The present invention relates to methods for biological wastewater treatment for Se control in Se-laden wastewater. The Se contaminants in the wastewater include the Se oxyanions selenate (SeO.sub.4.sup.2-) and selenite (HSeO.sub.3.sup.?), which are biochemically reduced and transformed to elemental selenium (Se.sup.0) by microorganisms through anaerobic biological reduction. The resulting Se.sup.0 is entrained in the biomass, which is further processed to enable the efficient recovery of concentrated Se.sup.0.

A product, including digestate, that has been pasteurized through thermal hydrolysis, thermal alkaline hydrolysis, or thermal carbonization is cured to enhance its marketability. Variations of this disclosure include embodiments where pasteurized material is inoculated to further enhance marketability where the inoculation is performed by injecting a fungicide, other means of inoculation by injecting beneficial microorganisms to produce characteristics in digestate that are anti-fungal or produce suitable enzyme cofactors or nutrients to stabilize digestate, injections of vitamins to enhance the ability of plants grown using select digestate to thrive in adverse conditions, injection of chemicals to enhance the ability of digestate to retain heat and prevent freezing during wintry conditions, or any combination thereof. Other embodiments include using recycled waste heat generated from wastewater treatment or another process or solar energy for accelerating the drying process which occurs before, during or after curing.

A method and apparatus for organic waste treatment are disclosed. The method comprises the steps of adding a sorbent to a waste product to form a fluid matrix which may then be subjected to a compressive force to dewater the matrix. Thermal desorption and pasteurisation of the matrix may then be carried out. The sorbent added is draff, which may be obtained as a by-product from various industries, including the distillation of spirits. The apparatus comprises generally a dewatering compressor, but may also include a thermal desorption unit, which may thermally dewater the matrix and pasteurise it.

A method and apparatus for organic waste treatment are disclosed. The method comprises the steps of adding a sorbent to a waste product to form a fluid matrix which may then be subjected to a compressive force to dewater the matrix. Thermal desorption and pasteurisation of the matrix may then be carried out. The sorbent added is draff, which may be obtained as a by-product from various industries, including the distillation of spirits. The apparatus comprises generally a dewatering compressor, but may also include a thermal desorption unit, which may thermally dewater the matrix and pasteurise it.

Wastewater sludge is treated by combining the sludge with a carbon-based dielectric additive that includes carbon to yield a modified sludge, irradiating the modified sludge with microwave radiation to yield a treated sludge, and providing the treated sludge to an anaerobic digester.

An apparatus for separating out and removing screenings from wastewater includes a screening device having a screen surface through which the wastewater flows during operation of the screening device and screenings carried along in the wastewater are at least intermittently retained. The apparatus includes a sensor and a controller. The sensor monitors the screenings in the area upstream from the screen surface and/or in the area of the screen surface. The controller outputs a message when the screenings have one or several properties which have been defined and have been recognized by the sensor. In addition, a method for operating the apparatus and a system including the apparatus are provided.

An apparatus for separating out and removing screenings from wastewater includes a screening device having a screen surface through which the wastewater flows during operation of the screening device and screenings carried along in the wastewater are at least intermittently retained. The apparatus includes a sensor and a controller. The sensor monitors the screenings in the area upstream from the screen surface and/or in the area of the screen surface. The controller outputs a message when the screenings have one or several properties which have been defined and have been recognized by the sensor. In addition, a method for operating the apparatus and a system including the apparatus are provided.

A system (1) for drying sludge (2) comprises a drying surface (4) to accommodate the sludge (2) as well as a moveable sludge turner (3) as well as two travel paths (5.1, 5.2) that extend at least partially on opposite longitudinal sides (L) of the drying surface (4) and are separated from the drying surface (4) by a barrier (18). The sludge turner (3) comprises at least a first and a second wheel (14.1, 14.2) mounted on opposite sides of a common gantry (7) of the sludge turner (3). While the sludge turner (3) is in operation, the first wheel (14.1) rolls on the first travel path (5.1) and the second wheel (14.2) on the travel path (5.1) as the respective travel plane. In the region of the first travel path (5.1), the barrier (18) comprises a first guide (16.1) and a second guide (16.1) in the region of the second travel path (5.2) extending in the direction of travel (F) of the sludge turner (3), wherein the sludge turner (3)while the latter is travelingis guided transversely to the direction of travel (F) with the aid of the guides (16.1, 16.2), and wherein the guides (16.1, 16.2) extend upwards from the drying surface (4) and act as a barrier for the sludge (2) spread on the drying surface (4) to keep sludge (2) away from the travel paths (5.1, 5.2).

A system (1) for drying sludge (2) comprises a drying surface (4) to accommodate the sludge (2) as well as a moveable sludge turner (3) as well as two travel paths (5.1, 5.2) that extend at least partially on opposite longitudinal sides (L) of the drying surface (4) and are separated from the drying surface (4) by a barrier (18). The sludge turner (3) comprises at least a first and a second wheel (14.1, 14.2) mounted on opposite sides of a common gantry (7) of the sludge turner (3). While the sludge turner (3) is in operation, the first wheel (14.1) rolls on the first travel path (5.1) and the second wheel (14.2) on the travel path (5.1) as the respective travel plane. In the region of the first travel path (5.1), the barrier (18) comprises a first guide (16.1) and a second guide (16.1) in the region of the second travel path (5.2) extending in the direction of travel (F) of the sludge turner (3), wherein the sludge turner (3)while the latter is travelingis guided transversely to the direction of travel (F) with the aid of the guides (16.1, 16.2), and wherein the guides (16.1, 16.2) extend upwards from the drying surface (4) and act as a barrier for the sludge (2) spread on the drying surface (4) to keep sludge (2) away from the travel paths (5.1, 5.2).

The present invention provides a method and apparatus for dewatering a biological solid material employing both microwave irradiation and solvent extraction. The method comprises microwave irradiation pretreatment, solvent extraction dewatering, solid-liquid separation, and solvent recovery. Through microwave irradiation of an aqueous biological solid material, gaps in the solid material are increased, and the biological material is fractured, thus releasing more bound water in the solid material. Subsequently, the microwave-irradiated biological solid material is brought into full contact with an organic solvent, allowing the solvent to absorb and extract moisture from the solid, thus removing moisture from the solid. The aqueous solvent is then subjected to evaporation under reduced pressure or gasification under reduced pressure in a separation apparatus so as to separate the moisture and the solvent. The solvent is then compressed, condensed and recovered for recycling. Also provided is a device for implementing the dewatering method.