Treatment Of Dairy Industry Wastewater Research Articles

Electrocoagulation using zinc electrodes for dairy industry wastewater treatment

Electrocoagulation using zinc electrodes for dairy industry wastewater treatment

Süt Endüstrisi Atıksularının Kimyasal Arıtımının Yanıt Yüzey Yöntemi ile Optimizasyonu

Bu çalışmada, yüksek kirletici yükleri ile karakterize edilen süt endüstrisi atıksularının kimyasal arıtımı amaçlanmıştır. Arıtımda koagülant olarak demir III klorür (FeCl3.6H2O) ve alüminyum sülfat (Al2(SO4)3.18H2O) kullanılmış, her iki koagülant için optimizasyon metodu olarak yanıt yüzey yönteminin (YYY) merkezi kompozit tasarımı (MKT) uygulanarak atıksudan kimyasal oksijen ihtiyacı (KOİ) ve askıda katı madde (AKM) giderimleri incelenmiştir. Yöntem yardımıyla KOİ ve AKM giderim verimlerinin hesaplanabileceği denklemler elde edilmiş, arıtma prosesini etkileyen en önemli parametreler ortaya konularak giderimleri maksimum yapan şartlar belirlenmiştir. Demir III klorür ile yapılan çalışmalarda KOİ ve AKM giderim verimlerini maksimum yapan şartlar; pH: 7.41, doz: 158.579 mg L-1 elde edilmiş ve bu şartlarda KOİ ve AKM giderim verimleri sırasıyla %80.84 ve %98.10 olmuştur. Alüminyum sülfat (alüm) ile yapılan çalışmalarda KOİ ve AKM giderim verimlerini maksimum yapan şartlar; pH: 7.29, doz: 197.475 mg L-1 elde edilmiş ve bu şartlarda KOİ ve AKM giderim verimleri ise sırasıyla %73.33 ve %96.21 olmuştur.

Treatment of Dairy Industry Wastewater Using Up-Flow Anaerobic Sludge Blanket/Activated Sludge Reactors

Bu çalışmada süt endüstrisi atıksularını yukarı akışlı çamur yataklı anaerobik reaktör (UASB) ve aktif çamur reaktör sistemleri kullanılarak altı aylık süre boyunca arıtım verimleri incelenmiştir. Arıtılabilirlik çalışmalarında atıksular önce UASB reaktöre sonra aktif çamur reaktör sistemlerine verilmiştir. Her bir reaktör ve sistemden çıkan sular için 5 günlük biyokimyasal oksijen ihtiyacı (BOİ5), toplam organik karbon (TOK) ve askıda katı madde (AKM) parametreleri incelenmiştir. Çıkış atıksuyunda BOİ5, TOK ve AKM parametrelerinde elde edilen arıtma verimleri sırasıyla %99,33, %94,55 ve %89,23 olduğu tespit edilmiştir. Elde edilen sonuçlar değerlendirildiğinde süt endüstrisi atıksularının UASB ve aktif çamur reaktörleri ile etkin bir şekilde arıtılabileceği belirlenmiştir.

Applications of Sequencing Batch Reactor in the Degradation of Dairy Industry Wastewater

Biodegradation using sequencing batch reactor is one of the best method of treating the wastewater from the diary industries. Milk and milk based products has become most essential and important role in day-to-day life of human. The raw milk undergoes various processing in dairy industries to produce other milk based products. The large quantities of water and other chemicals are required in a diary plant. The volume of water used in a diary industry varies with respect to the availability of water, processing method and type of flow. The waste water after every step of processing is discharged into either the natural water bodies or to the environment which alters the ecological balance. This research work on the laboratory scale model is used for the analysis and treatment of dairy industry wastewater. The parameters studied are the biological oxygen demand, chemical oxygen demand, dissolved oxygen, total dissolved solids, suspended solids, pH and other substances present in the diary waste water. In this study, biodegradation of dairy wastewater was investigated under a sequencing batch reactor under aerobic conditions. It is performed on three different phases with variable reaction time to study the reductions in BOD, COD and other parameters respectively.

Grey water footprint of a dairy industry wastewater treatment plant: a comparative study

Abstract Available fresh water demand of a growing population is a fundamental concern of water resource sustainability. Dairy industry wastewater treatment plants have been considered a major polluter due to the high organic content and large wastewater discharges. Grey water footprint (GWF) was developed by the Water Footprint Network (WFN) as a measure of the water pollution loading. In this study, four treatment scenarios including no treatment process (Scenario-1), primary treatment using Dissolved Air Flotation (DAF) (Scenario-2), secondary treatment using DAF and a Upflow Sludge Bed (UASB) reactor (Scenario-3), and a DAF and UASB with a reuse application applying reverse osmosis (RO) (Scenario-4) have been studied for a full-scale dairy industry wastewater treatment plant. For these four scenarios, GWF assessment was undertaken using the WFN method by taking into consideration three pollutant parameters, chemical oxygen demand (COD), fats, oil and grease (FOG) and total suspended solids (TSS). The results show that the GWF of Scenario-4 for COD was lowest with the value of −5,609 m3/d and Scenario-1 has the highest GWF for TSS with the value of 41,026 m3/d. According to the assessment results, reuse applications decrease the GWF values.

Environmental and Agronomical Aspects of Sludge Produced from Tannin-Based Coagulants in Dairy Industry Wastewater Treatment

A study was carried out of the environmental and agronomic features of the sludge generated by a dissolved air flotation process applying a tannin-based coagulant in a dairy factory. First, the chemical and physical characteristics of the sludge were examined. Subsequently, a solubilization test was performed to evaluate the potential of groundwater contamination after the application of sludge on soil. The data obtained were compared to the United States Environmental Protection Agency (US-EPA) criteria for evaluation and classification of solid residues for land application. The results show that the studied sludge is a non-hazardous waste, and all evaluated parameters are lower than the maximum reference values according to international criteria. Based on the set of parameters which were evaluated, no organic pollutants were found. Additionally, the agronomic characterization shows good potential for agricultural purposes. However, in the solubilization test, chemicals such as phenols, cyanide, nitrate and fluoride were solubilized from the studied residue. As a result, the water showed concentrations above the limits required by the international criteria for drinking water established by US-EPA and World Health Organization. In conclusion, although tannin-based coagulants produce sludge with the potential for agronomic applications, some limits have to be considered to avoid environmental impacts.

Sequential hydrogen and methane production with simultaneous treatment of dairy industry wastewater: Bioenergy profit approach

A sequential study for hydrogen and methane production with pollutants reduction from dairy industry wastewater (DIWW) was conducted using bacterial strain of Enterobacter aerogens and methanogenic bacteria of cow dung. Among the different selected concentrations of DIWW viz: 25%, 50%, 75% and 100%, the 75% concentration depicted the best feasibility for biomass growth rate (0.21 h−1) as well as hydrogen (105 ml H2/g-Chemical Oxygen Demand (COD) and 0.562 L-H2 L−1 DIWW) and methane (190 CH4 ml/g-COD and 0.59 L CH4 L−1-FDIWW) production with the selected substrate. Experimental results were tested with various kinetic models viz. (Monod, Moser, Hanes–woolf and Eadie–Hofestee) to observe substrate utilization and growth pattern of bacteria. Hanes equation (R2 = 0.95) was the best fitted model observed in the present study. Economic Assessment of produced energy (0.22$/m3 DIWW and 0.336$/m3-FDIWW) illustrates the selected pathway has the viability of the system for treatment simultaneous with bioenergy production.

Evaluation of a membrane bioreactor on dairy wastewater treatment and reuse in Uruguay

Eutrophication episodes have been recently observed in the Santa Lucia river basin (SLRB) in Uruguay, the main drinking water source for approximately 60% of the Uruguayan population. The local environmental authorities have been strengthening the discharge standards for that particular river basin. There are several industries currently discharging their wastewater directly into the SLRB; some of these industries are required to upgrade their current wastewater treatment systems to comply with the new regulations. This study evaluated the performance of a membrane bioreactor (MBR) on dairy wastewater as a potential treatment technology for fulfilling the new discharge standards. A pilot MBR was placed at the dairy industry wastewater treatment system at two different locations: (i) receiving the wastewater from the industrial process after passing through a grease removal pond (high load stream); and (ii) receiving the wastewater after passing through the grease removal pond and an anaerobic pond (low load stream). The pilot MBR was operated at the following conditions for approximately four months: total sludge retention, hydraulic retention time (HRT) of 25 h, an average influent flow rate of 1.3 m3 day−1, and at two different average chemical oxygen demand (COD) influent concentrations: 1300 mg L−1 (high load stream) and 385 mg L−1 (low load stream). The average reported removal efficiencies on COD, biological oxygen demand (BOD), and ammonium (NH4-N) were 94.1, 98.1, and 99.6%, respectively. In addition, it was observed that for a COD/N ratio above 10, total nitrogen (TN) and total phosphorous (TP) were well removed with average removal efficiencies of 93.1 and 91.0%, respectively. The MBR effluent met the new Uruguayan standards for discharging into the SLRB, and it can be further considered for water reuse at the industrial process. Moreover, a financial feasibility study was carried out for the implementation of a full scale MBR at the existing dairy facility. The results of the feasibility study suggested to accept the investment for the implementation of the MBR technology at the dairy industry. The results of the feasibility analysis considered the high impact of penalties and fines imposed by the local government to the industry when not complying with the effluent discharge standards, as well as the critical situation regarding eutrophication of the SLRB while being the most important source for drinking water in Uruguay.

<b>Efficiency and operating cost of electrocoagulation system applied to the treatment of dairy industry wastewater

The objective of this study was to apply the technique of electrocoagulation (EC) in the treatment of dairy industry wastewater, using a system of bench. It was used a source of 10 amps and an electrode of iron containing six plates of 14x6 cm. Were made variation of pH (4.5 to 6), intensity of electric current (1 to 2A) and time of electrolysis (30 to 60 min.). The efficiency of the treatment was confirmed by analysis of turbidity, color and COD. The reduction of turbidity was greater than 98%, reaching a record 99.98%. The largest reduction in color was 94.90% and 11 of the 27 tests the efficiency was greater than 90%. The greatest reduction of COD was 96.36%. The treatment proved to be more efficient at pH 4.5, time 60 min. and current 1.5A. The estimated cost of operation was US$ 1.04 m 3 which demonstrates the viability of treatment of dairy industry wastewater.

Electrocoagulation Process Coupled with Advance Oxidation Techniques to Treatment of Dairy Industry Wastewater

Electrocoagulation Process Coupled with Advance Oxidation Techniques to Treatment of Dairy Industry Wastewater

Evaluation of dairy industry wastewater treatment and simultaneous bioelectricity generation in a catalyst-less and mediator-less membrane microbial fuel cell

Increased human activity and consumption of natural energy resources have led to decline in fossil fuel. These current methods of energy production are not compatible with the environment. In this study catalyst-less and mediator-less membrane microbial fuel cell (CAML-MMFC) represents a new method for simultaneous dairy industry wastewater treatment and bioelectricity generation. The CAML-MMFC used was designed as two chambered that included an anaerobic anode and aerobic cathode compartment and was separated from each other by a proton exchange membrane. The anode and cathode electrodes were made from graphite plate. Current intensity, power density and voltage produced from wastewater as fuel were measured and the effluent from the anode compartment was examined to evaluate pollutant decrease. The maximum current intensity and power density produced were respectively 3.74mA and 621.13mW/m2 on the anode surface, at OLR equal to 53.22kgCOD/m3d and at the external resistance of 1kΩ. The maximum voltage produced was 0.856V at OLR equal to 53.22kgCOD/m3d and at temperature 35oC. The maximum coulombic efficiency of 37.16% was achieved at OLR equal to 17.74kgCOD/m3d. The HRT was examined as a factor influencing the power generation and when it was 5 day, maximum voltage and power density were obtained. The maximum removal efficiency of COD, BOD5, NH3, NH4+, dissolved phosphorus, phosphorus in suspended solids, SO42−, TSS, and VSS was respectively achieved at 90.46%, 81.72%, 73.22%, 69.43%, 31.18%, 72.45%, 39.43%, 70.17% and 64.6%. The results showed that generating bioelectricity and dairy industry wastewater treatment by CAML-MMFC are a good alternative for producing energy and treating wastewater at the same time.

Treatment of dairy industry wastewater by oxygen injection: performance and outlay parameters from the full scale implementation

This work presents the application of a new system for wastewater treatment in the food industry, which is based in the injection of pure oxygen in the homogenization tank of a traditional physicochemical treatment. This system operates stably under a wide variety of both input chemical oxygen demand (COD) and total suspended solids (TSS). Compared with the previous physicochemical system, it has been proved that the new one is more efficient and implies important economic savings for the dairy. Compared with a traditional anaerobic treatment, it has been shown that the oxygen injection system avoids the relatively high costs associated to the initial investment and operating costs and is environmentally friendlier. In this work it is shown that oxygen injection may be an interesting option for the dairy industry wastewater treatment.

Dairy wastewater treatment using an activated sludge-microalgae system at different light intensities.

A microalgae-bacteria system was used for dairy industry wastewater treatment in sequenced batch mode in a photobioreactor. The research investigated the influence of two light intensities: 360 and 820 μmol m(-2)s(-1) on treatment performances, microalgal cell recovery and dynamics of the protozoan community. Results showed that the light intensity of 360 μmol m(-2)s(-1) was found to be insufficient to support photosynthetic activity after the increase of bacterial biomass leading to the decrease of organic matter and ammonium removal efficiencies from 95 to 78% and 95 to 41%, respectively. Maximum microalgal cells recovery was about 63%. Continuous modification in the protozoan community was also noticed during this test. Increasing the light intensity to 820 μmol m(-2)s(-1) led to better microalgal cells recovery (up to 88%) and improved treatment performances. However, the decrease of protozoan richness to small flagellates and free-swimming ciliates was noticed. Moreover, the developed protozoan trophic network was found to be different from that identified in the conventional activated sludge system. The study emphasized that high increase of bacterial biomass promoted in nutrient- and organic matter-rich wastewater can strongly affect the treatment performances as a result of the shadow effect produced on the photoautotrophic microalgae aggregates.

An integrated mechanical-enzymatic reverse osmosis treatment of dairy industry wastewater and milk protein recovery as a fat replacer: a closed loop approach

The dairy industry can be classified among the most polluting of the food industries in volume in regard to its large water consumption, generating from 0.2 to 10 L of effluent per liter of processed milk. Dairy industry effluents usually include highly dissolved organic matter with varying characteristics, and a correct waste management project is required to handle. In a framework of natural water resource availability and cost increase, wastewater treatment for water reuse can lower the overall water consumption and the global effluent volume of industrial plants. Moreover, correct dismissal of dairy industry wastewater is sometimes neglected by the operators , increasing the environmental impact due to the chemical and biological characteristics of such effluents. On the other hand, in the case of whey effluents, several by-products are still present inside, such as lactose and milk proteins. Membrane technology has some advantages including a high degree of reliability in removing dissolved, colloidal and particulate matter, like the selectivity in size of pollutants to be removed and the possibility of very compact treatment plants. For example, Reverse Osmosis (RO) technology has been successfully applied for the treatment of dairy wastes (1), and as a technology for concentration and fractionation of whey. In this work a membrane treatment approach using reverse osmosis technology is investigated and implemented: the permeate obtained can be reused as clean warm water for cleaning and sanitation of production plants, while concentrated milk proteins are modified by using transglutaminase enzyme obtaining a high temperature resistant fat replacer to be used in different low-fat products like for example mozzarella cheese.

An integrated mechanical-enzymatic reverse osmosis treatment of dairy industry wastewater and milk protein recovery as a fat replacer: a closed loop approach

The dairy industry can be classified among the most polluting of the food industries in volume in regard to its large water consumption, generating from 0.2 to 10 L of effluent per liter of processed milk. Dairy industry effluents usually include highly dissolved organic matter with varying characteristics, and a correct waste management project is required to handle. In a framework of natural water resource availability and cost increase, wastewater treatment for water reuse can lower the overall water consumption and the global effluent volume of industrial plants. Moreover, correct dismissal of dairy industry wastewater is sometimes neglected by the operators , increasing the environmental impact due to the chemical and biological characteristics of such effluents. On the other hand, in the case of whey effluents, several by-products are still present inside, such as lactose and milk proteins. Membrane technology has some advantages including a high degree of reliability in removing dissolved, colloidal and particulate matter, like the selectivity in size of pollutants to be removed and the possibility of very compact treatment plants. For example, Reverse Osmosis (RO) technology has been successfully applied for the treatment of dairy wastes (1), and as a technology for concentration and fractionation of whey. In this work a membrane treatment approach using reverse osmosis technology is investigated and implemented: the permeate obtained can be reused as clean warm water for cleaning and sanitation of production plants, while concentrated milk proteins are modified by using transglutaminase enzyme obtaining a high temperature resistant fat replacer to be used in different low-fat products like for example mozzarella cheese.

Effects of reactive filters based on modified zeolite in dairy industry wastewater treatment process

Application of adsorbents based on organo-zeolites has certain advantages over conventional methods applied in food industry wastewater treatment process. The case study presented in this paper examines the possibilities and effects of treatment of dairy industry wastewater by using adsorbents based on organo-zeolites. The obtained results indicate favorable filtration properties of organo-zeolite, their high level of adsorption of organic matter and nitrate nitrogen in the analyzed wastewater. This paper concludes with recommendations of optimal technical and technological parameters for the application of these filters in practice.

The investigation of dairy industry wastewater treatment in a biological high performance membrane system

The dairy industry is generally considered to be the largest source of food processing wastewater in many countries. The highly variable nature of dairy wastewaters in terms of volumes and flowrates and in terms of high organic materials contents such as COD 921–9004 mg L −1, BOD 483–6080 mg L −1, TN of 8–230 mg L −1 and SS of 134–804 mg L −1 makes the choice of an effective wastewater treatment regime difficult. A high performance bioreactor, an aerobic jet loop reactor, combined with a ceramic membrane filtration unit, was used to investigate its suitability for the treatment of the dairy processing wastewater. The oxygen transfer rates of the bioreactor were found to be very high (100–285 h −1) on the operating conditions. A loading rate of 53 kg COD m −3 d −1 resulted in 97–98% COD removal efficiencies under 3 h hydraulic retention time. The high MLSS concentrations could be retained in the system (up to 38,000 mg L −1) with the contribution of UF (ultrafiltration) unit. During the filtration of activated sludge, the fluxes decreased with increasing MLSS. Cake formation fouling was determined as dominant fouling mechanisms. The results demonstrate that jet loop membrane bioreactor system was a suitable and effective treatment choice for treating dairy industry wastewater.

Treatment of dairy industry wastewater by EC and EF processes using hybrid FeAl plate electrodes

AbstractBACKGROUND: In this study electrochemical treatment of dairy industry wastewater (DW) was investigated using a combined electrode system consisting of iron and aluminum as sacrificial electrodes. The dairy industry generates strong wastewaters characterized by high biological oxygen demand and chemical oxygen demand concentrations. Dairy industry waste effluents are concentrated in nature, and the main contributors of organic load to these effluents are carbohydrates, proteins and fats originating from the milk. Since dairy waste streams contain high concentrations of organic matter, these effluents may cause serious environmental problems.RESULTS: A pole changer device was employed to change polarization in given time intervals to generate iron and aluminum based coagulants respectively. The effects of current density, initial pH, sodium sulfate (Na2SO4) and H2O2 concentrations on the removal efficiency were investigated. The best experimental conditions obtained in electrochemical studies were as follows: current density = 15 mA cm−2, natural pH, without supporting electrolyte addition, H2O2 concentration = 3 × 1000 mg L−1. Under these conditions, 79.2% COD removal from DW was achieved.CONCLUSION: According to the results, 20 min electrolysis is enough, since insignificant variations in COD removal were observed after this time. These methods were found to be successful for the treatment of DW. Copyright © 2011 Society of Chemical Industry

Use of Moringa oleifera Seed as a Natural Adsorbent for Wastewater Treatment

Moringa oleifera (MO) is a multipurpose, medium- or small-sized tree, from regions of north-west India and indigenous to many parts of Asia, Africa, and South America. Its pods have been employed as an inexpensive and effective sorbent for the removal of organics, and coagulant for water treatment. It is a non-toxic natural organic polymer. The main objective of this work was to use the MO seeds as a natural adsorbent for the treatment of dairy industry wastewater (DIW). The effects of agitation time, pH, MO biomass dose, and DIW concentration were evaluated. Removal efficiencies of up to 98%, for both color and turbidity, were reached using 0.2 g MO and 0.2 L of 1.0 g/L sorbate solution (DIW). The obtained results showed that MO seed keeps its adsorption power under a pH range between 5 and 8. The adsorption data was fitted to Langmuir isotherm. There was a significant uptake capacity of MO biomass, qmax, which suggested a good affinity between DIW components and sorbent. We conclude that the MO biomass has the potential to be used in the dairy industry wastewater treatment in an efficient way and with low cost.

Treatment of dairy industry wastewater by reverse osmosis for water reuse

The dairy industry is among the most polluting of the food industries in volume in regard to its large water consumption. The present work was related to investigations about practices of water management of 11 dairy plants. Treatment of the process water produced in the starting, equilibrating, stopping and rinsing processing units was proposed to produce water for reuse in the plant and to lower the effluent volume. Reverse osmosis of such wastewaters, collected in dairy plants, was performed after a prior check of their stability during storage. Filtration performances were focused on permeate flux versus water recovery and on water quality (TOC, conductivity). Reverse osmosis water similar to available vapour condensates (produced in drying processes) can be achieved allowing this water to be reused for heating, cleaning and cooling purposes. A 540 m 2 RO unit is required to treat 100 m 3/d of wastewater with 95% water recovery.