Anaerobic wastewater treatment

Aerobic treatment is generally appHed to lower strength wastewaters, whereas anaerobic treatment is employed as a pretreatment for high strength wastewaters. The choice of process depends both on the concentration of organics and the volume of wastewater to be treated. 

Anaerobic treatment is usually employed for high strength wastewaters. In anaerobic treatment, complex organics are broken down through a sequence of reactions to end products of methane gas, CH, and carbon dioxide, CO2 ... 

Corbo, P. and Ahlert, R.C., Anaerobic treatment of concentrated industrial wastewater, Environ. Prog., 4, 22-26, 1986. 

The wastewaters generated by the adhesive industries contain high concentrations of both carbon and nitrogen compounds. The process chosen to treat these wastewaters will depend on their COD/N ratio. When the COD/N ratio is high, an anaerobic treatment is the best option as it will save costs... 

Different kinds of bioreactors and configurations have been used to treat wastewater containing formaldehyde and urea, and three different kinds of treatments can be applied anaerobic treatment, aerobic treatment, and combined nitrification and denitrification treatments. 

Anaerobic treatment is recommended for highly concentrated COD wastewater, as the amount of methane generated can compensate for the energy cost in maintaining the temperature of the reactor. 

In this section, we will discuss selected anaerobic treatment systems that are in use for food industry wastewater treatment. 

Anaerobic treatment systems such as AFs, UASBs, and AFBRs are available for the treatment. Factors such as the organic strength of the target wastewater stream, footprint, and cost of operation are important when it comes to the selection of suitable technology. 

Kalyuzhnyi, S.V., Saucedo, J.V., and Martinez, J.R., The anaerobic treatment of soft drink wastewater in UASB and hybrid reactors, Applied Biochemistry and Biotechnology, 66, 291-301, 1997. 

Fanga HHP, Lianga DW, Zhanga T, Liu Y (2006) Anaerobic treatment of phenol in wastewater under thermophilic condition. Water Res 40 427-434... 

Tanemura, K., Kida, K., Ikbal, Matsumoto, J., and Sonoda, Y., Anaerobic Treatment of Wastewater with High Salt Content from a Pickled-Plum Manufacturing Process, J. Ferm. Bioeng. 77 188 (1994a)... 

El-Gohary FA, Badawy MI, El-Khateeb MA, El-Kalliny AS (2009) Integrated treatment of olive mill wastewater (OMW) by the combination of Fenton s reaction and anaerobic treatment. J Hazard Mat 162 1536-1541... 

Costs of treatment techniques vary strongly. The costs not only depend on the type of treatment process but also on the concentrations of the pollutants to be removed, and the required removal efficiency of the pollutants. Most treatment steps have been developed for the treatment of wastewater at a temperature above zero degree Celsius as lower limit and somewhat above ambient temperature as upper limit. An exception is anaerobic treatment, which is often also applied at temperatures of about 60°C. In general little or no experience is available with the purification of wastewater at temperatures above 50° C. Experimental research is necessary to assess the feasibility of a treatment step in that temperature range. 

For the assumed type of wastewater this pretreatment step is very often followed by an anaerobic treatment step. This is especially the case if the... 

Some type of toxic pollutants which at present may be present in the wastewater will be banned out. This makes the composition of the wastewater less complex so that compounds can more easily be recovered for reuse. Taking these aspects into account, together with other specific aspects related to closed water loop systems, it can be expected that future developments in the treatment technology of wastewater will be focused on Anaerobic treatment... 

Many wastewater flows in industry can not be treated by standard aerobic or anaerobic treatment methods due to the presence of relatively low concentration of toxic pollutants. Ozone can be used as a pretreatment step for the selective oxidation of these toxic pollutants. Due to the high costs of ozone it is important to minimise the loss of ozone due to reaction of ozone with non-toxic easily biodegradable compounds, ozone decay and discharge of ozone with the effluent from the ozone reactor. By means of a mathematical model, set up for a plug flow reactor and a continuos flow stirred tank reactor, it is possible to calculate more quantitatively the efficiency of the ozone use, independent of reaction kinetics, mass transfer rates of ozone and reactor type. The model predicts that the oxidation process is most efficiently realised by application of a plug flow reactor instead of a continuous flow stirred tank reactor. 

V. Suryavati, S. Sharma, S. Sharma, P. Saxena, S. Pandey, R. Grover, S. Kumar and P.K. Sharma, Acute toxicity of textile dye wastewaters (untreated and treated) of Sanganer on male reproductive systems of albino rats and mice. Reprod. Toxicol., 19 (2005) 547-556. B. dos Santos, A.E. Bisschops, F.J. Cervantes and J.B. van Lier, The transformation and toxicity of anthraquinone dyes during thermophilic and mesophilic anaerobic treatments. J. Biotechnol., 115 (2005) 345-353. 

J.P. Steyer, D. Roland, J.C. Bouvier, and R. Moletta. Hybrid fuzzy neural network for diagnosis - Application to the anaerobic treatment of wine distillery wastewater in a fluidized bed reactor. Wat. Sci. TechnoL, 36(6-7) 209-217,... 

D. J. Batstone, J. Keller, R.B. Newell, and M. Newland. Model development and full scale validation for anaerobic treatment of protein and fat based wastewater. Wat. Sci. TechnoL, 36 423-431, 1997. 

The activated sludge process has been found to be the most efficient treatment for various categories of pharmaceutical wastewater [14,15,19,42-46]. It has also been reported that this process can be successfully employed for the removal of tert-butanol, a common solvent in pharmaceutical wastewater that cannot be degraded by anaerobic treatment [44]. At a volumetric loading rate of 1.05 kg COD/m day, HRT (hydraulic retention time) of 17 hours, and mixed liquor dissolved oxygen concentration of 1 mg/dm, the tert-butanol can be completely removed by the activated sludge process. 

Anaerobic treatment of high-strength wastewater containing high sulfate poses several unique problems. The conversion of sulfate to sulfide inhibits methanogenesis in anaerobic treatment processes and thus reduces the overall performance efficiency of the system. Treatment of high sulfate pharmaceutical wastewater via an anaerobic baffled reactor coupled... 

Table 13 Commercial Suppliers of Full-Scale Anaerobic Treatment Plants for Industrial Wastewaters...

HaU, E.R. Anaerobic treatment of wastewaters in suspended growth and fixed film processes. In Design of Anaerobic Processes for the Treatment of Industrial and Municipal Wastes , Malin, J.F. Pohland, F.G., Eds. Technomics Lancaster, PA, 1992, 41-118. 

Iza, J. Colleran, E. Paris, J.M. Wu, W.M. International workshop on anaerobic treatment technology for municipal and industrial wastewaters - summary paper. Water Set Technol. 1991, 24 (8), 1-16. 

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