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This revision's objective was to consult, analyze and conclude the main treatments applied to waste waters from dairy industries. The most used technologies are the biological and physical-chemical ones, along with beneficial microorganisms, micro algae, coagulants, etc. Nevertheless, anaerobic digestion is a biological process applied to waters of this sort, due to the fact it has greater advantages if compared to other treatments, like a higher stabilization degree and a low biomass growth. It was found that waste waters have high levels of dissolved or suspended solids, including fat, oils and nutrients such as ammonia, minerals and phosphates. [ABSTRACT FROM AUTHOR]

The generation of solid wastes and wastewater in Mexico, as other countries, has increased considerably of late years, so its treatment is very important to reduce the pollution. In this work are presented the results on the anaerobic digestion of lixiviate generated with the hydrolysis and acidogenesis of the organic fraction of municipal solid waste recollected in the Universidad Autónoma Metropolitana-Unidad Iztapalapa coffee shop. Theses lixiviated were diluted with municipal wastewater to different organic loads (2,3-20 gCOD/L.d) and after treated anaerobically in UASB reactor. Biogas's average production in the last load of the UASB reactor was up to 12 L/L.d with an efficiency to remove COD on top of 90 % and a production of methane of 0,38 LCH4gVSS-1. [ABSTRACT FROM AUTHOR]

Introduction. Dairy industry is one of the most important sectors in industrialized and developing countries. Approximately 90% of the milk used in cheese industries is eliminated as whey (or lactoserum). Statistics indicate that lactoserum or whey is discarded as an effluent and brings a serious environmental problem, due to the fact that it affects, physically and chemically, the soil's structure. This reduces the performance of crops and, when whey is disposed by being pouring it into water bodies, aquatic life is reduced because it drains the dissolved oxygen. Objective. Evaluate a UASB reactor by means of anaerobic digestion, using two organic loads of 3 g/L/.day COD and 4 g/L/.day COD. Materials and methods. Different laboratory analyses were performed on both loads: COD, protein, sugars, VFA, methane and ammonium. Results. The results indicated that the COD efficiency was above 65%; the sugars' degradation was total and the protein degradation was higher that 78%, while the ammonium, methane and VFA concentrations were all within the normal parameters for the reactor's correct work. Conclusion. The UASB reactor is a god option to treat waste water, as it contains whey in two different organic loads. [ABSTRACT FROM AUTHOR]

Introduction. For this research work, the acid whey produced by Oaxaca cheese industry in a UASB reactor was used. The reactor was subjected to three constant charges and three punctual charges of the whey. The reactor had a nominal capacity of 2.9 L with 1.9 days of hydraulic retention with an upward flow and a sludge blanket of 40% of the reactor's volume. Objective. Evaluate the behavior of the UASB reactor with three different charges of whey. Materials and methods. Three different constant charges of whey were used (5200, 7800 and 10500 mg CDO/L each one) during 22 days, and punctual charges of 32000, 47000 and 65000 mg DQO/L per day of whey, for each one, during 24 hours. Both the influent and the effluent were determined: total of sugars, volatile fatty acids (VFA's) protein, pH, methane and CDO. Results. The findings demonstrated that in the constant charges used the removal efficiency of CDO was 26 %, and for the punctual charges was 57 %. The sugar degradation efficiency was 95% for the constant and the punctual charges. For the protein, the removal efficiencies in the constant charges were above 27 % and for the punctual charges the efficiency was 46 %. Conclusion. The values of volatile fatty acids and methane were all within the limits for a good functioning of the reactor. Nevertheless, the pH had acid values below the ones recommended. [ABSTRACT FROM AUTHOR]

Due to its advantages over aerobic process in terms of higher degree of wastewater stabilization, lower microbial yield and nutrient requirement, no oxigen requirement and methane production, anaerobic digestion presents as a viable alternative for dairy industry wastewater treatment. in this investigation the performance and capacity of an upflow anaerobic blanket reactor (UASB) treating whey for the organic matter removal were evaluated. the uasB reactor was operated at a hydraulic retention time (HRT) of 1,3 d and organic loading rates ranging from 1.7 to 18.5 g cod/l.d. the maximum total chemical oxygen demand (COD) and total volatile solids (TVS) reduction was 98 and 97,2 % respectively occurred at the loading rates of 9.6 g cod/l.d. the cod removal efficiency was reduced to 77 % when the organic loading rate was increasing to 18,6 g cod/l. d. the maximum anaerobic methane generation for the cheese whey studied was found to be 0,27 l cH4/g cod influent and the biogas methane content was 56%. Based on these results, it is recommended to use a uasB reactor for the anaerobic treatment of cheese whey to produce a good effluent quality. [ABSTRACT FROM AUTHOR]

Introduction. Urban societies produce solid and liquid waste in a growing quantity. For a long time, several alternatives have been used for managing such wastes in an integrated way, but those alternatives are now out fashioned. Objective. To compare two anaerobic digestion systems with and without separation of the hydrolytic phase in a laboratory scale, for the biomethanization of the organic fraction of urban solid waste (FORSU, in Spanish) and domestic waste water (ARD in Spanish), evaluating its performance under efficiency for eliminating organic matter and methane generation terms. Materials and methods. Two systems of anaerobic methanization were compared in a laboratory scale. Mesophilic, the first one, was an anaerobic reactor of ascending flow (R1) and the second was a system separated into two phases: Hydrolytic reactor of ascending flow (R2) and an anaerobic ascending flow reactor of sludge blanket (UASB). The carbon source used was the organic fraction of urban solid waste and domestic urban waste water. Both systems were evaluated during 120 days. Results. For R1, the maximum organic charge speed (VCO in Spanish) was 4,7 Kg, chemical oxygen demand (COD)/m³-d, time of hydraulic retention (HRT), 24 hours, pH 7,01 at 7,77 to obtain a methane performance of 0,17 L/g initial volatile solid. On the other hand, the R2+UASB, the maximum organic charge speed to depurate was 17 Kg chemical oxygen demand m³-d, the HRT for R2 was 24 hours and for the UASB was 12 hours, with a pH for R2 between 4,92 and 5,34, and for the UASB, between 6,60 and 7,80, obtaining a methane performance of 0,29 L/g initial volatile solid. The highest production of volatile fatty acids was registered in R2 with 46,96g/L expressed in acetic acid (HAc). The elimination rate of chemical oxygen demand in R1 was 91% and the elimination rate of volatile solid was 92%. For R2 +UASB the chemical oxygen demand eliminated was 96% and the volatile solid was 97%. Conclusion. Applying a hydrolytic reactor to an UASB allowed removing more organic charge and a better methane production. [ABSTRACT FROM AUTHOR]

In this study it war fulfilled a quality and quantity diagnosis of the leached that war generated in the land-fill "El Guayabal" of San José of Cúcuta city and the two systems of Biological treatment were appraised in one laboratory scale for the treatmen of this types of residual water. At moment of experience leached presented one COD rank from 7650 to 28250 mg/L. The tretment tried systems were: an UASB type anaerobic reactor, and one Rotating Biological Contactor system. The biggest load adsorbed by Rotating Biological contactor system was 31 g COD/m²*d, with an average of removal efficiency about COD of 70 %; and greatest removal efficiency over 90 % for a very best load in one rank from 15 to 20 g COD/m²*d, moreover this system presented great stability in front of important variatons on leched characteristics and absence of desagreeble faint odors. The removal percentages of COD in UASB reactor were very variable, whit low additional amount, and descents very marked, this indicate that there was not very best fuctión of the process during the most part of operating time of UASB reactor, this was principally due to that the stric system condictions weren't done. [ABSTRACT FROM AUTHOR]

The start-up period of anaerobic reactors is a critical and relatively slow step since it has to develop a sufficient and well-balanced microbial population that frequently determines the operation's efficiency of the reactor. The biomass activity depends on many factors; with relation to the micro-nutrients, the lack of one can limit the biological process; and methanogenic bacteria have also shown a critical dependence on iron. The influence of the continuous addition of ferric chloride on the improvement of a sludge used as inoculum at the start-up of an anaerobic reactor has been evaluated. The sludge came from an anaerobic UASB reactor used for treating domestic sewage and presenting the characteristics of a flocculent sludge, with low methanogenic activity and settleability. The ferric chloride dosage of 4.83 mg/l was equivalent to a soluble iron concentration of 0.5 mg/l. Two reactors were used, the first one was utilized as control (R1) and on the second (R2 reactor) ferric chloride was continuously added. Both reactors achieved an organic rate load -- ORL up to 3 6.40 kg COD/m³.d and an up-flow velocity of 8.55 cm/h. Compared with the control reactor (R1), the R2 reactor was less susceptible, with better COD removal efficiencies, in shorter times. Additionally, the sludge quality at the end of the start-up was better in terms of methanogenic activity and settleability. The strategy used to improve the sludge quality, showed its viability and favorable effects on the sludge quality of poor characteristics used as inocula to start- up anaerobic reactors. [ABSTRACT FROM AUTHOR]

It is carried out a study on the establishment of a system of treatment of wastes of sugar alcohol distillery using digesters UASB. As bases for the analysis the waste of sugar alcohol distillery Nauyú was characterized and the reactor was evaluated at bank scale, the efficiency of the treatment, the composition of the effluent and of the slurry. They were also considered the economic benefits that are derived from the use of the biogas as fuel for the feeding of the boiler, the slurry as animal food and the effluent as fertilizer of sugar cane. The integral system proposed redeems the investment approximately in three years, for what is considered a sustainable economic alternative. [ABSTRACT FROM AUTHOR]