Affiliations: State Key Laboratory of Environmental Aquatic
Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of
Sciences, Beijing 100085, China | Institute of Environment and Resource, Shanxi
University, Taiyuan 030002, China | Shenzhen Water Group Co., Ltd., Shenzhen 518031,
China
Abstract: Systematic investigation on enhancing removal of natural organic
matter (NOM) using inorganic polymer flocculant (IPF), polyaluminum chloride
(PACI) and polyacrylamide (PAM) was performed in a typical south-China source
water. Enhanced coagulation and applying polymer flocculant-aid were compared
through jar tests and pilot tests. Raw water and settled water were
characterized and fractionated by resin adsorption. The results show that DOC
composes major part of TOC. The DOC distribution keeps relatively stable all
around the year with typical high amounts of the hydrophilic matter around 50%.
The distribution between HoB, HoA and HoN varies and undergoes fluctuation with
the year round. During the summer season, the HoN becomes gradually the major
part in hydrophobic parts. PACl with the species being tailor-made shows little
pH effect during coagulation. The enhanced coagulation dosage for PACl could be
4.5 mg/L for the typical source water. The highest TOC removal achieved 31%. To
be economically, 3 mg/L dose is the optimum dosage. Although hydrophilic
fractions of NOM of both treatment strategies are removed about 30%, NOM
causing UV_{254} absorbance were well removed (about 90%).
Hydrophobic bases and acids fractions are much more removed under enhanced
conditions. The hydrophilic fraction could be better removed using PAM, the
polymer coagulant aid.
Keywords: enhanced coagulation, PACI, PAM, NOM fractionation
