A method for synthesizing a supported molecular sieve membrane by microwaves includes the steps of aging, heating and synthesizing. The aging step is to make a support in contact with a synthetic liquid at 25 C. to 70 C. for 10 hours to 24 hours; the heating step is to raise a temperature of an aged system from an aging temperature to a synthesis temperature within 1 minute to 10 minutes; and the synthesizing step is to synthesize at 80 C. to 120 C. for 2 minutes to 15 minutes. The steps of heating and synthesizing are powered by microwaves.

Provided is a heavy metal adsorbent consisting of a zeolite with a median diameter on a volume basis of 10.0 ?m or more and a pore volume measured in a pore volume calculation range of 10 nm to 1000 nm by a mercury intrusion method of 0.1000 cm.sup.3/g or less.

Provided is a heavy metal adsorbent consisting of a zeolite with a median diameter on a volume basis of 10.0 ?m or more and a pore volume measured in a pore volume calculation range of 10 nm to 1000 nm by a mercury intrusion method of 0.1000 cm.sup.3/g or less.

Provided is a heavy metal adsorbent consisting of a zeolite with a median diameter on a volume basis of 10.0 ?m or more and a pore volume measured in a pore volume calculation range of 10 nm to 1000 nm by a mercury intrusion method of 0.1000 cm.sup.3/g or less.

Provided is a heavy metal adsorbent consisting of a zeolite with a median diameter on a volume basis of 10.0 ?m or more and a pore volume measured in a pore volume calculation range of 10 nm to 1000 nm by a mercury intrusion method of 0.1000 cm.sup.3/g or less.

A zeolite includes Si, Al, Ag and at least one of an alkali metal or alkaline earth metal, and satisfies the relation 0.02Ag[mol %]/(Si[mol %]+10T[mol %])0.17 (wherein, T[mol %] denotes the molar concentration of the alkali metal and alkaline earth metal.)

A zeolite includes Si, Al, Ag and at least one of an alkali metal or alkaline earth metal, and satisfies the relation 0.02Ag[mol %]/(Si[mol %]+10T[mol %])0.17 (wherein, T[mol %] denotes the molar concentration of the alkali metal and alkaline earth metal.)