Treatment Of Dairy Industry Wastewater Research Articles

Performance of Dairy Factory Wastewater Treatment Plant (Case Study of Pasuruan Dairy Factory East Java)

The 'ILP' company produces bottled milk with chocolate, melon, strawberry, and vanilla flavors in colorless HDPE (High-Density Polyethylene) plastic bottles and aluminum foil covers. The 'ILP' dairy industry wastewater treatment process stages include bar screen, grease trap, equalization tank, flocculation-coagulation, primary clarifier, aeration tank/activated sludge, and secondary clarifier. The research aims to determine the performance of the dairy factory's WWTP (Wastewater Treatment Plant) in terms of TSS (Total Suspended Solids) and COD (Chemical Oxygen Demand) parameters. This field-scale research was carried out for approximately 5 weeks (35 days) at the wastewater treatment plant of the ILP company. Wastewater sampling is carried out at the inlet point, equalization tank, primary sedimentation, aeration tank, and outlet point of WWTP. Wastewater examination conducted in the company's internal laboratory, including temperature, pH, total suspended solids (TSS), and chemical oxygen demand (COD). The dairy factory WWTP (wastewater treatment plant) can generate TSS (total suspended solids) effluent of 22 mg/L and COD (chemical oxygen demand) of 26.8 mg/L to meet the applicable wastewater quality standards. The treatment efficiency of the dairy industry WWTP for TSS is 94.7% and COD is 98.1%.

Comparative evaluation between Taguchi method and response surface method for optimization of electrocoagulation process in the context of treatment of dairy industry wastewater.

The presence of a large amount of organic and inorganic pollutants in dairy effluent is a substantial environmental issue. This study investigated electrocoagulation (EC) as a potential treatment method for dairy wastewater under different operating conditions, such as applied voltage (5-25V), electrolysis time (30-90min), and inter-electrode distance (1-2cm) by using aluminum electrodes. This study focuses on achieving the maximum removal of BOD, COD, and nitrate in dairy effluents with the aforementioned operating conditions. The process was optimized using the response surface methodology (RSM) and Taguchi method. RSM method optimized the electrocoagulation operating conditions such as the voltage at 23.75V, time of 90min, and inter-electrode distance at 1.07cm. This optimization achieved the maximum removal percentage of BOD, COD, and nitrate at 79.06%, 84.35%, and 79.64%, respectively, in dairy effluent. Taguchi method optimized the electrocoagulation parameters such as the voltage at 25V, time duration of 90min, and inter-electrode distance of 1.00cm, showcasing improved removal percentages of BOD, COD, and nitrate as 90.54%, 89.28%, and 82.74% respectively. The current study attempts to understand the optimization efficiencies between Taguchi method and response surface method for diary wastewater treatment.

The influence of inoculum source and pretreatment on the biohydrogen production in the dark fermentation process

The production of biohydrogen from food waste (FW) by dark fermentation (DF) is a promising technology for commercialisation, as it is both a clean fuel and a suitable means of sustainable waste management. The described experiments compared the biohydrogen production yields obtained after the use of inoculum from two different sources: digested sludge from the wastewater treatment plant (WWTP) in Lodz and sludge from the anaerobic treatment of dairy industry wastewater (DIW) (unconcentrated and double-concentrated). In addition, the effect of different temperatures (70, 90 and 121°C) of inoculum pretreatment on the biohydrogen production in DF was tested. The process was carried out batchwise at 37°C. The highest yield of hydrogen production was obtained after the inoculum pretreatment at 70°C. In addition, a higher amount of hydrogen could be obtained by using sludge from the WWTP as the inoculum (96 cm3 H2/gTVSFW) than unthickened sludge from the DIW (85 cm 3 H 2/g TVSFW). However, after thickening the sludge from the dairy industry, and at the same time balancing the dry matter of both sludges, the hydrogen production potential was comparable for bothsludges (for the WWTP sludge – 96 and for the DIW sludge – 93 cm 3 H 2/g TVSFW). The kinetics of hydrogen production was described by modified Gompertz equation, which showed a good fit (determination coefficient R2 between 0.909 and 0.999) to the experimental data.

Experimental and statistical modeling of the effect of process modification and wastewater characterization on greenhouse gas emissions for a dairy industry wastewater treatment plant: A minimization approach

Abstract This study aimed to determine the effect of design conditions and wastewater characterization on greenhouse gas (GHG) emissions from an industrial wastewater treatment plant. Analysis of variance, correlation analyses, heat-mapping, and principal component analyses (PCA) were performed to determine the correspondence between GHG emissions and wastewater characterization. Then, a new empirical model based on the correlation of wastewater characterization has been developed. This study has concentrated on using process modification to mitigate GHG emissions. If an aeration tank is operated at 36 h of hydraulic retention time and 20 days of solid retention time at design conditions, an average reduction of 45.4, 45.3, and 45.2% in carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions, respectively, have been ensured. According to correlation analysis, a moderately significant positive correlation was found between effluent chemical oxygen demand values and CO2 and CH4 values (r = 0.909, r = 0.937). N2O emissions were closely related to Total Kjeldahl Nitrogen input values (r = 0.876). GHG emissions have been calculated using this correlation, and the results overlapped with the monitoring values. The estimated results of GHG emissions based on wastewater characterization have converged to in situ monitoring results, by an average of 82%.

Enhancement of biomethane potential of brown sludge by pre-treatment using vortex based hydrodynamic cavitation

Novel, non-thermal and economically benign pre-treatment process was developed for enhancing valorisation potential of brown sludge generated by dairy industry wastewater treatment plant (WWTP). Vortex-based hydrodynamic cavitation (HC) device was used to quantify influence of pretreatment by measuring biomethane potential (BMP) of untreated and treated brown sludge. Pre-treatment parameters, primarily, pressure drop and number of passes through the cavitation device were varied to quantify influence on BMP. BMP tests were performed at 39 °C containing 5% of total solids in each reactors using an automatic BMP measurement system containing 15 reactors with each volume of 500 mL fitted with overhead stirrer. HC treatment increased the soluble chemical oxygen demand (sCOD) by more than 25% which increased the BMP. HC treatment was able to push the BMP of treated sludge to more than 80% of the theoretical BMP. Volatile solids (VS) removal was more than 65%. Highest methane yield was 376 mL/g-VS of sludge. The methodology and results presented here show significant potential to valorise brown dairy sludge via vortex based hydrodynamic cavitation.

Evaluation of Arthrospira (Spirulina) platensis growth on cheese whey in the context of circular economy

Cultivation of microalgae using wastewater could be considered as a cost-effective treatment method, while providing the necessary nutrients to for the production of high-value biomass. The potential use of cheese whey for Arthrospira (spirulina) platensis cultivation could provide a sustainable solution aligned with circular economy principles for the treatment of dairy industry wastewater, in regions such as North Aegean (Greece). The aim of this research is to investigate the parameters that influence the growth of Arthrospira platensis biomass on whey rich solutions, as a substitute to chemical nutrient feeds, according to the practices of circular economy and sustainable development. Specifically, the effect of different whey dilution ratios and irradiation conditions on biomass productivity, nutrient consumption and COD removal were examined in batch experiments. Results show that the concentration of 10% (v/v) cheese whey exhibited the best performance in both experimental illumination sets; continuous and light/dark cycles. The highest biomass production (1.06 g l−1) was achieved in 14-day experiments at a pH 10.5 and with a photoperiod of 12 h dark/light. In the culture with light/dark cycle, approximately 85% COD removal and 70% NO3−−N consumption were measured. Overall, Arthrospira platensis cultures demonstrate a consistent growth performance in a wide range of conditions and can be considered as an efficient method of treating cheese whey wastewater. Concurrently, Arthrospira biomass production presents interest, due to the low cost associated with the unsterile nature of the cheese whey waste and the utilization of the whey waste as a nutrient for growth.

Dairy industry wastewater treatment by MOF and 2D nanomaterial engineered PVDF membranes based aerobic MBR: Membrane fouling mitigation and stability study

In the present research work, PVDF membranes are embedded using zinc imidazolate framework-8 and molybdenum disulfide. The membrane's impact is investigated using their permeability, separation performance, reusability and stability performance and fouling resistance. Results show that the ZIF-8 and MoS2 based PVDF nanocomposite membranes have superior pure water flux performance, such as 27.71 L/m2 h and 32.53 L/m2 h, respectively. The FRR of the ZIF-8 and MoS2-based PVDF nanocomposite membranes is obtained at 95.65 % and 97.04 %, respectively. The flux recovery ratio and water contact angle studies show that prepared membranes have better antifouling performance than pristine PVDF membranes. The pollutant removal performance for COD, BOD5, TN, NH4-N and TP is obtained as 94.08 %, 95.31 %, 94.5 %, 95.56 % and 94.64 %, respectively, from dairy industry wastewater. Also, the microbial culture growth study report that the ZIF-8 and MoS2 based PVDF membranes reject maximum microbes from the treated water. Therefore, the prepared PVDF nanocomposite membranes show outstanding filtration performance, reusability, and long-term stability performance. Hence, the ZIF-8 and MoS2 nanomaterials significantly improved the PVDF membrane's characteristics and could be a promising nanocomposite membrane for practical application in different wastewater treatments.

Evaluation of Monoraphidium contortum for the tertiary treatment of dairy industry wastewater and biomass production with nitrogen supplementation

The present study sought to evaluate the secondary wastewater from dairy industry as a culture medium for Monoraphidium contortum, in bench-scale tubular photobioreactor, aiming at tertiary wastewater treatment and microalgae biomass production. Since the used secondary wastewater contained residual phosphorus (P) but negligible residual nitrogen (N), we also evaluated the nitrogen supplementation, following Redfield ratio (N:P = 16:1) and the same N:P proportion of Bold Medium (N:P = 1.71:1). These cultures were compared to secondary wastewater without N and Bold Medium (control). Secondary wastewater without N addition provided lower values of maximum biomass concentration, indicating the importance of this supplementation. The nitrogen supplementation following Bold Medium represented the best protocol, since biomass productivity was higher than that in control culture, but with lower nitrogen addition (in comparison with the supplementation following Redfield proportion). The biomass of M. contortum showed to be an excellent candidate for oil production, which could be employed as feedstock for biodiesel, for example.

Combination of chemical coagulation and membrane-based separation for dairy wastewater treatment.

An important factor resulted from the ascension of the milk and milk-based by-products production is many effluents directly released into the environment. The main objective of this study was to evaluate the efficiency of the combination of the chemical coagulation, with ferric chloride as a coagulant, and the membrane separation processes (MSP) and reverse osmosis (RO) processes in the treatment of effluents from a powdered milk dairy industry. To evaluate the effectiveness of the integration of these mechanisms, the characterization of the effluents was carried out through Total Nitrogen (Ntotal), Total Organic Carbon (TOC), Chemical Oxygen Demand (COD), color, pH, and turbidity analysis. Regarding the treatments with ferric chloride, the Ntotal removal was up to 55.7% (concentration of 1.2g L- 1) and the color up to 50% (0.7g L- 1). For the MSP and RO treatments, the color removal was up to 100% (1st RO), turbidity up to 100% (1st RO), COD up to 98.7% (3rd RO), and TOC up to 96.7% (3rd RO). Finally, the integration of the chemical coagulation and MSP processes was efficient for the treatment of dairy industry wastewater and provides the return of water in appropriate characteristics according to legislation.

Environmental and economic feasibility of the treatment of dairy industry wastewater by photo-Fenton and electrocoagulation process: Multicriteria optimization by desirability function

The objective of this study was to treat of dairy wastewater by two-step optimized process, which included the photo-Fenton (UV/Fe2+/H2O2) followed by electrocoagulation (EC), aiming to achieve environmental and economic feasibility. An empirical statistical model was defined by Box-Behnken Design (BBD) and linked to the mathematical programming of maximization of the parameters that characterized the organic matter removal. The response surface by BBD and parametric effects of main factors of the treatment were rigorously investigated. Multicriteria optimization approach by desirability function has been used to simultaneously minimize operating cost of EC and maximize COD and TOC removals according to desirable current efficiency and electrode dissolution of the Al electrode. The optimized UV/Fe2+/H2O2 treatment conditions (14,000 mg L−1 H2O2; 198 mg L−1 Fe2+ and initial pH 3.5) led to maximum removal of COD (≈ 60%) and TOC (≈ 73%), with a final pH of about 3 after 180 min of reaction, costing around US $ 40.24 per kg COD removed. The minimum energy consumption during EC was reached when ≈ 107.14 A m−2; ≈ 35 min and initial pH ≤ 6 (around US $ 8.97 per kg COD removed). Thus, the potential of two well-known processes were successfully designed, allowing the combination of both to maximize the removal of organic matter, with energy efficiency and, the minimum operating cost.

Treatment of dairy industry wastewater by variations of coagulation-flocculation and ozonation

In this study, COD removal efficiencies were investigated in dairy industry wastewater by using variations of coagulation-flocculation and ozone oxidation in laboratory. Coagulation-flocculation (CF), ozonation (O), ozonation following coagulation-flocculation (CF+O) and coagulation-flocculation following ozonation (O+CF) processes were applied to the wastewater. Optimum pH and optimum dosages were studied at various pH values and at various coagulant doses at room temperature (25oC). In ozone oxidation, wastewater was taken to ozonation reactor and ozone was given 1 g/hour dose and COD removal efficiencies were determined by taking samples in 15, 30, 45, 60, 90, 150, 210 and 240 minutes. Treatment performance of coagulation and flocculation and ozonation processes and their variations were evaluated by COD removal efficiencies. The optimum pHs for the Al2(SO4)3 and FeCl3 were found as 7 and 6 respectively. The optimum dosages were 1200 mg/L for Al2(SO4)3 and 500 mg/L for FeCl3. At optimum conditions, approximately 45% and 28% of COD were removed by using FeCl3 and Al2(SO4)3 respectively. When only ozonation was applied, COD removal efficiency was determined as 20% at the end of 240 minutes. COD removal efficiency was 65% with the application of ozonation after coagulation-flocculation (CF+O). When the coagulation-flocculation process was applied after the ozonation process (O+CF), COD removal efficiency remained at 52%.

Treatment of dairy industry wastewater using bacterial biomass isolated from eutrophic lake sediments for the production of agricultural water

In the present study, the treatment of dairy industry wastewater using bacterial biomass isolated from eutrophic lake sediments was carried out to produce water for agricultural use. Microorganisms were isolated from lake sediment to establish bacterial consortiums efficient in the removal of organic matter from dairy wastewater. The nature of the effluents varied according to the treatment system and parameter evaluated. In the anaerobic treatment, chlorides, sulfates, phosphates and chemical oxygen demand recorded the highest average values. In the aerobic treatment, turbidity, electrical conductivity, ammonium, total suspended solids and biochemical oxygen demand recorded the highest average values. The analysis of the percentage of similarity of the anaerobic (BSI1) and aerobic (BSI2) bacterial consortia with a contribution of more than 1% revealed a 91.38% contribution. In anaerobic reactors the orders Clostridiales (14.27%) and Lactobacillales (12.44%) predominated and in aerobic reactors the order Burkholderiales (20.67%).

Biological treatment of dairy industry wastewater in a suspended growth batch reactor: performance evaluation and biodegradation kinetics

This research work was carried out to evaluate the kinetic constants for the biological treatment of dairy industry wastewater in a suspended growth batch reactor. The study was performed in a lab-scale batch reactor which is a prototype of an aeration tank unit of the activated sludge system. Samples of dairy wastewater were collected from a dairy plant near Kolkata on regular time interval and in different seasons of a year to establish mean values of the major wastewater parameters. A synthetic simulated sample was made on the basis of evaluated characteristics of dairy wastewater. Kinetics study in batch reactor was done to find kinetic coefficients (Y, Ks, kd and k). The value of the maximum substrate removal rate (k) at preliminary concentration of COD 700–720 mg/L was 4.42 day−1; half velocity constant (Ks) was 206.81 mg/L and k value at initial NH4 +–N level of 48–54 mg/L was found 2.5 per day, Ks was 24.5 mg/L. Isolation and identification of the most potent strains for the carbon oxidation and nitrification was also done and by using those isolated strains kinetic coefficients for pure culture was determined.

Comparison of chitosan based nano-adsorbents for dairy industry wastewater treatment through response surface methodology and artificial neural network models.

The present investigation was focused to compare chitosan based nano-adsorbents (CZnO and CTiO2) for efficient treatment of dairy industry wastewater using Response Surface Methodology (RSM) and Artificial Neural Network (ANN) models. The nano-adsorbents were synthesized using chemical precipitation method and characterized by using scanning electron microscope with elemental detection sensor (SEM-EDS) and atomic force microscope (AFM). Maximum %RBOD (96.71 and 87.56%) and %RCOD (90.48 and 82.10%) for CZnO and CTiO2 nano-adsorbents were obtained at adsorbent dosage of 1.25 mg/L, initial biological oxygen demand (BOD) and chemical oxygen demand (COD) concentration of 100 and 200 mg/L, pH of 7.0 and 2.00, contact time of 100 and 60 min, respectively. The results obtained for both the nano-adsorbents were subject to RSM and ANN models for determination of goodness of fit in terms of sum of square errors (SSE), root mean square error (RMSE), R2 and Adj. R2, respectively. The well trained ANN model was found superior over RSM in prediction of the treatment effect. Hence, the developed CZnO and CTiO2 nano-adsorbents could be effectively used for dairy industry wastewater treatment.

Tertiary treatment of dairy industry wastewater with production of Chlorella vulgaris biomass: evaluation of effluent dilution

Secondary wastewaters from the dairy industry may cause eutrophication of water bodies when not properly treated, mainly because they contain nutrients such as phosphorus and nitrogen. Tertiary treatment using microalgae could be an adequate solution for Minas Gerais State, the largest Brazilian milk producer, contributing to the reduction of environmental impacts, as well as providing biomass for oil extraction, and obtaining active compounds and inputs (including proteins) for animal feeding. In this work, dilutions (with distilled water) of the secondary wastewater from the dairy industry were evaluated to cultivate Chlorella vulgaris in a bench-scale tubular photobioreactor. The results indicate the feasibility of using wastewater from the dairy industry, after secondary treatment, to cultivate microalgae, showing cell growth like that obtained in control cultures (Bold basal medium). The secondary wastewater without dilution (100% wastewater) provided the best condition for biomass production. The biomass obtained in wastewater showed no differences from the biomass obtained in the Bold basal medium (control) in terms of protein, lipid content, or fatty acid profile.

Investigation of different treatment strategies such as membrane filtration and Fenton processes in the treatment of dairy industry wastewater

Investigation of different treatment strategies such as membrane filtration and Fenton processes in the treatment of dairy industry wastewater

Treatment of Dairy Industry Wastewater - Special Reference to Design of Aerated Lagoon

Industrial revolution brought diversified industries to produce goods to meet the demand of increasing population. Such a rapid growth of industrial sector caused water pollution to a great extent. Dairy industry is not an exception, causing significant water pollution. The dairy sector in India grew at a rate of 6.4 per cent annually in the last four years against the global growth rate 1.7 per cent demonstrating significant increase in milk productivity. Around 80 million rural Indian households are engaged in milk production with very high proportion being landless, small and marginal farmers. But on the other hand, water pollution being caused from these dairy industries is quite significant. Various biological treatment technologies were tried for treating dairy wastewater. An attempt has been made by the authors of the present paper to design aerated lagoon including screen chamber, primary clarifier, quiescent settling zone and sludge disposal with success to treat dairy wastewater.

Experimental analysis on the synergistic effect of combined use of ozone and UV radiation for the treatment of dairy industry wastewater

The present study focused on the various advanced oxidation processes; Ozone, UV radiation, O<sub>3</sub>/H<sub>2</sub>O<sub>2</sub>, O<sub>3</sub>/UV, UV/H<sub>2</sub>O<sub>2</sub> and O<sub>3</sub>/UV/H<sub>2</sub>O<sub>2</sub> for treatability of dairy industry wastewater. With this aim, the trials were carried out in cylindrical reactor fortified with UV radiation and Ozone injection. Efficiency of the treatment process was evaluated considering Chemical Oxygen Demand (COD), lactose reduction and process parameters were determined to be reaction time, pH, circulation rate, and H<sub>2</sub>O<sub>2</sub> dosage. 32.5%, 35.2% , 25%, 83% COD and 40.6%, 43.6%, 38.2%, 80% lactose reduction efficiency were obtained under the operating conditions for O<sub>3</sub>/H<sub>2</sub>O<sub>2</sub>, O<sub>3</sub>/UV, UV/H<sub>2</sub>O<sub>2</sub> and O<sub>3</sub>/UV/H<sub>2</sub>O<sub>2</sub> processes, respectively. As per this outcome, UV/H<sub>2</sub>O<sub>2</sub>/O<sub>3</sub> process gave more than 65% of COD and 52.36% of lactose reduction efficiency than other hybrid processes. Optimum conditions for UV/H<sub>2</sub>O<sub>2</sub>/O<sub>3</sub> process (pH = 5, time = 180 mins, circulation rate = 50 mL/h and H<sub>2</sub>O<sub>2</sub> dosage of 0.5 mL) resulted in 88% of COD and 93.4% lactose reduction.

Energy cost assessment of a dairy industry wastewater treatment plant

Water and energy are closely interlinked during their production and consumption processes. The limited and temporary distribution of energy and water resources poses a significant environmental challenge. Industrial wastewater treatment plants are essential elements of water production and also significant energy consumers. This study proposes a methodology for energy management of a wastewater treatment plant. Specifically, it examines the impact of optimum operating conditions on energy costs for a dairy wastewater treatment plant using a dissolved air flotation process. Monte Carlo simulation was used to optimize the parameters and to determine the reuse potential of dairy effluent. Firstly, the optimum operating conditions were determined. The results revealed a maximum fat, oil, and grease removal efficiency of 97% and a chemical oxygen demand removal efficiency of 70%. The optimum conditions were pH of 8, a saturation pressure of 5 bars, and a recirculation ratio of 33%. The optimum concentrations of coagulant and flocculant that contain polyaluminum chloride and cationic polymer were 20 mg/L and 25 mg/L, respectively. The results of the simulation study gave a recirculation ratio of 26.31%, a polyaluminum chloride concentration of 42.5 mg/L, a cationic polymer concentration of 36.31 mg/L, and a saturation pressure of 4.61 bars. Finally, energy cost assessment was performed using a newly developed model which showed that the energy cost indicator of the existing process was lower than optimum operating conditions. The reuse potential of dairy effluent as cooling water was found to be 52%.

Treatment of dairy industry wastewater by combined aerated electrocoagulation and phytoremediation process

As dairy industries has been emerged as one of the most rapidly developing industry in both small as well as large scale, the volume of effluent generated is also very high. In the present study, aerated electrocoagulation combined with phytoremediation treatment was conducted in dairy industry wastewater. Electrocoagulation was performed with aluminium and iron electrodes and effect of various operating parameters such as electrode combination, pH, and voltage were tested. Electrocoagulation was found effective at neutral pH and its efficiency increased with increase in applied voltage. The maximum COD removal efficiency of 86.4% was obtained in case of Al–Fe electrode combination with aeration at 120 min reaction time, initial pH 7, voltage 5 V. Significant growth of Canna indica was observed in electrocoagulation treated wastewater compared to raw dairy wastewater. COD removal of 97% was achieved when combined electrocoagulation and phytoremediation process was used. Thus, it proves to be a proficient method for the treatment of dairy industry wastewater. In addition to the above, bacterial toxicity tests were performed to investigate the toxic nature of wastewater and the results showed that both treated and untreated wastewater favoured bacterial growth.