biological removal of lead was observed in this study during treatment of synthetic solutions of this heavy metal by a sample of waste activated sludge (was) having mlss concentration of 10000 mg/l. the objective was determining the capability of was in removal of lead in three different conditions of treatment: without any aeration and feeding, by simultaneous aeration and feeding and by aerat...

sludge, which is produced as a by-product of all treatment processes, has considerable potential as a fertilizer and soil conditioner. many authorities now discharge the sludge after treatment directly to agricultural land in liquid form, while some others dewater and dry it first. in either case, with proper marketing, it is generally possible for an authority to earn revenue by this means, al...

Background and purpose: Disposing sludge from industrial wastewater treatment plants (IWWTPs) is a serious issue because it can affect human and animals health, and also environmental quality. In this study, sludge from an IWWTP was analyzed regarding its physicochemical characteristics and disposal options. Materials and Methods: Grab sampling was used to collect 12 sludge samples biweekly (Ma...

The temperature effect on denitrification rate of a two-sludge system has been studied. An industrial high-strength wastewater and an industrial by-product containing mainly methanol, as external carbon source, were used in this study. The maximum denitrification rate (MDR) was determined at six different temperatures: 6, 8, 10, 15, 20 and 25oC in batch mode. The temperature coefficient was fou...

Membrane Bioreactor (MBR) process consists of a biological reactor integrated with membranes that combine clarification and filtration of an activated sludge process into a simplified, single step process. The membrane is an absolute barrier to suspended matter and microorganisms and it offers the possibility of operating the system at high mixed liquor suspended solids (MLSS) concentration. Th...

Sludge incineration in fluidized bed is a very complex process, producing gaseous pollutants (carbon monoxide (CO) and nitrogen oxides (NOx)). The legislative norms need to be respected in spite of variations of sludge in composition and in quantity. The NOx formation, due to lots of chemical reactions from sludge nitrogen, is partly unknown. This paper deals with the design of a dynamic model ...

in this paper the risk of heavy metals discharged from the acidic sludge leachate into groundwater in a landfill located in fajr industrial area )garmsar( has been assessed using iwem software. acidic sludge as one of the industrial hazardous wastes is produced during purification of used oil with mienken )acidic( method. the concentrations of heavy metals )cd, ni, co, pb, zn, mn, cu( in the ac...

The effluent treatment plant sludge is one of the major sources of contamination with toxic metals. Since the sludge contains heavy metals, it must be pretreated to reduce the contamination. The heavy metals from the sludge can be reduced/ separated by washing it with a suitable leaching solution. In the present study, the efficiencies of three leaching solutions to remove the contaminants from...

A pot culture study has been undertaken to evaluate the effect of rolling and pickling industrial sludge amendments on growth response and bioaccumulation of heavy metal in wheat seedlings. Processed acidic waste was first treated with three doses of lime (0, 0.5 and 1%) and then mixed with two soils in different ratios (0, 10 and 20%). Samples were filled in earthen pots (2Kg/pot) one week bef...

Background & Aims of the Study: Industrial wastewater sludges must be disposed in a safe way because they have hazardous effects on the human and environment. The aim of this study is to investigate the physicochemical characteristics and disposal options of sludges from oil-water separator (OWS) and dissolved air flotation (DAF) clarifier of a Refinery wastewater treatment plant. Material...