Search results for "Sludges"
showing 3 items of 3 documents
Preparation and Characterization of Pulp and Paper Mill Sludge-Activated Biochars Using Alkaline Activation : A Box–Behnken Design Approach
2022
This study utilized pulp and paper mill sludge as a carbon source to produce activated biochar adsorbents. The response surface methodology (RSM) application for predicting and optimizing the activated biochar preparation conditions was investigated. Biochars were prepared based on a Box–Behnken design (BBD) approach with three independent factors (i.e., pyrolysis temperature, holding time, and KOH:biomass ratio), and the responses evaluated were specific surface area (SSA), micropore area (Smicro), and mesopore area (Smeso). According to the RSM and BBD analysis, a pyrolysis temperature of 800 °C for 3 h of holding and an impregnation ratio of 1:1 (biomass:KOH) are the optimum conditions f…
13C/12C composition, a novel parameter to study the downward migration of paper sludge in soils
2002
δ13C values of crop and forest soils were measured 8 years after disposal of paper sewage sludge. The carbon transfer from paper sludge downward to the first humic layer is evidenced by a 13C-enrichnient of up to + 5.6‰ due to the input of 13C-enriched sludge carbonates. 13C/12C composition is thus a novel, sensitive parameter to follow the downward transfer of paper sludge carbon.
Aerobic composting and anaerobic digestion of pulp and paper mill sludges
1997
The feasibility of aerobic vessel composting and anaerobic digestion for the treatment of pulp and paper mill sludges were studied. The composting studies made use of primary and secondary sludge from a de-inking and paper mill. In six parallely aerated 500 1 vessels with various carbon : nitrogen (C:N) -ratios, the most optimal performance was obtained with C:N -ratios of c. 22–35, while higher and lower ratios delayed the temperature increase. With the optimal ratios, the thermophilic stage was reached within 36 h, and the stage lasted for about seven days. In the scale-up study (18 m3 compost vessel), the thermophilic stage was reached within 24 h. An effective dehydratation of the mass …