▁Lev iel ▁wrote ▁the ▁first ▁edition ▁of ▁Le ▁Mé ment o ▁Te chni que ▁de ▁l ’ E au , ▁a ▁book ▁containing ▁their ▁combined ▁knowledge ▁of ▁water ▁chem istry ▁and ▁water ▁treatment . ▁At ▁first ▁only ▁internally ▁distributed , ▁the ▁first ▁public ▁edition ▁was ▁published ▁in ▁French ▁in ▁ 1 9 5 1 . ▁There ▁have ▁been ▁ 1 0 ▁French - language ▁ed itions ▁since ▁then . ▁The ▁Water ▁Tre at ment ▁Hand book , ▁the ▁title ▁in ▁English , ▁is ▁currently ▁in ▁its ▁ 7 th ▁English - language ▁edition , ▁published ▁by ▁Lav ois ier ▁in ▁ 2 0 0 7 . ▁ ▁References ▁ ▁External ▁links ▁▁ ▁S uez ▁En viron nement ▁-- ▁D egr ém ont ▁Website ▁ ▁D egr ém ont ▁Water ▁Tre at ment ▁Hand book ▁ ▁Category : 1 9 0 8 ▁birth s ▁Category : 1 9 7 4 ▁death s <0x0A> </s> ▁David ▁G . ▁He ck el ▁( born ▁ 1 9 5 3 ) ▁is ▁an ▁American ▁ent om ologist . ▁ ▁Scient ific ▁career ▁ ▁After ▁studying ▁bi ology ▁and ▁mathematics ▁at ▁the ▁University ▁of ▁Ro chester , ▁New ▁York , ▁he ▁finished ▁his ▁under grad uate ▁studies ▁with ▁a ▁B A ▁in ▁bi ology ▁& ▁mathematics ▁in ▁ 1 9 7 5 . ▁He ▁received ▁his ▁Ph D ▁ ▁in ▁bi ological ▁sciences ▁from ▁Stan ford ▁University ▁in ▁ 1 9 8 0 . ▁From ▁ 1 9 8 0 ▁until ▁ 1 9 9 9 ▁he ▁worked