Apparatus for biological treatment of water and method for biological treatment of water using said apparatus

A method for biological treatment of water in which water containing organic matter is biologically treated to decompose and remove the organic matter, which method uses an apparatus for biological treatment of water comprising

• (a) a treatment vessel for effecting the biological treatment of water to be treated,
• (b) a first water pipe connected with the bottom of said treatment vessel,
• (c) an aeration means provided at the bottom side of said treatment vessel,
• (d) a second water pipe connected with the top of said treatment vessel, and
• (e) a shaped material comprising a felt activated carbon fiber cloth having adjacent surfaces with a cloth-to-cloth distance therebetween, accommodated in said treatment vessel as a packing medium, said felt activated carbon fiber cloth having a specific surface area, which is the ratio of surface area (cm.sup.2) of felt activated carbon fiber cloth to effective volume (cm.sup.3) of said treatment vessel, of 0.5-50 cm.sup.2 /cm.sup.3, and said felt activated carbon fiber cloth being arranged so that the cloth surface is vertical and the cloth-to-cloth distance is 0.5-2.0 cm,
• and which method comprises introducing water to be treated, containing total organic carbon in an amount of 5 mg C/l or less, into the treatment vessel through either one of the first and second water pipes, passing the water along the surface of felt activated carbon fiber cloth, subjecting the organic matter in the water to biological decomposition and removal under aerobic conditions by microorganisms living on the felt activated carbon fiber cloth while subjecting the water to aeration or no aeration, and discharging the treated water outside the treatment vessel through the other water pipe.

An apparatus incorporated into a pure water production system and used for biological treatment of waste water arising from the use of pure water supplied from the pure water production system, in which said waste water containing total organic carbon in an amount of 5 mg C/l or less is biologically treated to decompose and remove total organic carbon for reuse as pure water, which apparatus comprises

• (a) a treatment vessel for effecting the biological treatment of the water to be treated,
• (b) a first water pipe connected to the bottom of said treatment vessel,
• (c) an aeration means provided at the bottom side of said treatment vessel,
• (d) a second water pipe connected to the top of said treatment vessel, and
• (e) a formed material comprising an activated carbon fiber felt cloth having adjacent surfaces with a cloth-to-cloth distance therebetween, accommodated in said treatment vessel as a packing medium, said activated carbon fiber felt cloth having a specific surface area, which is the ratio of surface area (cm.sup.2) of activated carbon fiber felt cloth to effective volume (cm.sup.3) of said treatment vessel, of 0.5-50 cm.sup.2 /cm.sup.3, and said activated carbon fiber felt cloth being arranged so that the cloth surface is vertical and the cloth-to-cloth distance is 0.5-2.0 cm,
• (f) a membrane separator connected to either one of the first and second water pipes,
• said apparatus conducting an operation comprising introducing said waste water to be treated containing organic matter into the treatment vessel through either one of the first and second water pipes, passing the water along the surface of the activated carbon fiber felt cloth, subject the organic matter in the water to biological decomposition and removal under aerobic conditions by microorganisms attached to the activated carbon fiber felt cloth while subjecting the water to aeration or no aeration, introducing the treated water to the membrane separator through the other water pipe to eliminate microorganisms, and returning the filtered water to the feed water of the pure water production system.

A method for biological treatment of waste water arising from the use of pure water supplied from the pure water production system, in which said waste water containing total organic carbon in an amount of 5 mg C/l or less is biologically treated to decompose and remove organic compounds, which method uses an apparatus incorporated into a pure water production system and used for biological treatment of said waste water comprising

• (a) a treatment vessel for effecting the biological treatment of water to be treated,
• (b) a first water pipe connected with the bottom of said treatment vessel,
• (c) an aeration means provided at the bottom side of said treatment vessel,
• (d) a second water pipe connected to the top of said treatment vessel, and
• (e) a formed material comprising an activated carbon fiber felt cloth having adjacent surfaces with a cloth-to-cloth distance therebetween, accommodated in said treatment vessel as a packing medium, said activated carbon fiber felt cloth having a specific surface area, which is the ratio of surface area (cm.sup.2) of activated carbon fiber felt cloth to effective volume (cm.sup.3) of said treatment vessel, of 0.5-50 cm.sup.2 /cm.sup.3, and said activated carbon fiber felt cloth being arranged so that the cloth surface is vertical and the cloth-to-cloth distance is 0.5-2.0 cm,
• (f) a membrane separator connected to either one of the first and second water pipes,
• said apparatus can conducting an operation comprising introducing said waste water to be treated, containing organic compounds into the treatment vessel through either one of the first and second water pipes, passing the water along the surface of the activated carbon fiber felt cloth, subjecting the organic matter in the water to biological decomposition and removal under aerobic conditions by microorganisms attached to the activated carbon fiber felt cloth while subjecting the water to aeration or no aeration, introducing the treated water to the membrane separator through the other water pipe to eliminate microorganisms, and returning the filtered water to the feed and after of the pure water production system.