Where is the trash directory for PCManFM and xfe

You can find the answers in the The FreeDesktop.org Trash specification:

Some excerpts:

$topdir/.Trash-$uid directory is to be used as the user's trash directory for this device/partition. $uid is the user's numeric identifier.

The $trash/files directory contains the files and directories that were trashed.

The $trash/info directory contains an “information file” for every file and directory in $trash/files.

There is no reference to expunge directory, though.

Those files you removed may actually still be opened by another process. In that case the file space will become available when that process closes it's handle to the file.

You can lookup these files with lsof:

lsof |grep "var/log"|grep deleted