Abstract: Provided is a method for operating an RO-membrane treatment system that includes an energy recovery device that recovers energy from the concentrate of an RO-membrane device and the RO-membrane treatment system that reduce the occurrence of biofouling in not only the RO-membrane device but also the energy recovery device in order to increase the energy efficiency of the entire system and operate the RO-membrane treatment system with consistency. The method includes adding at least one slime-control agent selected from a combined-chlorine slime-control agent and a stabilized-bromine slime-control agent to water that is to be treated with the reverse-osmosis-membrane device such that a residual halogen concentration in the concentrate that is to be introduced into the energy recovery device is 0.1 to 10000 mg/L as total chlorine.

Abstract: Provided is a method for operating an RO-membrane treatment system that includes an energy recovery device that recovers energy from the concentrate of an RO-membrane device and the RO-membrane treatment system that reduce the occurrence of biofouling in not only the RO-membrane device but also the energy recovery device in order to increase the energy efficiency of the entire system and operate the RO-membrane treatment system with consistency. The method includes adding at least one slime-control agent selected from a combined-chlorine slime-control agent and a stabilized-bromine slime-control agent to water that is to be treated with the reverse-osmosis-membrane device such that a residual halogen concentration in the concentrate that is to be introduced into the energy recovery device is 0.1 to 10000 mg/L as total chlorine.

Abstract: Clogging of membrane by slime adhesion is efficiently prevented and stable treatment can be carried out for a long period of time at a low cost by a small amount of chemicals without membrane deterioration and trihalomethane formation, even if applied to the water having a large number of viable cell counts and a harsh water quality by supplying water to be treated to a membrane separation apparatus 4, adding intermittently to the water to be treated a combined chlorine agent containing sulfamic compound, and repeating a non-addition feeding period in which water to be treated is supplied for 6-120 hours without addition of the combined chlorine agent, and an intermittent addition feeding period in which water to be treated is supplied for 0.5-40 hours under the addition of a combined chlorine agent at a biofilm exfoliating concentration in an early stage of biofilm formation during the non-addition feeding period.

Abstract: Clogging of membrane by slime adhesion is efficiently prevented and stable treatment can be carried out for a long period of time at a low cost by a small amount of chemicals without the membrane deterioration and trihalomethane formation even if applied to the water having a large number of viable cell counts and having water quality of harsh. The method comprises supplying water to be treated to a membrane separation apparatus 4, adding intermittently to the water to be treated a combined chlorine agent comprising sulfamic compound, and repeating a non-addition feeding period in which water to be treated is supplied for 6-120 hours without addition of combined chlorine agent, and an intermittent addition feeding period in which water to be treated is supplied for 0.

Abstract: A semiconductor substrate having first and second opposing surfaces is provided with a plurality of semiconductor elements having their electrodes arranged on the first surface. A plurality of small recesses are first formed in the second surface at locations opposite selected ones of the electrodes of the semiconductor elements. After the formation of the small recesses, the material of the substrate in and around the small recesses is etched away so that a larger recess encompassing the small recesses is formed and, at the same time, the small recesses are caused to extend through the substrate to thereby form through-holes which extend from the larger recess to the selected ones of the electrodes.