초록 ▼

A secondary sewage treatment system is provided with a treatment vessel disposed within a septic tank. The treatment vessel has a draft tube for aerating and circulating waste liquor through the treatment vessel and through media contained within the treatment vessel. The media has one part that is

A secondary sewage treatment system is provided with a treatment vessel disposed within a septic tank. The treatment vessel has a draft tube for aerating and circulating waste liquor through the treatment vessel and through media contained within the treatment vessel. The media has one part that is submerged media and another part that is an unsubmerged trickle media. The operation of the draft tube circulated waste liquor within the treatment vessel through the submerged media and up through the draft tube where it is expelled and trickles down through the trickle media back into the liquor in the lower portion of the treatment vessel.

대표청구항 ▼

A sewage treatment system which comprises a tank having an influent inlet to the interior of the tank located in the upper region of said tank; treatment vessel means disposed within said tank having an upper end portion extending above the tank inlet and a lower end portion disposed within the tank

A sewage treatment system which comprises a tank having an influent inlet to the interior of the tank located in the upper region of said tank; treatment vessel means disposed within said tank having an upper end portion extending above the tank inlet and a lower end portion disposed within the tank interior below said tank inlet; a first microbial growth-supporting media contained within said treatment vessel lower end portion; and a second microbial growth-supporting media contained within said treatment vessel upper end portion, the second media being located above the first media; said treatment vessel means and said first and second media being constructed and arranged so that, when said tank is filled to operating levels with liquid effluent, said first media is substantially submerged and said second media is unsubmerged; liquid aerating means comprising a draft tube disposed within said treatment vessel and air supply apparatus; said draft tube extending through said second media and into said first media and having an upper end adjacent the treatment vessel upper end above said tank inlet and above said second media and a lower end below said tank inlet, said draft tube having a liquid effluent inlet located within said first media in liquid communication with the interior of said treatment vessel below said tank inlet; said air supply apparatus being connected to said treatment vessel to supply air to said draft tube; said aerating means supplying air into said draft tube so that liquid within said draft tube will be both aerated and conducted upward through said draft tube and expelled from said draft tube into the treatment vessel upper end portion so that at least a first portion of liquid expelled from said draft tube will trickle through said second media and so that the first portion of liquid that trickled through said second media will flow through said first media, and so that liquid within said treatment vessel will be circulated through said first media and mixed with the first portion of liquid and then conducted through the draft tube liquid inlet into said draft tube; and effluent outlet means in said treatment vessel upper end portion for collecting a second portion of liquid expelled from said draft tube so that said second portion can be collected at an elevation above said tank inlet and discharged from said system.