Dewatered sludge cakes from bench scale anaerobic digesters operated at mesophilic temperatures and solids retention times (SRT) ranging from 10 days to 40 days were evaluated for their sulfur odor generation potential. Extracellular Polymeric Substances (EPS) extraction for digested sludge samples was also carried out. Static headspace sulfur gas analysis was successfully used to compare diffe...

The Combined Activated Sludge-Anaerobic Digestion Model (CASADM) quantifies the effects of recycling anaerobic-digester (AD) sludge on the performance of a hybrid activated sludge (AS)-AD system. The model includes nitrification, denitrification, hydrolysis, fermentation, methanogenesis, and production/utilization of soluble microbial products and extracellular polymeric substances (EPS). A CAS...

Source-separated black water (BW) (toilet water) containing 38% of the organic material and 68% of the phosphorus in the total household waste (water) stream including kitchen waste, is a potential source for energy and phosphorus recovery. The energy recovered, in the form of electricity and heat, is more than sufficient for anaerobic treatment, nitrogen removal and phosphorus recovery. The ph...

Four selected azo dyes (acid orange 6, acid orange 7, methyl orange and methyl red) were completely decolourised in the presence of anaerobic granular sludge, while only methyl red was degraded in aerobic conditions using a conventional activated sludge. Additional experiments with culture broth devoid of cells showed that anaerobic decolourisation of azo dyes was performed by extracellular red...

Conventional petroleum-derived plastics are recalcitrant to biodegradation and can be problematic as they accumulate in the environment. In contrast, it may be possible to add novel, biodegradable bioplastics to anaerobic digesters at municipal water resource recovery facilities along with primary sludge to produce more biomethane. In this study, thermal and chemical bioplastic pretreatments we...

The up flow anaerobic sludge bed (UASB)-digester system is one promising low temperature anaerobic process for sewage treatment. In this study, the effects of height of UASB sludge transfer (HUST) on performance of a UASB-digester system treating sewage at 15°C were studied. The studied HUSTs were 27, 47 and 67 cm in the UASB sludge bed of 70 cm, from which sludge was transferred to the digeste...

This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digester performance for untreated primary, excess activated and mixed sludge were compared to combined microwave-ultrasonic pretreated primary, excess activated and mixed sludge. All sl...

Disintegration by hydrodynamic cavitation has a positive effect on the degree and rate of sludge anaerobic digestion. By applying hydrodynamic disintegration the lysis of cells occurs in minutes instead of days. The intracellular and extracellular components are set free and are immediately available for biological degradation which leads to an improvement of the subsequent anaerobic process. H...

This research was conducted to study the anaerobic sludge filtration capacity regarding helminth egg removal in upflow anaerobic sludge blanket (UASB) reactors. Two 25 L lab-scale UASB reactors were operated at an ambient temperature which varied between 17.1 and 28.6 °C. Ascaris suum egg was selected as the model egg considering its similarity in terms of size and morphology to Ascaris lumbric...

Biochemical degradation test of food coal-tar dyes using sludge was studied in order to evaluate their safety. It was found that some dyes were little decomposed under aerobic condition but four azo dyes were readily decomposed under anaerobic condition. These were Food Yellow No. 4, No. 5, and Food Red No. 2, No. 102. Decomposed products of these four azo dyes by sludge under anaerobic conditi...