The Sewage Sludge Biochar at Low Pyrolysis Temperature Had Better Improvement in Urban Soil and Turf Grass

Abstract

In recent years, continuous efforts have been made to understand the impact of biochar on arable soil fertility. Little is known about whether the biochar derived from municipal sewage sludge has positive impacts on urban soil. In this study, we pyrolyzed spray-dried municipal sewage sludge at 200 °C, 300 °C, 500 °C, and 700 °C for 2 h in a muffle furnace and then amended it into an urban soil to grow turf grass in pots. The outcomes demonstrated that biochar incorporation caused remarkable increases in soil organic C, black C, total N, available P, and K by 3–8, 7–25, 2–9, 10–19, and 1.4–2 times, respectively. The dry matter of turf grass increased by 43–147%, probably due to the nutritional improvement after biochar addition. The turf grass grown in biochar-added soil had 4–70% lower heavy metals than that in the control, although the soils had much higher total heavy metals, which might imply that biochar amendment reduced the bioavailability of heavy metals. Considering the cost of biochar production and its impacts on both urban soil and grass, it would be alternative to convert the spray-dried municipal sewage sludge into biochar at 200 °C for 2 h and then used as an urban soil amendment.

Long‐term effects of sewage sludge–derived biochar on the accumulation and availability of trace elements in a tropical soil

“…(2019). The low accumulation of TEs over the long term observed in this work differs from several results obtained in the short term (Tian et al., 2019; Yue et al., 2017), in which higher doses (1–50%) of SSBC were used compared with those of the present study (0.7%). Among the TEs analyzed, Zn was the only one that accumulated in the soil over the years.…”

“…All studies on SSBC complied in Supplemental Table S1 refer to short‐term effects because they encompass one or two (at most) cultural cycles or two agricultural years (Figueiredo, Chagas, da Silva, & Paz‐Ferreiro, 2019; Khan, Chao, Waqas, Arp, & Zhu, 2013; Khanmohammadi, Afyuni, & Mosaddeghi, 2017). In addition, about 75% of these short‐term studies were conducted in pots or soil incubations (Méndez et al., 2012; Tian, Cui, Lin, Li, & Zhao, 2019; Waqas, Khan, Qing, Reid, & Chao, 2014). Therefore, the long‐term effects remain unknown for SSBC and field application conditions.…”

Induced changes of pyrolysis temperature on the physicochemical traits of sewage sludge and on the potential ecological risks

“…The EC of the SS (4.0 ± 0.0 dS m −1 ) was higher than that observed for SSB 350 (2.2 ± 0.0 dS m −1 ), SSB 450 (1.6 ± 0.0 dS m −1 ), and SSB 600 (1.5 ± 0.0 dS m −1 ; Table 2 ). During SS pyrolysis, the ash content increases, whereas the solubility of salts and metals decreases 63 , 64 . This occurs because the water-soluble concentrations of K + , Ca 2+ , Mg 2+ , and P increase in biochar produced up to 200 °C, but above that temperature it is likely that they will form crystals like whitlockite [(Ca, Mg) 3 (PO 4 ) 2 ].…”

Removal and recovery of nutrients and value-added products from wastewater: technological options and practical perspective

“…Process conditions used: pyrolyzed and spray-dried municipal sewage sludge at 200 °C, 300 °C, 500 °C, and 700 °C for 2 h in a muffle furnace Biochar incorporation caused a remarkable increase in soil organic C, black C, total N, available P, and K content [171] Manure, sewage sludge, biodegradable wastes, and agricultural slurry treatment was accomplished By anaerobic (oxygen free) digestion of organic materials, biogas production was accomplished and it serves as an important source of energy in heat and electricity generation Biogas production with the components: CH Treatment method for sewage sludge in Malaysia Anaerobic digestion and anaerobic co-digestion for various organic waste components present in the sewage sludge Improves the economic viability due to higher methane production [136] Enhancing the sewage sludge disintegration via pretreatment technologies Ultrasonic, microwave assisted, electrokinetic and highpressure homogenization, thermal, acidic, alkali, ozonation, Fenton and Fe(II)-activated persulfate oxidation Temperature-phased anaerobic digestion and microbial electrolysis cell was used for improving the biogas production [173] reviewed the potentials of nutrients recovery from different types of wastewater, including fruit, vegetable, meat, and seafood processing wastewaters. Some industrial wastewaters are severely polluted with toxic chemicals and heavy metals, and they are also a source of disease-causing bacteria and parasites.…”