Synthesis and Dewatering Properties of Cellulose Derivative-Grafting DMC Amphoteric Biodegradable Flocculants

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ORIGINAL PAPER

Synthesis and Dewatering Properties of Cellulose Derivative‑Grafting DMC Amphoteric Biodegradable Flocculants Xiaodong Chen1 · Danfeng Wang1,2 · Shuang Wang1 · Hongying Song1 · Qiang Gu1 · Yumin Zhang1 Accepted: 22 September 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020

Abstract Flocculant played an important role in water treatment and sludge dewatering. It is imperative to design and synthesize an eco-friendly and biodegradable flocculant based on natural polymer. In the present work, a new amphoteric CMC-based flocculant, CMC-g-PDMC was synthesized via grafting DMC onto hydroxyl of CMC initiated by potassium persulfate under traditional heating condition. The optimal graft copolymerization condition was optimized by orthogonal experiment. The structure, morphology and thermostability of the obtained graft copolymer were characterized by measuring FT-IR, XRD, SEM and TGA analyzer, respectively. Moreover, comparing with the commercial flocculant PAM, PAC and CPAM, the dewatering capacity of municipal sludge was evaluated using CMC-g-PDMC by FCMC, SRF, SVI and light transmittance. It suggested that the flocculation to municipal sludge was related to the ion properties of the flocculant. Keywords  Cellulose-grafting copolymer · Mechanism · Flocculation · Sludge dewatering · Municipal sludge

Introduction With the acceleration of industrialization and urbanization, activated sludge produced from industrial and domestic wastewater treatments are giving rise to increasingly serious environmental problems [1, 2]. Because the sludge enriched in insoluble or refractory organic species and heavy metals, it is universally considered to pose serious risks to the ecosystem and human health [3, 4]. Worse still, the moisture content of the sludge is normally higher than 95%. 95% [5, 6], the discharge of sludge containing large volumes of water will take a large number of storage area and waste resources except for increasing the cost for transportation. Besides, sludge is a negatively charged colloid mixture where sludge small particles steadily scattered in water are extremely difficult to be separated from the water phase. Therefore, the sludge dewatering is one of the most challenging subjects in the field of wastewater treatment.

* Yumin Zhang [email protected] 1



College of Chemistry, Jilin University, Changchun 130012, People’s Republic of China



Electronic Equipment Research Institute of Sichuan Aerospace, Chengdu 610100, People’s Republic of China

2

It is known that solid/liquid separation is a central technology in environmental engineering and water treatment. The extensive use of flocculation and settling performance was due to its cost-efficient solid/liquid separation performance [7–9]. It is particularly helpful for separating sludge based on different particle weights [10–15]. What’s more, it is of great significance to reduce the volume of sludge for disposal and sludge transport costs. At present, synthetic flocculants, for example, polyacrylamide and poly