Posttreatment of a brewery wastewater using a sequencing batch reactor

Sequencing Batch Reactor Performance Evaluation on Orthophosphates and COD Removal from Brewery Wastewater

The discharge of industrial effluent constituting high orthophosphates and organic pollutants in water receiving bodies compromises freshwater quality and perpetuates eutrophication. In this study, an anaerobic–aerobic sequencing batch reactor (SBR) under activated sludge was investigated for orthophosphates and chemical oxygen demand (COD) removal from brewery wastewater. Raw brewery wastewater samples were collected on a daily basis for a period of 4 weeks. The findings of the study are reported based on overall removal efficiencies recording 69% for orthophosphates and 54% for total COD for a sludge retention time (SRT) of 7 days and hydraulic retention time of 18 h at mesophilic temperature conditions of ±25 °C. Moreover, the SBR system showed stability on orthophosphate removal at a SRT ranging from 3 to 7 days with a variation in organic volumetric loading rate ranging from 1.14 to 4.83 kg COD/m3.day. The anaerobic reaction period was experimentally found to be 4 h with the aerobic phase lasting for 14 h. The SBR system demonstrated feasibility on orthophosphates and COD removal with variation in organic loading rate.

Applying novel methods in conventional activated sludge plants to treat low-strength wastewater

Conventional activated sludge system is confidently widely used for biological treatment plants of municipal wastewater but suffering from operation problems that affect their efficiencies and effluent qualities, especially when treating low-strength wastewater with increasing incoming flow. The objective of this study is to evaluate and compare the novel methods used in upgrading conventional activated sludge treatment systems receiving low-strength wastewater to generate good effluent quality. GPS-X Simulator V 8.0 was used for model calibration and plant performance prediction. The calibrated GPS-X model proved that eliminating primary settling from the treatment process does not affect BOD₅ and COD removal, while TSS removal is decreased, and NH₄-N removal is increased. Increasing the return activated sludge flow from 50 to 150% of influent flow does not affect conventional activated sludge process, while the change of waste activated flow had a vital effect on process performance. The presence of an anoxic zone in conventional activated sludge processes treating low-strength wastewater has no significant impact on plant performance. Also, the model outputs proved that adding filling media to the aeration tank was able to handle an increase of influent flow and a stable performance of BOD₅, and NH₄-N removal was observed.

Effect of brewery wastewater obtained from different phases of treatment plant on seed germination of chickpea (Cicer arietinum), maize (Zea mays), and pigeon pea (Cajanus cajan)

Brewing industry releases large quantities of wastewater after product generation. Brewery wastewater contains organic compounds which are biodegradable in nature. These biodegradable wastes can be recycled and reused and hence considered as suitable products for agriculture. But before using wastewater for agriculture, it is better to evaluate the phytotoxic effects of wastewater on crops. Hence, the main objective of this study is to evaluate the effects of brewery effluent on seed germination and growth parameters of selected crop species like chickpea (Cicer arietinum), maize (Zea mays), and pigeon pea (Cajanus cajan). Study comprised seven types of water treatments-tap water as control, diluted UASBR effluent (50% effluent + 50% distilled water): UASBR50, undiluted UASBR effluent: UASBR100, diluted TC effluent (50% effluent + 50% distilled water): ETP50,TC effluent without dilution: ETP100, 10% diluted reverse osmosis (RO10) reject (10% RO reject + 90% distilled water), and 25% diluted reverse osmosis(RO25) reject (25% RO reject + 75% distilled water) with three replications in completely randomized design. Germination test was performed in petri plates for 5 days. Parameters like germination percentage, germination rate index, seedling length, phytotoxicity index, seed vigor index, and biomass were calculated. All parameters decreased with increase in respective effluent concentration. Among all treatments, RO25 showed highest inhibitory effect on all three crops. Even though undiluted effluent of UASBR and ETP effluent showed positive effect on germination, seedling growth of three crops was promoted to the maximum by UASBR50 and ETP50. Hence, from the study, it was concluded that dilution of brewery effluent can be recommended before using it for irrigational purpose.

The effects of Parachlorella kessleri cultivation on brewery wastewater

Bioindustrial wastewaters, often characterised by high carbon and nitrogen contents, have shown promise as a valuable resource for the cultivation of beneficial microorganisms. The purpose of this study was to assess if Parachlorella kessleri could utilise brewery wastewater (Br WW) for growth and production of metabolites. P. kessleri was cultivated on different concentrations of Br WW over 14 days. Higher concentrations of Br WW led to an approximate two-fold increase in dry cell weight yielding a maximum of 12.3 g DCW/L. High glucose and nitrogen utilisation was associated with high algal biomass yields, with a 97% reduction in glucose achieved in 50% (v/v) Br WW cultures after 14 days. Assessing the benefits to P. kessleri, increases in oleic and α-linoleic acids were seen in 50 and 10% (v/v) Br WW cultures. Concentration of Br WW did not have an impact on the overall antioxidant activities of microalgal cultures, however, it did affect phenolic levels (2.4-fold increase) in 50% (v/v) Br WW cultures. This research demonstrated that P. kessleri did utilise the carbon and nitrogen content in the Br WW for growth and metabolite production, thereby reducing the nutrient load of the Br WW.

A two-stage SBR process for removal of organic substrate and nitrogen via nitrite-type nitrification-denitrification

A two-stage SBR process (TSSBR) was applied for the treatment of wastewater with high strength COD and nitrogen. Most of organic substrate was removed in the first stage SBR reactor (SBR1) under the aerobic condition. Subsequently the second stage SBR reactor (SBR2) firstly was operated under the aerobic condition for simultaneous nitrite-type nitrification and removal of a small amount of residual organic substrate. Nitrification was controlled to the nitrite-type nitrification. Then denitrification in which the wastewater was used as external carbon sources occurred in SBR2 under the anoxic condition. The experimental results indicated that two kinds of biomass with the different function were cultured in a TSSBR system, which was beneficial to increase the proportion of Nitrosomonas in the microorganism of SBR2. It avoided the inhibition of the high organic loading to nitrification and C/N was not the limiting factor affecting the nitrogen removal efficiency. The rate of COD degradation and nitrification was improved, 8 kg COD/kg MLSS/d and 0.25 kg NH4+-N/kg MLSS/d, respectively. The final effluent COD concentration further reduced because the organic substrate that was left in SBR1 effluent was removed in SBR2. Consequently, when compared to a single SBR process, a two-stage SBR (TSSBR) not only improved the treatment efficiency, but also saved the operational cost.