초록 ▼

A method and system for treating wastewater in an onboard ship sewage treatment system having controlled suspended solids, the method comprising the steps of collecting wastewater in a collection tank and transferring the wastewater to a bioreactor to oxidize organic material contained in the wastew

A method and system for treating wastewater in an onboard ship sewage treatment system having controlled suspended solids, the method comprising the steps of collecting wastewater in a collection tank and transferring the wastewater to a bioreactor to oxidize organic material contained in the wastewater by adding oxygen-containing gas thereto. The bioreactor is operated to provide a mixed liquor having a solids concentration of at least 5 g/l and the solids concentration is continuously increased in the mixed liquor in the bioreactor to not greater than 30 g/l. When the solids concentration in the mixed liquor reaches at least 15 g/l, a portion of the mixed liquor is removed from the bioreactor. Thereafter, wastewater is added to the bioreactor to decrease the solids concentration of remaining or residual mixed liquor to not less than 5 g/l. The bioreactor is further operated to increase the solids content again. A hollow fiber membrane is used to remove water from the mixed liquor to provide treated effluent.

대표청구항 ▼

1. A method for treating wastewater in an onboard ship treatment system having controlled suspended solids, the method comprising the steps of:(a) providing wastewater in a bioreactor to oxidize organic material contained in said wastewater by adding oxygen-containing gas thereto; (b) operating said

1. A method for treating wastewater in an onboard ship treatment system having controlled suspended solids, the method comprising the steps of:(a) providing wastewater in a bioreactor to oxidize organic material contained in said wastewater by adding oxygen-containing gas thereto; (b) operating said bioreactor to provide a mixed liquor having a solids concentration of at least 5 g/l; (c) continuously increasing said solids concentration in said mixed liquor in said bioreactor to not greater than 30 g/l; (d) when the solids concentration in said mixed liquor reaches at least 15 g/l, removing a portion of the mixed liquor from said bioreactor; (e) thereafter adding wastewater to said bioreactor to decrease said solids concentration of remaining mixed liquor to not less than 5 g/l; (f) then further operating said bioreactor to increase said solids content again; (g) providing a module having an array of hollow fiber membranes in a membrane container in liquid communication with said bioreactor; (h) sweeping said hollow fiber membranes with gas; (j) directing a flow of mixed liquor from said bioreactor to said container to cover said membranes to avoid substantial exposure of said hollow fibers membrane during motion of said ship; (k) returning concentrate and mixed liquor from said hollow fiber membrane container to said bioreactor; and (l) removing purified water from said mixed liquor through said hollow fiber membranes as permeate to provide treated effluent.