Abstract

JACOBO LOPEZ, Adriana; ESPARZA SOTO, Mario; CHAVEZ, Mercedes Lucero  and  FALL, Cheikh. TREATMENT OF INDUSTRIAL RESIDUAL WATER AT PSYCHROPHILIC TEMPERATURE WITH A UASB REACTOR. Rev. Int. Contam. Ambient [online]. 2019, vol.35, n.4, pp.905-915.  Epub Dec 22, 2020. ISSN 0188-4999.  https://doi.org/10.20937/rica.2019.35.04.10.

In the present work, a laboratory scale anaerobic upflow reactor (UASB) was operated with a hydraulic retention time (6 h) and at psychrophilic temperature (< 20 ºC). The UASB reactor treated wastewater from a chocolate industry with two applied organic volumetric loads (OLRapl). Each OLRapl corresponded to an experimental stage: experimental stage I with 1.8 ± 0.8 kg soluble oxygen chemical demand ([DQOs]/m3/d) and experimental stage II with 3.5 ± 0.9 kg CODs/m3/d. The objective of this research was to evaluate the removal efficiency of CODs (RE), biogas production (BP) and experimental cell yield (Y exp ) within the laboratory scale UASB reactor. The control parameters monitored were pH, temperature and flow. Alkalinity, volatile fatty acids and CODs were analyzed in the influent and effluent, while suspended solids were analyzed inside the reactor and in the effluent. The RE during the steady state of the two experimental stages was greater than 90 %. The high RE obtained showed that the UASB reactor efficiently treated the industrial wastewater at low temperature with the OLRapl. BP increased when OLRapl increased (1.6 ± 0.8 and 3.5 ± 1.3 L/d of OLRapl of 1.8 and 3.5 kg CODs/m3/d, respectively [1 atm, 273 K]). The Y exp of experimental stage II was high (0.11 kg SSV/kg CODrem). The high Y exp of experimental stage II could be due to the influence of psychrophilic temperature in the growth rate of anaerobic microorganisms.

Keywords : low temperature; organic volumetric load; biogas and cell yield.