WATER TREATMENT METHOD AND SYSTEM

• Main Authors: GOTO YUUKAI, KONDO KAZUSHI
• Format: Patent
• Language: English; Japanese
• Published: 22.06.2015
• Subjects: CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PROBLEM TO BE SOLVED: To prevent breeding of microbes inside an active carbon, and to stably and surely remove a residual chlorine from a treatment water.SOLUTION: In a water treatment method, the concentration of residual chlorine in the water treated by an active carbon is set to a value of more than 0 mg/L and equal to or less than 1.0 mg/L so as to hold the inside of an active carbon tower 18 under the environment making it possible to execute a dechlorination and sterilization of the active carbon by the residual chlorine while making compatible, and then a primary dechlorination treatment is performed. Accordingly, although the residual chlorine exists in the active carbon treatment water after the primary dechlorination (the water flowing in a piping 22 connecting the active carbon tower 18 to an ultraviolet exposure device 24), it becomes possible to reduce or remove the residual chlorine to the level satisfying a standard by carrying out a secondary dechlorination process of the active carbon treatment water (flow after the ultraviolet exposure device 24). Besides, the residual chlorine concentration in the active carbon treatment water can be controlled by controlling the injection amount of an oxidant by an oxidant injection pump 20 in the upstream of the tower 18, the water flow condition in the tower 18 by a raw water supply pump 14 and the like. 【課題】活性炭内部での微生物の繁殖を防止し、処理水からの残留塩素の除去を安定して確実に行う。【解決手段】活性炭塔１８内を、脱塩素処理と残留塩素による活性炭の除菌とを両立して実施可能な環境に保持するように、活性炭処理水中の残留塩素の濃度を、０を超え１．０ｍｇ／Ｌ以下の値に設定し、一次脱塩素処理を行う。従って、一次脱塩素処理後の活性炭処理水（活性炭塔１８と紫外線露光装置２４とを接続する配管２２を流れる水）の中には、残留塩素が存在するが、活性炭処理水を二次脱塩素工程（紫外線露光装置２４以降のフロー）に付することで、基準を満たす状態にまで残留塩素の低減又は除去を行うことが可能となる。又、活性炭処理水中の残留塩素濃度の調整は、活性炭塔１８の上流における、酸化剤注入ポンプ２０による酸化剤の注入量や、原水供給ポンプ１４による、活性炭塔１８における通水条件等を調整することにより行うことが可能である。【選択図】図１