Integration of sodium hypochlorite pretreatment with co-immobilized microalgae/bacteria treatment of meat processing wastewater

Abstract

Wastewater with 0.2, 0.4, 0.8, 1.0 mg/L free chlorine was biologically treated using co-immobilized microalgae/ bacteria. In contrast, non-pretreated wastewater was treated with beads (control) and blank beads (blank) under the same operating condition. Results showed that NaClO pretreatment removed 8-33% total nitrogen (TN), 31-45% true color and 0.7-2.5 log CFU/mL aerobic-bacteria. At the end of treatment, maximum algal biomass (2,027 dry weight mg/L) was achieved with 0.2 mg/L free chlorine. Bacterial growth in wastewater was decreased by NaClO pretreatment before reaching 7.2-7.7 log CFU/mL on the fifth day. Beads with microor-1 digitalcommons.unl.edu

Emerging technologies of algae‐based wastewater remediation for bio‐fertilizer production: a promising pathway to sustainable agriculture

“…High removal efficiency of nutrients is expected in the algae‐based wastewater remediation to ensure that the effluent can meet the requirements of current regulations. Up to now, it has been proven that a variety of agriculture‐related wastewater, such as animal manure, food processing effluent, aquaculture wastewater, can be treated by the algae 7,19,20 . As shown in Table 1, algae, including microalgae and cyanobacteria, could effectively remove a portion of nutrients in wastewater, and at the same time, produce biomass.…”

“…Secondly, chemical oxidation can be employed to pretreat the wastewater, converting suspended organics into dissolved nutrients for algae growth. The chemical oxidation methods applied in the wastewater pretreatment process include the Fenton‐iron oxidation, hypochlorite oxidation, and so forth 7,22 . Thirdly, the co‐culture of algae with bacteria or yeast in wastewater could also be employed to promote the nutrients recovery 23 .…”

“…Up to now, it has been proven that a variety of agriculture-related wastewater, such as animal manure, food processing effluent, aquaculture wastewater, can be treated by the algae. 7,19,20 As shown in Table 1, algae, including microalgae and cyanobacteria, could effectively remove a portion of nutrients in wastewater, and at the same time, produce biomass. In addition, compared with municipal wastewater and industrial effluent, agriculture-related wastewater contains no or much fewer toxic compounds and are more likely to be easily obtained in rural areas.…”

“…As a category of organic fertilizer made from eukaryotic microalgae or prokaryotic cyanobacteria, algal fertilizer, which can capture carbon dioxide (CO 2 ), fix nitrogen, and improve soil fertility, is emerging into the limelight 4,5 . In addition, since algae are able to recover nutrients from wastewater, algae cultivation could also be employed for wastewater remediation 6,7 . Therefore, a novel concept of integrating wastewater‐based algae culture with the exploitation of biomass as bio‐fertilizer has been proposed and studied as an emerging technology for eco‐friendly agriculture 8,9 …”

“…4,5 In addition, since algae are able to recover nutrients from wastewater, algae cultivation could also be employed for wastewater remediation. 6,7 Therefore, a novel concept of integrating wastewater-based algae culture with the exploitation of biomass as bio-fertilizer has been proposed and studied as an emerging technology for eco-friendly agriculture. 8,9 Current studies in this field cover algae-based wastewater remediation, bio-fertilizer processing, soil ecosystem protection, plants or crops growth, and food safety chain.…”