Influence of pyrolysis temperature on characteristics and heavy metal adsorptive performance of biochar derived from municipal sewage sludge.

Thermochemical conversion of sewage sludge: A critical review

Critical review on dewatering of sewage sludge: Influential mechanism, conditioning technologies and implications to sludge re-utilizations.

Risk analysis of pyrolyzed biochar made from paper mill effluent treatment plant sludge for bioavailability and eco-toxicity of heavy metals

Recent developments in lignocellulosic biomass catalytic fast pyrolysis: Strategies for the optimization of bio-oil quality and yield

Thermal disposal of sewage sludge is likely to cause serious nitrogen related environmental pollution since it contains considerable amounts of nitrogen, the species of which are quite different from those in coal. Considering that lime (CaO) is a widely applied chemical conditioner for sewage sludge dewatering, this study investigated the catalytic role of conditioner CaO in nitrogen transformation during sewage sludge pyrolysis in a drop-tube/fixed-bed furnace at 873 K, 1073 K and 1273 K, respectively. Model compounds were also used to further clarify the mechanisms involved. According to the results, conditioner CaO increased the fraction of more stable protein-N as well as amine-N. The solid phase reactions produced CaC x N y , thus enhancing the nitrogen retention in char. Correspondingly, decreased relative ratio of nitrates-N/nitrites-N and oxygenated organics in sludge conditioning contributed to less NO emission. Meanwhile, conditioner CaO promoted the conversion of HCN to NH 3 , as well as the deamination of proteins, amine, and other N-containing compounds in tar and char, leading to increased NH 3 generation. Subsequently, CaC x , the decomposition product of CaC x N y , captured NH 3 , driving down the final production of NH 3 . In addition, Ca(OH) 2 hindered the transformation of nitrile-N in char to HCN, decreasing HCN generation. CaO reacted with HCN, further reducing its releasing amount. CaC x N y derived from different sources decomposed to produce a very large amount of N 2 . These indicate that reusing conditioner CaO is a promising strategy for reducing the productions of NO x precursors efficiently and increasing the formation of non-polluting N 2 dramatically.

Catalytic role of conditioner CaO in nitrogen transformation during sewage sludge pyrolysis

Findings of proper temperatures for arsenic capture by CaO in the simulated flue gas with and without SO2

Comparison of CaO's effect on the fate of heavy metals during thermal treatment of two typical types of MSWI fly ashes in China.

Emission characteristics of nitrogen- and sulfur-containing odorous compounds during different sewage sludge chemical conditioning processes

The fate of sulfur during rapid pyrolysis of scrap tires

Hongyun Hu

Papers

Catalytic role of conditioner CaO in nitrogen transformation during sewage sludge pyrolysis

Findings of proper temperatures for arsenic capture by CaO in the simulated flue gas with and without SO2

Comparison of CaO's effect on the fate of heavy metals during thermal treatment of two typical types of MSWI fly ashes in China.

Emission characteristics of nitrogen- and sulfur-containing odorous compounds during different sewage sludge chemical conditioning processes

The fate of sulfur during rapid pyrolysis of scrap tires