Evaluation of calcined textile sludge as a stabilizing material for highway soil

The textile industry is a pioneer in the industrialization process in Brazil and is relevant to the Brazilian economy. However, it also generates as operational residue a solid waste,commonly called textile sludge. Pavement construction, which mobilizes large volumes of soil, constitutes an alternative to the reuse of residue, especially when stabilization is involved. The use of stabilized soils with the addition of waste can provide technical,economic and environmentally friendly advantages. This research aimed to study the use of chemical stabilization technique with sludge and three additives(lime, cement and asphalt emulsion) applied in base and subbase of pavements. The scope of this study was divided into four phases, i) characterization tests, ii) physical stabilization, iii) chemical stabilization and determination of heavy metals in the sludge, and iv) addition of 10% of textile sludge and chemical stabilizers(lime, cement, and asphalt emulsion) in amounts of 3%, 5% and 7% as additives in a soil, based on the results obtained in the second phase. Test results indicated that the stabilization of mixtures of soil with textile sludge has the potential to be used in pavement layers(base and subbase). The addition of cement promotes the best chemical stabilization for the sludge. The use of textile sludge stabilization presents greater environmental benefits, given the malfunctions and problems that the incorrect waste disposal can cause to the environment.

Characteristics and aluminum reuse of textile sludge incineration residues after acidification

The chemical composition and aluminum speciation of sludge incineration residue （SIR） were determined. Cementation of aluminum from sulfuric acid solution using SIR was studied. The results showed that acid-soluble inorganic aluminum was the predominant component in the sludge, and the total leached aluminum increased from 62.2% to 92.9% after incineration. Sulfuric acid dosage and reaction time were found to affect aluminum recovery positively. Conversely, the increase in temperature significantly inhibited recovery reactions. The optimized leaching condition was 1.66 g sulfuric acid per gram of SIR with a reaction time of 3 hr at 20°C, resulting in the highest aluminum leaching rate of 96.7%. Compared to commercial aluminum sulfate solution coagulants, the leaching solution demonstrated higher CODCr, turbidity and color removal efficiency for textile wastewater.

Energetic,bio-oil,biochar,and ash performances of co-pyrolysis-gasification of textile dyeing sludge and Chinese medicine residues in response to K_(2)CO_(3),atmosphere type,blend ratio,and temperature

Hazardous waste stream needs to be managed so as not to exceed stock-and rate-limited properties of its recipient ecosystems.The co-pyrolysis of Chinese medicine residue(CMR)and textile dyeing sludge(TDS)and its bio-oil,biochar,and ash quality and quantity were characterized as a function of the immersion of K_(2)CO_(3),atmosphere type,blend ratio,and temperature.Compared to the mono-pyrolysis of TDS,its co-pyrolysis performance with CMR(the comprehensive performance index(CPI))significantly improved by 33.9%in the N_(2)atmosphere and 33.2%in the CO_(2)atmosphere.The impregnation catalyzed the co-pyrolysis at 370℃,reduced its activation energy by 77.3 kJ/mol in the N_(2)atmosphere and 134.6 kJ/mol in the CO_(2)atmosphere,and enriched the degree of coke gasification by 44.25%in the CO_(2)atmosphere.The impregnation increased the decomposition rate of the co-pyrolysis by weakening the bond energy of fatty side chains and bridge bonds,its catalytic and secondary products,and its bio-oil yield by 66.19%.Its bio-oils mainly contained olefins,aromatic structural substances,and alcohols.The immersion of K_(2)CO_(3)improved the aromaticity of the copyrolytic biochars and reduced the contact between K and Si which made it convenient for Mg to react with SiO_(2)to form magnesium-silicate.The co-pyrolytic biochar surfaces mainly included-OH,-CH_(2),C=C,and Si-O-Si.The main phases in the co-pyrolytic ash included Ca_(5)(PO_(4))_(3)(OH),Al_(2)O_(3),and magnesium-silicate.

Formation of organic chloride in the treatment of textile dyeing sludge by Fenton system

In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton and Fenton-like system from the aspects of the influence of Cl^(-),the removal of polycyclic aromatic hydrocarbons (PAHs) and organic carbon,and the removal and formation mechanism of organic chlorine.The results showed that the organic halogen in sludge was mainly hydrophobic organic chlorine,and the content of adsorbable organic chlorine (AOCl) was 0.30 mg/g (dry sludge).In the Fenton system with pH=3,500 mg/L Cl-,30 mmol/L Fe^(2+)and 30 mmol/L H_(2)O_(2),the removal of phenanthrene was promoted by chlorine radicals (·Cl),and the AOCl in sludge solid phase increased to 0.55 mg/g (dry sludge) at 30 min.According to spectral analysis,it was found that ·Cl could chlorinate aromatic and aliphatic compounds (excluding PAHs) in solid phase at the same time,and eventually led to the accumulation of aromatic chlorides in solid phase.Strengthening the oxidation ability of Fenton system increased the formation of organic chlorines in liquid and solid phases.In weak acidity,the oxidation and desorption of superoxide anion promoted the removal and migration of PAHs and organic carbon in solid phase,and reduced the formation of total organic chlorine.The Fenton-like system dominated by nonhydroxyl radical could realize the mineralization of PAHs,organic carbon and organic chlorines instead of migration.This paper builds a basis for the selection of sludge conditioning methods.