This specification describes systems and methods for treating wastewater, for example digestate. The wastewater is separated into a liquid fraction and a solid fraction. The solid fraction of the wastewater is composted. The liquid fraction of the wastewater can be treated, which may result in further by-products. Optionally, at least some of the liquid fraction may be reused in the process. The by-products produced in treating the liquid fraction and/or additional organic solid waste, for example green waste, brought into the treatment facility can be added to the compost. The compost breaks down through aerobic and/or anaerobic digestion processes. Thermophilic conditions may develop in composting piles and increase the rate of evaporation of excess water. When sufficiently dry, the compost may be used as a fertilizer or soil enhancement product.

This specification describes systems and methods for treating wastewater, for example digestate. The wastewater is separated into a liquid fraction and a solid fraction. The solid fraction of the wastewater is composted. The liquid fraction of the wastewater can be treated, which may result in further by-products. Optionally, at least some of the liquid fraction may be reused in the process. The by-products produced in treating the liquid fraction and/or additional organic solid waste, for example green waste, brought into the treatment facility can be added to the compost. The compost breaks down through aerobic and/or anaerobic digestion processes. Thermophilic conditions may develop in composting piles and increase the rate of evaporation of excess water. When sufficiently dry, the compost may be used as a fertilizer or soil enhancement product.

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.

Embodiments relate to a continuous process for treating tailings that includes providing tailings for treatment having at least 10 wt % solids, providing a mixing apparatus having a first inlet for feeding the tailings, a second inlet for feeding a non-dispersion liquid flocculant that includes a polyethylene glycol having a weight average molecular weight from 100 g/mol to 2,000 g/mol, and an outlet for a mixture of the tailings and the non-dispersion liquid flocculant, continuously introducing into the mixing apparatus the tailings through the first inlet and the non-dispersion liquid flocculant through the second inlet, and allowing the tailings and the non-dispersion liquid flocculant to mix to from the mixture of the tailings and the non-dispersion liquid flocculant.

The invention is a system and method for transforming food waste into a commercial cleaning product. The system is containable in an enclosed facility and installable in urban environments. Food waste is sorted and ground into uniformly sized particles, heated to an acceleration temperature, inoculated with an inoculant including lactic acid bacteria, which is mixed into the ground waste. The waste then undergoes sedentary fermentation for times as short as 24 hours or less. The fermented waste is separated into liquids and solids, and liquids are further separated into at least one distillation stream. Solids are dried to obtain a second distillation stream.

The invention relates to a method for recovering phosphorus from sludge in sewage plants, wherein: the sludge is pre-acidified under anaerobic process conditions and the pH value is then increased to a pH value <7 by adding at least one alkaline calcium-containing chemical; brushite crystals are formed by calcium ions of the chemical and are precipitated, and deposited brushite crystals are removed; and the phosphorus-reduced sludge is then supplied to a digestion process.

The invention relates to a method for recovering phosphorus from sludge in sewage plants, wherein: the sludge is pre-acidified under anaerobic process conditions and the pH value is then increased to a pH value <7 by adding at least one alkaline calcium-containing chemical; brushite crystals are formed by calcium ions of the chemical and are precipitated, and deposited brushite crystals are removed; and the phosphorus-reduced sludge is then supplied to a digestion process.

A water treatment system includes a coagulating and flocculating system, an ultrafiltration membrane, and a fluid driver. The coagulating and flocculating system includes a first inlet for receiving water and a second inlet configured to receive a coagulating and flocculating agent. The coagulating and flocculating system is configured to precipitate dissolved phosphorous from the water, and to provide a flocculated effluent at an outlet of the coagulating and flocculating system. The ultrafiltration membrane includes an inlet that is fluidly coupled to an outlet of the coagulating and flocculating system. The ultrafiltration membrane is configured to separate the precipitated phosphorus from the flocculated effluent. The fluid driver is adapted to transfer the flocculated effluent from the outlet of the coagulating and flocculating system to the inlet of the ultrafiltration membrane at sustained flux rates of at least 150 LMH.

Apparatus and associated methods relate to drying a wet coated seed material stream comprising an incoming wet granular biosolids stream mixed with a controlled size dried seed material recycling stream to produce a moist air and pellet stream, separating an uncontrolled size dried pellet stream from the moist air and pellet stream, diverting a recycle portion of the uncontrolled size dried pellet stream to be recycled, diverting the remainder of the uncontrolled size dried pellet stream to an outlet, resizing oversized pellets from the recycle portion of the uncontrolled size dried pellet stream to produce the controlled size dried seed material recycling stream, and mixing the controlled size dried seed material recycling stream with the incoming wet granular biosolids stream to produce the wet coated seed material stream. Oversized pellets may be selected using a screen. The oversized pellets may be resized using a crusher inline with the recycle stream.