Biochemical Oxygen Demand Test Research Articles

Impact of Indian almond leaves on aquarium water quality

There are very few studies done to understand the impact of Indian almond leaves (IAL) on aquarium water quality. Therefore, in this study, Indian almond leaves (IAL) were used to investigate the impacts on water quality in an aquarium with Betta fish as they are hardy fish, tolerant to changes in water quality, comparatively cheaper and more readily available in tropical countries. For this study, the powdered form of IAL was used for faster dilution or mixing. As for the aquarium tank, smaller tanks with a capacity of 4.5 litres are used since Betta fish is small in size and it is easy to be accommodated in the aquarium. The various dosage of IAL in power form (0-200 mg/L) was used to determine physical, chemical and biological parameters of aquarium water quality in the presence of Betta fish. The parameters were Biochemical Oxygen Demand (BOD5), Dissolved Oxygen (DO), turbidity, pH, chlorine and survivability test and tests were conducted on day 1, 3, 7, 14, 21 and 28. All experiments had an increasing value of DO until Day 21 and gradually decreased, while BOD5 increased with increased IAL dosage. Ammonia concentration increased between day 5-10 and then started to decline at day 21 and pH values were decreasing with increased IAL dosage. The total coliform test has the highest total coliform count on day 28 for IAL dosage. The study revealed that Betta fish could survive for 28 days without any application of de-chlorinator. The optimum dosage of 50 mg/L of IAL can eliminate any requirement for de-chlorination for Betta fish.

The effect of hydrogen peroxide on the biochemical oxygen demand (BOD) values measured during ionizing radiation treatment of wastewater

As biochemical oxygen demand (BOD) properly illustrates transformation of toxic organic compounds to harmless and biodegradable substances, it is often used to demonstrate the efficiency of wastewater treatment technologies. Nevertheless, H2O2 can form when solutions are subjected to advanced oxidation processes (AOP). H2O2 production is typical in high energy irradiation treatments. Toxic effect of H2O2 on microbes is a well known fact in the field of biology, however, the impact of H2O2 is usually not taken into account when evaluating effectiveness of AOP. To quantify the impact of the forming H2O2 on the outcome of BOD tests, the BOD of glucose-glutamic acid reference solution was determined in the presence of hydrogen peroxide in the 0.1 and 75 mg dm−3 concentration range. Results showed that H2O2 distorts the BOD measurement in two ways. Prolonged lag period takes place that ensures adaptation of microbes to toxic environment and promotes production of catalase enzyme that decomposes hydrogen peroxide. On the other hand, appearance of catalase producing bacterial groups leads to reduced BOD values because the oxygen released from the H2O2 results in a negative error as it acts against oxygen depletion. The correlation between H2O2 concentration and the shift in lag period was described, as well as the relationship between the initial H2O2 concentration and the final BOD results. To validate the effects studied, BOD was measured in 0.1 mmol dm−3 oxacillin solutions irradiated with gamma rays. It was confirmed that the presence of H2O2 may lead to underestimation of the actual BOD as increase in BOD was observed when hydrogen peroxide was eliminated from the solution before starting the measurement.

Novel techniques to determine dilution ratios of raw wastewater and wastewater treatment plant effluent in the 5-day biochemical oxygen demand test

The current 5-day biochemical oxygen demand (BOD5) test methods lack detailed information on sample dilution, which typically leads to an incorrect dilution ratio of samples and failed BOD5 testing. This study proposed an improved dilution technique that effectively determines the dilution ratios for raw wastewater and wastewater treatment plants (WWTPs) effluent. The numbers of raw wastewater and WWTPs effluent samples used in the BOD5 tests were 201 and 61, respectively. The experimental results demonstrated that both the raw wastewater and WWTPs effluent varied in BOD5 values with the sample dilution ratio, and these changes were more noticeable when the dissolved oxygen consumption ratio (DOCR) was less than 20% or when the dilution ratio was large. Assuming that the BOD5 value over the DOCR range of 40%–70% was true, the optimal DOCR range was 40%–90% for the raw wastewater and 40%–70% and 80%–90% for the WWTPs effluent, where the relative error of BOD5 values in these DOCR ranges was less than 10% depending on the dilution ratio. The correlation between the sample dilution ratio and the BOD5 value over the optimal DOCR range was considerably higher than that over the entire DOCR range. This was combined with the correlation equation between BOD5 and chemical oxygen demand to propose an equation that could determine more accurate sample dilution ratios for raw wastewater and WWTPs effluent compared to the conventional sample dilution methods for the BOD5 test.

Effect of colloid-size copper-based pesticides and wood-preservatives against microbial activities of Gram-positive Bacillus species using five-day biochemical oxygen demand test

Copper-based pesticides and wood preservatives could end up in the environment during production, use, and end-of-life via different pathways that could cause unintended ecological and adverse health effects. This paper provides the effect of colloid-size Cu-based pesticides (CuPRO and Kocide), micronized Cu azole (MCA-1 and MCA-2) and alkaline Cu quaternary (ACQ) treated woods, Cu2+, Cu2+ spiked untreated wood (UTW), and CuCO3 solutions against Gram-positive Bacillus species using five-day biochemical oxygen demand (BOD5) standard test. The total Cu leached from MCA-1, MCA-2, and ACQ in Milli-Q water after 5 days were ~0.1, ~0.11, and ~0.64 g/kg of wood, respectively. However, the form of Cu leached from MCA woods was mostly ionic (> 90%). The total organic carbon (TOC) content of any tested wood (UTW/MCA-1/MCA-2/ACQ) was ~99% of its corresponding total carbon (TC) content, whereas the TOC of any tested wood sawdust exceeded that of its corresponding piece/block by > 300%. The dissolved oxygen (DO) consumption value in the presence of Cu2+, CuCO3, CuPRO, and Kocide solutions was significantly influenced by Cu particles/ions. However, the DO consumption value in the presence of UTW/MCA-1/MCA-2/ACQ woods was significantly influenced by organics leached from woods. On the other hand, the DO consumption of MCA sawdust was greater than (300%) that of MCA pieces/block. The findings of this study provide more insight into how organics leached from woods significantly reduce the toxic effects of Cu ions against Gram-positive Bacillus species.

Development of a Biochemical Oxygen Demand Incubator Prototype based on Thermoelectric Effect with Monitoring System

In the last decades various internal refrigeration or heating equipment has been developed mainly for a specific use, such as refrigerators air conditioning and freezers each with technology for temperature control. The incubators greenhouses were originally developed to incubate long-lasting biochemical oxygen demand (BOD) tests. The objective of this work was to build a low-cost BOD incubator and to technically evaluate temperature control through an adjustment to the electrical current in the system supply in addition to wireless monitoring. The project consisted of the dimensioning and projection of the materials for the refrigeration system, the realization of the algorithm that connects the physical part with the logical part of the system, with the development of hardware and software using Arduino to the 3D mechanical part. with the construction of the incubator for the validation of the complete system. It is concluded that the use of thermoelectric TEC1-12706 was possible with the variables presented for the cooling of a small volume. Thus, the prototype of the BOD incubator achieved a minimum temperature of 13 C and maximum of 40 C with an approximate error of 0.2 C. Our BOD system presented an excellent control system through a smartphone that helps in experiments in the laboratory to guarantee the ideal temperature. In addition, the incubator is inexpensive portable and lightweight.

Evaluation of two commercial inoculates and a probiotic food additive as seeds in BOD testing

Five-day seeded Biochemical oxygen demand (BOD) tests using Glucose-­Glutamic acid (GGA) substrate were carried out. The seeds used are a regular seed an NX seed and an over-the-counter food supplement commonly referred to as a probiotic. The purpose was to determine if seed type influenced 5-day BOD test results. The NX seed contained a chemical formulation designed to inhibit nitrification. Test results indicate that 5-day BOD varied significantly with each seed. Micrographs of stained samples prepared from cultures of the three seeds identified Gram-stain negative rods present in all the three inoculates.

Sustainable coating material based on chitosan-clay composite and paraffin wax for slow-release DAP fertilizer

The coating of fertilizers by polymers is one of the most efficient tools for their slow and control release into soil. This strategy avoids excessive use of the fertilizers and increases their availability to the crops needs. In the present paper, hydro-soluble diammonium phosphates (DAP) fertilizer was double coated following the dip-coating process by chitosan-clay composites as inner coating and paraffin wax as an outer coating. The chitosan composite preparation and characterization were deeply investigated. The montmorillonite (MMT) clay incorporation as filler improves the water barrier diffusion, mechanical properties, and thermal stability of the composite. The combination of the swelling behavior of the chitosan-clay composite (inner coating) and the hydrophobic property of paraffin wax (outer coating) was confirmed by the water holding capacity evaluation and the phosphorus release essays in water and soil. Indeed, the phosphorus dissolution from the coated DAP granules was significantly delayed compared to the uncoated DAP. Moreover, the biodegradation study of composite material in soil and the biochemical oxygen demand (BOD) tests revealed that the coating system proposed could be considered as a carbon source for microorganisms after the fertilization process, which confirms its sustainability.

General characteristics of BOD kinetics in long-term experiments with water from Karelian waterbodies of various types

Long-term experiments (84–126 days long) on biochemical oxygen demand (BOD) were conducted to study the BOD kinetics in water samples from more than 30 waterbodies of the Karelian region and from the White Sea in different seasons of 2012–2017.The experiments were conducted under two incubation temperatures (10 and 20 °C or 2 and 10 °C) to estimate the temperature coefficient. Two approaches were applied to describe the BOD kinetics. The first one originated from a compilation of the data previously obtained for natural, contaminated and waste waters. The second one was based on visual classification involving BOD curves plotted for different waterbodies of Karelia. The distinctive feature of the long-term BOD test conducted here is that the BOD curve developed by the “apparent exponent” (APE) model during 30–80 days from the beginning of the experiments in some studied cases. This situation is completely different from the classical case, where autochthonous organic matter oxidation follows the exponential model in the first 15–20 days. BOD curve kinetic parameters were compared for еру APE and exponential models. The origins of APE curve formation were identified and described. The suspension of BOD development under various temperature conditions was explained. In the future, long-term BOD tests can be applied for water quality assessment together with the characteristics of organic matter content.

排污入海河口及临近海域水质中的生化需氧量检测关键控制技术

排污入海河口及临近海域水质中的生化需氧量检测关键控制技术

Characterization of selected municipal solid waste components to estimate their biodegradability

Biological treatments of Residual Municipal Solid Waste (RMSW) allow to divert biodegradable materials from landfilling and recover valuable alternative resources. The biodegradability of the waste components needs however to be assessed in order to design the bioprocesses properly. The present study investigated complementary approaches to aerobic and anaerobic biotests for a more rapid evaluation. A representative sample of residual MSW was collected from a Mechanical Biological Treatment (MBT) plant and sorted out into 13 fractions according to the French standard procedure MODECOM™. The different fractions were analyzed for organic matter content, leaching behavior, contents in biochemical constituents (determined by Van Soest's acid detergent fiber method), Biochemical Oxygen Demand (BOD) and Bio-Methane Potential (BMP). Experimental data were statistically treated by Principal Components Analysis (PCA). Cumulative oxygen consumption from BOD tests and cumulative methane production from BMP tests were found to be positively correlated in all waste fractions. No correlation was observed between the results from BOD or BMP bioassays and the contents in cellulose-like, hemicelluloses-like or labile organic compounds. No correlation was observed either with the results from leaching tests (Soluble COD). The contents in lignin-like compounds, evaluated as the non-extracted RES fraction in Van Soest's method, was found however to impact negatively the biodegradability assessed by BOD or BMP tests. Since cellulose, hemicelluloses and lignin are the polymers responsible for the structuration of lignocellulosic complexes, it was concluded that the structural organization of the organic matter in the different waste fractions was more determinant on biodegradability than the respective contents in individual biopolymers.

Surface water characteristics in the vicinity of lakes and drainage network

The quality analysis of surface water from a selected set of six lakes has been carried out for major ionic as well as trace elements for three different periods. The surface water quality is within the permissible limits. Furthermore, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) tests signify a relative oxygen-depletion effect and are known as a measure of pollution effect. Bimonthly variations of BOD and COD indicate high concentration in water samples and are given as bar charts. The concentration of total nitrogen (TN) and total phosphate (TP) expressed in terms of trophic status index (TSI) is a measure of water column productivity to assess water lake quality. High concentrations of BOD, COD, TN, and TP may be attributed to the urban sewage. The TSI based on TN and TP concentration of lake water and sediment samples indicate that all the six studied lakes are under hyper eutrophic condition. Classification of surface water by Piper and Wilcox diagrams indicates a high sodium and salinity hazard.

Microorganism Degradation Efficiency in BOD Analysis Formulating a Specific Microbial Consortium in a Pulp and Paper Mill Effluent

Pulp and paper mills are a major source of pollution, generating huge amounts of intensely colored effluent that goes to the receiving end of a wastewater treatment plant. The biochemical oxygen demand test (BOD5) relies heavily on the microorganism metabolic capability added to the test as seeding material. The seeding material in the testing is obtained from sewage sampling or from commercial sources. Specific organic pollutants that are present in paper and pulp mill effluent can only be degraded by specific microbes; therefore, common sewage or synthetic seed may lead to erroneous BOD5 estimations. In this study, specific microbial species were selected to evaluate their degradation efficiency, both individually and in combination. The microorganisms selected in the formulated seed exhibit BOD5 in a reproducible and synergistic manner. The formulation of this specific microbial consortium can be used to develop bioremediation strategies.

A simple cost-effective manometric respirometer: design and application in wastewater biomonitoring

Application of respirometric tools in wastewater engineering fields is still not getting familiarity and acceptance by academy or industry in developing countries as compared to the use of conventional biochemical oxygen demand (BOD) approach. To justify the applicability of respirometry, a low-cost respirometric device suitable for monitoring biodegradation process in wastewater has been developed. This device contains six independently operating reactors placed in a temperature control unit for the bioassay of five wastewater samples simultaneously (along with one blank). Each reactor is equipped with a magnetic stirrer for the continuous agitation of the test sample. Six manometers, linked with the individual reactors, measure the pressure and volume changes in the headspace gas phase of the reactor. Working formulae have been derived to convert the ‘volume-change in gas phase’ data to ‘the oxygen depletion in the whole liquid–gas system’ data. The performance of the device has been tested with glucose–glutamic acid standard solution and found satisfactory. Conventional BOD test and the respirometric measurements were performed simultaneously and it is found that in addition to measuring the BOD of the sample, this device gives oxygen uptake profile for further analysis to determine the biokinetic coefficients. Additionally, in some cases, following a specific test protocol, the respirometer can indirectly estimate the carbon dioxide evolved during biodegradation process for calculating respiratory activity parameter such as respiratory quotient. It is concluded that the device can be used in the laboratories associated with the activated sludge plants and also for teaching and research purposes in developing countries.

Biodegradability of 27 pyrrolidinium, morpholinium, piperidinium, imidazolium and pyridinium ionic liquid cations under aerobic conditions

The chemical and thermal stability of ionic liquids (ILs) makes them interesting for a large variety of applications in nearly all areas of the chemical industry. However, this stability is often reflected in their recalcitrance towards biodegradation, which comes with the risk of persistence when they are released into the environment. In this study we carried out a systematic investigation of the biodegradability of pyrrolidinium, morpholinium, piperidinium, imidazolium and pyridinium-based IL cations substituted with different alkyl or functionalised side chains and using halide counterions. We examined their primary degradability by specific analysis and/or their ultimate biodegradability using biochemical oxygen demand tests according to OECD guideline 301F. Biological transformation products were investigated using mass spectrometry. A comparison of the biodegradation potential of these ILs shows that for all five head groups, representatives can be found that are readily or inherently biodegradable, thus permitting the structural design of ILs with a reduced environmental hazard.

The comparison of different mathematical methods to determine the BOD parameters, a new developed method and impacts of these parameters variations on the design of WWTPs

One of the most common tests for the determination of strength and organic content of wastewater is the biochemical oxygen demand (BOD). This test is widely applied to define organic water pollution and to control the performance of wastewater treatment plants. Generally, BOD is standardized by the measurement of oxygen consumption in 5days (BOD5). But, determination of the ultimate biochemical oxygen demand (BODu), which is taken 28days and the reaction rate constant (k) are necessary to understand the organic strength of the wastewater. In this study, the different mathematical methods in order to determine the BOD parameters (BODu, k) and two different BOD test method (respirometer and dilution method) are investigated comparatively. Also, a new method based on cubic spline method to estimate ultimate BOD values is developed. Moreover, the impacts of BOD parameters on the design of an activated sludge and aerated lagoon systems are analyzed by using a written user-friend program, which is developed for designing WWTPs by the mean of C++ programming language.Analytical results show that there is a satisfactory linear relationship between respirometric and dilution BOD values. Also, the mathematical methods, including new developed method generally provide consistent results with high correlation coefficients. On the other hand, it is found that LOG differences method for respirometric test and the new developed method for dilution test do not give good correlation coefficients. Moreover, activated sludge and aerated lagoons systems’ sizes show significant changing depending on the variations of the BOD parameters. Consequently, BOD parameters show significant changes depending on the different test and mathematical methods. Therefore, the changing of these parameters impact a lot of situation such as ultimate BOD estimation, the wastewater treatment plants design, the dimensions of the plants and cost of the plants.

Oxygen Demand of Aircraft and Airfield Pavement Deicers and Alternative Freezing Point Depressants

Aircraft and pavement deicing formulations and other potential freezing point depressants were tested for biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Propylene glycol-based aircraft deicers exhibited greater BOD5 than ethylene glycol-based aircraft deicers, and ethylene glycol-based products had lower degradation rates than propylene glycol-based products. Sodium formate pavement deicers had lower COD than acetate-based pavement deicers. The BOD and COD results for acetate-based pavement deicers (PDMs) were consistently lower than those for aircraft deicers, but degradation rates were greater in the acetate-based PDM than in aircraft deicers. In a 40-day testing of aircraft and pavement deicers, BOD results at 20°C (standard) were consistently greater than the results from 5°C (low) tests. The degree of difference between standard and low temperature BOD results varied among tested products. Freshwater BOD test results were not substantially different from marine water tests at 20°C, but glycols degraded slower in marine water than in fresh water for low temperature tests. Acetate-based products had greater percentage degradation than glycols at both temperatures. An additive component of the sodium formate pavement deicer exhibited toxicity to the microorganisms, so BOD testing did not work properly for this formulation. BOD testing of alternative freezing point depressants worked well for some, there was little response for some, and for others there was a lag in response while microorganisms acclimated to the freezing point depressant as a food source. Where the traditional BOD5 test performed adequately, values ranged from 251 to 1,580 g/kg. Where the modified test performed adequately, values of BOD28 ranged from 242 to 1,540 g/kg.

Restructuring BOD : COD Ratio of Dairy Milk Industrial Wastewaters in BOD Analysis by Formulating a Specific Microbial Seed

BOD (Biochemical oxygen demand) is the pollution index of any water sample. One of the main factors influencing the estimation of BOD is the nature of microorganisms used as seeding material. In order to meet the variation in wastewater characteristics, one has to be specific in choosing the biological component that is the seeding material. The present study deals with the estimation of BOD of dairy wastewater using a specific microbial consortium and compares of the results with seeding material (BODSEED). Bacterial strains were isolated from 5 different sources and were screened by the conventional BOD method. The selected microbial seed comprises of Enterobacter sp., Pseudomonas sp. BOD : COD (Chemical oxygen demand) ratio using the formulated seed comes in the range of 0.7-0.8 whereas that using BODSEED comes in the ratio of 0.5-0.6. The ultimate BOD (UBOD) was also performed by exceeding the 3-day dilution BOD test. After 90 days, it has been observed that the ratio of BOD : COD increased in case of selected consortium 7 up to 0.91 in comparison to 0.74 by BODSEED. The results were analyzed statistically by t-test and it was observed that selected consortium was more significant than the BODSEED.

Reaction kinetics and validity of BOD test for domestic wastewater released in marine ecosystems

With urbanization of coastal cities, marine pollution is becoming a severe problem. The rates of biodegradation, decomposition, and ratification of pollutants get slowed down due to salinity. The higher temperatures prevalent in tropical regions significantly affect reaction rates. Multiple factors influence the rate of biodegradation, making the process complex. Hence, prediction and evaluation of the assimilative capacity of the marine environment due to wastewater discharges is becoming a difficult task. Biochemical oxygen demand (BOD) is a wet oxidation process, which follows first-order kinetics. The values of kinetic rate constants are expected to differ with varying salinities and temperatures. Research is carried out using glucose-glutamic acid and domestic wastewater to evaluate the impact of salinity on biodegradation of carbonaceous waste at 20°C and 27°C. The findings confirm the hypothesis of slow biodegradation of carbonaceous organic matter in marine waters. An inverse relationship between rate of biodegradation and salinity was observed. BOD exertion at 20°C (5days) and 27°C (3days) for the marine environment is comparable at selected salinities thereby confirming the validity of BOD test of shorter duration at elevated temperature.

Bio-based biodegradable hydrogels prepared by crosslinking of microbial poly(γ-glutamic acid) with L-lysine in aqueous solution

Bio-based biodegradable hydrogels were prepared by crosslinking microbial homo poly(amino acid), poly(γ-glutamic acid) (PGA), with L-lysine in a one-pot synthesis in the presence of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) at 25 °C. The crosslinking was carried out in aqueous solution and the yields of the gels prepared with DMT-MM were higher than those prepared with water-soluble carbodiimide. The water absorption of the PGA gels crosslinked with L-lysine ranged from 300 to 2100 g/g. The water absorption of the PGA gel was affected by the amount of crosslinker and DMT-MM, which had an effect on the crosslinking density of the PGA gel. It was confirmed in a hydrolysis test in a buffer of pH 9 at 37 °C that the obtained gel that was crosslinked with L-lysine by amide bonds was more resistant to hydrolysis than the gel crosslinked by ester bonds. biochemical oxygen demand-biodegradability of the PGA gel crosslinked with L-lysine reached 60% in activated sludge at 25 °C. Bio-based biodegradable hydrogels were prepared by crosslinking microbial poly(γ-glutamic acid) (PGA) with L-lysine in aqueous solution in the presence of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) in a one-pot synthesis. The crosslinking was carried out in aqueous solution in a high yield. The gels obtained in this study were readily biodegraded in the biochemical oxygen demand test. The PGA gel and the crosslinking method by DMT-MM in aqueous solution will be applicable to the development of functional bio-based materials. WSC, water-soluble carbodiimide.

Whole-cell bacterial biosensors for rapid and effective monitoring of heavy metals and inorganic pollutants in wastewater

The increasing number of potentially harmful pollutants in the wastewater effluent discharge necessitates the need for the development of fast and cost effective analytical techniques for extensive monitoring programmes to assess the effectiveness of the treatment process. This study compared the use of bacterial biosensors to the conventional Daphnia magna assay, Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) tests as well as chemical analysis, for monitoring the toxicity of wastewater. The bacterial biosensors constructed in this study, using S. sonnei and E. coli, were found to be sensitive to the toxicity of the wastewater effluents. A linear increase in bioluminescence with increasing concentration of heavy metals and inorganic pollutants in water was observed, with a correlation coefficient (r(2)) as high as 0.995 and 0.997, respectively. No notable correlation between biosensor toxicity and BOD and COD test results was observed. These bacterial biosensors could provide appropriate alternatives for a rapid, sensitive and cost effective detection of wastewater quality. However, the differences in sensitivity obtained for the different systems suggest that the use of a battery of toxicity assays may be required to provide a real ecotoxicological assessment of wastewater samples.