Treatment of Pharmaceutical Process Wastewater with Hybrid Separation Method: Distillation and Hydrophilic Pervaporation

The work is motivated by an industrial problem, which is alcohol removal from pharmaceutical process wastewater. The aim of the study was to develop a complete hybrid operation is investigated. Ethanol dehydration, in combination with distillation and hydrophilic pervaporation, is used to investigate about the extent of separation of the ethanol-water mixture. The aim of this research is to rigorously model and optimize this hybrid operation in professional flowsheet simulator environment. The number of minimal theoretical plates of distillation column and minimal effective membrane transfer area are determined. Cost estimation is also examined according to Douglas methodology. Considering our results it can be concluded that, the distillation and hydrophilic pervaporation processes are suitable for separation ethanol and water in 99.5 weight percent purity

COD reduction of process wastewater with vacuum evaporation

Washing detergents in process wastewaters from fine chemical industry produce high Chemical Oxygen Demand (COD), which poses a serious environmental problem. Method has to be found, which follows the principles of circular economy so that the treated water can be recycled or reused. Heat pump vacuum evaporator is evaluated in order to reduce the Chemical Oxygen Demand of process wastewater with washing detergent content from initial 7500 mg O2/L to a lower value below the effluent limit , which is 1000 mg O2/L. Yield and COD rejection are determined for the evaluation of selected treatment. Experiments are investigated with LED Italia R150-v3 pilot apparatus. Different evaporation pressures were applied during measurements. It The highest removal or reduction of in the Chemical Oxygen Demand was reached certainly using the lowest possible pressure, which is 40 mbar.

Complex whey utilization: the propionic acid alternative

Whey is the complex waste of the dairy industry. Despite the fact, that it has numerous applications (like different form of food supplements), its major amount is still handled as waste. The carbohydrate, protein and lactic acid content, as well as the COD and BOD, are sufficiently high warranting disposal as waste resulting in high costs; however, their levels are insufficient for the cost-effective isolation and purification. Most of the numerous reports on whey utilisation focus on lactose utilization, while lactic acid removal is complex, but necessary, particularly in case of sour whey decontamination. According to our best knowledge among the microbial fermentation, the only lactic acid (as carbon source) utilization process is propionic acid fermentation. Propionic acid is an attractive product with a wide application range. In this study, two propionic acid producing microorganisms were investigated in terms of industrial applicability. The propionic acid producing bacteria are generally characterized by anaerobic metabolism (except the pathogenic P. acne); but, for application in a biorefinery, facultative anaerobe behavior is the most appropriate and cost-effective. In this study, the aero-tolerances of Propionibacterium freudenreichii subsp. shermanii and Propionibacterium acidipropionici were examined; their propionic acid-producing properties (yield, concentration, substrate preference, productivity) were compared.

Lactic acid production from cane molasses

Molasses, a by-product of the sugar manufacturing process, generally comprises approximately 50% (w/w) of total sugars, but it is currently used primarily [1] as an animal feed and as a raw material in alcohol production. Currently, the sugar production is more than 160 million tones worldwide. Its byproduct molasses contain heavy metals which have growthinhibitory effect. The main sugar content in molasses is sucrose which often need to be hydrolyzed to glucose and fructose especially for utilization by Lactobacillus species. Lactobacillus species can convert sugar content to lactic acid with great efficiency, which is a valuable chemical. Lactic acid production from sugar molasses using batch fermentations with Lactobacillus casei and Lactobacillus sp. MKT878 were investigated in this study. Results showed, that both examined Lactobacillus species could grow on molasses despite the heavy metals inhibitory effects. The conversion of sugar content to lactic acid was successful with yield between 55-80 g/g.

Whey utilization in a two-stage fermentation process

Whey is a major by-product of the cheese and dairy industry and has valuable nutritional constituents, however poses a major environmental risk if disposed of without prior treatment. The main components of whey except of water are lactose, lactic acid, soluble proteins, lipids, vitamins and mineral salts which give a very high biochemical oxygen demand (BOD) and chemical oxygen demand (COD) load (30,000 - 50,000 ppm and 60.000 - 80,000 ppm, respectively) to the whey. This composition provides adequate nitrogen and carbon source to be utilized by microorganisms. The aim of this study was to examine the whey utilization in a two-stage fermentation process using Lactobacillus species and Propionibacterium acidipropionici. In the first stage Lactobacillus species utilise the main part of the nitrogen source while covert lactose content to lactic acid. In the second stage Propionibacterium acidipropionici utilize lactic acid and produce propionic acid. This two-stage fermentation process can be a feasible option, both for bioremediation of whey and production of propionic acid from waste sources. High lactose conversion (>90%) to lactic acid was achieved at the first stage, but its conversion to propionic acid during the second stage was insufficient (~30%). The COD was successfully decreased during the fermentations.

Methanogenesis inhibition by phosphorus in anaerobic liquid waste treatment

The effect of a sudden influent phosphorus concentration increase on a completely mixed reactor of an anaerobic liquid waste treatment process was evaluated. Chemical oxygen demand (COD), volatile fatty acids (VFA), suspended solids, pH and gas production were measured for process monitoring. Optical and scanning electron microscopic observations were also performed. Kinetic parameters were estimated from substrate and microorganisms concentrations, mass balances and experimental data. After phosphorus concentration increase, VFA concentration enhanced by 500% approximately and COD removal, gas production, bacterial growth coefficient (Y) and maximum bacterial growth rate (μmax) decreased 20%, 18%, 54% and 35% respectively. An excessive growth of filamentous microorganisms was also observed. The equilibrium established between acidogenic and methanogenic microorganisms was visibly affected causing a decrease of methanogenic activity. The experimental results showed that phosphorous arises as a methanogenesis inhibitor and a growth factor for filamentous microorganism under anaerobic conditions.

Optimisation of the emulsion liquid membrane composition and demulsification for rhodium extraction

This study was aimed at designing an optimised emulsion liquid membrane (ELM) for the extraction of rhodium from precious metal refinery wastewaters. The demulsification process and the structure of the optimised ELM are reported on. Two optimised ELMs were prepared. The first one contained a 30 % solution of toluene in kerosene as diluent with the following concentrations of the ELM components: 30.000 g/L (w/v) polyisobutylene, 10.870 g/L (m/v) of trioctyl amine and 51.001 g/L (m/v) of SPAN 80. The second ELM contained the same diluent, but the concentrations of the other ELM components in it were as follows: 20.000 g/l of polyisobutylene, 10.268 g/l trioctyl amine and 50.024 g/l of SPAN 80. The stripping phase was the same in both optimised ELMs, namely a 2 M solution of HNO3. The stripping phase and the diluent solution were mixed together in ratios of 1:1 and 2:1, respectively. Two methods were used to characterise the microdroplet diameters, i.e. optical microscopy and the Zeta-sizer. For the t-test, the p-value of 0.3018 at 5 % level of significance showed that there was statistically no significant difference in the mean micro-droplet size for 1:2 ELMs containing 20 g/l and 30 g/l of polyisobutylene after 40 minutes of emulsification. The best demulsification results were obtained using the chemical demulsification with polyethylene glycol with molecular weight of 400 g/mol (PEG 400) at 50 ± 1 °C for 24 hours. However, significant carryover of toluene, trioctyl amine and polyethylene glycol into the aqueous phase was observed.

Survival of Bifidobacteria and their usefulness in Faecal Source Tracking

Bifidobacteria have long since been recommended as indicators of human and animal pollution. Concentration ratio (tracking ratio) of the sorbitol-utilising bifidobacteria (SUB) and the total bifidobacteria (TB) can be used to distinguish between animal and human sources of faecal water contamination. The cut-off value needs to be calibrated in a given geographical area. Seven sites with permanent faecal contamination were selected in South Africa. Concentrations of SUB ranged from 10-50000 cells/100 mL, while TB ranged from 0-8000 cells/100 mL. The tracking ratio ranged from 0.10 to 6.25, but no clear cut-off value could be established. The YN-17 agar was replaced for TB with the modified Beerens medium with pH = 5.70, to suppress the growth of faecal streptococci. Tracking ratios observed are most likely the results of different survival rates of SUB and TB. Bifidobacteria die-off due to nutrients was not found to be significant using design of experiment. Thus a lack of continuous input or oxygen levels in water may be major factors. This would limit the ratios used as a faecal source tracking method.