Using thermal-acidic-modified kaolin as a physical-chemical conditioner for waste activated sludge dewatering

Synthesis of a novel MMK/β‐CD‐A material and its tetracycline removal efficiency

“…The increased specific surface area at the higher reaction temperature was due to the higher concentration HNO 3 more easily opening the kaolin pores . 21 The water-bath temperature of 90 °C was selected in the following sections.…”

“…The XRD spectra of original kaolin and MMK illustrated again that H (from HNO 3 ) reacted with Al-O-Si, resulting in the leaching of Al, and eventual structural change of kaolin . 21,22 It is reported that the leaching of Al can create abundant pore structures in kaolin, which indirectly caused a substantial increase in the specific surface area. 25 The N 2 adsorption-desorption isotherms and the pore structure parameters of MMK and kaolin are shown in Fig.…”

The enhanced dewaterability of sludge by a starch-based flocculant combined with attapulgite

“…The coagulation and skeleton builder combination process is based on the coagulation and the addition of some skeleton builders, as filter aids, to condition the sludge 5 . Some skeleton builders, such as bentonite, fly ash and biomass ash, are widely available and inexpensive, besides, contain high levels of SiO 2 with a good mechanical strength 4 , 15 – 17 . With the support of the skeleton builders, the sludge cake contains rigid and porous microstructure even under a high mechanical pressure, reducing the compressibility of sludge, allowing the water contained in the sludge cakes to drain out easily, and thus improving the permeability and mechanical strength of sludge to achieve a high solid content in sludge (> 30% dry sludge volume) 4 , 15 – 17 .…”

“…Some skeleton builders, such as bentonite, fly ash and biomass ash, are widely available and inexpensive, besides, contain high levels of SiO 2 with a good mechanical strength 4 , 15 – 17 . With the support of the skeleton builders, the sludge cake contains rigid and porous microstructure even under a high mechanical pressure, reducing the compressibility of sludge, allowing the water contained in the sludge cakes to drain out easily, and thus improving the permeability and mechanical strength of sludge to achieve a high solid content in sludge (> 30% dry sludge volume) 4 , 15 – 17 . The coagulation and skeleton builder combination process thus has the advantages of high-cost performance and ease of operation by the direct addition of flocculants and skeleton builders without any adjustment 6 , 7 ; besides, the porous and rigid structures of the skeleton builders can easily change the sludge compressibility and further enhance the sludge dewatering performance by this combining process.…”

“…St-CTA has thus shown a notable effect on sludge dewatering according to previous reports 13 , 19 . Besides, some clays, such as montmorillonite and kaolin, have been confirmed as efficient skeleton builders in combination with various flocculants for effective conditioning of sludge 17 , 20 . Attapulgite (ATP), a popular clay in China, has the characteristics of the high specific surface area, the rigid and porous structure and good adsorption properties to many organic matters 21 , 22 .…”