Introduction: Polycyclic aromatic hydrocarbons (PAHs) are small organic matters found also in the interstellar space [1]. They are subjects of interest as distant ancestors of organic matters in our Solar system, in view of the life cycle of solid matters in space. Data and analysis: AKARI, Japanese infrared astronomical satellite, surveyed all the sky in the 9, 18, 65, 90 and 160 micron bands....

Activated sludge is now one of the most widely used biological processes for the treatment of wastewaters from medium to large populations. It produces high amounts of sewage sludge that can be managed and perceived in two main ways: as a waste it is discharged in landfill, as a fertilizer it is disposed in agriculture with direct application to soil or subjected to anaerobic digestion and comp...

Activated sludge systems are biological processes greatly used in wastewater treatment plants (WWTPs). These systems are composed of an aerated tank where the biochemical phase occurs and a settler where the physical phase takes place. Solid-liquid separation is one of the most critical steps in activated sludge processes. This stage presents three main objectives: sludge thickening, effluent c...

Pollutants in dye wastewater significantly vary due to the large number of dyes and other chemical compounds used in dyeing processes. The major compounds in dye wastewater are desizing and scouring agents, bleaches, reducing agents, detergents and wetting agents, finishing agents, organic acids and dyes, and fluorescent brighteners1). Physical, chemical and biological methods have been applied...

The oxidation of leachate coming from the composting of two organic wastes (wastewater sludge and organic fraction of municipal solid wastes) using the Fenton's reagent was studied using different ratios [Fe(2+)]/[COD](0) and maintaining a ratio [H(2)O(2)]/[COD](0) equal to 1. The optimal conditions for Fenton reaction were found at a ratio [Fe(2+)]/[COD](0) equal to 0.1. Both leachates were si...

The enrichment or spiking of sewage sludge with heavy metals for experimental purposes is a fairly widely used, although sometimes controversial, technique. A study was undertaken, using a sequential fractionation scheme, to assess the degree of incorporation of Cu, Ni, and Zn into sewage sludge samples spiked with these metals and incubated for 6 mo. For all three metals, substantial proportio...

The pyrolysis residue (SP) of sewage sludge (SS) produced at 500 degrees C was subjected to batch and column leaching tests to investigate the release of its organic and inorganic constituents and metals. For comparison, incineration ash (SI) obtained from a SS incinerator was also tested. Pyrolysis and incineration reduced organic matter of SS from 0.78 kg kg(-1)-dry SS to 0.16 and 0.01 kg kg(...

This paper focuses on the feasibility of septage treatment by sludge drying reed beds (SDRB). Different designs and operation conditions of SRDB pilot-scales were tested on system efficiencies such as the top filtration layer (sand or compost) and the organic load (30 and 50 kg SSm(-2)y(-1)). Results focus on the obtained performances considering sludge characteristics, filtration efficiencies,...

The practical application of the Fenton-based treatment method for organic compounds-contaminated water purification is limited mainly because of the large amount of ferric sludge formed during the treatment, where ferrous iron (Fe(II)) is used as the activator of the hydrogen peroxide oxidation processes. Reuse of ferric sludge collected from clarifiers to substitute Fe(II) salts allows reduci...

Sago industries effluent containing large amounts of organic content produced excess sludge which is a serious problem in wastewater treatment. In this study ozonation has been employed for the reduction of excess sludge production in activated sludge process. Central composite design is used to study the effect of ozone treatment for the reduction of excess sludge production in sago effluent a...