Anaerobic Wastewater Treatment in the Food Processing Industry: Two Case Studies

Abstract

This article relates two experiments with wastewater treatment in the food processing industry. One of them refers to the use of an anaerobic filter (meat processing industry) and the other to the use of an upflow anaerobic sludge blanket reactor-UASB (vegetable and fruit processing industry). In the first case, the study describes the performance of an anaerobic filter which has been working for 6 years and provides COD removal efficiency (including primary treatment) equal or better than 80% with an organic loading of 1.4 kg of COD/m3 day. The reactor has a bed of broken stones with size of 0.75 m having a medium hydraulic detention time of 13 h. Discharges of accumulated sludge in a false bottom below the filter are made at intervals of 2 or 3 months.In the second case, the study describes the performance of an upflow anaerobic sludge blanket reactor (88 m3) during 255 days of operation including the adaptation phase or startup. This reactor receives wastewater from vegetable and fruit processing including tomato , corn, guava and peach. At the end of each operational phase studied, the COD removal efficiency was about 80%. In the last phase (7.5 h hydraulic detention time), the organic loading was 1.4 kg of COD/m3 day and the hydraulic loading was 3.2 m3/m3 day.

Mesophilic and thermophilic anaerobic digestion of biologically pretreated abattoir wastewaters in an upflow anaerobic filter

“…The VFA levels in thermophilic digester increased with the increase of OLR from 6 to 9 g COD/L d (442-965 mg/L). Organic loads used in this work were considerably comparable with those found in the literature [38,50,51]. Higher COD loadings appear to lead to poorer performance.…”

Characteristics of Raw Wastewater from Albanian Dairy Processing Plants and Some Treatment Options

“…Anaerobic treatment of dairy waste water treatment for biogas production in anaerobic batch reactor is another mean for optional treatment dairy industry sludge. Use as a fertilizer for an acid soil is already investigated by different authors (8,11,12).The utilization of dairy waste effluent provides nutrients and water for crop growth is also studied. 5% dairy waste solids in feeding diet of sheep and swine is an alternative means for combating solid disposal problem of dairy industry (11,12).…”

Performance and kinetics of an upflow anaerobic sludge blanket (UASB) reactor treating slaughterhouse wastewater

“…At steady state, substituting from eqns (2) and (3) for substrate removal rate in eqn (6) and solving for X,: 1/q (kg VSSdaykg'cODremoved) 5 …”

“…The upflow anaerobic sludge blanket (UASB) reactor has been used increasingly in recent years to treat a variety of industrial wastes, in particular those produced by food processing industries, for example: brewery and maize starch wastewaters [1], whey permeates [2], ice-cream wastewaters [3,4] and fruit and vegetable processing liquors [5]. The UASB process, which has been described in greater detail elsewhere [6], involves the anaerobic degradation of organic wastes using a biomass which is not attached to a support medium but which aggregates under favourable conditions to produce particles with good settlement characteristics.…”