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Enhanced Coagulation for Landfill Leachate Pretreatment
W K Bai
1
, F Liu
2
and H You
1, 2,*
1
Environmental school,Harbin Institute of Technology,Harbin 150090, P. R. China
2
School of Marine Science and Technology,Harbin Institute of Technology
(Weihai),Weihai 264209, P. R. China
Corresponding author and e-mail: H You, youhong@hit.edu.cn
Abstract. Coagulation was used in this paper to pretreat the waste incineration plant leachate
to reduce the subsequent processing load. This work strengthened the traditional coagulation
by compound coagulant and two-time coagulation. Results showed that the coagulation effect
of poly aluminum chloride and polymeric ferric sulfate compound coagulant is better than
that of polymeric aluminum chloride alone. The turbidity decreased from 74.0 NTU to 21.2
NTU, and the COD removal rate increased from 29.7% to 33%. In the case of the same
dosage, the effect of two-time coagulation is stronger than that of one-time coagulation.
1. Introduction
A large amount of high concentration leachate was produced in the waste incineration plant, which is
mostly produced by garbage stacking 5~7d [1]. The leachate of waste incineration plant is
characterized by high COD concentration, high metal content, large variation of water quality and
quantity, imbalance of nutrient proportion and low pH [2]. Because there are a lot of refractory
organic matter in leachate, the traditional biological treatment methods are limited [3], which is more
difficult for the high concentration leachate in the waste incineration plant. Physical and chemical
methods have been used by more and more researchers to deal with landfill leachate, such as
photocatalytic oxidation [4], electrolysis Fenton [5], membrane treatment method [6] and so on.
Coagulation is one of the most commonly-used physical and chemical methods [7]. Pretreatment of
landfill leachate by coagulation could flocculate and precipitate part of the refractory organic matter
and remove toxic substances from leachate, and provide a good operation environment for biological
treatment.
The traditional coagulant treatment of landfill leachate need a large dosage of coagulant and have
poor coagulation effect. In order to solve these problems, compound coagulant [8] and two-time
coagulation are used to treat landfill leachate. The combination of coagulants is polyaluminum
chloride (PAC) and polyferric sulfate (PFS). The two-time coagulation is after one coagulation,
coagulant is added to the effluent again.
Bai, W., Liu, F. and You, H.
Enhanced Coagulation for Landfill Leachate Pretreatment.
In Proceedings of the International Workshop on Environmental Management, Science and Engineering (IWEMSE 2018), pages 431-436
ISBN: 978-989-758-344-5
Copyright © 2018 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved
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