Is an Effective Recovery of Heavy Metals from Industrial Effluents Feasible?© Lehrstuhl fĂĽr Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2016)
Metallic elements and their compounds represent, depending on their concentration and bioavailability, a potential hazard to the health of humans, animals, plants and other living organisms. Large volumes of water contaminated with heavy metals or radioactive elements are generated e.g. during mining processes or industrial productions. In general, legal limits are low and strict to ensure purifying of wastewater.
Membrane Filtration of Wastewater Split Flows originating from Paper Industry and Biological Wastewater Treatment of the generated Membrane
Concentrates© DIV Deutscher Industrieverlag GmbH / Vulkan-Verlag GmbH (9/2011)
Wastewater effluents from deinking- and TMP processes were taken and were concentrated in 2 stages consisting of ultra- and nanofi ltration. Futher more, the concentrates were biologically treated with a single aerobic and a hybrid anaerobic-aerobic process. With a continuous anaerobic reactor and an aerobic SBR reactor experiments were conducted to study the variations in hydraulic retention time (HRT), food to biomass ratio (F/M) and wastewater concentrate. For the deinking wastewater concentrate, an overall average COD elimination of 51 % and 57 % was achieved for aerobic and anaerobic-aerobic treatment, respectively. Single stage aerobic treatment of TMP wastewater concentrate had an mean COD elimination effi ciency of 61 % and the hybrid anaerobic-aerobic treatment yielded 73 %. The temperature in the aerobic biological SBR reactor was kept stable at 30 °C with an F/M ratio between 0.01 and 0.5 gBOD5/(gSS · d).
Mine Water Treatment by Membrane Filtration Processes – Upscale Experiments© DIV Deutscher Industrieverlag GmbH / Vulkan-Verlag GmbH (9/2011)
The worlds’ diminishing water resources together with stricter environmental legislation lead to the development of new technologies for the treatment of water for mining activities. In arid and remote mining areas a promising approach is the integration of membrane technology into state of the art mine water treatment processes. Reverse Osmosis (RO) as well as the lower pressure nanofi ltration (NF) may be suitable operations to be considered. Recently an NF membrane identifi ed in previous tests was subject to further investigation in two upscale modules. The acidic water, containing sulphate and a variety of metals, was fed into a disc- and a Spacer Tube® spiral wound module in recycle mode. The setup was tested at different working points over 145 h for each run. The results show applicability of NF for desalination of AMD under the mentioned conditions. No visible drop in permeate fl ux was observed, although some scaling occurred.
Challenge of High Water Hardness and Elevated Temperature: MBR Pilot Trials in the Paper Industry under Mesophilic and Thermophilic Conditions© DIV Deutscher Industrieverlag GmbH / Vulkan-Verlag GmbH (9/2011)
The results of two MBR pilot trials conducted in paper mills are discussed. In the fi rst trial it was possible to operate a MBR pilot plant under the challenges of extremely high water hardness and a mean calcium concentration of 770 mg/L that caused massive scaling problems. An upstream lime softening pilot plant was designed and constructed. As a result, the fl ux increased again and the cleaning intervals could be extended signifi cantly. With the help of lime softening, 50–80 % of the calcium was removed upstream of the MBR pilot plant. The second part of the paper describes trials using a thermophilic aerobic MBR (TMBR) at 50 °C. A new and innovative use of submerged fl at-sheet MBR-modules to treat paper industry circuit wastewater was studied. The elimination rates of the TMBR regarding COD and BOD5 were 83 % and 99 %, respectively. A pilot trial was conducted at a fl ux of 4.5 to 8.5 L/m2/h. Lab experiments with a smaller membrane module had shown a higher fl ux of 8 to 13 L/m2/h.
Evaluation of Carbonaceous Organic Matter and Nitrogen Removal of Wastewater in Membrane Bioreactor© DIV Deutscher Industrieverlag GmbH / Vulkan-Verlag GmbH (9/2011)
This study aimed to evaluate the carbonaceous organic matter and nitrogen removal as well as the determination of critical fl ux in membrane bioreactor (MBR), with pre-anoxic zone, treating industrial wastewater of amino acids production. The reactor was operated under organic loading rate of 1.91 kg DQO/m3 · day and 0.18 kg NTK/m3 · day, the recirculation from aerobic reactor to anoxic reactor was 4 times the infl uent fl ow rate. The system showed an average removal of COD, TKN and TN of 97 %, 98 % and 92 %, respectively. The ultrafi ltration system was tested at various fl uxes between 25 and 37 L/m2·h, to determine the critical fl ux of 28 L/m2·h operating at 11.4 g/L of TSS and 35 days of sludge retention time. The results showed the technical feasibility of using MBR to remove organic matter from industrial wastewater of amino acids production.
A Screening Methodology for AOP Selection as Pre-Treatment in the Anaerobic Degradation of Olive Mill Effluent© PSP - Parlar Scientific Publications (12/2010)
In this study, individual and combined effects of various advanced oxidation processes (individual experiments: UV, O3, US, H2O2; combined experiments: UV/US, UV/O3, US/O3, UV/H2O2, US/H2O2, O3/H2O2, UV/US/O3, UV/US/H2O2, UV/ O3/H2O2, US/ O3/H2O2 and UV/US/O3/H2O2) as a pre-treatment option for olive mill effluent (OME), which is known to contain a significant amount of inhibitory compounds (e.g., phenolics and tannins), were comparatively evaluated in order to enhance the anaerobic degradation of OME.
Treatability Studies on Traditional Hand-Printed Textile Industry Wastewaters Using Fenton and Fenton-Like Processes: Plant Design and Cost Analysis© PSP - Parlar Scientific Publications (12/2010)
In this paper, the results of hand-printed textile wastewater using physico-chemical and biological treatment as well as Fenton and Fenton-like processes are presented. Fenton and Fenton-like processes showed high COD (>85%) and color (>90%) removal performance on evaluated effluents. On the other hand, capital and operation/maintenance (O&M) costs of conventional (physical/chemical/ biological) and Fenton process (physical/ Fenton process) treatment systems are presented, and specific capital costs for Fenton process system were estimated to be ca. 16% lower than that of conventional treatment. But detailed cost estimations reveal that Fenton process leads to slightly higher O&M costs.
Ozone Application as an Alternative Method to the Chemical Treatment Technique for Textile Wastewater© PSP - Parlar Scientific Publications (12/2010)
In this study, chemical oxidation demand (COD) and color removal efficiencies of a textile industry were tested using chemical and ozone oxidation treatment techniques. The industry uses chemical processes to treat its wastewater, so it needs much time and operation cost. Herein, the applicability of ozone oxidation techniques was discussed as an alternative to the chemical treatment.