Bio-treatment of maize processing wastewater using indigenous microorganisms

Abstract

Wastewater arising from maize processing industry is rich in proteins, amino acids, carbohydrates and nitrogenous compounds. Discharging of such wastewaters to the main water bodies without proper treatment creates environmental risks. The present research aimed to reduce maize processing wastewater contaminants by indigenous microorganisms. Industrial wastewater samples of maize processing factory at 10th of Ramadan city, Egypt were collected. The chemical and microbiological characteristics of samples were evaluated. An in vitro batch experiment was conducted in triplicates using 5 L Erlenmeyer flasks enriched with 2 L of the maize processing wastewater and incubated under shaking ambient conditions at 120 rpm for 30 d. Another 2 L Erlenmeyer flask was enriched with 2 L of the wastewater sample, and incubated under static ambient conditions, used as control. The biodegradation of nitrogenous and organic compounds was followed up by measuring Total Kjeldahl Nitrogen (TKN), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Dissolved Oxygen (DO) and pH. The biomass growth rate was monitored by counting the viable bacterial cells (TBC) and fungal cells. The concentration of TKN, BOD and COD was reduced from 2330, 9000 and 12,000 mg L − 1 to 420, 220 and 430 mg L − 1 , respectively. DO concentrations were ranged between 6 to 12 mg L − 1 and the pH value was elevated from 6.9 to 9.3. TBC was elevated from 2 × 10 6 to 4 × 10 10 CFU mL − 1 , while the yeast count was reduced from 12 × 10 6 to 2.2 × 10 4 CFU mL − 1 . Microbial identification by Analytical Profile Index (API) profiling kits indicated that Saccharomyces cerevisiae, Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus licheniformis are the strains involved in bio-treatment.

Diversity and Characterization of the Bacterial Communities of Different Water Resources in Egypt Concerning Contamination Type

“…The bacterial community of the industrially contaminated drain water (Al-Khadrawiya drain) was characterized by a high number of Gram negative rods (68.4%) as indicated in table (9) and fig ( 5). The bulk of the community is included in two genera; Pseudomonas (25.7%) and Bacillus (21.8%), these two prompt genera have been reported in the literature as strong bio-removers for chemical contamination of water so, they could predominate the community (Ewida, 2014;Jahin et al, 2014;Chuahan et al, 2016;Pathak et al, 2016;Ewida, 2020;Ewida et al, 2021). The total number of identified genera in the community was 9, so, it is considered of moderate diversity.…”