background: the occurrence of heavy metals in the environment is of important concern due to their toxicity and health effects on humans, including cancer. because metals have been extensively used for centuries in commerce, environmental contamination is widespread; moreover, exposure to metals and metal compounds continues to be a significant public health problem. electroplating sludge conta...

Sewage sludge is frequently applied to land. It has been shown, however, that sludges contain many toxic components and pathogenic organisms. Keratinolytic and associated non-keratinolytic fungi are considered potentially pathogenic. Our knowledge on the incidence of the fungi in the sludge environment is still insufficient. Sludge from the Bytom-Miechowice wastewater treatment plant in Upper S...

DNA was isolated from phenol-digesting activated sludge, and partial fragments of the 16S ribosomal DNA (rDNA) and the gene encoding the largest subunit of multicomponent phenol hydroxylase (LmPH) were amplified by PCR. An analysis of the amplified fragments by temperature gradient gel electrophoresis (TGGE) demonstrated that two major 16S rDNA bands (bands R2 and R3) and two major LmPH gene ba...

he 23 US. Army installations engaged in plating employ a variety of techniques to treat wastewater. While some sites have implemented recovery and T reuse, a majority still find it advantageous to precipitate the metals and discharge the wastewater. Sludge is collected in clarifiers, treated by gravity thickening, then dewatered in pressure or vacuum filters, lagoons or drying beds. The dewater...

The selective recovery of heavy metals of Cu, Zn, Ni and Cr from a mixed plating sludge by sulfidation and oxidation treatment was targeted in this study. At first, the mixed plating sludge was simultaneously subjected to an extraction and Cu sulfidation process at pH=1.5 to dissolve heavy metals and to precipitate Cu as CuS. In the next step, the sulfidation treatment of Zn was carried out at ...

As discharge restrictions become stricter and sludge dlisposal costs rise, traditional technologies for the removal of metals from plating shop wastewater such as lime and ferric chloride become increasingly less attractive. One technology that is of use of dithiocarbamates to complex a highly insoluble, dense sludge, effluent water and greatly reduced sludge volumes. Despite the benefits avail...

Over 300 bacterial strains were isolated from seven samples of activated sludge by plating on sewage agar. Gram-negative bacteria of the genera Zoogloea and Comamonas predominated. Many isolates (51%) showed sudanophilic inclusions of poly-beta-hydroxybutyric acid, whereas 34% accumulated iodophilic material on media containing starch. A large number required either vitamins or amino acids, or ...

Sludge from a treatment process using iron was exposed to a mildly acidic solution to investigate iron hydroxide's capacity to collect metals from waste. Batches of iron hydroxide were regenerated and reused 50 times to treat both synthetic and real plating waste. Treatment efficiency was very high and steady, and there was no indication of deterioration in any aspect of process performance. Ov...

Hexavalent chromium wastes need to be chemically reduced to trivalent chrome in the shop’s treatment plant. This necessitates the use of expensive chemicals such as sulfur dioxide, sodium metabisulfite or sodium borohydride. Also considerable hazardous sludge is generated during the neutralization step of the treatment process due to the high chromium concentration of the plating solutions. Haz...

Abstract— The effect of calcination temperature on the morphology of plating sludge generated from waste water treatment plant was studied. This waste was hazardous waste due to high toxic metal content [1]. It must be recovered, reuse or recycled before the process but its properties should determined in order to decide recovery method [2]. Previous researches were shown that this kind of wast...