mineral colloidal suspension includes magnesium hydroxide. In an alternative embodiment dry finely divided magnesium hydroxide can be added and then dispersed into an industrial sludge. Conventional flocculants and/or coagulants can also be added. Conventional physical separation processes can be used to separate the destabilized industrial sludge.

A method of separating sludge which involves adding an insoluble mineral colloidal suspension into an industrial sludge to destabilize the industrial sludge and separating destabilized components of the industrial sludge. The insoluble mineral colloidal suspension includes magnesium hydroxide. In an alternative embodiment dry finely divided magnesium hydroxide can be added and then dispersed into an industrial sludge. Conventional flocculants and/or coagulants can also be added. Conventional physical separation processes can be used to separate the destabilized industrial sludge.

The invention relates to a process for treating wastewater or sludge, in which a wastewater or sludge stream (2) is conveyed through a first mixing unit (15), wherein a base/alkaline solution (17) or a phosphate-fixing compound/liquid containing a phosphate-fixing compound (17) is metered or mixed into the first mixing unit (15).

The invention further relates to a device (100) for treating a wastewater or sludge stream (2), especially for carrying out the aforementioned process.

The invention relates to a process for treating wastewater or sludge, in which a wastewater or sludge stream (2) is conveyed through a first mixing unit (15), wherein a base/alkaline solution (17) or a phosphate-fixing compound/liquid containing a phosphate-fixing compound (17) is metered or mixed into the first mixing unit (15).

The invention further relates to a device (100) for treating a wastewater or sludge stream (2), especially for carrying out the aforementioned process.

Methods and systems for reducing greenhouse gas emissions from sediments containing organic materials via treatment with lime are disclosed herein. In some embodiments, the method comprises (i) providing sediments comprising a first pH less than 10.0, fermentable organic materials, and microbes configured to produce carbon dioxide and/or methane via degradation of the organic material; (ii) adding a coagulant comprising lime to the sediment to produce a mixture comprising a second pH of at least 11.0 and excess soluble calcium ions; and (iii) after adding the coagulant, forming a buffer comprising soluble sodium and calcium bicarbonates within the mixture by enabling the excess soluble sodium and calcium ions to react with carbon dioxide. Forming the buffer can comprise decreasing the pH of the mixture from the second pH to a third pH of 8.0 or greater.

Methods and systems for reducing greenhouse gas emissions from sediments containing organic materials via treatment with lime are disclosed herein. In some embodiments, the method comprises (i) providing sediments comprising a first pH less than 10.0, fermentable organic materials, and microbes configured to produce carbon dioxide and/or methane via degradation of the organic material; (ii) adding a coagulant comprising lime to the sediment to produce a mixture comprising a second pH of at least 11.0 and excess soluble calcium ions; and (iii) after adding the coagulant, forming a buffer comprising soluble sodium and calcium bicarbonates within the mixture by enabling the excess soluble sodium and calcium ions to react with carbon dioxide. Forming the buffer can comprise decreasing the pH of the mixture from the second pH to a third pH of 8.0 or greater.

Methods and systems for treating tailings at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises (i) providing a tailings stream comprising bicarbonates and a pH less than 9.0, (ii) adding a coagulant comprising calcium hydroxide to the tailings stream to form a mixture having a pH of at least 11.5 and a soluble calcium level no more than 800 mg/L, and (iii) dewatering the mixture to produce a product having a solids content of at least 40% by weight. In some embodiments, the pH and soluble calcium level of the mixture cause chemical modification of clay materials of the mixture via pozzolanic reactions. In some embodiments, the undrained shear strength of the product increases over a period of time of at least two days.

Methods and systems for treating tailings at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises (i) providing a tailings stream comprising bicarbonates and a pH less than 9.0, (ii) adding a coagulant comprising calcium hydroxide to the tailings stream to form a mixture having a pH of at least 11.5 and a soluble calcium level no more than 800 mg/L, and (iii) dewatering the mixture to produce a product having a solids content of at least 40% by weight. In some embodiments, the pH and soluble calcium level of the mixture cause chemical modification of clay materials of the mixture via pozzolanic reactions. In some embodiments, the undrained shear strength of the product increases over a period of time of at least two days.

Methods and systems for reducing greenhouse gas emissions from sediments containing organic materials via treatment with lime are disclosed herein. In some embodiments, the method comprises (i) providing sediments comprising a first pH less than 10.0, fermentable organic materials, and microbes configured to produce carbon dioxide and/or methane via degradation of the organic material; (ii) adding a coagulant comprising lime to the sediment to produce a mixture comprising a second pH of at least 11.0 and excess soluble calcium ions; and (iii) after adding the coagulant, forming a buffer comprising soluble sodium and calcium bicarbonates within the mixture by enabling the excess soluble sodium and calcium ions to react with carbon dioxide. Forming the buffer can comprise decreasing the pH of the mixture from the second pH to a third pH of 8.0 or greater.

Methods and systems for reducing greenhouse gas emissions from sediments containing organic materials via treatment with lime are disclosed herein. In some embodiments, the method comprises (i) providing sediments comprising a first pH less than 10.0, fermentable organic materials, and microbes configured to produce carbon dioxide and/or methane via degradation of the organic material; (ii) adding a coagulant comprising lime to the sediment to produce a mixture comprising a second pH of at least 11.0 and excess soluble calcium ions; and (iii) after adding the coagulant, forming a buffer comprising soluble sodium and calcium bicarbonates within the mixture by enabling the excess soluble sodium and calcium ions to react with carbon dioxide. Forming the buffer can comprise decreasing the pH of the mixture from the second pH to a third pH of 8.0 or greater.