In this study, sludge treatment and dewatering alternatives for a selected leather tanning wastewater treatment plant were evaluated by evaluating the best available technology for sludge management. In addition, different combinations of sludge treatment alternatives were compared on the basis of investment and maintenance costs.

Introduction :By ever-increasing of population, shortage of water resources and the necessity of wastewater treatment, huge volumes of sludge that is a byproduct of wastewater treatment, requires to be disposed in environmentally secure ways. The target of specifying strategic preferences of reuse of sludge has been to find the correct way of disposal or beneficial use of sludge. Material and ...

Large quantities of sludge are produced in biological wastewater treatment. Sludge has a high putrescibility and therefore has to be stabilizsed in order to enable an environmentally safe utilization or disposal. The anaerobic digestion is the standard technique to stabilize the sludge. Digestion produces biogas and reduces the amount of organic matter. The amount of excess sludge production fr...

The performance of mesophilic anaerobic digesters of four large Italian wastewater treatment plants without primary sedimentation were studied. Only the waste activated sludge is stabilised by means of the mesophilic (35–37 8C) anaerobic digestion process. The anaerobic digesters generally worked with a hydraulic retention time in a range of 20–40 days and an organic loading rate of some 1 kg V...

The occurrence of five endocrine-disrupting compounds (EDCs), namely 4-n-nonylphenol (4-n-NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), triclosan (TCS) and bisphenol A (BPA), was assessed in the raw, treated wastewater and sewage sludge of eight sewage treatment plants (STPs) in Greece. The analytes were extracted by solid-phase extraction (dissolved phase) or sonic...

Endocrine-disrupting compounds (EDCs), such as estrogen, are known to be present in the aquatic environment at concentrations that negatively affect fish and other wildlife. Wastewater treatment plants (WWTPs) are major contributors of EDCs into the environment. EDCs are released via effluent discharge and land application of biosolids. Estrogen removal in WWTPs has been studied in the aqueous ...

A common approach to wastewater pretreatment in the food industry is the utilization of dissolved air flotation @AF) cells. DAF units are common for BOD, TSS, and FOG reduction when wastewater is discharged to a municipal wastewater treatment plant. A growing problem for all DAF systems is that of sludge disposal. In the o p t i o n of a DAF, contaminants are removed in the form of a concentrat...

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...

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...