A METHOD FOR BIOLOGICAL ANAEROBIC TREATMENT OF WATER, AND A POND

摘要

The invention relates to a method for biological anaerobic treatment of wastewater using an Up-flow Anaerobic Sludge Blanket (UASB) process. According to the present invention, the method involves the use of a pond comprising a flexible polymer-based gas-impermeable cover, and a baffle below the flexible polymer-based gas-impermeable cover suitable for deflecting methane-comprising gas-bubbles rising in the body of water, the baffle being inclined at an angle to the horizontal of 40°-70°, the baffle defining a settling zone above the baffle and an uplift-zone below the baffle, the baffle allowing for the passage of water above the baffle from the uplift-zone to the settling zone and the passage of settled material from the settling zone into the body of water below the baffle, wherein the wastewater is subjected to micro-organisms in the pond causing methane comprising gas bubbles to form and to rise to the surface of the pond below the cover; water entrained by rising methane-comprising gas bubbles and the gas bubbles are deflected in the uplift-zone by the baffle resulting in a stream of water passing from the deflecting zone to the settling zone; gas from gas-bubbles breaking through the surface of the body of water below the cover is collected and removed to yield methane- comprising gas; and micro-organisms comprising particles in the water in the settling zone above the baffle are allowed to settle and pass from the settling zone into the body of water below the baffle.