<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31473207</termId><termName>settling tanks</termName><termType>PT</termType><termNote><![CDATA[ Components of modern sewage-treatment systems where waste water is passed through a series of tanks following coarse screening to remove large objects. Grit chambers settle out sand and cinders; primary settling tanks remove heavy organic solids; and aeration tanks mix the incoming sewage with activated, bacteria-rich sludge and fine air bubbles, causing the rapid oxidation of organic matter. Final settling tanks remove the remaining suspended solids from the mixture. ]]></termNote><termCreatedDate>2026-03-30 21:07:20</termCreatedDate><relation><relationType>UF</relationType><termId>31473208</termId><termName>sedimentation tanks</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31473209</termId><termName>settling tank</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31473210</termId><termName>tanks, settling</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31459955</termId><termName>sewage treatment plants</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31432039</termId><termName>settling basins</termName><termType>PT</termType></relation></term>  </Zthes>