There is a major concern among scientists over the elevated levels of arsenic (As) in drinking water in Bangladesh and some parts of India. Investigating the release of As from water filter sludge in soil and its uptake by plants may provide information about the management of As contaminated filter sludge. In this macrocosm study, iron based sludge containing granular ferric hydroxide (GFH) wa...

Petroleum exploitation in oilfields, especially drilling, generates an oily sludge mixed with hydrocarbons and mineral solids. This oily sludge is sometimes treated by bioremediation and phytoremediation. This investigation established that landfarmed oil sludge provided adequate soil conditions to grow jack beans (Canavalia ensiformis) that in turn rhizoand phytoremediated residual aliphatic a...

The chemical basis for improved removal rates of toxic heavy metals such as Zn and Cu from wastewater secondary sludge has been demonstrated in this study. Instead of using excess corrosive chemicals as the source of free nitrous acid (FNA) for improved solubility of heavy metals in the sludge (in order to enhance electrokinetics), an optimized use of aqua regia has been proposed as an alternat...

This study aimed to determine the influence of sewage sludge alkalization and acidification on the qualitative and quantitative composition of keratinolytic and keratinophilic fungi in a model experiment. The sludge was alkalized to pH 9 with 0.5N NaOH, 0.5N KOH, 0.5N NH 4 OH or with 2% burnt lime mixed with powdered limestone (20g CaO + 5g CaCO 3 ), and acidified to pH 4 with 0.5N HCl, 0.5N HN...

Virus loss in activated sludge appeared to be caused by microorganisms. This conclusion is supported by the finding that poliovirus infectivity decreased during incubation in mixed-liquor suspended solids, primarily because of a sedimentable, heat-sensitive component. Furthermore, broth spiked with mixed-liquor suspended solids acquired antiviral activity during incubation.

Co-digestion of sludge with external substrates at wastewater treatment plants is a common means to use residual wastes, utilise available capacity in the digester and boost biogas production. The Benchmark Simulation Model No. 2 (BSM2) is a platform for comparing plant-wide control strategies and includes among other things a model of the activated sludge process and the digester at a treatmen...

polyhydroxyalkanoates (phas) is known to be temporarily stored by microorganisms in activated sludge, especially in the anaerobic-aerobic processes. the main objective of this study was to investigate the effects of fatty acids (vfas) compounds coexistence in substrate of sbr on phas productivity of activated sludge. it has been found that addition of different concentrations of vfas results in...

Extracellular polymeric substances (EPS) appear to play a critical role in the formation of bioaggregates, such as sludge flocs, in activated sludge processes. Here, we systematically investigated the composition and chemical structure of various EPS fractions excreted from an activated sludge culture using multi-analysis techniques to examine the ability of the sludge to aggregate. Chemical an...

Leather processing is an important industry in China, and the discharge of chromium waste has been severely circumscribed. Though traditional processes for treating chromium waste have been widely used in tannery plants, technology adopting high efficiency and economic simultaneously is deficient. In order to develop an economic treatment for tannery waste, a mixed alkali of sodium hydroxide an...