Batch anaerobic digestion tests of primary sludge and waste activated sludge were conducted for a duration of 123 days to determine the ultimate degradability of the sludges. For primary sludges the inert fraction of the particulate COD that was predicted by the wastewater models could be employed to predict their biodegradability under anaerobic conditions. The degradation of waste activated s...

Despite the obvious advantages of anaerobic sludge digestion viz. sludge reduction and sustainable management, it has some drawbacks. In particular, anaerobic digestion produces a complex and unknown residue sludge which is difficult to treat and to dewater. Because dewatering mainly involves rheological solid characteristics, this paper focuses on the similarities between these residues with o...

To understand the diversity and abundance of antibiotic resistance genes (ARGs) in pharmaceutical wastewater treatment bioreactors, the ARGs in sludge from two full-scale pharmaceutical wastewater treatment plants (PWWTPs) were investigated and compared with sludge samples from three sewage treatment plants (STPs) using metagenomic approach. The results showed that the ARG abundances in PWWTP s...

Rheological characterization of high-solid sludge is a fundamental requirement for optimizing the mixing and transport of high-solid sludge during anaerobic digestion in waste water treatment systems. We investigate the time evolution of physico chemical properties and rheological characteristics of high-solid digested sludge with total solids (TS) 15–20 wt.% during anaerobic digestion. A serie...

An anaerobic sludge (AS), capable of decolorizing a variety of synthetic dyes, was acclimated and is reported here. The sludge presented a much better dye decolorizing ability than that of different individual strains. A broad spectrum of dyes could be decolorized by the sludge. Continuous decolorization tests showed that the sludge exhibited the ability to decolorize repeated additions of dye....

To support the development of safe and feasible sludge management strategies, the accumulation rates of sludge and its characteristics were studied in four primary wastewater stabilization ponds (WSPs) in central Mexico (three facultative and one anaerobic). The accumulation rates and distribution of sludge were determined by measuring the thickness of the sludge layer at 8-40 locations through...

The sewage sludge production in Egypt is rapidly increasing resulting from the continuous increase of population, urban planning and industrial developments. This sludge needs to be adequately treated and environmentally managed to reduce the negative impacts of its application or disposal. Therefore, the main currently pressing needs are to find/develop more efficient, economical and sustainab...

Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days,...

A 2-year sampling campaign was conducted in three wastewater treatment plants of various sizes in the Rome area to assess the occurrence of nutrients and micropollutants among primary, secondary and digested sludge. The primary purpose was to evaluate the quality of different sludge types and their suitability for agricultural use. Primary sludge was consistently more polluted than secondary in...

in this research, a plot consisting of two sequencing batch reactors (sbr) both reactors were anaerobic stageand its aeration time was had the primary anaerobic stage witling change inthe'touilr:eaction time (9.5 hours).the average concentration of influent phosphorus and rector were 7.5 and 800 miligram per litre respectively. in two months periods the average effeciencies of phosphorus r...