Preparation of modified waterworks sludge particles as adsorbent
to enhance coagulation of slightly polluted source water
Taoyua n Che n
Received: 19 March 2017 /Accepted: 14 June 2017 /Published online: 4 July 2017
Springer-Verlag GmbH Germany 2017
Abstract Without treatment, waterworks sludge is ineffective
as an adsorbent. In this study, raw waterworks sludge was
used as the raw material to prepare modified sludge particles
through high-temperature calcination and alkali modification.
The feasibility of using a combination of modified particles
and polyaluminum chloride (PAC) as a coagulant for treat-
ment of slightly polluted source water was also investigated.
The composition, structure, and surface properties of the mod-
ified particles were characterized, and their capabilities for
removing ammonia nitrogen and turbidity were determined.
The results indicate that the optimal preparation conditions for
the modified sludge particles were achieved by preparing the
particles with a roasting temperature of 483.12 °C, a roasting
time of 3.32 h, and a lye concentration of 3.75%. Furthermore,
enhanced coagulation is strengthened with the addition of
modified sludge particles, which is reflected by reduction of
the required PAC dose and enhancement of the removal effi-
ciency of ammonia nitrogen and turbidity by over 80 and
93%, respectively. Additional factors such as pH, temperature,
dose, and dosing sequence were also evaluated. The optimum
doses of modified particles and PAC were 40 and 15 mg/L,
respectively, and adding modified particles at the same time as
or prior to adding PAC improves removal efficiency.
Keywords Modified waterworks sludge particles
Sludge from drinking waterworks, which is the by-product of
drinking water treatment processes, is considered a form of
water industrial waste (Feng et al. 2014). Large quantities of
waterworks sludge are produced in China. The amount of dry
sludge can reach 6.25 × 10
t every year, and the average annual
growth rate may reach 13% (Yang et al. 2015a).
Traditionally, waterworks sludge has mainly been disposed of
in sanitary landfills, incineration, ocean discharge, building ma-
terials, and land application (Babatunde and Zhao 2007;Guan
et al. 2005;Haleetal.2012). However, no method is ideal in
terms of both costs and practicalities. In addition, the composi-
tion of waterworks sludge is complex and potentially danger-
ous. Sludge typically consists of inorganic salts, heavy metals,
pathogenic microorganisms, and small amounts of organic con-
taminants (Dong et al. 2013; Leader et al. 2008). If treated
inappropriately, waterworks sludge can seriously threaten the
ecological environment and human activities. Recently, the
challenge of ensuring the harmlessness and even usefulness
of waterworks sludge has attracted widespread attention.
In recent years, the preparation of adsorbent using
waterworks sludge has been studied extensively based
on its advantages of low costs and high adsorption effi-
ciency to achieve the goal of turning waste into wealth.
An adsorbent based on sludge can be applied in waste-
water treatment to remove certain pollutants, such as the
heavy metals cadmium and chrome (Cheng and Huang
forms of phosphorus (Kim et al. 2002;Lietal.2013;
Responsible editor: Philippe Garrigues
Electronic supplementary material The online version of this article
(doi:10.1007/s11356-017-9563-7) contains supplementary material,
which is available to authorized users.
* Hang Xu
Key Laboratory of Integrated Regulation and Resource Development
of Shallow Lakes, Hohai University, Nanjing 210098, China
College of Environment, Hohai University, Nanjing 210098, China
Environ Sci Pollut Res (2017) 24:19393–19401