Dairy Wastewater Research Articles

Performance of cationic hemicelluloses arising from peanut shell residue from agroindustry in application as primary coagulant in physical-chemical treatment of dairy wastewater

Cationic hemicelluloses (CH) are increasingly studied as an alternative to the use of inorganic coagulants. However, the CH has been used as coagulation aids. In the present study shows its potential to be used directly as a coagulant in a physical chemical treatment of synthetic dairy wastewater (SDW). Hemicelluloses were cationized by etherification reaction in alkaline medium with ETA. FTIR indicated cationization by increase of the methyl group band (1475 cm−1), supported by theoretical analysis. CH elemental analysis showed 1.92% (±0.09) of nitrogen and degree of substitution (DS) of 0.32 (±0.01). Turbidity, apparent color, TSS, COD and BOD5.20 was performed in a jartest with coagulation pH (5–11) and dosages range (100–900 ppm). Coagulation diagrams were determined for spatial interpolation by Kringing regression model. The optimal point selected occurred at the dosage of 400 ppm (coagulation pH 9.00 and 7.38), promoting removals for CH/TSG, respectively, of: 94.79%/98.67% (turbidity); 56.72%/65.21% (apparent color); 79.76%/97,22% (TSS); 47.83%/62.50% (COD) and 73.93%/62.39% (BOD5.20). The flakes morphology was analyzed by the image capture non-intrusive method. Fractal dimension (Df) of the flakes stabilized after 10 min at values of 1.319 (±0.020) and 1.871 (±0.001), with range diameters of 0.023–0.254 mm and 0.032–5.718 mm, for CH and TSG, respectively. Consequently, CH are a promising alternative for application as primary coagulants, provided removal of turbidity, apparent color and organic matter, not altering the pH and not promoting addition of color in the SDW.

Effect of magneto-active filling on the effectiveness of methane fermentation of dairy wastewaters

ABSTRACT The goal of this study was to determine the effectiveness of methane fermentation in dairy wastewaters in terms of the volume and qualitative composition of biogas produced in an anaerobic reactor with magneto-active filling (MAF) mounted in the zone of hydrolysis and acidogenesis. Experiments were conducted on the fractional-technical scale in a vertical fermentation reactor with a labyrinth flow. Synthetic dairy wastewaters prepared based on milk powder were used as a substrate. The analyzed filling was made of plastic covered with iron and copper powders and was additionally equipped with fluid magnetizers (FM) in the form of neodymium magnets. The study demonstrated that MAF incorporation into the technological system significantly improved the effectiveness of biogas production, increased methane concentration and lowered the content of hydrogen sulfide in gaseous metabolites of fermentative bacteria. A significant increase was also observed in the effectiveness of COD removal from dairy wastewaters. The reported experiments proved a correlation between the effectiveness of methane fermentation and the number of MAF elements introduced into the anaerobic reactor.

Biofuel recovery from microalgae biomass grown in dairy wastewater treated with activated sludge: The next step in sustainable production

Microalgae biofuel could be the next step in avoiding the excessive use of fossil fuels and reducing negative impacts on the environment. In the present study, two species of microalgae (Scenedesmus obliquus and Chlorella vulgaris) were used for biomass production, grown in dairy wastewater treated by activated sludge systems. The photobioreactors were operated in batch and in continuous mode. The dry biomass produced was in the range of 2.30 to 3.10 g L−1. The highest volumetric yields for lipids and carbohydrates were 0.068 and 0.114 g L−1 day−1. Maximum CO2 biofixation (750 mg L−1 day−1) was obtained in continuous mode. The maximum values for lipids (21%) and carbohydrates (39%) were recorded in the batch process with species Scenedesmus obliquus. In all of the experiments, the Linolenic acid concentration (C18:3) was greater than 12%, achieving satisfactory oxidative stability and good quality. Projected biofuel production could vary between 4,863,708 kg and 9,246,456 kg year−1 if all the dairy wastewater produced in Brazil were used for this purpose. Two hectares would be needed to produce 24,99 × 109 L year−1 of microalgae bioethanol, a far lower value than used in cultivating sugar cane. If all dairy wastewater generated annually in Brazil were used to produce microalgae biomass, it would be possible to obtain approximately 30,609 to 53,647 barrels of biodiesel per year. These data show that only by using dairy wastewater would biofuels be produced to replace 17% to 40% of the fossil fuels currently used in Brazil.

Dairy wastewater treatment using immobilized bacteria on calcium alginate in a microbial electrochemical system

The present study was conducted to assess the effect of immobilized Pseudomonas aeruginosa at calcium alginate beads for improving protease and lipase production as the main biocatalysts for dairy wastewater treatment in a microbial electrochemical system. A single-chamber cylindrical bioreactor with adequate volume of 3 L equipped with circular steel mesh and carbon cloth as the cathode and anode electrodes was utilized for the experiments. The main operating variables, including percent of alginate beads, pH, concentration, current density, and time were studied. The obtained results showed that the maximum production of protease and lipase in pH = 6.0 and induced current of 8.0 mA were 193.81 and 47.89 IU/L, respectively. The best precentage of calcium alginate in the bioreactor were obtained 40%. Moreover, the enzyme production time compared to the non-alginate reactor decreased from 12 to 4 h. According to the obtained results, the immobilization of Pseudomonas aeruginosa on calcium alginate along with the electrical stimulation of the bacteria increases the enzyme activities and thus reduces the time of treatment of dairy wastewater in the microbial electrochemical system.

Minimize environmental impact of dairy production through improve the life cycle. Part 1: Pollution load from Dairy wastewater in 6 of October Industrial City.

Minimize environmental impact of dairy production through improve the life cycle. Part 1: Pollution load from Dairy wastewater in 6 of October Industrial City.

Co-valorization of corn cobs and dairy wastewater for simultaneous saccharification and lactic acid production: Process optimization and kinetic assessment

This study optimized the co-valorization of corn cob wastes (CCW) and dairy wastewater for simultaneous saccharification and lactic acid (LA) production (sDWW-SSF). Subsequently, the kinetics of Lactobacillus plantarum growth and LA production was assessed using the optimized conditions under microaerophilic (sDWW-SSFmicroaerophilic) and anaerobic (sDWW-SSFanaerobic) conditions, and thereafter compared to De Man, Rogosa and Sharpe (MRS) medium modified with pretreated CCW (mMRS-SSFmicroaerophilic). Optimized sDWW-SSF conditions produced maximum LA concentration and conversion of 11.15 ± 0.42 g/L and 18.90 ± 0.75%, respectively. Kinetic studies revealed that although the mMRS-SSFmicroaerophilic system obtained a higher maximum specific growth rate (μmax) and maximum potential LA concentration (Pm) compared to the wastewater-based bioprocesses, the data obtained for the latter were comparable when taking the resources and costs into consideration. These findings represent the potential to eliminate the use of valuable resources in lignocellulosic bioprocesses and provide insights on innovation towards driving a sustainable economy in line with the food-energy-water nexus.

Local Wastewater Treatment Plant for Dairy Production: Challenges and Solutions

Main factors that can negatively affect the operation of wastewater treatment plant for dairy production were identified. The main negative factors are: low automation of the process, high concentrations of chemical reagents that have a detrimental effect on the biological treatment stage, temporary fluctuations in pH values, insufficient amount of dissolved oxygen at the biological treatment stage. One of the main operation problems of local dairy wastewater treatment plant is a fluctuation of pH value over a wide range, especially at treatment plants of small enterprises. Biological treatment methods were considered as one of the most suitable technologies for the removal of organic substances from dairy wastewater. It was concluded that there are quite stringent conditions for each treatment stage. The pH range is almost neutral and fluctuate within 6-8.5. The average temperature of wastewater should be 20-30°C for optimal biochemical reactions. The concentration of dissolved oxygen plays an overriding concern for biological treatment stage, since good operation of processes of nitrification, denitrification and biological phosphorus removal are based on this indicator and will not proceed in case of deviations from the normal.

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.

Sustainable cultivation of Haematococcus pluvialis and Chromochloris zofingiensis for the production of astaxanthin and co‐products

AbstractLarge‐scale cultivation of microalgae for the production of high‐value compounds raises concerns on sustainability due to intense consumption of water resources. Use of wastewater for microalgae cultivation is considered a promising alternative, because it not only reduces water consumption, but also provides nutrients required for microalgae growth. In the present study, Haematococcus pluvialis and Chromochloris zofingiensis were cultivated in synthetic dairy wastewater (DWW) to identify the potential of developing high‐value product first biorefineries, with astaxanthin as the main product. H. pluvialis and C. zofingiensis cultivated in DWW achieved biomass concentrations of 0.55 ± 0.01 and 0.65 ± 0.01 g/L, respectively. Astaxanthin contents of 2.1 ± 0.1% and 0.4 ± 0.1% were observed in H. pluvialis and C. zofingiensis grown in DWW. Minimum freshwater consumption for cultivation was 69.93 L/gastaxanthin in control growth media, which could be eliminated by cultivation of microalgae in DWW. COD, TN, and TP removal efficiencies were in the range of 94%–96%, 79%–81%, and 57%–79%, respectively, indicating capability for simultaneous biomass production and phycoremediation. Presence of carbohydrates and lipids in residual biomass suggested the applicability as feedstock for biorefining. Potential avenues to integrate wastewater treatment, astaxanthin production, and valorization of residual biomass were discussed in context of high‐value product first biorefineries.

Potential of Moringa Oleifera Seed as a Natural Adsorbent for Wastewater Treatment

The present study deals with the appropriateness of the coagulation process using natural coagulant Moringa oleifera seed. Natural coagulants are useful for the treatment of wastewater because of its sustainability, cost-effectiveness, non-toxicity and lesser quantity of sludge formation. M. oleifera seed having a chemical composition of polypeptides having 6 amino acids like arginine acid, methionine acid, glutamic acid, phenylalanine, threonine, and histidine. M. oleifera is also known as a cationic polyelectrolyte and having molecular weight 6,000 to16,000 Dalton. The main objective of research work is the application of the M. oleifera seed as a natural adsorbent to treat synthetic dairy wastewater. The effects of pH, agitation time, the dose of sorbent and efficacy of M. oleifera seeds kernel for turbidity removal was assessed. M. oleifera seed eliminates turbidity 95 % and colour 94 % using 0.22 gm pod powder, and 0.2 L of 1.0 g/L synthetic dairy wastewater. Naturally dried M. oleifera seeds remove turbidity 95 %, sundried seeds remove turbidity 52 % and oven-dried seeds 45 %. As naturally dried M. oleifera pod having more surface area for adsorption and inter-particulate bridging which extract the extra active ingredients. pH range between 5 and 8 is more suitable to degrade the turbidity and colour. It is concluded that in the presence of an aqueous soluble cationic coagulant protein has great potential to remove the turbidity and colour of wastewater.
 HIGHLIGHTS
 
 oleifera seed having a chemical composition of polypeptides having 6 amino acids like arginine acid, methionine acid, glutamic acid, phenylalanine, threonine, and histidine
 oleifera seeds consist of crude fiber, lignin, hemicellulose, and cellulose. It also contains amino functional groups (R-NH3), carboxyl group (C=O), and fiber carbonaceous. The functional group present in M. oleifera seeds is dissociated during the adsorption process at various pH
 oleifera has good property of coagulation-flocculation (C-F)
 The effectiveness of naturally dried seed kernel is more effective than other seed kernels
 
 GRAPHICAL ABSTRACT

Effects of three surfactants on co-conversion of endogenous carbon and nitrogen of dairy wastewater in mesophilic hydrolytic acidification coupled microalgae culture system.

To determine the feasibility of enhancing co-conversion of endogenous C and N in dairy wastewater by surfactants, the effects of varying dosages of sodium lignosulfonate (LS), sodium dodecyl sulfate (SDS), and Tween-80 on mesophilic hydrolytic acidification coupled microalgae culture system were investigated. Tween-80 had a positive effect on hydrolytic acidification, while LS had no clear effect and SDS had a negative effect. Tween-80 significantly increased the C/N ratio in hydrolytic acidification liquor (HAL) (maximum HAc/NH4+-N rate reached 7.90 in 2.9% Tween-80 test). Pyrosequencing analysis demonstrated that community richness and diversity decreased and the proportion of acidobacteria increased with increasing Tween-80 dosage. Furthermore, the effect of Tween-80-enhanced HAL on microalgae (Chlorella pyrenoidosa) growth and nitrogen removal and the assimilation of C and N on the microalgae culture system were investigated. The biomass concentration and a C and N assimilation yield of 4.8% Tween-80 test (1.75 g/L, 825.01 mg/L, 126.68 mg/L) were significantly higher than those of both the low-concentration Tween-80 tests and control. The yield of protein and carbohydrates and higher heating value in the microalgae culture system were also promoted by Tween-80.

Mixotrophic cultivation of Monoraphidium sp. In dairy wastewater using Flat-Panel photobioreactor and photosynthetic performance

Monoraphidium sp. SVMIICT6 was isolated and mixotrophically cultivated in a flat-panel photobioreactor (8 days) to treat synthetic dairy wastewater. COD, nitrates, and phosphates removal efficiencies were 75%, 85%, and 60% respectively. The nutrient removal supported the growth of microalgae in terms of biomass productivity (50 mg L-1d-1), and accumulation of carbohydrate (228.8 mg g-1), protein (88.8 mg g-1), and lipid content (25%). Elemental analysis of microalgal biomass revealed carbon (50.6%) as a major fraction. Quantum yield and electron transport rate (ETR) from PSII to PSI increased with time correlating well with chlorophyll pigments (89.53 mg g-1). The lipid profile resulted in a major fraction of Heptadecanoic acid (C17:0; 51.5%), followed by Myristoleic acid (C14:1; 24.3%) with potent nutraceutical properties. The isolated strain showed efficient treatment of dairy wastewater yielding biomass for diverse applications.

Dairy Wastewater Treatment through Synergies of the Biological and Hybrid Membrane: A Systematic Review

Wastewater treatment techniques have two categories: pre- and post-treatment. Physical, chemical, and biological pretreatment techniques are commonly employed to treat dairy wastewater. Secondly, dairy wastewater post-treatment techniques include physico-chemical and membrane treatment approaches. This review article aims to critically examine and describe pre- and post-treatment techniques for dairy wastewater treatment. The benefits, drawbacks, performance comparisons, and features of each pre - and posttreatment have been extensively investigated. This article uses a systematic literature review method to review and examine other research findings. The results indicate that despite extensive studies on pre- and post-treatment techniques, both have limitations. In this context, aerobic pre-treatment, for example, has high lactose levels, low water capacity, and efficiency concerns. Furthermore, anaerobic pretreatment has issues with lengthy starting times, a high fermentable lactose content, poor residual alkalinity, and fat consumption. In physico-chemical post-treatment, there are high amounts of sludge production and high quantities of chemicals required for pH corrections. Likewise, membrane post-treatment, for instance, has a short membrane lifespan, low selectivity and flux, linear up-scaling, and concentration polarization membrane fouling. Therefore, a synergy of physico-chemical and aerobic, for example, adsorption-aerobic, and synergy of pre-hydrolysis and anaerobic, such as enzymatic hydrolysis-anaerobic treatment, will help to overcome the drawbacks of both anaerobic and aerobic treatment techniques. In conclusion, the most promising techniques for dairy wastewater treatment are combinations of adsorption-aerobic and enzymatic hydrolysis-anaerobic with microfiltration, nanofiltration, reverse osmosis, and ultrafiltration.

Using Of Different Electrocoagulation Cell Configuration Parameters for Treating of Abu-Ghraib Dairy Products Wastewater

One of the most significant issues that people throughout the world will confront in the future years is a lack of clean and safe water. Anthropogenic activities, in particular, are polluting water systems. With rising population, urbanization, and climate change, water reuse has become a requirement in some areas of the globe, putting pressure on the development of effective water treatment methods for a range of contaminants. High biological oxygen demand (BOD), chemical oxygen demand (COD), oil-grease, and other pollutant loads define dairy sector effluent. Improved technology is required to address these issues. Electrocoagulation is a new type of therapy. It’s simple to use, ecologically friendly, and removes a wide range of contaminants from a variety of water types. The goal of this study was to see how operational factors such applied voltage, number of electrodes, distance between electrodes, electrode shape, and reaction time affected the electrocoagulation of actual dairy effluent. Aluminum and iron electrodes are used for this purpose. It was discovered that raising the applied voltage, reaction time, and decreasing the distance between electrodes improved COD, BOD, EC, TDS, color, and oil-grease removal efficiency. Moreover, switch between square, triangular electrodes and perforated cylindrical. The data show that electrocoagulation is effective at the maximum COD, BOD removal efficiency of first electrode at 20 holes of cylindrical shape is (88.03) %, (87.97) %, respectively. Second triangle shape is (100) %, (100) % respectively. Third square shape is (99.38) %, (99.42) % respectively. the maximum removal of TDS, EC efficiency of first electrode at 20 holes of cylindrical shape is (67.57) %, (62.34) %, respectively. Second triangle shape is (77.45) %, (67.68) % respectively. Third square shape is (81.96) %, (71.25) % respectively. The maximum color and oil-grease removal efficiency of first electrode at 20 holes of cylindrical shape is (100) %, (100) %, respectively. Second triangle shape is (100) %, (100) % respectively. Third square shape is (100) %, (100) % respectively. Electrocoagulation methods for the treatment of dairy wastewaters were shown to be successful in the research. Finally, the findings indicated that electrocoagulation is a technically feasible method for removing contaminants from dairy wastewaters.

Perspectives on the Fate of Absorbed Nitrogen in Dairy Farms

The demand for milk rises dramatically due to the increased global population without damaging the standard of living. As a result, the scale of the dairy industry in the world is growing rapidly. Consequently, a concomitant problem that needs to be faced is the environmental impact of the by-products produced during the operation of the dairy farm. Among the substances produced in dairy farms, the most harmful pollutant to the environment is nitrogen (N). In addition, the N pollution from dairy farms is significant and N has a great danger to human health and society. This study provides a systematic review on how to alleviate N pollution from dairy cows during milk production and the removal of ammonia and nitrate from dairy wastewater via biochar adsorption. First, from a physiological perspective, the metabolic pathways of amino acids and ammonia in the rumen, portal-drained viscera, liver, and mammary gland of dairy cows are elaborated, as well as the measures to improve N utilization. In the second part, the progress of research on the removal of ammonia and nitrate by biochar adsorption and the involved mechanisms are summarized. Modified biochar has a significant improvement in nitrate removal due to weakening the repulsive effect of ions. Based on the review of this paper, it can provide relevant theoretical support for future studies on N pollution mitigation from dairy farms.

Innovation in a food SME to match the UN2030 sustainable development goals

Sustainable development goals may be reached with some bold country policies but also optimizing any manufacturing process. Awareness of the large amount of waste produced along the dairy supply chain, for instance, raised great concern: continuous questions are raised about the consequences that will affect environmental sustainability, the continuous waste of resources and, above all, the future health of the entire ecosystem. In fact, dairy wastewater cannot be disposed of as simple wastewater (due to the high organic load and the nutrients it contains); therefore, adequate disposal processes and techniques are requested. The latter have a huge impact on company production costs.In this regard, coherently with some goals of Agenda2030, the study focuses on the search for a technological solution that could guarantee a reduction in the volume of whey, in order to reduce the number of monthly trips dedicated to disposal and the consequent environmental impact. The optimal selection could improve from one side corporate finances but, at the same time, could result in a green technological solution allowing a more harmonious production within the Pollino National Park in which the farm is located.

Simultaneous Nutrients Removal and Biocompounds Production from Anaerobic Digestate of Dairy Wastewater with Chlorella Sorokiniana Su-1 Culture

Simultaneous Nutrients Removal and Biocompounds Production from Anaerobic Digestate of Dairy Wastewater with Chlorella Sorokiniana Su-1 Culture

Optimal Electrocoagulation as a Post-Treatment to Photochemical Oxidation: Minimal Electrical Energy Consumption and Lower Acute Toxicity of Dairy Wastewater

Optimal Electrocoagulation as a Post-Treatment to Photochemical Oxidation: Minimal Electrical Energy Consumption and Lower Acute Toxicity of Dairy Wastewater

Fouling Mitigation of Intermittent Aeration in Membrane Bioreactor (Mbr) for Flocculated Dairy Wastewater Treatment: A Pilot Study

Fouling Mitigation of Intermittent Aeration in Membrane Bioreactor (Mbr) for Flocculated Dairy Wastewater Treatment: A Pilot Study

Pilot-Scale Hybrid Wetland System for the Final Treatment of Dairy Wastewater

Pilot-Scale Hybrid Wetland System for the Final Treatment of Dairy Wastewater