Integrated anaerobic treatment of dairy industrial wastewater and sludge (original) (raw)
Related papers
Bioresource Technology, 2004
The feasibility of using upflow anaerobic sludge blanket (UASB) reactors for the treatment of dairy wastewaters was explored. Two types of UASBs were used––one operating on anaerobic sludge granules developed by us from digested cowdung slurry (DCDS) and the other on the granules obtained from the reactors of M/s EID Parry treating sugar industry wastewaters. The reactors were operated at HRT of 3 and 12 h and on COD loading rates ranging from 2.4 kg per m3 of digester volume, per day to 13.5 kg m−3 d−1. At the 3 h HRT, the maximum COD reduction in the DCDS-seeded and the industrial sludge-seeded reactors was 95.6% and 96.3%, respectively, better than at 12 h HRT (90% and 92%, respectively). In both the reactors, the maximum, the second best, and the third best COD reduction occurred at the loading rates of 10.8, 8.6 and 7.2 kg m3 d−1, respectively. At loading rates higher than 10.8 kg, the reactor performance dropped precipitously.Whereas in the first few months the reactors operating on sludge from EID Parry achieved better biodegradation of the waste, compared to the reactors operated on DCDS, the performance of the latter gradually improved and matched with the performance of the former.
Dairy industries have shown us great growth in size and number in most countries of the world. In recent times, the dairy industries have started incorporating sophisticated processing equipments with CIP cleaning systems and PLC based process automation systems. The dairy mill effluent is characteristically biodegradable with BOD 5 , of 2500-3500 mg/l and COD restricted to 4000-5000 mg/l and p H from 5.6-8.6 .The biodegradability range of dairy effluent is from 0.63 to 0.72 .The hybrid anaerobic reactor is assessed with a pilot model (8 litres) for the treatment of dairy effluent .The present study evaluates the performance of hybrid anaerobic reactor under different seasons, viz , rainy and winter for treating dairy effluent .The model was made run under varying operating conditions , viz ,influent flow rate(2.083,2.500,3.571,5.000,8.330lit/hr) and influent COD (1599.88,2091.98,2564.46 mg/l), OLR(Rainy season) (0.025,0.031,0.036 kg/COD/m 2 day),(winter season)(0.018,0.026,0.032kg/COD/m 2 day) and HRT (6.00,10.00,14.00,20.00,24.00hrs)are interpreted for the respective conditions .The COD removal was observed for minimum of 78.10% starting from 78.86% for rainy season and maximum of 79.10% from 80.61%COD removal for winter season .
11.[43-48]Treatability Studies of Dairy Wastewater by Upflow Anaerobic Sludge Blanket Reactor
In any dairy plant, the quantity and characteristics of effluent is depending upon the extent of production activities, pasteurization of several milk products. The anaerobic digesters are used in the first phase of treatment, which is followed by high rate aerobic treatment. It remains as the most common effluent treatment scheme for dairy plants. The Indian dairy industry is stated to have the growth at more than 15% and waste water is poised to cross 150 million tones / annum. The requirement for milk and milk products is keep growing in steady state, making a significant impact on the Indian agriculture domain. The dairy industries require large quantity of water for the purpose of washing of cans, machinery and floor, the liquid waste in a dairy originates from manufacturing process, utilities and service section. So there is every need to reuse the waste water generated with proper and efficient treatment methods. Biological wastewater treatment has been performed in many different ways .In order to overcome the limitations of suspended and attached growth systems. Upflow Anaerobic Sludge Blanket reactors are designed. UASB is a hybrid type of reactor, involving both suspended and attached growth process. This study involves the treatment of dairy industry wastewater by UASB reactor by varying the retention times in days for a particular organic loading rate . This has effectively removed BOD, COD and other parameters because of the combined suspended and attached growth processes
Desalination, 2008
The feasibility of using an up-flow anaerobic sludge blanket (UASB) reactor followed by activated sludge (AS system) for the treatment of wastewater discharged from dairy factory was explored. The UASB reactor was operated at a hydraulic retention time (HRT) of 24 h and organic loading rates (OLRs) ranging from 1.9 to 4.4 kgCOD/m 3 .d. The average total chemical oxygen demand (COD total ) and total biological oxygen demand (BOD 5total ) concentrations of the UASB reactor effluent were 1385 and 576 mg/l, corresponding to percentage removal of 69% and 79%, respectively. Total suspended solids (TSS) and volatile suspended solids (VSS) removal averaged above 72% and 75%, respectively. Residual phosphorous and oil and grease concentrations of the UASB reactor effluent were 8.2 and 44 mg/l, corresponding to percentage removal values of 63% and 83%, respectively. This good performance could be attributed to the relatively long sludge residence time (SRT =76 d) imposed to the reactor. Total and faecal coliform counts were reduced in the treated effluent by a value of 1.07 and 0.9 log 10 , respectively. The net sludge yield coefficient was found to be 0.2 g VSS per g COD total removed per day, corresponding to 20% of the total influent COD imposed to the UASB reactor. The volatile solids / total solids (VS/TS) ratio of 0.66 of excess sludge revealed its good quality. Preliminary batch experiments of the AS system treating UASB reactor effluent indicated first-order removal kinetics between total organic carbon (TOC) and contact time. The TOC removal reached 80%, resulting in only 47 mg/l in the final effluent at a HRT of 2.0 h. Accordingly, the AS system was operated at a HRT of 2.0 h. The system achieved a substantial reduction of COD total , BOD 5 total , TSS and oil and grease resulting effluent quality with residual values of only 35.0, 7.0, 14.0 and 2.8 mg/l, respectively. The geometric mean of total and faecal coliform counts was reduced by a value of 1.28 and 1.64 log 10 , respectively. Based on these results, it is recommended to use of an integrated system consisting of a UASB reactor followed by the AS system for the treatment of a combined dairy and domestic wastewater to produce a good effluent quality complying with the standards for discharge into agricultural drains.
11.Treatability Studies of Dairy Wastewater by Upflow Anaerobic Sludge Blanket Reactor
In any dairy plant, the quantity and characteristics of effluent is depending upon the extent of production activities, pasteurization of several milk products. The anaerobic digesters are used in the first phase of treatment, which is followed by high rate aerobic treatment. It remains as the most common effluent treatment scheme for dairy plants. The Indian dairy industry is stated to have the growth at more than 15% and waste water is poised to cross 150 million tones / annum. The requirement for milk and milk products is keep growing in steady state, making a significant impact on the Indian agriculture domain. The dairy industries require large quantity of water for the purpose of washing of cans, machinery and floor, the liquid waste in a dairy originates from manufacturing process, utilities and service section. So there is every need to reuse the waste water generated with proper and efficient treatment methods. Biological wastewater treatment has been performed in many different ways .In order to overcome the limitations of suspended and attached growth systems. Upflow Anaerobic Sludge Blanket reactors are designed. UASB is a hybrid type of reactor, involving both suspended and attached growth process. This study involves the treatment of dairy industry wastewater by UASB reactor by varying the retention times in days for a particular organic loading rate . This has effectively removed BOD, COD and other parameters because of the combined suspended and attached growth processes
Water research, 2003
The wastewaters discharged by raw milk quality control laboratories are more complex than the ones commonly generated by dairy factories because of the presence of certain chemicals such as sodium azide or chloramphenicol, which are used for preserving milk before analysis. The treatment of these effluents has been carried out in a full-scale plant comprising a 12 m(3) anaerobic filter (AF) reactor and a 28 m(3) sequential batch reactor (SBR). After more than 2 years of operation, a successful anaerobic treatment of these effluents was achieved, without fat removal prior to the anaerobic reactor. The organic loading rates maintained in the AF reactor were 5-6 kg COD/m(3) d, with COD removal being higher than 90%. No biomass washout was observed, and most of the fat contained in the wastewaters was successfully degraded. The addition of alkalinity is crucial for the maintenance of a proper buffer medium to ensure pH stability. The effluent of the AF reactor was successfully treated i...
A comparison of two bench-scale anaerobic systems used for the treatment of dairy effluents
International Journal of Dairy Technology, 2010
The objective of this work was to compare two anaerobic reactor configurations, a hybrid upflow anaerobic sludge blanket (UASBh) reactor and an anaerobic sequencing batch reactor with immobilised biomass (ASBBR) treating dairy effluents. The reactors were fed with effluent from the milk pasteurisation process (effluent 1-E1) and later with effluent from the same process combined with the one from the cheese manufacturing (effluent 2-E2). The ASBBR reactor showed average organic matter removal efficiency of 95.2% for E1 and 93.5% for E2, while the hybrid UASB reactor showed removal efficiencies of 90.3% and 80.1% respectively.
Sequencing batch reactors has been receiving increasing attention in recent years, having been applied in the treatment of dairy wastewater in bench scale studies, especially because dairy plants work in a batch regime, which offer a good opportunity to use the sequential batch process for wastewater treatment. This study compared two reactors in pilot-scale, the Anaerobic Sequencing Batch Reactor (ASBR) and the Anaerobic Sequencing Biofilm Batch Reactor (ASBBR), in the treatment of wastewater from dairy plant. The reactors were fed with wastewater from dairy plant and they were operated with two time cycle: 48-h and 24-h. Before to be sent to anaerobic sequencing batch reactors, the wastewater was pumped through a tank of fat separation, following by gravity to an equalization tank which reduced variation in flow, pH and composition of wastewater. Lime and sodium bicarbonate were used for pH adjustment. The organic matter concentration in influent, measured as chemical oxygen demand (COD), was approximately 4,500 mg/L. ASBR showed high efficiency in removing organic matter (over 92 %), with an actual production of the bicarbonate alkalinity and low concentration of volatile fatty acids in effluent for both time cycle. in contrast, the ASBBR showed a decrease in efficiency of organic matter removal when the cycle time was changed to 24h, the ASBR showed the same performance in relation to total COD removal observed for 48-hour cycle. In contrast, ASBBR showed a considerable drop in removal efficiency of organic matter and greater instability in the operation, a lower bicarbonate alkalinity concentration in the effluent compared to ASBR and it presented a high concentration of volatile fatty acids in the end of cycles (714 ± 491 mg / L). In addition, It was verified the feasibility of applying the ASBR in the treatment of dairy effluent, since this reactor showed high removal efficiency of organic matter to a 24-h cycle.
Performance of a two-phase anaerobic digestion system when treating dairy wastewater
Water Research, 1998
ÐPerformance of a laboratory-scale two-phase anaerobic digestion system treating dairy wastewater was investigated using the predetermined operating criteria for the anaerobic acidi®cation reactor. The results, obtained from a 9 month operation, showed that overall, 90% COD and 95% BOD removal eciencies at an organic loading rate (OLR) of 5 kg COD/m 3 d and a hydraulic retention time (HRT) of 2 days were achieved. The acidogenic phase completely stirred tank reactor was operated up to an OLR of 23 kg COD/m 3 d with a HRT of 0.5 days whereas the methanogenic-phase up¯ow anaerobic ®lter was loaded up to an OLR of 7 kg COD/m 3 d with a HRT of approximately 1.5 days. In the pre-acidi®cation reactor, a maximum of 60% conversion rate of COD to volatile fatty acids (VFAs) was achieved at an OLR of 12 kg COD/m 3 d after which the conversion rate remained reasonably constant while a 60% removal of total fatty matter was obtained. Good separation of acid and methane phases was achieved as indicated by low and high methane yields in the ®rst and second phases respectively. VFAs produced during the acidogenic phase were eectively consumed in the methanogenic phase.
In recent years due to the increase in the population, a high demand for the more efficient use of water resources and its reuse has tremendously changed in both urban & rural areas. The main objective of this study was to evaluate the removal efficiency & performance of effluent treatment plant in a diary industry in terms of COD, BOD, TSS, TDS, oil and grease, alkalinity, total hardness, chlorides and dissolved oxygen removal. An intensive analytical programme was followed for 6 months for monitoring dairy wastewater. Samples of wastewater were collected from the effluent treatment plant from the dairy for the characteristic analysis. This study revealed that average concentrations of COD, BOD, TSS, TDS, oil and grease, alkalinity and chlorides removal in the effluent from the effluent plant were 155 mg /l, 85 mg /l, 34.5 mg/l, 661 mg/l, 6.3 mg/l, 7.05 mg/l and 81 mg/l respectively, which met the effluent standards for all the above described parameters. The efficiency of treating dairy wastewater was studied and its performance was assessed by monitoring COD, BOD, TSS, TDS, oil and grease, alkalinity and chlorides removal .The reactor achieved COD, BOD, TSS, TDS, oil and grease and chlorides removal efficiency was observed as 77.0 %, 87.0 %, 47.1%, 57.0 %, 92.0 % and 49.8 % respectively. The data presented also revealed that the order of efficiency was TSS < chlorides < TDS < COD < BOD < oil & grease.