Advanced technologies for the treatment of wastewaters from agro-processing industries and cogeneration of by-products: a case of slaughterhouse, dairy and beverage industries (original) (raw)
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Anaerobic processing of slaughterhouse wastewater in a SBR
Abattoir effluents reaching rivers and streams may contribute significant levels of biological oxygen demand (BOD) and other nutrients, resulting in riverbed and stream pollution. At the present time, there is no economical, stable, efficient, easyto-use and operate process to stabilize, deodorize, or recover usable energy from slaughterhouse wastewater. The Agriculture and Agri-Food Canada Research Center is currently evaluating the feasibility of using anaerobic digestion in sequencing batch reactors to treat slaughterhouse effluents. Experiments were conducted in four, 42 L bioreactors operated at 30°C. Preliminary results indicate that this process is very effective in reducing odours and the pollution potential of slaughterhouse wastewater. The process removed up to 98% and 91% of the total COD and suspended solids respectively. It also yielded a large quantity of high quality biogas (0.54-0.67L / g of VS fed) with a methane content of 70 to 75%. The proposed process is very stable and easy-to-operate.
Anaerobic Fermentation of Industrial Wastewater(Review Article)
Open Journal of Chemical Engineering and Science, 2014
Anaerobic Digestion is a series of chemical reactions during which organic material is decomposed through the metabolic pathways of naturally occurring microorganisms in an oxygendepleted environment. In nature this type of breakdown typically occurs in warm wet and dark environments, such as in the digestive tracts. The microorganisms are exploited in the biotechnological process of anaerobic digestion both to reduce the pollution caused by organic wastes and to produce methane, which can be used as a fuel. The number and types of microorganisms present in digesters are likely to depend upon the type of digester, its operating conditions and the waste composition. Anaerobic Digesters can be used on any carbon containing industrial wastewater i.e. food processing; pulp and paper; sugar and distillery; slaughterhouse; cheese whey and diary units; brewing industry and municipal sludge. Also, they provide an effective method for turning residues from different wastes, biogas (rich in methane which can be used to generate heat and/or electricity); fiber (this can be used as a nutrient-rich soil conditioner) and liquor (this can be used as liquid fertilizer). In the review paper, the special emphasis on some of the environmental requirements; indicators of treatment unbalance; types of high rate anaerobic reactors; the application of anaerobic fermentation of selected high strength industrial wastewaters; modelling of anaerobic digestion, and finally, there is a case study.
DESALINATION AND WATER TREATMENT
The sustainable management of a slaughterhouse wastewater calls for feasible treatment technologies to protect the environment and public wastewater treatment facilities. The technology of up-flow anaerobic sludge blanket provides an adequate procedural condition for the reduction of carbonaceous matter from the high organic wastewater resulted from the slaughterhouses. The scope of this research included a rapid review on current treatment technologies for the slaughterhouse wastewaters and an investigation of the treatment efficiency of an aerobic stage after a pre-anaerobic treatment in a batch system. A batch reactor system of 1 m 3 volume with a mixer was developed. The anaerobic stage of the batch reactor was initiated using 400 L of fresh slaughterhouse wastewater mixed with 40 L of primary sludge. Three samples from the anaerobic batch reactor were collected at 10 d interval and then five samples were collected from the reactor after being under aerobic condition at 4 d interval. The removal efficiency of biochemical oxygen demand, chemical oxygen demand, total Kjeldahl nitrogen and PO 4 was 25%, 62%, 42%, and 9% in 30 d, respectively. After the start of aeration system, the removal efficiency was improved up to 94%, 69%, and 93%, respectively, except for PO 4 that showed high variations within the sampling periods.
Review: Anaerobic Biotechnology for Industrial Wastewater Treatment
2019
There has been the microbiological formation of methane since ages in many diverse habitats such as paddies, marshes, hot springs, benthic deposits, deep ocean trenches, pigs, trees, cattle, termites, iguanas and human beings. Anaerobic digestion has been proved as the most appropriate technique for the treatment of high strength organic effluents. This technique is more reliable and advanced as compared to the conventional water treatment procedures. It uses very less amount of chemicals and treats the wastes in a facile and effective manner and has been considered as an attractive option for effluents treatment. The anaerobic technology causes the decrease of high level of waste materials and different reactors were developed for this particular purpose. It generates best level of fuels used as biogas. The biogas produced in anaerobic digestion burns cleanly and the biogas plants make more energy than they consume to operate, whereas the energy produced by aerobic digestion is ver...
Journal of Bioremediation & Biodegradation, 2016
In the eastern Africa sub-region, many industries discharge untreated effluents to nearby water resources, thereby polluting the environment. This is because the technologies applicable for wastewater treatment are expensive for these small-medium sized companies with low profit margins. Slaughterhouses belong to this category of industrial setup. The objective of this study was to investigate treatment of meat processing wastewater using anaerobicaerobic/anoxic Sequencing Batch Reactors (SBRs) operated in series. Reactors were operated for one year using meat processing wastewater. Hydraulic retention time was 2 days for the anaerobic SBR, and 1 day for the aerobic/ anoxic SBR while the organic loading was 12.8 kg COD/m 3 /day. In the anaerobic SBR, removal efficiencies for total and soluble chemical oxygen demand (TCOD and SCOD), total suspended solids (TSS) and turbidity were 79, 76, 79, and 70%, respectively, with effluent mean concentrations of 3554 ± 58 mg/L, 762 ± 3 mg/L, 2307 ± 21, and 2800 ± 9 FAU. Conductivity, ammonia-nitrogen, ortho-phosphates and total phosphorus concentrations increased by 38, 80, 81 and 71%. Pollutant removal efficiencies in the aerobic/anoxic SBR were 98, 96, 97, 89, 74, 97, 91, 90, and 86% for TCOD, SCOD, BOD, TSS, turbidity, ammonium nitrogen (NH 4 +-N), total nitrogen (TN), orthophosphorus (o-PO 4 3-P), and total phosphorus (TP), respectively. Except TKN (35 ± 4 mg/L) and o-PO 4 3-P (8 ± 1 mg/L), all other parameters in the aerobically treated effluent met national discharge standards. Thus, abattoir effluent can be treated using anaerobic-aerobic/anoxic SBR system.
2017
The introduction of cleaner technologies through the reuse of wastes for energy recovery can improve the environmental performance of agro processing industries. However, existing waste treatment methods in Ethiopian agro processing industries do not innovatively add value to the wastes by recovering bio-energy to contribute to the ever increasing energy demands in the country and reduce greenhouse gas emissions. In this study anaerobic codigestion of agro-industrial wastes: tannery waste water (TWW), tannery solid waste (TSW) and dairy waste water (DWW) was investigated using two phase anaerobic sequencing batch reactor (ASBR) for enhanced waste to energy conversion. Laboratory scale anaerobic digesters; one used for acidogensis and the other for methanogensis with 0.4L and 0.6L working volumes, respectively, were used in semi continuous mode operation under mesophilic range (38+2 0 C). Operational parameters such as mixing ratios of substrates, hydraulic retention time (HRT) and organic loading rate (OLR) were optimized for improved process performance and stability of both hydrolytic-acidogenic and methanogenic steps. The optimum operational conditions of hydrolytic-acidogenic step at four mixing ratios of
Anaerobic treatment of waste beer
Environmental Progress, 2005
This research study focused on the biotreatability of waste beer in an anaerobic environment. A comparison of two bioreactors, ASBR (anaerobic sequencing batch reactor) and UASB (upflow anaerobic sludge blanket) reactors, was performed. The experiments were carried out in the two reactors under identical conditions at room temperature and 35°C under organic loading rates (OLRs) from 2 to 20 kg chemical oxygen demand (COD) m Ϫ3 day Ϫ1. The results show that the performance in the ASBR was better than that in the UASB reactor without a recirculation system at the two temperatures under all organic loading levels. In the ASBR, soluble COD reductions of 95 to 57% and 93 to 70% were obtained as the OLR increased from 2 to 20 kg COD m Ϫ3 day Ϫ1 at room temperature and 35°C , respectively. In the UASB reactor without a recirculation system, the soluble COD reduction was 78 to 49% and 80 to 65% under the same increase in OLR as the ASBR at room temperature and 35°C, respectively. Methane production was measured in the ASBR at both temperatures. Results for methane production were close to the expected yields of 0.39 m 3 /kg COD removed for an OLR of 2 to 6 kg COD m Ϫ3 day Ϫ1 , and lower than the expected values for an OLR of 8 to 20 kg COD m Ϫ3 day Ϫ1. Therefore, anaerobic treatment of beer is sustainable by both reactors if the organic load is limited to 6 kg COD m Ϫ3 day Ϫ1 .
Treatment of slaughterhouse wastewaters using anaerobic filters
Environmental Technology, 2014
In this paper, a laboratory-scale experimentation allowed comparing the performances of two upflow anaerobic packedbed filters filled with different packing materials and operating at mesophilic conditions (30 • C) for treating slaughterhouse wastewaters. Methane production was experimentally evaluated considering different volumetric organic loading rates as well as feeding overloading conditions. Although filter performances declined with loading rates higher than 6 kg COD in m −3 d −1 , the chemical oxygen demand (COD) removal efficiency remained always above 60%. The experimental results allowed for determining kinetic parameters for bacterial growth rate and methane production, following Monod and Chen-Hashimoto models, respectively. Results demonstrated that the reactors reached a cellular retention time significantly greater than the hydraulic retention time. The kinetic parameter values (K s , μ max ) revealed the low microorganisms' affinity for the substrate and confirmed the moderate biodegradability of slaughterhouse wastewater. The kinetic analysis also allowed the comparison of the filters performances with another anaerobic system and the assessment of the parameters useful for real-scale plant design. The system design, applied to a medium-sized Argentinean slaughterhouse, demonstrated to (i) be energetically self-sufficient and (ii) contribute to the plant's water heating requirements. growth reactors [11]: fluidized bed reactors, anaerobic expanded bed reactors and upflow packed-bed reactors (UPBR) or filters (UPBF). Saravanan and Sreekrishnan argued that to optimize the design and scale break, mathematical models are needed. In anaerobic reactors, performances are affected by the hydrodynamics of the reactor (i.e. pattern flow), the mass transfer in the biofilm and the kinetic effects, which are also influenced by the high loading rates and the presence of toxic compounds. The methods for analysing the models that describe the studied systems are mainly based on the process phenomenology and the concentration gradient. The determination of the parameters describing the behaviour of a system can be accomplished using empirical facts or applying mathematical models. For model application, empirical data provided by operating plants, laboratory and pilot-plant experiences, collected using effluents of similar characteristics to those presently under study, are necessary. However, the assay conditions, the technology used and the loading rate cannot always be identical, adding a degree of uncertainty in the evaluation of alternatives. Moreover, if the purpose is the process control, the use