Removal of phenols and methane production with coffee processing wastewater supplemented with phosphorous

Abstract

This manuscript addresses the evaluation of the methane production and removal of organic matter and phenols from coffee fruits processing wastewater (CPW). The systems consisted of two serial upflow anaerobic sludge blankets (UASB1 and UASB2) and one sequential batch reactor (SBR). The organic loading rate (OLR) was increased from 3 to 6 g COD/L.d, and the hydraulic retention times (HRT) applied to UASB1, UASB2 and SBR were 60, 30 and 75 h, respectively. Similar OLRs were tested with raw CPW (tests 1 and 2) and CPW after the addition of Simple Super Phosphate (SSP) (tests 3 and 4). The COD removals in the two stages UASB ? SBR were approximately 85 % in tests 1 and 3 and 88 % in tests 2 and 4. The total phenols (TF) removal ranged between 70 and 92 %. The highest bioenergy productivities were achieved in UASB1, i.e., approximately 0.33 and 0.70 L CH 4 /L.d with OLR of approximately 3 and 6 g COD/L.d. Although, the addition of SSP did not induce a superior methane production or TF removal, it promoted enabled a faster biomass growth after acidification time. SBR was tested with two cycles-cycle 1 with anaerobic ? aerobic reactions (tests 1 and 2) and cycle 2 with anaerobic ? aerobic ? anaerobic reactions and lower sedimentation time (tests 3 and 4). Cycle 2 obtained higher COD and TF removal. The addition of SSP enhanced the SBR performance and increased between 13 and 24 % the TF removal.

Predominance of syntrophic bacteria, Methanosaeta and Methanoculleus in a two-stage up-flow anaerobic sludge blanket reactor treating coffee processing wastewater at high organic loading rate

“…Accordingly, a strong Pearson's correlation (p < 0.001) was evidenced between MPR and OLR variables in both reactors, which indicate that gradual increase of the OLR allows a satisfactory methane production. These results were consistent with the highest levels of organic load removal observed in the same period and were higher with respect to those previously reported in anaerobic digestion systems treating CPW (Guardia-Puebla et al, 2014;Jung et al, 2012;Selvamurugan et al, 2010;Villa-Montoya et al, 2017) due to the higher OLR reached.…”

“…The application of the up-flow anaerobic sludge blanket (UASB) or related technologies constitutes a promising strategy for this purpose, which can be submitted to high organic loading rates (OLRs) to enhance the energy recovery. However, three major drawbacks should be attended to optimize this process: i) the high content of easily fermentable sugars and low alkalinity of CPW, which can produce an acid accumulation that inhibits the methanogenic activity; ii) the reduction of the effluent quality by application of high OLR and iii) the lack of knowledge of the associated microbiota, since previous works have only focused on operational aspects or analysis limited to study of cultivable microorganisms (Pires et al, 2017;Villa-Montoya et al, 2017).…”

Desenvolvimento e caracterização de compósitos produzidos a partir da reciclagem dos resíduos de café para uso na construção civil

“…Porém, exige mão de obra especializada e ainda a tecnologia não é consolidada para resíduos agrícolas em escalas comerciais (BATISTA,2014). Ademais, a estrutura lignocelulósica dos resíduos agrícolas dificultam a sua biodegradabilidade, exigindo pré-tratamentos para a diminuição da sua cristalinidade e rigidez (VILLA-MONTOYA et al, 2017;ABU TAYEH et al, 2016).…”