Wastewater treatment with ultraviolet disinfection and increased capacity

A process for treating fresh sewage containing organic liquid and solid wastes, comprising:

• separating the solids from the liquids by filtration through a paper filter medium while the sewage is fresh, and producing a liquid component low in suspended solid material;
• directing the liquid component immediately through a filtrate outlet line just downstream of the filter medium;
• exposing the liquid component, flowing through the filtrate outlet line at generally the flow rate of the filtration, to ultraviolet radiation including germicidal wavelength, to destroy pathogens but not beneficial nutrients present in the liquid component;
• introducing ozone in the liquid component to react with pathogens to form stable compounds and to produce residual hydrogen peroxide for deterring subsequent pathogen growth;
• and
• dispersing the nutrient-rich treated liquid component to unsaturated ground.

A process for treating fresh sewage containing organic liquid and solid wastes, comprising:

• separating the solids from the liquids while the sewage is fresh, through an organic compostible filter medium, to produce a liquid component low in suspended solid material;
• exposing the liquid component to ultraviolet radiation including germicidal wavelength, to destroy pathogens but not beneficial nutrients present in the liquid component;
• introducing ozone in the liquid component to react with pathogens to form stable compounds and to produce residual hydrogen peroxide for deterring subsequent pathogen growth;
• dispersing the nutrient-rich treated liquid component to unsaturated ground;
• and
• composting the separated solids along with used filter medium.

A method of treating wastewater wherein wastewater is delivered to a holding tank above a filter medium, then is filtered through the filter medium with suction applied below the medium comprising:

• providing, below the filter medium, a filtrate reservoir connectable with the filtrate side of the medium;
• pumping stored filtrate out of the reservoir, thereby creating a suction in the reservoir;
• connecting the reservoir with the holding tank near its top, to transfer suction thereto and to draw a charge of wastewater into the holding tank;
• releasing the charge of wastewater from the holding tank to the filter medium;
• disconnecting the reservoir from the holding tank and connecting it through a suction filtrate line to an enclosure at the filtrate side of the filter medium, thereby to increase the filtration rate of the filtration cycle and refill the reservoir with filtrate;
• and
• exposing the liquid filtrate to ultraviolet radiation while it is in the filtrate suction line, just downstream of the filter medium, to destroy pathogens, whereby efficiency of the ultraviolet radiation is maximized by immediate irradiation, before significant pathogen growth, agglomeration and solids formation can occur and by irradiation at a location of low filtrate flow rate.

Apparatus for treating fresh sewage containing organic liquid and solid waste, comprising:

• filtering means for separating the solids from the liquids while the sewage is fresh, and for producing a liquid filtrate low in suspended solid material, including means providing for filtration of the sewage in successive cycles and means for applying suction to the filtrate side of the filter medium and for drawing a charge of air through the filter medium at the end of each filtering cycle, thereby introducing substantial entrained air to the filtrate liquid;
• means for removing the solids along with used filter medium;
• means just downstream of the filter medium for exposing the liquid filtrate to ultraviolet radiation, to destroy pathogens, said ultraviolet radiation including ozone-producing ultraviolet wavelength for converting much of the oxygen in the entrained air of the filtrate to ozone, which reacts with pathogens in the liquid to form stable compounds and leaves residual hydrogen peroxide in the liquid for deterring subsequent growth of organisms;
• and
• means for dispersing the nutrient-rich filtrate to unsaturaged ground.

A continuous wastewater filtration process including a method of delivering wastewater to a holding tank above the filter medium, which holding tank is connected to a source of wastewater below and of providing suction to the filtrate side of the filter medium, comprising:

• providing at a location below the height of the filter medium, a pair of filtrate reservoirs connectible with the filtrate side of the medium;
• pumping stored filtrate out of the first reservoir, thereby creating a suction in the first reservoir;
• connecting the first reservoir with the holding tank near its top to transfer suction thereto and to draw a charge of wastewater into the holding tank;
• releasing the charge of wastewater from the holding tank to the filter medium;
• disconnecting the first reservoir from the holding tank and connecting it to an enclosure at the filtrate side of the filter medium, thereby to increase the filtration rate of the filtration cycle and refill the first reservoir with filtrate;
• while filtration is proceeding with the first reservoir connected to the filtrate enclosure, before filtration of that charge of wastewater is completed, pumping stored filtrate out of the second reservoir, thereby creating a suction in the second reservoir;
• connecting the second reservoir with the holding tank near its top to transfer suction thereto and to draw a second charge of wastewater into the holding tank;
• releasing the second charge of wastewater from the holding tank to the filter medium;
• while filtration continues, disconnecting the second reservoir from the holding tank and connecting it to the enclosure at the filtrate side of the filter medium, while simultaneously disconnecting the first reservoir from the enclosure;
• and
• repeating the cycle, commencing with pumping stored filtrate out of the first reservoir while filtration is proceeding with the second reservoir connected to the filtrate enclosure.

Apparatus for continuous separation of solid wastes from liquid wastes in wastewater, comprising:

• filtering means for receiving fresh wastewater and separating it into solid wastes and liquid filtrate wastes, with an enclosure at the filtrate side of the filtering means;
• a wastewater inlet line from a source of fresh wastewater;
• a buffer tank positioned over the filtering means and at an elevated position above the inlet line, with a bottom outlet positioned over the filtering means;
• a riser pipe connecting the inlet line with an inlet near the top of the buffer reservoir;
• first and second power reservoirs positioned below the filtering means;
• and
• pump means for selectively pumping stored liquid out of the first power reservoir or out of the second power reservoir, thereby creating a suction in the respective reservoir;
• means for selectively connecting one of the power reservoirs with the buffer tank, near its top, to draw a charge of wastewater into the tank;
• means for releasing the charge of wastewater to the filtering means when the buffer tank is filled;
• means for selectively connecting one of the power reservoirs with the enclosure at the filtrate side of the filter medium;
• means for sensing a preselected intermediate level of wastewater on the filtering means, prior to the completion of filtration of a charge of wastewater;
• whereby suction caused by pumpdown of the first power reservoir may be first applied to the buffer tank to draw in a first charge of wastewater, which is then released to the filtering means, then the suction may be applied to the filtering means enclosure to increase the rate of filtration and to direct filtrate into the first power reservoir, then, when said preselected intermediate level of wastewater on the filtering means is sensed, stored liquid may be pumped from the second power reservoir to create suction therein, which may be applied to the buffer tank to draw in a second charge of wastewater, which is released to the filtering means, and while filtering proceeds, suction from the first reservoir may be disconnected while suction from the second reservoir is applied to the filtering means enclosure, and the cycle may be repeated, providing continuous filtration of the wastewater.