Further treatment of coking wastewater treated in AO-MBR by the nanofiltration-powder activated carbon hybrid system.

In this study, further treatment of coking wastewater treated in anoxic-oxic-membrane bioreactor (AO-MBR) was investigated to meet the standards of the ministry by means of nanofiltration (NF) (with two different membranes and different pressures), microfiltration -powder activated carbon (MF-PAC) hybrid system and NF-PAC (with two different membranes and five different PAC concentrations) hybrid system. In addition to the parameters determined by the ministry, other parameters such as ammonium, thiocyanate (SCN), hydrogen cyanide (HCN), dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), color were also examined to evaluate the flux performance and treatment efficiency of the hybrid processes. According to the results, chemical oxygen demand (COD) in the NF process, COD and total cyanide (T-CN) in the MF-PAC process could not meet the discharge standards.

Prioritization of the treatment and disposal methods of wastes containing polychlorinated biphenyl by fuzzy multi-criteria decision-making and risk assessment.

A total of 209 different types of polychlorinated biphenyls (PCBs) with various properties have been produced from 1930 to 1970s in which they have been banned due to their toxic effects. Total produced PCBs in the world are around 15 to 20 million tons, and up to now, 5.4 million tons of PCB-containing or PCB-contaminated equipment/materials has been eliminated.

Effect of carbon to nitrogen ratio of feed wastewater and sludge retention time on activated sludge in a submerged membrane bioreactor.

This paper investigated the effects of extracellular polymeric substances (EPS) on the activated sludge rheology in a submerged membrane bioreactor (sMBR) operated at different sludge retention time (SRT) values and different carbon to nitrogen ratios (C/N) of feed wastewater. The C/N ratios of the feed were adjusted accordingly so that synthetic wastewaters prepared simulated municipal wastewater, non-toxic wastewater with high C/N ratio and non-toxic wastewater with low C/N ratio. A number of important operational parameters such as mixed liquor suspended solid (MLSS), protein fraction of EPS (EPSp), carbohydrate fraction of EPS (EPSc), protein fraction of soluble microbial product (SMPp), carbohydrate fraction of SMP (SMPc), apparent viscosity, critical flux and hydrophobicity in mixed liquor and their correlations were investigated in the sMBR systems operated.

The effect of shock loading on the performance of a thermophilic anaerobic contact reactor at constant organic loading rate.

The influences of organic loading disturbances on the process performance of a thermophilic anaerobic contact reactor treating potato-processing wastewater were investigated. For this purpose, while the reactor was operated at steady state conditions with organic loading rate of 5.5 kg COD/m(3) · day, an instant acetate concentration increase (1 g/L) was introduced to the reactor.

The effect of transient loading on the performance of a mesophilic anaerobic contact reactor at constant feed strength.

Anaerobic contact reactor is a high rate anaerobic process consisting of an agitated reactor and a solids settling tank for recycling. It was proved earlier that this type of reactor design offers highly efficient performance in the conversion of organic matter to biogas. In this study, the effect of transient loading on reactor performance in terms of a number of key intermediates and parameters such as, COD removal, pH and alkalinity change, VFAs, effluent MLSS concentration and biogas efficiency over time was examined.

Evaluation of a fast wastewater odour characterisation procedure using a chemical sensor array.

Sewage treatment works are one of the major sources that cause atmospheric odour pollution. The increase in the number of complaints about odour nuisance is due to the increase in environmental concerns. Unfortunately, the legislation on odour nuisance from sewage treatment works is very limited.

Metal concentrations of simulated aerobic and anaerobic pilot scale landfill reactors.

Leachate and solid waste samples from aerobic and anaerobic simulated landfill reactors operated with and without leachate recirculation were characterized in terms of metals such as Fe, Ca, K, Na, Cd, Cr, Cu, Pb, Ni, and Zn. Metal concentrations of aerobic landfill reactor leachate samples are always below the regulation limits. The higher concentrations in anaerobic landfill leachate samples decreased to regulation limits after the landfill becomes methanogenic.

Leaching of silver from solid waste using ultrasound assisted thiourea method.

Thiourea leaching of precious metals such as gold and silver from ores has several advantages when compared with conventional cyanidation process. In recent years, the use of ultrasound in leaching processes is becoming increasingly popular in hydrometallurgy. This paper deals with combining these two techniques for silver leaching from solid waste of a cyanidation leach plant located in Kutahya, Turkey.