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For the first time, paint sludge waste (PS) was used as a pore forming agent in the preparation of sewage sludge derived carbon (SC). The tuning role and mechanism of PS for characteristics of SC were explored. It was found that a sludge carbon (SC PS-Zn ) with rich macro-, meso- and micro- porous could be produced by one-step pyrolytic process of sludge in the presence of PS and ZnCl 2. Its surface area could reach as high as 680.5 m 2 g −1 as 88.4 times and 4.8 times of sludge carbon without addition of PS and ZnCl 2 (SC) and only addition of ZnCl 2 (SC Zn ) , respectively. The macro- pores fabricated by PS provided much inner-space for ZnCl 2 to generate meso- and micro- porous, leading to a hierarchical porous structure. SC PS-Zn showed a high adsorption capacity of 685.4 mg g −1 for Chrysophenine, which is 1.3 and 1.7 times that of SC PS and SC Zn respectively. The adsorption difference could be simply attributed to the fact that the great molecules were difficult to enter micro- pores of SC Zn . It was also found that the difference was also dependent on orientation of Chrysophenine, which was related to pH value of solution. [ABSTRACT FROM AUTHOR]

A kind of effective cyclic Fenton process was investigated, in which Fe species were reused as homogeneous catalysts after the acid dissolution of Fe-containing sludge. It was observed that the degradation of phenol was abruptly accelerated (i.e., triggering effect) after an induction phase of ca. 30 min for non-first runs. The abrupt acceleration was attributed to the rapid reduction of Fe(III) by poly-phenol intermediates, such as 1,2-hydroquinone, 1,4-hydroquinone and 1,2,4-trihydroxybenzene. Specially, it was found that sludge carbon (SC) could not only improve the precipitation performance of Fe and Al species, decreasing residual concentration of Fe and Al species to 0.11 mg L −1 and 4.6 mg L −1 , respectively, but also reduce considerably induction phase of the degradation, promoting the advent of the triggering effect in advance. The promotion of SC was stemmed from its unique co-catalytic property, by which Fe(III) was continuously reduced to active Fe(II) and H 2 O 2 was turned to stronger oxidizing OH and 1 O 2 . [ABSTRACT FROM AUTHOR]

• Piezoelectric effect was firstly used to sludge dewatering. • Moisture content of sludge was reduced from 96.7% to 63.9% by piezo-dewatering. • Moisture content of sludge was further reduced to 54.9% by its coupling with PAM. • The dewatering was due to piezocatalytic oxidation and remnant piezo-field effect. Piezoelectric effect was firstly employed to improve dewatering efficiency of sludge. It was found that the piezoelectric effect could be driven directly by the pressure of pressure filtration process, without any additional energy. This piezo-dewatering process coupled piezoelectric effect with pressure filtration could efficiently remove moisture of sludge. Under 0.6 MPa for 2 h, moisture content (MC) and weight of sludge could be reduced to 63.9% and 3.2 g from 96.7% and 50 g by the piezo-dewatering process with 0.45 g t -BaTiO 3. This piezo-dewatering efficiency was much higher than that of usual conditioning-pressure filtrations using CaO, FeCl 3 or polyacrylamide (PAM) as the conditioners. And the piezo-dewatering process assisted by PAM could further decrease MC and weight of the sludge to 54.9% and 2.1 g, correspondingly, which complied to the advanced dewatering requirement (MC < 60%). The favorable piezo-dewatering efficiency was contributed to the piezo-catalytic oxidation and the electric role of remnant piezo-field. The finding of this piezo-dewatering mechanism offered an inspiring look at developing the emerging dewatering technology. [Display omitted] [ABSTRACT FROM AUTHOR]