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In this research, the technique of the jar using alum as coagulant was used as the most common in the world and abundance in the Iraqi environment, the preparation of artificial samples similar to the real dairy wastewater and taking the temperature of the laboratory as a reference in the completion of experiments. Experiments have seen the ability of aluminium sulphate to remove phosphorus from wastewater of the dairy plant by up to 95%. These removals are realized at certain working conditions in terms of the speed of rotation of the paddle which expressed as gradient velocity that achieved at 1076.915 sec-1 and the potential energy that can lead to better collision between the particles to achieve an increase in particle size and then sedimentation. This led to optimum dosage of aluminium equal to 0.5 mg/L at 20 °C.

The dairy industry has become a great source of human development in terms of providing the necessary amount of energy and calories, in addition to the vitamins needed to sustain life. Iraq is one of the largest countries that are dairy-producing and it is expected that the average per capita consumption of dairy products will increase from 52 litres to more than 60 litres during the next three years, then to more than 90 litres by 2025. Dairy production needs to consume large quantities of water It needs to consume 2-6 cubic meters of water to produce one ton of milk. These large quantities of water will lead to the discharge of large amounts of wastewater, which may reach 70% of the water used. Over the years I have used various techniques and methods for treating dairy wastewater. In this study, the membrane permeation removal technique (MD) was used to find out how efficient this technique is in removing the magnesium ion from the milk laboratory wastewater. The results came with the possibility of this technique in removing a small percentage of up to 9.76% at a temperature of approximately 45 degrees Celsius, which is a small percentage compared to the concentration of the interior and the effort exerted. For this reason, it is not recommended to use this mechanism to remove magnesium from dairy wastewater.

In this research the membranes distillation was used to remove calcium ions from heavy sewers at dairy plants in Iraq. This method is easy to operate, easy to manage and has many economic benefits. A chemical treatment was carried out on it using alum as a coagulant, different tests achieved samples before and after passing MD, according to APHA, AWWA, WEF. The results showed that obtained in water treatment trust that has been manufactured and edited according to the characteristics of the water waste the interests of the dairy capacity of this method to remove the calcium ion to a certain extent it is when the concentration reaches the inside of this ion to 1428.57 mg per liter, where to start the composition of hydroxides of calcium responsible for pain. The optimal working temperature ranges from 20-22 ° C and the flow is around 0.66 kg.m-2.h-1, here was the result of a layer of plaster that led to clogged membrane and folding and was stopped for washing and cleaning.

The study aimed to assess the operation of the mechanical and biological wastewater treatment plant in Michów (Poland) in terms of the effectiveness of removing contaminants from mixed wastewater (dairy and domestic) and technological reliability. The wastewater treatment plant is owned by the Dairy Cooperative "Michowianka." It is intended to treat mixed sewage, consisting of technological and sanitary sewage as well as part of rainwater from the plant, domestic wastewater supplied by a sewerage system from Michów, and wastewater delivered from septic tanks. In 2017 and in the first quarter of 2018, the permeate from the whey thickening process was also sent to the treatment plant. The period 2017-2021 was covered by the analysis. The analysis included the indicators from the fundamental group (TSS, BOD5, COD), biogenic indices (total phosphorus, total nitrogen, and ammonium nitrogen). The applied technology ensured the removal of total suspended solids, BOD5, and COD at the level of over 96%. Total phosphorus was removed with an average efficiency of 91%. Slightly lower effects were found in the elimination of total nitrogen — 78.5% on average, while the ammonium nitrogen removal rate was 88% on average. Due to the high efficiency of the facility, the values of the standard contamination indicators at the outflow, as a rule, met the requirements specified in the water permit. The technological reliability of the wastewater treatment plant in Michów, determined by the Weibull method, was at a high level, usually exceeding 90%. The reliability analysis shows that the facility in Michów has a high capacity to treat wastewater to the extent required for the wastewater receiver, and that the treated wastewater discharge does not cause negative changes in the environment. It indicates a high probability of obtaining the wastewater quality at the outflow from the treatment plant meeting the water permit requirements.

The aim of this study is to synthesise SPEEK composite proton exchange membrane with the addition of TiO2 nanofillers for microbial fuel cell application. SPEEK composite membrane with varying weight percentage of TiO2 (2.5, 5, 7.5 and 10%) was prepared to study the effect of TiO2 concentration on membrane performance. Synthesized composite membranes were subjected to various characterization studies such as FT-IR, XRD, Raman spectroscopy, TGA, UTM and SEM. Physico-chemical properties of membrane such as water uptake capacity, ion exchange capacity and thickness were also analyzed. 5% TiO2 – SPEEK composite membrane exhibited the higher water uptake capacity value and Ion exchange capacity value of 31% and 1.71 meq/g respectively. Performance of the MFC system with TiO2 – SPEEK membranes were evaluated and compared with the pristine SPEEK and Nafion membrane. 5% TiO2 – SPEEK membrane produced the higher power density (1.22 W/m2) and voltage (0.635 V) than the other membranes investigated. Efficacy of MFC in wastewater treatment was evaluated based on the chemical oxygen demand (COD), total organic carbon content and turbidity. Biofilm growth over the surface of the electrodes was also analyzed using scanning electron microscopy. HIGHLIGHTS Use of TiO2 – SPEEK composite membrane as alternate for the Nafion 117.; Energy generation from dairy wastewater was investigated using dual chambered MFC.; Low cost membrane.; Green energy.; TiO2 – SPEEK can be used to overcome drawbacks of Nafion 117.

The paper investigates an alternative treatment plant for the typical wastewater effluent of a cheese-making industry, mainly composed of acid or sweet whey mixed with washing-water. Two variable parameters have been considered during the tests: four treatment temperatures (39, 46, 53 and 60 °C) and three solid content values (30%, 50% and 70%) of the concentrated product. The minimum and maximum values of the removal efficiency (pollutant amount into concentrate related to raw whey) range from 94.6% to 97.7% for conductivity, from 98.3% to 99.5% for BOD5, from 98.7% to 99.6% for COD and from 98.2% to 99.3% for Total Nitrogen. The plant capacity ranges from about 2 L/h (at 39 °C) to 6 L/h (at 60 °C) of processed whey. On the basis of the experimental findings, the proposed purification technology has demonstrated its suitability both to purify the effluent wastewater and to recover high-quality products (e.g., whey protein concentrate, lactose), thanks to its low thermal damage on the treated product and to its relatively low energy consumption from 0.4 kWh/L (at 60 °C) to 1.0 kWh/L (at 39 °C) of processed whey, with a Coefficient of Performance from approximately 0.6 up to 1.5.

The development of wastewater treatment systems, including competitive methods for nitrogen and phosphorus removal, is focused on intensifying final technological effects with due care taken for economic and environmental concerns. Given the possibility of integrating wastewater treatment processes with biofuel production, the prospective seems to be technologies harnessing microalgal biomass. The present study aimed to verify the feasibility of applying T. subcordiformis genus microalgae as the third stage of the dairy wastewater treatment process and to determine microalgae biomass production effectiveness and hydrogen yield in the biophotolysis process. The study proved that microalgae cultivation with dairy wastewater was nearly 35% less effective compared to that with a chemically pure medium. Nitrogen and phosphorus compounds contaminating wastewater were found to represent an available source of nutrients for T. subcordiformis population. The volume of hydrogen produced ranged from 116 ± 7 cm3 to 162 ± 7 cm3, and the percentage of H2 content in the biogas ranged from 55.4 ± 2.2% to 57.2 ± 4.1%. A significantly higher hydrogen yield per initial biomass concentration, reaching 69 ± 4.2 cm3/go.d.m., was determined in the variant with wastewater accounting for 50% of the culture medium. The respective value noted in the control respirometer was 54 ± 2.1 cm3/go.d.m.

This research aimed at investigating the anaerobic digestion (AD) of selenium (Se)-rich and lipid-rich wastewaters via evaluating the operational parameters in sequential and continuous bioreactors. In the first part of the study, batch AD of dissolved air floatation (DAF) slurry derived from dairy wastewater showed methane yield was improved up to 177% after up to three folds dilution. Similarly, adjustment of the initial pH to 6.0 resulted in a higher methane yield, which was 23% higher than the control without pH adjustment. Following this, the potential of granular activated carbon (GAC) supplementation to enhance the AD of dairy wastewater was studied in sequential batch reactors (SBR). The methane production increased by up to 500% in the GAC-amended SBR when compared to the Control SBR. GAC addition led to faster lipid degradation and promoted the activity of syntrophic and electroactive microorganisms such as Geobacter, Synergistes, Methanolinea and Methanosaeta. The second part of the study evaluated the effect of Se oxyanions on AD of different model substrates and real waste/wastewater. AD of dairy wastewater based DAF slurry supplemented with 0.05 and 0.10 mM Se oxyanions achieved a similar cumulative methane yield of 180 mL/g COD as that of digestion of Se free DAF slurry after 65 days of incubation. The IC50 was 0.08 mM for selenate and 0.07 mM for selenite. Following this, the influence of pH, heat treatment (HT) of inoculum and Se oxyanions on volatile fatty acids (VFA) production from food waste was studied. The highest VFA yield (0.516 g COD/g VS) was achieved at pH 10, which was 45% higher than that at pH 5. The VFA composition was dominated by acetic and propionic acids at pH 10 with non-heat treated inoculum, which diversified at other test conditions. HT and Se resulted in VFA accumulation in alkaline pH, but HT was detrimental for selenate reduction (< 15 % Se removal after 20 days). Finally, a long term, continuous and simultaneous methane production and Se bioremediation was demonstrated in up-flow anaerobic sludge blanket reactors. About 150 mL/g COD daily methane yield was achieved which was comparable with that of the control until 400 µM selenate. Simultaneously, more than 90% Se removal was accomplished. Biosynthesis of Se nanoparticles and metal selenides were observed, supported by X-ray diffraction, scanning and transmission electron microscopy. However, methane production deteriorated when selenate was increased to 500 µM, due to inhibition in the activity of Methanosaeta. Remarkably, Se facilitated sludge granulation. The selenate concentration, but not the COD/selenate ratio, was found to govern the AD of selenate rich wastewaters.

In this research, the methane potential of the codigestion of cattle manure (CM) with guinea pig manure (GPM) and dairy wastewater (DW) was evaluated. The effect of the addition of nutrients, inoculum (I) and co-substrates on methane production was studied. Later, two low-cost tubular biodigesters were implemented, at a rural farm in the cold climate municipality of Cumbal, fed with the mixture of CM and co-substrates that produced higher biogas production at the lab scale. The results evidenced that the addition of nutrients had no significant effect on methane potential. The mixture CM + GPM + DW + I, produced a theoretical biomethane potential (BMP) of 69.07%, significantly higher than the percentage of the theoretical BMP obtained individually, 43.81% and 34.49% for CM + I and DW+ I respectively. Further, it was observed that the addition of inoculum avoided problems of acidification. Finally, it was proved that this process can reduce environmental contamination and, at the same time, be a sustainable source of renewable energy for rural families in Cumbal (Nariño-Colombia).

Intermittent sand filters (ISFs) are widely used in rural areas to treat domestic and dilute agricultural wastewater due to their simplicity, efficacy and relative low cost. However, filter clogging reduces their operational lifetime and sustainability. To reduce the potential of filter clogging, this study examined pre-treatment of dairy wastewater (DWW) by coagulation with ferric chloride (FeCl3) prior to treatment in replicated, pilot-scale ISFs and monitored their performance over an entire milking season (301 days). Over the study duration and at the end of the study, the extent of clogging across hybrid coagulation-ISFs was quantified and the results were compared to ISFs treating raw DWW without a coagulation pre-treatment, but otherwise operated under the same conditions. During operation, biomass growth/extent of clogging was higher in ISFs treating raw DWW, which were fully clogged after 280 days of operation. The hybrid coagulation-ISFs remained fully operational until the end of the study. Examination of the filter media in both filter types showed that the ISFs treating raw DWW lost approximately 85% of their initial infiltration capacity in the uppermost layer due to biomass build-up versus 40% loss for hybrid coagulation-ISFs. Furthermore, ISFs treating raw DWW retained more organic matter and proportionally higher amounts of phosphorus, nitrogen and sulphur than the pre-treated DWW, with values decreasing with depth below the filter surface. Overall, hybrid coagulation-ISFs are likely to sustain infiltration capacity for a longer period than filters treating raw wastewater; therefore, requiring smaller surface area for treatment and minimal maintenance. The authors would like to acknowledge Teagasc for the grant of a Walsh Fellowship to the first author [funding number: RMIS-0386]. The authors appreciate the help of technical staff: Seamus McShane, Adrian Hawe, Tomas Condon & John Paul Murphy (Teagasc Moorepark), Denis Brennan (Teagasc Johnstown Castle), and Emma McDermott (Centre for Microscopy and Imaging, University of Galway). peer-reviewed

Due to the massive amounts of freshwater consumed in dairy industries, as a result, thousands of liters of wastewater were produced as one liter of milk produces 10 liters of wastewater which represents a major threat to the surrounding environment and aquatic life. The application of a promising technology called “effective microorganism (EM)” was the key solution due to its low operating cost, low technology, and eco-friendly condition. Three different effective microorganisms were used, such as Bacillus bacteria (EM1), Staphylococcus bacteria (EM2), and EM stoste + Molasses (EM3). EM1 and EM2 were isolated from the dairy wastewater by using streaking for isolation on an agar plate process, while EM3 was prepared by mixing 12 % EM stoste, 6% molasses, and 82% distilled water. A laboratory pilot consists of aeration and final settling tanks, both tanks followed by an activated carbon filter. Four trials were performed, the first trial was without any EM, the second trial was adding EM1 with a dose of 50 ml to the aeration tank, the third trial was EM2 with a dose of 50 ml to the aeration tank, finally adding EM3 with a dose of 30 ml to the aeration tank. Results showed that using Bacillus bacteria (EM1) was the most effective trial as it was effective in reducing TSS (total suspended solids), BOD (biological oxygen demand), COD (chemical oxygen demand), TN (total nitrogen), and TP (total phosphorous) concentrations by removal efficiency of 93%, 96.2%, 95.9%, 94%, and 64%, respectively which were below the limitations of the Egyptian code for reuse for irrigation purposes.

Constructed wetlands (CWs) are a cost-effective and sustainable treatment technology that may be used on farms to treat dairy wastewater (DWW). However, CWs require a large area for optimal treatment and have poor long-term phosphorus removal. To overcome these limitations, this study uses a novel, pilot-scale coagulation-sedimentation process prior to loading CWs with DWW. This hybrid system, which was operated on an Irish farm over an entire milking season, performed well at higher hydraulic loading rates than conventional CWs, and obtained removal efficiencies ≥99 % for all measured water quality parameters (chemical oxygen demand, total nitrogen and phosphorus, total suspended solids and turbidity), which complied with EU directives concerning urban wastewater treatment. Overall, the hybrid coagulation-CW is a promising technology that requires a smaller area than conventional CWs and minimal operator input, and produces high effluent quality. The authors are grateful to Teagasc for the award of a Walsh Fellowship to the first author [grant number: RMIS-0386]. The authors appreciate the help of technical staff: Adrian Hawe; Seamus McShane, JohnPaul Murphy & Tomas Condon (Teagasc Moorepark), and Denis Brennan (Teagasc Johnstown Castle). peer-reviewed

Fil: Nocetti, Emanuel. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Los efluentes lácteos poseen elevado contenido de compuestos nitrogenados, además de materia orgánica y fósforo. Debido a que Santa Fe se localiza en una región caracterizada por un significante número de industrias lácteas, el tratamiento de sus efluentes es un tema que concierne a la región. El objetivo general de la presente Tesis fue evaluar el rendimiento de humedales construidos para tratar el efluente de una industria láctea local. Para esto, se realizaron estudios en humedales a escala microcosmos en invernadero y a escala piloto en campo. Los objetivos de los estudios a escala microcosmos fueron seleccionar la especie de macrófita y sustrato más adecuado y cuantificar la influencia de la vegetación en el tratamiento mediante la aplicación de un modelo cinético simple de primer orden. Los estudios en la escala piloto se enfocaron en determinar la eficiencia de remoción de contaminantes y evaluar el efecto de diferentes velocidades de carga superficial sobre la velocidad de remoción superficial de materia orgánica y nutrientes bajo condiciones reales. Los datos colectados del sistema a escala piloto fueron utilizados para calibrar parámetros de modelos en un esfuerzo de predecir el rendimiento del humedal bajo diferentes posibles escenarios de operación. Las simulaciones realizadas permitieron demostrar la competencia establecida por el consumo de oxígeno entre los contaminantes. El sistema de humedales ha demostrado ser eficiente en el tratamiento del efluente lácteo para las estrategias evaluadas. Dairy wastewater has a high content of nitrogenous compounds, in addition to organic matter and phosphorus. Since Santa Fe is located in a region characterized by a significant number of dairy industries, the treatment of their effluents is an issue that concerns the region. This work focused on evaluating constructed wetland performance to treat these wastewaters. For this, microcosms and pilot-scale wetland studies were carried out. The aims of the studies at microcosms-scale were to select the most suitable macrophyte species and substrate to be used in wetlands for the treatment of wastewater from a local dairy industry, and to quantify the influence of plant species by applying a simple first-order kinetic model. The studies at the pilot-scale wetland was aimed to determine pollutant removal efficiencies from the dairy wastewater and evaluate the effect of different surface loading rate on surface removal rate of organic matter and nutrient under real conditions. The collected data from pilot-scale system were used to fit model parameters in an effort to predict wetland performance under different possible operating scenarios. The simulations carried out demonstrated the competition that establishes the consumption of oxygen among pollutants. The system demonstrated to be efficient in the treatment of the dairy wastewater for the strategies evaluated. Consejo Nacional de Investigaciones Científicas y Técnicas Agencia Nacional de Promoción Científica y Tecnológica Universidad Nacional del Litoral

A significant increase in phosphorus-rich dairy wastewater coincides with a decrease in the availability of fossil phosphate rock resources in Europe. This confluence of events has led to the development of technologies for phosphorus recovery from dairy wastewater. This study aims to inform and guide such development with regard to life cycle environmental impacts prior to their implementation in dairy contexts. With the lack of inventory data at this point and the non-existence of earlier life cycle assessments on the use of phosphorus recovery technologies in a dairy context in literature, we performed a meta-analysis where we extracted and compared published results on life cycle environmental impacts from two fields (1) dairy industries, with a focus on the dairy wastewater treatment and (2) phosphorus recovery technologies in a municipal wastewater treatment context. The results show that despite its intended effect, normal dairy wastewater treatment in many cases still contributes significantly to eutrophication. Most of the phosphorus recovery technologies examined here exhibited a lower global warming potential and cumulative energy demand than those of dairy wastewater treatment processes. It indicates that problem shifting could be avoided when phosphorus recovery is introduced. However, no technologies involving incineration have had the impact of acidification reported which represents a potential knowledge gap since impacts are expected related to incineration emissions. A comparison between the extracted data for phosphorus recovery technologies shows that there are lower impacts related to technologies that recover phosphorus from the liquid phase, than from sludge or ash.

This study investigates the potential of utilizing three food wastes: cheese whey (CW), beet molasses (BM), and corn steep liquor (CSL) as alternative nutrient sources for the cultivation of the diatom Phaeodactylum tricornutum, a promising source of polyunsaturated eicosapentaenoic acid (EPA) and the carotenoid fucoxanthin. The CW media tested did not significantly impact the growth rate of P. tricornutum; however, CW hydrolysate significantly enhances cell growth. BM in cultivation medium enhances biomass production and fucoxanthin yield. The optimization of the new food waste medium was conducted through the application of a response surface methodology (RSM) using hydrolyzed CW, BM, and CSL as factors. The results showed a significant positive impact of these factors (p < 0.005), with an optimized biomass yield of 2.35 g L-1 and a fucoxanthin yield of 3.64 mg L-1 using a medium composed of 33 mL L-1 of CW, 2.3 g L-1 of BM, and 2.24 g L-1 of CSL. The experimental results reported in this study showed that some food by-products from a biorefinery perspective could be utilized for the efficient production of fucoxanthin and other high-added-value products such as eicosapentaenoic acid (EPA)., Italian Ministry of Education, Universities, and Research (MIUR), The Spanish Ministry of Science, Education, and Universities/Spanish State Research Agency (PCI2018-093178), Co-funding by the European Union’s Horizon 2020 research and innovation program

The main purpose of this study was to investigate the effect of operating conditions on the performance of two methods used for dairy wastewater treatment. First, conventional activated sludge (AS). Second, conventional sequencing batch reactor (SBR). On one side, the study included the comparison between the two basic systems. On the other side, it studied the influence of adding plastic media on both systems. The modified systems are known as biofilm conventional activated sludge (BAS) and biofilm sequencing batch reactor (BSBR). Four pilot-scale bioreactors, were operated in parallel under different conditions of temperature; 20, 35 and 45 °C. Synthetic dairy wastewater was used with characterizations of COD; 5000 mg/l, NH3-N; 250 mg/l and TP; 50 mg/l. The results recorded that the optimum temperature was 35 °C where removal efficiencies for COD were (93.52%, 96.63%, 94.74% and 97.79%), (89.01%, 91.14%, 90.45% and 93.22%) for NH3-N, and the concentration of NO3-N in effluents was (7.56 mg/l, 10.58 mg/l, 8.72 mg/l and 14.12 mg/l) for AS, BAS, SBR and BSBR respectively. At temperature equals to 45 °C; the oxygen consumption recorded the highest level of consumption, it was (1.07 mg/l, 1.64 mg/l, 0.98 mg/l and 1.23 mg/l) for AS, BAS, SBR and BSBR respectively. The results indicated that the sludge settleability was enhanced with the decrease of temperature. Furthermore GPS-X simulator was employed to predicting the performances of the biological systems under high COD concentrating reaching up to 17500 mg/l. GPS-X results indicated that SBR effluent could comply with Egyptian standard NO 2000. An overview, comparing with various treatment systems, it can be concluded that the SBR was the optimum treatment method for dairy wastewater based on the investigated conditions.

Volatile fatty acids, intermediate products of anaerobic digestion, are one of the most promising biobased products. In this study, the effects of acidic (pH 5), neutral (without pH adjustment) and alkali (pH 10) pH on production efficiency and composition of volatile fatty acids (VFAs) and bacterial community profile were analyzed. The anaerobic sequencing batch reactors were fed cheese production wastewater as substrate and inoculated by anaerobic granular seed sludge. The results showed that acidic pH improved VFA production yield (0.92 at pH 5; 0.42 at pH 10 and 0.21 gCOD/gVS at neutral pH). Furthermore, propionic acid was dominant under both pH 10 (64 ± 20%) and neutral pH (72 ± 8%), whereas, acetic acid (23 ± 20%4), propionic acid (22 ± 3%), butyric acid (21 ± 4%) and valeric acid (15 ± 8%) were almost equally distributed under pH 5. Adaptation of bacterial community to different pH conditions might steer the acid profile: Bacteroidetes (50.07 ± 2%) under pH 10, Proteobacteria (40.74 ± 7%) under neutral pH and Firmicutes (47.64 ± 9%) under pH 5 were the most dominant phylum, respectively. Results indicated pH plays a significant role in VFA production, acid composition, and bacterial community structure. However, in order to gain a concrete understanding effects of pH, characterization of intracellular and extracellular metabolites with dynamics of the microbial community is required.

The objective of this study was to evaluate the efficiency of dissolved ozone flotation (DOF) in comparison to dissolved air flotation (DAF) for treatment of milk industry wastewater (MW). In the first phase of the experiment, a synthetic milk wastewater (SMW) was used to evaluate DOF and DAF, with and without addition of hydrogen peroxide, at pH 4.0 and pH 11.4. In the DOF tests, the concentration of ozone was equal to 19 (± 0.5) mg L-1 and in the tests with addition of hydrogen peroxide, the H2O2/O3 ratios tested were 0.5, 1.0 and 1.5. In the second phase, tests were performed using three MW from three different industries to validate the results obtained and to determine the DOF system's ability to treat this type of effluent. The parameters tested during validation were turbidity, total suspended solids, oils and greases (O&G), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total nitrogen (TN) and total phosphorus (TP). It was observed that the efficiency of the treatments was better at pH 4.0. The results showed a reduction of the efficiency with the use of DOF. The addition of H2O2 in DAF and DOF also resulted in reduced system efficiency. The results obtained with SMW only approximated those obtained with the MW from one of the industries that contained the largest traces of milk and cheese. Resumo O objetivo deste estudo foi avaliar a eficiência da flotação por ar e ozônio dissolvido (FAOD) em comparação à flotação por ar dissolvido (FAD) no tratamento da água residuária de laticínios (ARL). Na primeira fase do experimento foi utilizada água residuária de laticínios sintética (ARLS) para avaliar a FAD e a FAOD, com e sem a adição de peróxido de hidrogênio em dois valores de pH, 4,0 e 11,4. Nos testes de FAOD, a concentração de ozônio utilizada no ar foi igual a 19 (± 0,5) mg L-1 e nos testes com adição de peróxido de hidrogênio, as relações H2O2/O3 testadas foram de 0,5, 1,0 e 1,5. Na segunda parte do experimento, foram realizados testes com três ARL de três diferentes laticínios para validar os resultados obtidos e determinar a capacidade do sistema FAOD para tratar esse tipo de efluente. Os parâmetros testados durante a validação foram: turbidez, sólidos totais suspensos, óleos e graxas (O&G), demanda química de oxigênio (DQO), demanda bioquímica de oxigênio (DBO), nitrogênio total (NT) e fósforo total (PT). Ao final do experimento, observou-se que a eficiência dos tratamentos foi melhor em pH 4. Os resultados mostraram uma redução da eficiência com o uso da FAOD. A adição de H2O2 na FAD e FAOD também resultou em menor eficiência nos dois sistemas. Os resultados obtidos com ARLS aproximaram-se apenas dos obtidos com o ARL de uma das indústrias que continham os maiores traços de leite e queijo.

Background: A high volume of wastewater is produced in dairy industries. These effluents contain high concentration of organic matters and nutrient elements (nitrogen and phosphorus). Discharging nitrogen and phosphorus to the environment leads to algal excessive growth, aquatics death, eutrophication and consequently, destruction of aquatic ecosystems. Methods: This study was an experimental-laboratory study that was carried out to evaluate the efficiency of nitrogen and phosphorus removal from dairy wastewater by combined process of chemical coagulation and Fenton. In the first stage, the effect of different doses of coagulant poly-aluminum chloride (PAC) on removal efficiency of Chemical oxygen demand (COD), Total Kjeldahl nitrogen (TKN), and total phosphorus (TP) was assessed and optimum dosage of coagulant was determined. Then, the supernatant was used in Fenton process and optimum values of reaction time, pH, H2O2 concentration and Fe2+ concentration was determined. Findings: According to the results, the optimal values were a PAC dosage equal to 100 mg/l, pH = 3, reaction time = 120 minutes, H2O2 concentration = 650 mg/l, and Fe2+ concentration = 150 mg/L. In optimal condition, maximum removal efficiency of COD, TKN, and TP was 91.70%, 76.58%, and 82.56% respectively. Conclusion: The results illustrated that the coupled process of chemical coagulation and Fenton oxidation might be an effective method to reduce nitrogen and phosphorus concentration in dairy wastewater.

This study pointed out the performance of a full-scale internal circulation (IC) bioreactor (140 m3) inoculated with anaerobic granular sludge for the treatment of dairy wastewater for 91 days. The average COD removal was 80% and the average biogas was 69.8 m3 per influent COD/L per day. Then the anaerobic digestion of cheese whey (CW) at a pH 5–6 was examined at a laboratory level as a strategy to reduce the requirement for alkalinity. First, anaerobic granular sludge from IC bioreactor (pH 7–7.5), was exposed to pH 5–6 while utilizing acetic acid for 7 months. This laboratory adapted anaerobic granular sludge when fed with CW showed 30% higher methane generation under batch conditions compared to non-acclimatized granular sludge under the same conditions (pH 5–6). Higher percentage of hydrogenotrophic methanogens (mostly Methanolinea) and increase of Clostridium at the anaerobic granular sludge exposed to pH 5–6 compared to initial granular sludge was found. Propionic acid was the reaction limiting step for granular sludge under pH 5–6. Anaerobic digestion at moderately low pH required 68% less NaOH (50 %v/v) per m3 of CW however it can theoretically produce 53% less kWh per day compared to digestion at neutral pH.

This study evaluated the effects of sludge retention time (SRT) on the membrane filtration performance of an anaerobic membrane bioreactor (AnMBR) fed lipid-rich synthetic dairy wastewater. The membrane filtration performance was evaluated in two AnMBR systems operated at two different SRTs, i.e., 20 and 40 days. For the AnMBR operated at 40 days, SRT exhibited worse membrane filtration performance characterized by operational transmembrane pressures (TMP) exceeding the maximum allowed value and high total resistances to filtration (Rtotal). The sludge in the two reactors evaluated at the different SRTs showed similar sludge filterability properties. However, the sludge in the reactor operated at 40 days SRT was characterized by exhibiting the highest concentrations of: (i) total suspended solids (TSS), (ii) small-sized particles, (iii) extracellular polymeric substances (EPS), (iv) soluble microbial products (SMP), (v) fats, oils and grease (FOG), and (vi) long-chain fatty acids (LCFA). The cake layer resistance was the major contributor to the overall resistance to filtration. The high TSS concentration observed in the AnMBR systems apparently contributed to a less permeable cake layer introducing a negative effect on the membrane filtration performance.

A reduction in the availability of phosphate rock resources for fertiliser production coincides with an increase in phosphorus-rich dairy wastewater in Europe. This confluence of events has led to the development of technologies for phosphorus recovery from dairy wastewater and the use of the products as fertilisers in agriculture. This thesis aims to contribute both to the technical development of this emerging technical system and methodological development of assessing the sustainability of it with regard to (1) the identification and selection of sustainability indicators, and (2) the assessment of life cycle environmental impacts. The thesis describes an approach developed for identifying and selecting sustainability indicators by reviewing scientific documents and interviews as well as an approach employed for performing a meta-analysis of previously published life cycle assessment results to cope with lack of inventory data. The employed method for indicator selection narrows down an initial set of 382 sustainability indicators identified in the literature to 26, which were considered representative and useful for the assessment of the considered innovative conceptual system. The meta-analysis results suggested that the examined phosphorus recovery technologies exhibited a lower global warming potential and cumulative energy demand than those of dairy wastewater treatment processes and that those technologies recovering phosphorus from the liquid phase had lower impacts than those recovering phosphorus from sludge or ash.

A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates. Resumo Uma análise de viabilidade do tratamento terciário para Resíduos Agrícola Líquidos Orgânicos é apresentada usando algas filamentosas pertencentes ao gênero Cladophora sp. como alternativa ao tratamento químico terciário. Os tratamentos terciários que utilizam sistemas biológicos têm baixo custo de investimento e a dependência de variáveis ambientais é mínima. Neste trabalho, é demonstrado que essas algas filamentosas reduzem a carga nutricional de nitrato (circa 75%) e fosfato (circa 86%) dos efluentes de resíduos orgânicos provenientes de fazendas de leite em nove dias de cultura e tem a vantagem de que as algas podem ser facilmente coletadas posteriormente. Atualmente, as águas residuais orgânicas são descartadas nos campos e córregos locais. Posteriormente, as algas podem ser consideradas como matéria prima, uma vez que possuem várias utilidades como composto, celulose e biogás. Uma desvantagem desse sistema é que água limpa deve ser usada para obter transparência de água suficiente para permitir o crescimento de algas. Mesmo assim, o sistema de redução de nutrientes dos efluentes orgânicos propostos e amigável ao ecossistema, comparado aos tratamentos terciários que utilizam produtos químicos para precipitar e coletar nutrientes como nitratos e fosfatos.

Anaerobic dairy waste treatment requires effective control to avoid long-chain fatty acid (LCFA) inhibitory effects on anaerobic microorganisms, especially methanogens. The hybrid anaerobic baffled reactor (HABR) can provide system stability, but more needs to be done to understand how the microbial communities underpinning the HABR compartments behave and respond. Thus, this study aimed to examine the HABR's microbial community correlating its performance when subjected to an increase in organic loading rate (OLR) during simulated dairy wastewater treatment. Besides the elevation in OLR, the system could maintain a high COD removal efficiency, nearly to 91\%, and elevate the methane production to 53\%. Almost all of the organic matter removal occurred mainly in C1 and C2 compartments. The genera Methanosaeta, an acetoclastic methanogen, and Methanobacterium, a hydrogenotrophic methanogen, were the HABR's dominant species. The most representative phylum found was Bacteroidetes (12--28\%), Firmicutes (3--20\%), Chloroflexi (4--26\%), and Proteobacteria (4--14\\%). Species capable of syntrophic partnership with methanogens were also identified, belonging to the family of Syntrophomonadaceae and Syntrophaceae. Microorganisms able to perform the AD process as HA73, VadinCA02, T78, Longilinea, Clostridium, and Syntrophomonas were present in the HABR., Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES Finance Code 001 and process no. 23038.009805/2012–39, info:eu-repo/semantics/publishedVersion

An intermittent sand filter (ISF) is a simple and cost-effective treatment method that may be adopted on farms to treat dairy wastewater (DWW). However, the use of ISFs has been limited due to the large area required for treatment, and the risk of filter clogging and phosphorus (P) breakthrough, which decrease the operational lifetime. To overcome these limitations, this study uses a novel, pilot-scale coagulation-sedimentation process prior to loading ISFs with DWW. The performance and operational lifetime of this new hybrid coagulation-ISF system was compared to a conventional ISF system in a replicated outdoor pilot-scale experiment over a 43-wk study duration (covering an entire milking season on a farm in Ireland). The hybrid system was able to operate effectively at a higher hydraulic loading rate than a conventional ISF system. The effluent quality from the conventional ISF deteriorated over the timeframe of the study until clogging occurred, while the hybrid system continued to perform effectively without any evidence of clogging or P breakthrough. The hybrid system obtained removal efficiencies ≥99% for all measured water quality parameters (chemical oxygen demand, total suspended solids, total P, ammonium and turbidity), and complied with EU directives concerning urban wastewater treatment. Overall, the hybrid coagulation-ISF is a promising technology that requires a small area (75% reduction in footprint in comparison to a conventional ISF) and minimal operator input, and produces high effluent quality. The authors are grateful to Teagasc for the award of a Walsh Fellowship to the first author [grant number: RMIS-0386]. The authors appreciate the help of technical staff: Adrian Hawe; Seamus McShane, JohnPaul Murphy & Tomas Condon (Teagasc Moorepark), and Denis Brennan (Teagasc Johnstown Castle). peer-reviewed

Constructed wetland systems provide the ideal solution for small and medium dairy farms as they can be built close to the farm and are easy to manage and use. However, their perfomance is significantly affected by vegetation activity during the year. The aims of the present study were to assess the treatment of dairy wastewater (DWW) by a horizontal subsurface flow system (HSSFs) and the effect of plants in the removal efficiency (RE) of BOD5, COD, total N (TN) and total P (TP), in Sicily (Italy). The HSSFs treated 6/7 m3 per day of wastewater produced by a small dairy farm subsequent to biological treatment. The system included two units which were separately planted with Arundo donax L. and Cyperus alternifolius L. During a three-year study, the main chemical and microbiological characteristics were determined as well as pollutant RE. Plant growth analysis was carried out and biomass production was determined. All DWW parameters showed significant differences between inlet and outlet. In particular, for BOD5 and COD, average RE values were 77.8% and 61.6%, respectively. Arundo donax produced greater biomass than Cyperus alternifolius for both above- (4240.3 g m2/ year) and below-ground (6996.3 g m2/year) plant parts. A seasonal variation in RE of BOD5, COD, TN and TP was recorded due to plant growth rates. Our findings highlight that the contribution of plants in pollutant RE tends to vary seasonally.

To investigate the performance of microbial fuel cell (MFC) with a single-chamber membrane, Pseudomonas aeruginosa is used as a bio catalyst for various synthetic wastewaters rich in carbohydrate and is compared with real dairy wastewater in this experiment. Therefore, the choice of appropriate carbon, nitrogen, NaCl, inoculum content, temperature, and pH process parameters are used for preparing synthetic wastewater was agreed upon by one-variable-at-a time approach. Maximum levels of voltage generation attained from the synthetic wastewater was 485 mV when supple­mented with 1.5 % of lactose as a source of carbon, 0.3 % of ammonium chloride as a decent nitrogen source, 0.03 % of NaCl, inoculum concentration of 3 %, the temperature at 37 oC and pH 7. On the other hand, the maximum voltage attained with real dairy wastewater was 561 mV with high chemical oxygen demand (COD) value of 801 mg l-1. The maximum power density obtained from dairy wastewater was 73.54 mW m-2. Thus, High voltage achieved for MFC operating with real dairy wastewater suggests that it can be used not only for the industrial application to generate more renewable power, but also for the wastewater treatment carried out at the same time.

The aims of this work were to characterization of industrial wastewaters such as dairy and steel manufacturing wastewaters, possible treatment processes, and reusing the treated wastewater for irrigation purpose was discussed. Fresh wastewater samples were collected from Yörüksüt Dairy Factory and Erbil Steel Company and analyzed for 21 water quality parameters. Chemical oxygen demand (COD), color, total suspended solids (TSS) etc. were exceeded the standards for disposal of wastewater. Thus, treatment processes are essential prior disposal of wastewater to the environment or using for irrigation purpose. Based on the characteristics of the wastewaters, the treatment processes such as primary, secondary and tertiary were discussed. In addition, the quality of raw wastewater samples and proposed treated industrial wastewaters were compared with the guidelines for the irrigation purpose.

Background and Aim: Among the industries the dairy of the industry to recognize one of the most polluting Sources due to the presence of a high percentage of organic matter in the effluent. Recently, advanced oxidation processes, including Ultrasonic-persulfate with production of free radical such as sulfate and hydroxyl radicals is the efficient processes in wastewater treatment. Therefore, the aim of this study was evaluation efficiency of US-persulfate processes in treatment synthetic dairy wastewater. Materials and Methods: This research was an experimental-laboratory study. In this study, dry milk was used to make synthetic dairy wastewater and effect of pH (3, 5, 7, 9, 11), persulfate concentrations (50, 100, 250, 500, 750 mg/L), contact time (10, 30, 45, 60, 90 min) and intensity of waves US (35, 37, 130 kHz) was investigated on efficiency and the process efficiency was measured by calculating the residual chemical oxygen demand using spectrophotometrically at a wavelength of 600 nm. Results: According to the results, the efficiency increased by decreasing the pH value, increasing the concentration of hydrogen peroxide to an optimal level and increasing the contact time and ultrasound intensity and also was found that the efficiency of US-persulfate process at pH 3, concentration of persulfate500 mg/L, intensity of US 130 kHz and contact time 60 min had the highest efficiency that the amount of this efficiency was 74/53% and 61/1% for synthetic dairy wastewater and actual dairy sewerage respectively. Conclusion: According to the results, the acoustic-activated peroxylate process can be a good and high-performance method for removing organic matter from dairy wastewater.

Application of lab-scale sequencing batch (SBR) and sequencing batch biofilm reactors (SBBR) for treatment of dairy wastewater was investigated under organic loading of 1,130-1,560 gBOD5/m3·d. The main characteristics of the dairy wastewater were: pH=4.9, chemical oxygen demand (COD)=16,264 mg/l; biological oxygen demand (BOD5)=10,536 mg/l, PO4-P=342 mg/l; total nitrogen (TN)=224 mg/l. SBBR was filled with the Kaldnes K1 biocarrier at 30% of the volume of empty reactor. The SBR and SBBR were operated in fixed 24 h cycles, each consisting of 30 min fill up, 22 h aeration, 1.5 h settle, 30 min decant, and idle with a hydraulic retention time (HRT) of 8 days. Operational parameters such as pH, dissolved oxygen (DO), mixed liquor suspended solid (MLSS), solids retention time (SRT) and sludge volume index (SVI) were monitored during the whole cycle. The effects of these parameters on the COD, nitrogen and phosphorus removal were discussed in this paper. As a result, adding biocarrier to the reactor had a positive effect on organic with COD removal of 63.5% for SBR and 81.8% for SBBR and nutrient removal with ammonium removal of 66.0% for SBR and 85.1% for SBBR in treatment of dairy wastewater. © 2019, Korean Institute of Chemical Engineers, Seoul, Korea.

Advances in null-model approaches have resulted in a deeper understanding of community assembly mechanisms for a variety of complex microbiomes. One under-explored application is assembly of communities from the built-environment, especially during process disturbances. Anaerobic digestion for biological wastewater treatment is often underpinned by retaining millions of active granular biofilm aggregates. Flotation of granules is a major problem, resulting in process failure. Anaerobic aggregates were sampled from three identical bioreactors treating dairy wastewater. Microbiome structure was analysed using qPCR and 16S rRNA gene amplicon sequencing from DNA and cDNA. A comprehensive null-model approach quantified assembly mechanisms of floating and settled communities. Significant differences in diversity were observed between floating and settled granules, in particular, we highlight the changing abundances of Methanosaeta and Lactococcus. Both stochastic and deterministic processes were important for community assembly. Homogeneous selection was the primary mechanism for all categories, but dispersal processes also contributed. The lottery model was used to identify clade-level competition driving community assembly. Lottery “winners” were identified with different winners between floating and settled groups. Some groups changed their winner status when flotation occurred. Spirochaetaceae, for example, was only a winner in settled biomass (cDNA-level) and lost its winner status during flotation. Alternatively, Arcobacter butzerli gained winner status during flotation. This analysis provides a deeper understanding of changes that occur during process instabilities and identified groups which may be washed out—an important consideration for process control.

Made available in DSpace on 2021-06-25T10:23:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 This study aimed to assess the potential of the biochemical methane production and biodegradability of dairy wastewater employing a hybrid treatment: granular anaerobic sludge as inoculum and whole cells of Penicillium citrinum with high lipase activity. It was expected that mycelium-bound lipase from whole cells would enhance hydrolysis, contributing to the efficiency of anaerobic digestion by granular inoculum. Seven substrate and microbial combinations were prepared; five contained the inoculum and whole cells cultivated in different agroindustrial wastes and two were controls (inoculated and uninoculated). A synergistic microbial interaction was evidenced by the high cumulative methane production after 45 h of reaction, reaching 231 mL g−1 volatile solids. pH was maintained at values near neutrality in all treatments, and chemical oxygen demand removal ranged from 42 to 57 % in hybrid treatments. First-order and modified Gompertz kinetic models were fitted to experimental data, and a lag phase was not observed. The results show the potential of hybrid treatment of dairy wastewater with whole cells produced in waste-based media for biogas production. Federal University of Alfenas (UNIFAL) Science and Technology Institute São Paulo State University (UNESP) School of Pharmaceutical Sciences University of São Paulo (USP) Engineering School of Lorena São Paulo State University (UNESP) School of Pharmaceutical Sciences

Thai Environmental Engineering Journal (TEEJ), 35, 1, 43-52

International audience; The electrocoagulation (EC) process is an efficient and low-cost system for the purification of wastewater. The aim of this work was to investigate the efficiency of two types of aluminum (Al) electrodes (Al alloy and pure Al electrodes) for the treatment of synthetic semi-skimmed milk wastewater. Turbidity, chemical oxygen demand (COD), and concentration of Al species were monitored during the experiments. The effect of various parameters, such as current density and type and nature of the electrode were examined. The results showed that Al alloy electrodes exhibited a higher efficiency than pure Al electrodes. A quasi-total reduction of turbidity and a removal of approximately58% of the COD were achieved within 24 min at pH 7 and a current density of 14.3 mA cm(-2). It was also observed that the removal performance was not affected by the state of the electrode surfaces (polished) under the same operating conditions.

In this study, the impact of applied solids retention time (SRT) on the biological performance of an anaerobic membrane bioreactor (AnMBR) treating synthetic dairy wastewater with high lipid content was assessed. Two side-stream AnMBR systems were operated at an SRT of 20 and 40 days (R20 and R40, respectively), equipped with an inside-out tubular membrane operated in cross-flow mode under full-scale operational conditions, i.e. crossflow velocity, transmembrane pressure, membrane flux. Successful operation was achieved and removal efficiencies of both reactors were up to 99% applying an organic loading rate (OLR) of 4.7 g COD L−1 d−1. No precipitation of lipids was observed throughout the operational period, keeping the lipids available for the anaerobic degradation. Long chain fatty acid (LCFA) accumulation was very modest and amounted 148 and 115 mg LCFA-COD per gram of volatile suspended solids (VSS) for R20 and R40, respectively. At an SRT of 40 days, a slightly better biological conversion was obtained. Periodically performed specific methanogenic activity (SMA) tests showed stabilization of the SMA for R40 sludge, whereas for R20 sludge the SMA continued to decrease. This study revealed a more stable reactor performance operating the AnMBR at an SRT of 40 days compared to 20 days.

Second cheese whey (SCW) or “scotta” in Italian, is a side-stream from the manufacturing of “Ricotta” cheese, obtained after thermal coagulation of whey proteins residue in the cheese whey. Galdieria sulphuraria is a thermophilic red algae well known for its metabolic capabilities to grow on wastewater and other saline effluents. In this work, the valorisation of SCW as nutrient source for the growth of G. sulphuraria has been investigated using different concentrations of SCW. The biochemical and fatty acids composition of the biomass obtained has been evaluated too. Small differences have been observed in terms of biomass obtained after 12 days of cultivation between the SCW media and the relative control with the same amount of reducing sugars. The fatty acids composition of G. sulphuraria grown in SCW showed a higher content of polyunsaturated fatty acids compared to the control. The biomass productivity using SCW media has also been optimized through response surface methodologies with supplementation of nitrogen source obtaining a biomass dry weight higher than 10 g L−1.

Dairy manure needs to be treated to mitigate its adverse impacts on the environment. Vermifiltration, an emerging low-cost and environmentally friendly wastewater treatment, is one such potential treatment. For this study, we evaluated the efficacy of a vermifilter for treating dairy wastewater with respect to effluent quality and potential mitigations of air emissions. A pilot-scale unit was installed on a commercial dairy for these evaluations. Additional studies, at a lab-scale, investigated the effects of earthworm density, organic loading rate, and hydraulic loading rate on the performance of the vermifilter. Wastewater parameters of interest included: total solids, total suspended solids, chemical oxygen demand, total nitrogen, total ammonia-nitrogen, nitrate-nitrogen, total phosphorus, and orthophosphate. The vermifilter achieved organic, nutrients, and solids reduction efficiencies of up to 90%. Results indicated that vermifiltration has a high potential to reduce organics, nutrients, and solids concentration in dairy wastewater. Results also indicated potential reductions of up to 100% of ammonia, methane, and nitrous oxide emissions, implying that vermifilters have the potential for mitigating gaseous emissions from dairy wastewater. With respect to earthworm density, organics, nutrients, and solids; reductions of up to 95% were observed, with higher reductions occurring at higher earthworm densities (>10,000 worms m-3). Eisenia fetida densities beyond 10,000 worm m-3 did not improve the performance of the vermifilter unit towards reducing either organics, nutrients, or solids in dairy wastewater. Higher reductions of organics, solids, and nutrient occurred at lower HLR (< 1 m3 m-2 d-1) and OLR (< 2.5 kg [COD] m-2 d-1). These findings suggested that HLR

According to the concept of circular economy, food industry wastewater should be considered a secondary raw material that could be exploited, thus reducing the resources escaping from the production system. We aimed to assess the circular sustainability of dairy wastewater treatment by evaluating the possibility of transforming it from a cost to a valuable resource. We tested the non-photosynthetic WSZL mutant of Euglena gracilis as a bio-remediating organism for raw dairy wastewater to recover the resources herein present for biomass growth and simultaneously provide a source of paramylon, a high commercial value glucan. This mutant is an obligate osmotroph, which can synthesize paramylon up to 90% of the cell dry weight with the proper carbon source. We tested the mutant on the wastewater produced by a small dairy facility located near Pisa (Italy) using an indoor bench-scale fermenter allowing the alga to grow inside a dialysis tubing immersed in the effluent. We monitored the effluent variation of biochemical oxygen demand (BOD5), soluble chemical oxygen demand (COD), total suspended solids (TSS), ammonia nitrogen (NH3-N), nitrate nitrogen (NO3-N), orthophosphate (PO43--P), electric conductivity and pH. The alga can reduce the pollutant concentration to values allowing indirect discharge of the wastewater into public sewage plants and can be therefore considered a promising organism for tertiary treatment of dairy wastewater. The cells produced about 2.6 g L-1 of paramylon from 3.2 g L-1 biomass, an amount greater compared with that produced by batch cultures, confirming the possibility of recovering wastewater resources and transforming them in a high-value product. © 2020, Springer Nature B.V.

Fil: Schmidt, Erica Laura. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. La contaminación en la industria láctea se caracteriza por ser de tipo orgánica y biodegradable, en las últimas décadas a los sistemas estándares de tratamiento de efluentes se le han incorporado tecnologías de pretratamiento que permiten mejorar sus eficiencias, como es el caso de los separadores por flotación (Dissolved Air Flotation-DAF) que logran segregar una cantidad importante de grasas de los efluentes crudos. Los biosólidos generados en los DAF representan un nuevo problema ambiental ya que se genera en grandes cantidades, presenta una alta carga orgánica y su disposición final es un tema aún no resuelto en forma efectiva. Si bien la gestión de estos residuos es complicada es esperable que por su alta biodegradabilidad puedan ser procesados en reactores anaeróbicos o mediante co-compostaje aeróbico. En este sentido, diversos grupos de investigadores estudiaron con resultados favorables el co-compostaje de residuos de naturaleza lipídica lo que hizo suponer que este residuo proveniente del DAF seria eficientemente tratado en procesos de co-compostaje. Se evaluaron distintas concentraciones del residuo DAF, que fueron incorporados a un sustrato base compuesto por chips de poda y césped. Se realizó el seguimiento del proceso estudiando distintas variables y parámetros analíticos, asimismo se analizaron parámetros termofílicos que brindaron información sobre la eficiencia del sistema estudiado en cuanto a su comportamiento térmico. En base a los resultados obtenidos se pudo observar que el residuo DAF es factible de ser utilizado en procesos de codigestión aeróbica, estos resultados serán un aporte a la gestión de biosólidos de la industria láctea. Pollution in the dairy industry is mainly organic and biodegradable, in recent decades pre-treatment technologies have been incorporated into standard effluent treatment systems, that allow improving their efficiencies, such as the case of the separators by flotation (Dissolved Air Flotation-DAF) those segregate a significant amount of fat from the raw effluents. However, the biosolids generated in the DAF system represent a new environmental problem because this waste is generated in large quantities, has a high organic load and its final disposal is a problem that has not yet been effectively resolved. Although the management of these wastes is complicated, it is expected that due to their high biodegradability it can be processed in anaerobic reactors or through aerobic co-composting. In this sense, various groups of researchers studied with favorable results the co-composting of waste of a lipid nature, which led us to suppose that this waste from DAF would be efficiently treated in co-composting processes. Different concentrations of the DAF waste were evaluated, which were incorporated into a base substrate composed of pruning chips and grass, as structuring materials, and sources of C / N nutrients. The process was monitored by studying different variables and analytical parameters, that provided information on the efficiency of the system in terms of its thermal behavior. Based on the results obtained, it could be observed that the DAF waste is feasible to be used in aerobic co digestion processes, these results will be a contribution to the management of biosolids in the dairy industry. Instituto Nacional de Tecnología Industrial Instituto de Desarrollo Tecnológico para la Industria Química

Department of Chemical Engineering, National Institute of Technology Rourkela, Rourkela-769 008, Odisha, India E-mail: kaajalpurushothaman@gmail.com, hmjena@nitrkl.ac.in Manuscript received online 11 December 2020, accepted 31 December 2020 The dairy industry produces large amounts of wastewater that have higher potential to pollute environment if not properly treated. It is characterized by high levels of BOD, COD, organic and inorganic nutrients. This study focuses on the aerobic treatment of synthetic dairy wastewater in fluidized bed bioreactor using low density bio carrier wood particle at optimum conditions of temperature and pH and also the identification of the microbes which are effective for the degradation of the dairy waste. The microbial isolates were tentatively identified to be Lactobacillus and Bacillus. It is observed that with the increase in influent COD there is a decrease in the percentage COD reduction of the effluent The COD reduction at optimum temperature 30ºC and pH 7 is found to be 84% and BOD removal to be 75% efficient for an incubation period of 120 h. &nbsp

The Bioremediation consists of applying microorganisms to reduce, eliminate or transform organic or inorganic polluting compounds into inert substances. Solid and liquid wastes are generated daily in industrial activities and, among the food processing industries, the dairy sector presents a large number of liquid effluents due to its extensive use of water in various activities and sectors. For an efficient treatment of effluents, it is essential to understand the microbiota of the wastewater, its biochemical characteristics and metabolic activity, as well as the origin of the polluting compounds. The growing demand for products derived from livestock and agricultural activity drives the search for environmental technologies capable of providing sustainable development. In this scenario, biotechnological studies and bioremediation applications are increasingly gaining ground both for environmental control and for application in value-added products. The purpose of this review is to present and discuss the most recent and used technologies for bioremediation of effluents from dairy industries using bacteria. La biorremediación consiste en la aplicación de microorganismos para reducir, eliminar o transformar compuestos contaminantes orgánicos o inorgánicos en sustancias inertes. Los residuos sólidos y líquidos se generan diariamente en las actividades industriales y, dentro de las industrias de procesamiento de alimentos, el sector lácteo cuenta con una gran cantidad de efluentes líquidos debido a su amplio uso del agua en diversas actividades y sectores. Para un tratamiento eficaz de los efluentes es fundamental conocer la microbiota del efluente, sus características bioquímicas y actividad metabólica, así como el origen de los compuestos contaminantes. La creciente demanda de productos derivados de la actividad ganadera y agrícola impulsa la búsqueda de tecnologías ambientales capaces de proporcionar un desarrollo sostenible. En este escenario, los estudios biotecnológicos y las aplicaciones de biorremediación ganan cada vez más espacio tanto para el control ambiental como para su aplicación en productos de valor agregado. El objetivo de esta revisión es presentar y discutir las tecnologías más recientes y utilizadas para la biorremediación de efluentes de industrias lácteas utilizando bacterias. A biorremediação consiste na aplicação de microrganismos para reduzir, eliminar ou transformar compostos poluentes orgânicos ou inorgânicos em substâncias inertes. Resíduos sólidos e líquidos são gerados diariamente nas atividades industriais e, dentre as indústrias de processamento de alimentos, o setor de laticínios apresenta um grande número de efluentes líquidos devido ao seu amplo uso de água em diversas atividades e setores. Para um tratamento eficiente de efluentes, é essencial conhecer a microbiota do efluente, suas características bioquímicas e atividade metabólica, bem como a origem dos compostos poluentes. A crescente demanda por produtos derivados da atividade pecuária e agrícola impulsiona a busca por tecnologias ambientais capazes de proporcionar o desenvolvimento sustentável. Nesse cenário, estudos biotecnológicos e aplicações de biorremediação ganham cada vez mais espaço tanto para controle ambiental quanto para aplicação em produtos de valor agregado. O objetivo desta revisão é apresentar e discutir as tecnologias mais recentes e utilizadas para biorremediação de efluentes de indústrias de laticínios utilizando bactérias.

This study focuses on the recovery of resources from Latvian dairy industrial wastewater. Specifically, lipids are important resources from the wastewater, so the study aim is to check the quality of the wastewater through COD, BOD-5, total nitrogen, total phosphorus; to separate and characterize fatty acids through various chemicals and characterization (like FTIR, NMR, and GC-MS) techniques. The COD was found to be 1680 ± 20 mg L−1 and the BOD-5 was found to be 1196 ± 50 mg L−1, indicating that the dairy wastewater contains a considerable amount of oxidizable carbon. Also, spectral studies were done to identify the fatty acids in the wastewater. The FT-IR spectrum clearly showed the presence of C–O stretching at 1092 cm−1 and the 1H NMR indicated the peaks in the range 4.72–5.08 ppm and 5.43–6.33 ppm, confirming the presence of fatty acids. Total lipid content was extracted with solvent extraction method by using hexane, and it was found to be 5.2 g L−1. The acid value of the extracted lipids was found to be 56 mg KOH g−1. Finally, GC-MS analysis confirmed the presence of palmitic acid, stearic acid, myristic acid, oleic acid, linolenic acid, lauric acid, and linoleic acids in the total lipid. Therefore, the extraction of lipids from dairy wastewater is paramount in the applications of biodiesel production.

Department of Food Technology and Biochemical Engineering, Jadavpur University, Kolkata-700 032, India Department of Food Processing Technology, Mirmadan Mohanlal Govt. Polytechnic, Plassey, Nadia-741 156, West Bengal, India E-mail: sunitapramanik@gmail.com Manuscript received online 02 January 2020, accepted 20 June 2020 This research work was embraced to assess the kinetic coefficients values of a suspended growth type batch reactor for the dairy industry wastewater treatment. This examination was done in a research facility batch type arrangement which was comparable to the aeration tank of Effluent Treatment Plant (ETP). Wastewater samples were withdrawn on regular basis to characterize wastewater. Simulated dairy wastewater was made synthetically according to the characterization done which was found the COD of 640 mg/L and ammonium nitrogen concentration of 43 mg/L. Kinetic study was conducted to find kinetic coefficients (Y, Ks , kd and k).

Junior Engineer (Civil), Irrigation and Waterways Department, Government of West Bengal, India Lecturer, Food Processing Technology, Mirmadan Mohanlal Government Polytechnic, Plassey, Kaliganj, Nadia-741 156, India Professor, Civil Engineering Department, Jadavpur University, Kolkata-700 032, India E-mail: dipankarraha.jal@gmail.com, kundupradyut@yahoo.co.in, mukherjeesomnath19@gmail.com Manuscript received online 09 January 2020, accepted 25 June 2020 An investigation was done in a laboratory-scale sequencing batch reactor (SBR) for examining feasibility of treatment for com­bined removal of biodegradable organics (COD) and nutrients (nitrogen) from real-life dairy plant wastewater. The study was performed in a 5 L capacity model SBR with real life milk processing plant effluent containing average SCOD concentration of 1250±50 and NH4 +-N concentration of 40±5 mg/L as N. The maximum SCOD removal and ammonia nitrogen (NH4 +-N) was achieved 82.36 and 79.79% respectively after a total cycle period of 10 h.

Lipid-containing wastewaters, such as those arising from dairy processing, are frequently discharged at temperatures ≤ 20°C. Their valorization at low ambient temperatures offers opportunities to expand the application of high-rate anaerobic wastewater treatment toward achieving energy neutrality by minimizing the energy demand for heating. Lipid hydrolysis generates long-chain fatty acids (LCFAs), which incur operational challenges and hinder stable bioreactor operation by inducing sludge flotation and washout, coupled with the added challenge of treatment at lower temperature (20°C). These challenges are tackled together uniquely during the treatment of LCFA-rich synthetic dairy wastewater (SDW) (33% COD-LCFA) through de novo formed microbial granular sludge within the dynamic sludge chamber–fixed film (DSC-FF) reactor. The novel reactor design facilitated sludge retention for the entire operational period of 150 days by containing settled, flotating, and LCFA-encapsulated granular sludge and biofilm within a single module. High COD removal efficiencies (87–98%) were achieved in the three replicated DSC-FF reactors, along with complete LCFA removal at 18–72 h HRT (LCFA loading rate of 220–890 mgCOD-LCFA/L⋅day) and partial LCFA removal at 12 h HRT (LCFA loading rate of 1333 mgCOD-LCFA/L⋅day). The high removal efficiencies of unsaturated and saturated LCFAs achieved are reported for the first time during continuous anaerobic wastewater treatment at low temperatures (20°C). Moreover, de novo granulation was achieved within 8 days from a combination of inoculum mixtures at a high LCFA concentration (33% COD-LCFA) in SDW. The results demonstrate the feasibility of the DSC-FF reactor for treating LCFA-rich wastewaters at discharge temperatures and offer potential for expanded and more energetically productive anaerobic valorization of lipid-rich wastewater.

Hydrogen (H2) generation from cheese whey with simultaneous production and extraction of volatile fatty acids (VFAs) was studied in UASB reactors at two temperatures (20 and 35 °C) and pH values (5.0 and 4.5). The extraction module, installed through a recirculation loop, was a silicone tube coil submerged in water, which allows concentration-driven extraction of undissociated VFAs. Operating conditions were selected as a compromise for the recovery of both H2 and VFAs. Batch experiments showed a higher yield (0.9 mol H2 mol−1 glucoseeq.) at 35 °C and pH 5.0, regardless of the presence of the extraction module, whereas lower yields were obtained at pH 4.5 and 20 °C (0.5 and 0.3 mol H2 mol−1 glucoseeq., respectively). VFAs crossed the silicone membrane, with a strong preference for butyric over propionic and acetic acid due to its higher hydrophobicity. Sugars, lactic acid and nutrients were retained, resulting in an extracted solution of up to 2.5 g L−1 butyric acid with more than 90% purity. Continuous experiment confirmed those results, with production rates up to 2.0 L H2 L−1 d−1 and butyric acid extraction both in-line (from the UASB recirculation) and off-line (from the UASB effluent). In-line VFA extraction can reduce the operating costs of fermentation, facilitating downstream processing for the recovery of marketable VFAs without affecting the H2 production. This work was funded by the Science Foundation of Ireland (SFI) Research Professorship Programme on Innovative Energy Technologies for Bioenergy, Biofuels and a Sustainable Irish Bioeconomy (IETSBIO3 , award 15/RP/2763). Fabiano Asunis gratefully acknowledges Sardinian Regional Government for the financial support of his PhD scholarship (P.O.R. Sardegna F.S.E. - Operational Programme of the Autonomous Region of Sardinia, European Social Fund 2014-2020 - Axis III Education and training, Thematic goal 10, Investment Priority 10ii), Specific goal 10.5. peer-reviewed 2022-08-01

Wastewater discharges from dairy industries can cause a range of harmful effects in aquatic ecosystems, including a decline in biodiversity due to species evasion. Therefore, it is important to know the purification potential of rivers for the removal of pollutants released in dairy wastewater (DWW). The hypothesis adopted in this work was that the release of DWW into stretches of the Ribeirão dos Pombos River (São Paulo State, Brazil) might trigger an avoidance response, resulting in fish migrating to other regions, with the response being greater when the self-cleaning potential of the river is smaller. Therefore, the goals of the present study were to: (i) investigate how land use and seasonality of the rainfall regime influence the quality of the water in different areas of the river (P1: river source; P2: urban region; P3: rural region); (ii) assess the potential of the river to purify DWW; and (iii) evaluate the potential toxicity and repellency of DWW to the freshwater fish Danio rerio, using acute toxicity (mortality) and non-forced avoidance tests, respectively. P1 was shown to be the most preserved area. The chemical composition of the river varied seasonally, with higher concentrations of Cl- and SO42- at P3 during the rainy period. The river purification potential for DWW was higher at P2, due to greater microbiological activity (associated with higher BOD). The DWW was more acutely toxic in water from P2. The avoidance response was strongly determined by the concentration of DWW, especially for water from P2. The high capacity for self-cleaning at P2 did not seem sufficient to maintain the stability of the ecosystem. Finally, the non-forced exposure system proved to be a suitable approach that can assist in predicting how contaminants may affect the spatial distributions of organisms., Financial support for this work was provided by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, grant #14/22581–8). This study was financed in part by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES, Finance Code 001). CVMA is grateful to the Spanish Ministry of Science and Innovation for a Ramón y Cajal contract (RYC-2017-22324). This study was performed within the framework of the cooperation project MultiCecotox (COOPB20444; i-COOP2019 program from CSIC).

The aim of this study was the performance evaluation of anaerobic digestion of dairy wastewater in a multi-section horizontal flow reactor (HFAR) equipped with microwave and ultrasonic generators to stimulate biochemical processes. The effects of increasing organic loading rate (OLR) ranging from 1.0 g chemical oxygen demand (COD)/L·d to 4.0 g COD/L·d on treatment performance, biogas production, and percentage of methane yield were determined. The highest organic compounds removals (about 85% as COD and total organic carbon—TOC) were obtained at OLR of 1.0–2.0 g COD/L·d. The highest biogas yield of 0.33 ± 0.03 L/g COD removed and methane content in biogas of 68.1 ± 5.8% were recorded at OLR of 1.0 g COD/L·d, while at OLR of 2.0 g COD/L·d it was 0.31 ± 0.02 L/COD removed and 66.3 ± 5.7%, respectively. Increasing of the OLR led to a reduction in biogas productivity as well as a decrease in methane content in biogas. The best technological effects were recorded in series with an operating mode of ultrasonic generators of 2 min work/28 min break. More intensive sonication reduced the efficiency of anaerobic digestion of dairy wastewater as well as biogas production. A low nutrient removal efficiency was observed in all tested series of the experiment, which ranged from 2.04 ± 0.38 to 4.59 ± 0.68% for phosphorus and from 9.67 ± 3.36 to 20.36 ± 0.32% for nitrogen. The effects obtained in the study (referring to the efficiency of wastewater treatment, biogas production, as well as to the results of economic analysis) proved that the HFAR can be competitive to existing industrial technologies for food wastewater treatment.

High-rate anaerobic digestion (AD) is a reliable, efficient process to treat wastewaters and is often operated at temperatures exceeding 30°C, involving energy consumption of biogas in temperate regions, where wastewaters are often discharged at variable temperatures generally below 20°C. High-rate ambient temperature AD, without temperature control, is an economically attractive alternative that has been proven to be feasible at laboratory-scale. In this study, an ambient temperature pilot scale anaerobic reactor (2 m3) was employed to treat real dairy wastewater in situ at a milk processing plant, at organic loading rates of 1.3 ± 0.6 to 10.6 ± 3.7 kg COD/m3/day and hydraulic retention times (HRT) ranging from 36 to 6 h. Consistent high levels of COD removal efficiencies, ranging from 50 to 70% for total COD removal and 70 to 84% for soluble COD removal, were achieved during the trial. Within the reactor biomass, stable active archaeal populations were observed, consisting mainly of Methanothrix (previously Methanosaeta) species, which represented up to 47% of the relative abundant active species in the reactor. The decrease in HRT, combined with increases in the loading rate had a clear effect on shaping the structure and composition of the bacterial fraction of the microbial community, however, without affecting reactor performance. On the other hand, perturbances in influent pH had a strong impact, especially when pH went higher than 8.5, inducing shifts in the microbial community composition and, in some cases, affecting negatively the performance of the reactor in terms of COD removal and biogas methane content. For example, the main pH shock led to a drop in the methane content to 15%, COD removals decreased to 0%, while the archaeal population decreased to ~11% both at DNA and cDNA levels. Functional redundancy in the microbial community underpinned stable reactor performance and rapid reactor recovery after perturbations.

Before wastewater (WW) can be emitted into the municipal treatments plants, its organic matter content has to be assessed and found to comply with legislations. The chemical oxygen demand (COD) and total organic carbon (TOC) are among the most commonly used methods for such analysis. However, volatile organic compounds (VOC) present in the WW might hinder a correct organic matter estimation using these conventional methods. In this study, nuclear magnetic resonance (NMR) was used to identify and quantify VOC in dairy WW. It was determined that the NMR, COD and TOC analyses complement each other providing a more accurate estimation of the organic matter content in WW. In addition, NMR provides data on the metabolic composition of the dairy WW. This information was used to assess the possibility to reutilize dairy WW for the production of high added value compounds.