An aide at Wakefield High School in Arlington has been placed on leave without pay after a search of his apartment in which investigators seized allegedly pornographic materials depicting children, according to Fairfax County police and Arlington school officials.

Henry Gardner, assistant Arlington school superintendent for personnel, said last night that the man had worked for several years as a resource assistant, a position that includes such duties as helping teachers and monitoring the halls and cafeteria.

Fairfax County police spokesman Warren Carmichael said Fairfax police and federal investigators searched the man's apartment several weeks ago on a warrant.

Investigators said no charges have been placed against the aide. Carmichael said Fairfax and Arlington police have been working together to try to identify chil- dren in the seized photographs.

Arlington School Board Chairman Gail H. Nuckols said it is standard procedure to place an employe on leave without pay when the person is the subject of a police investigation or has been charged.

In Fairfax County yesterday, Arthur S. Pomerantz, a former psychologist in that county's schools, was released on $10,000 bond after being arraigned on a second charge of child sexual abuse.

Juvenile and Domestic Relations Court Judge Charles C. Dunn reduced Pomerantz's bond from $25,000 and set a preliminary hearing for Oct. 23 on a sodomy charge stemming from an alleged incident with a 13-year-old boy in 1983.

Pomerantz was charged last month with aggravated sexual battery against a minor in another alleged incident July 15.

Pomerantz, a school psychologist in Fairfax since 1965, was forced to resign in 1984 after twice going on leave during school investigations of complaints about him. Officials are investigating the schools' handling of those complaints.