The recent United Kingdom ban on the disposal of sewage sludge at sea has led to the prediction that land application of sludge will become more widespread. The positive aspect of recycling nutrients may, however, be offset by the risk of contamination by heavy metals that are frequently present in sludge. The environmental impact of applying metal-rich sewage sludge to agricultural land was, t...

Hazardous solid wastes may pose a serious risk to human health and to the environment, if not managed appropriately and disposed of safely. In this study, the effective stabilization of tannery sludge, a toxic industrial solid waste produced from the physico-chemical treatment of tannery wastewaters, was examined by the addition of ladle furnace slag (LFS), another industrial solid waste. Moreo...

This work illustrates that the removal of some endocrine-disrupting compounds from sewage treatment works effluent is dependent on parameters such as sludge age, influent concentrations, concentrations of co-pollutants and hydraulic retention time as well as physicochemical properties of the compound. Greater nonylphenol polyethoxylates (NPEO) and polybrominated diphenyl ether (PBDE) removal wa...

Various half-scale and lab-scale investigations have already shown that the disintegration of excess sludge is a possible pre-treatment to optimise anaerobic digestion. To verify these results, different methods of disintegration were investigated at a full-scale plant. Two stirred ball mills, a plant for oxidation with ozone, a lysate centrifuge and an ultrasonic homogeniser were applied. A po...

The removal of heavy metal from sludge before disposal or application to farmland is a necessary step to achieve a more safe sludge usage or disposal. Chemical extraction using inorganic acids (nitric, hydrochloric) and organic acids (citric, oxalic) were tested for extraction of chromium, copper, nickel, lead and zinc from contaminated sewage sludge at different pH and reaction time. Results r...

Low efficiency of conventional aeration techniques and the excessive production and disposal of sludge are great concerns in biological wastewater treatment systems. The present study aimed to evaluate the active sludge method using batch reactors under continuous operation to determine the efficiency of aeration and sludge production through microbubble and nanobubble aeration. The results ind...

BACKGROUND Biohythane is a new and high-value transportation fuel present as a mixture of biomethane and biohydrogen. It has been produced from different organic matters using anaerobic digestion. Bioenergy can be recovered from waste activated sludge through methane production during anaerobic digestion, but energy yield is often insufficient to sludge disposal. Microbial electrolysis cell (ME...

Under anaerobic conditions, organic pollutants in wastewater are degraded by microbes producing methane and carbon dioxide. The degradation process is effective compared to the more conventional aerobic processes and produces only 5-10% of sludge. This saves considerably on cost associated with the sludge disposal. Among anaerobic technologies, the most popular ones is the upflow anaerobic slud...