Biological Oxygen Demand Reduction Research Articles

Phenol biodegradation using bio-filter tower packed column with immobilized bacterial consortium: a batch test study.

The effluents from pulp and paper manufacturing industries contain high concentrations of phenol, which when discharged directly into surface water streams, increases the biological oxygen demand (BOD) and chemical oxygen demand (COD). In this study, two dominant bacteria SP-4 and SP-8 were isolated from the effluent emanating with a pulp and paper industry. The selected phenol-degrading isolates were identified as Staphylococcus sp. and Staphylococcus sciuri respectively by using nucleotide sequence alignment and phylogenetic analysis of 16S rRNA regions of the genome. The two isolates used for the biodegradation process effectively degraded phenol concentration of pulp and paper industry effluent upto 1600 and 1800mg/L resepctively. The individual isolates and consortium were immobilized using activated carbon, wood dust, and coal ash. Additionally, the effluent was treated using a bio-filter tower packed column immobilized with bacterial cells at a constant flow rate of 5 mL/min. The present study showed that the developed immobilized microbial consortium can effectively degrade 99% of the phenol present in pulp and paper industry effluents, resulting in a significant reduction in BOD and COD of the system. This study can be well implemented on real-scale systems as the bio-filter towers packed with immobilized bacterial consortium can effectively treat phenol concentrations up to 1800mg/L. The study can be implemented for bioremediation processes in phenolic wastewater-contaminated sites.

Assessment of the potentials of Autochthonous lipase-producing bacteria in the treatment of palm oil mill effluent

Pollution caused by the release of untreated palm oil mill effluent (POME) is a major environmental concern. This research assessed the potentials of single and consortium ofautochthonous lipase-producing bacteria as a non-invasive procedure in the biotreatment ofPOME. The identity of lipase-producing bacteria in POME were determined using morphological and biochemical techniques. Identified isolates were monitored for POME utilization by measurement of optical density at 600 nm in 25 ml Bushnell Haas broth supplemented with 0.25 ml sterilized POME. Individual isolates and consortium were then used for the bioremediation of POME. Quality parameters including pH, total suspended solid (TSS), oil and grease, chemical oxygen demand (COD), biological oxygen demand (BOD), total organic carbon (TOC), total organic matter (TOM) and total nitrogen (TN) of the raw and treated effluents were evaluated. The population (CFU/ml) of total heterotrophic, POME - utilizing and lipolytic bacteria were 3.9 x 106, 2.8 x 106 and 3.5 x 105 respectively. The lipolytic bacterial isolates include Brenneria nigrifluens, Bacillus circulans and Paenibacillus pectinilyticus. Results revealed varying pH of 5.03 and 6.81 - 7.26 for untreated and treated respectively. The lipolytic bacteria from POME caused reduction efficiency of 100% in TSS and oil and grease contents of the treated effluents relative to the raw samples. The COD, BOD, TOC, TOM and TN reduction ranged 17.90 - 93.55, 1.66 - 90.52, 16.34 - 59.79 %, 6.18 - 80.78 % and 11.71 - 93.66 % respectively. This research indicated that POME indigenous lipase-producing bacteria improved POME quality and therefore suggestive of their potentials in the bioremediation of POME-contaminated environment with the consortium being most effective.

Microbial-earthworm ecofilters (MEES) for urban wastewater treatment

Water is an absolute necessity for life and water scarcity is a major problem all over the world. Reusing household wastewater for non-potable water applications is one of the solutions to tackle this problem. Many developing countries lack the technological resources to construct and operate costly wastewater treatment plants. They need cost-effective wastewater treatment options so that both economic aspects and human needs can be met easily. Centralized sewage treatment systems are unable to achieve future demands for sustainable wastewater management in developing countries due to the growing population and needs. The present work examines the effectiveness of treating urban wastewater with microbial-earthworm eco filters (MEEs) (reactor 2) and the filter unit without earthworms (reactor 1). Results of the use of the vermi-biofiltration wastewater treatment unit comprising the biological filtration treatment unit, Eisenia fetida earthworm species, live soil organisms, and natural stones to treat household wastewater are reported herein. The biological oxygen demand (BOD), total dissolved solids (TDS), chemical oxygen demand (COD), and total organic carbon (TOC) were monitored for seven weeks. These parameters exhibited a decreasing trend in both the filtration units. A 75 % reduction in TOC for reactor 2 shows the effectiveness of the proposed system for the utilization of wastewater from urban households. Reactor 2 also showed a reduction in BOD, COD, and TDS approximately in the range of 85, 90, and 30 % respectively. This technique seems to be useful for developing a low-cost and useful household purification system in water-scarce areas using harmless bio-organisms.

Advanced Biological Oxidation of Domestic Sewage with the Use of Compost Beds in a Natural Treatment System for Wastewater

Due to the progressing problems with ensuring sufficient quantity and quality of water for municipal, irrigation and economic purposes, the pressure to reuse treated wastewater is increasing. This fact forces the development of advanced systems enabling more effective wastewater treatment. This article presents the results of a 2.5-year study period in which compost beds, which are part of a natural treatment system for wastewater (NTSW), were used to treat domestic sewage by fully removing easily degradable organic matter and by fully nitrifying ammonium nitrogen. It was shown that the compost environment provides complete access to oxygen for the coexisting heterotrophic and autotrophic bacteria, covering 100% of their oxygen demand. Moreover, the outflow of treated wastewater shows an oxygen content of 4–7 g O2/m3. Advanced biological oxidation occurring in the compost beds with an area of 1 m2 per inhabitant and a daily hydraulic load of about 100 L/m2 can effectively and without additional energy expenditure provide a 98% reduction in biological oxygen demand and a 99.5% reduction in ammonium nitrogen. In addition, the effluent from the compost filters meets the most stringent quality criteria for (1) treated wastewater used for irrigation and (2) bathing water in terms of microbiological contamination.

Studies on the efficiency of fish scale adsorbents for treatment of fish processing effluent

AbstractPollution of water by organic and inorganic contaminants is a serious environmental issue. The primary emphasis of this present investigation was to reduce wastewater pollution and environmental burden related to fish waste disposal. Prime pollutant parameters such as biological oxygen demand (BOD) and chemical oxygen demand (COD) in fish processing effluent were treated by adsorbents produced from waste fish scales viz., dried fish scale adsorbent and fish scale biochar. A control was used and the entire study was carried out in batch mode to assess the influence of adsorbent dosage levels, contact time, and pH conditions. The experiments revealed that prepared fish scale biochar was as effective as control in achieving a significant (p < 0.05) reduction of BOD (87%) and COD (84%) at 150 min treatment time with 0.24 and 0.48 g dosage level. The optimum pH range was found to be 6–8. The experimental data fitted well with pseudo‐second‐order and Langmuir isotherm models (R2 > 0.911). The influence of intraparticle diffusion in adsorption treatment was tested with Weber–Morris plot. The experiments were done in triplicate and all data were statistically tested using MS Excel, IBM SPSS (version 26), and OriginPro software packages.

The Effects of Abattoir Management on Consumer Health in Okene Local Government Area of Kogi State

Abattoir management in Nigeria has been of great concern. Almost every day in all urban and rural markets in our country, animals are slaughtered while the meats are sold to the public for consumption. The public health has become prone to a lot of sickness and illnesses that need an urgent overhaul of the abattoir in Okene Local Government Area of Kogi State. The issue of environmental pollution is perceived not simply as a narrow ecological problem of how to ensure a symbolic and cognitive interference between man and the environment. The activities of the abattoir are meant to regain the suitable and edible portion of slaughtered animals for human consumption. In the process, important quantities of waste materials are brought into existence. Health implications of improper waste disposed are enormous and cannot be ignored. Wastes that are not properly disposed can cause waste pollution, which may breed diseases like cholera, typhoid, among others, which point to the fact that a proper understanding of the disposal and management of waste becomes imperative for the study. A good number of researchers point out that slaughter house activities are responsible for the pollution of surface and underground water. In addition to the quality of air which directly or indirectly affect the health of residents living within the vicinity of abattoir. Inadequate discharge of blood and animal feces into streams caused a huge reduction in Biological Oxygen Demand (BOD), in water as well as nutrients over enrichment of the receiving system caused an increased rate of toxic accumulation. The reliability of BAT was determined using Kuder-Richardson 21. By administering the instrument to 30 abattoirs in two different zones in Okene Local Government Area of Kogi state, mean and standard deviation were used to answer the research questions while analysis of Chi-Square was employed to test the hypothesis at 0.05 level of significance. There should be cordial relationships between policy makers and the abattoirs for provision of essential resources for testing the healthy nature of slaughtered animals like laboratory, slaughtered slabs, and method of butchering, tender for selling meat, among others .

Studies on the Effect of Petrochemical Products on Sewage Degredation in a Septic Tank

In Nigeria, it is standard practice to discharge petrochemical compounds on sewage degradation in a septic tank, which has led to consistent sewage dislodgement in the septic tank that serves our household. The study was carried out to determine the effect of some petrochemical products, such as petrol, kerosene, and diesel. Some laboratory tests were conducted, which included biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, conductivity, and total coliform count. Under aerobic conditions, the researchers built four different experimental sewage treatment systems in the lab. We used a scale ratio of 2: 1 for the effluent and petrochemical products in order to get a total mixture of 200ml for both since the reagent bottle, we used for the test has a total measurement of 300ml. With respect to the above ratio, 33 mL of effluent and 67 mL of petrochemical products such as petrol, kerosene, and diesel were poured into each of the three samples (i.e., the 300 mL reagent bottle), and the last sample was used as the control. Samples were collected at a weekly interval for a period of four weeks for the laboratory tests. The findings of the tests revealed that there was a slow rise in the BOD and the COD during the second week, but that this rise eventually slowed down and became smaller over the course of time. Weekly, the pH, conductivity, and total coliform count decrease. The abrupt spike in the second for BOD and COD is due to the presence of additional carbon, hydrogen, and oxygen molecules, which eventually decrease with time. This merely indicates that petrochemical products have the potential to be utilised in the reduction of biological oxygen demand (BOD), chemical oxygen demand (COD), and coliform bacteria found in sewage.

Intensification of pharmaceutical wastewater treatment using hydrodynamic cavitation process

The presence of pharmaceuticals in wastewater is seen as an increasing environmental issue due to the toxicity of these substances and their ability to remain active chemically in the environment. Traditional wastewater treatment is inefficient due to the damaging and intractable activity of drugs that are accumulating in the environment. The cavitation is the phenomenon of initiation, nurture, and unstable collapse of bubbles in the suspension. This unstable collapses of bubbles in the suspension leads to the production of large amount of energy for instantaneous moment. In this study, the wastewater flowing out of the pharmaceutical industries is treated by oxidation approach. The oxidation was achieved with the help of chemically active radicals produced during the cavitation. The extent of oxidation with the single effect of cavitation was experimentally studied and reported in the manuscript. The optimization was achieved to target the maximum reduction in Biological Oxygen demand (BOD), Chemical Oxygen Demand (COD), and Total Dissolved Solids (TDS). The observed results were compared with the conventional method of the wastewater treatment. The highest TDS reduction was observed with the orifice plate arrangement, which was about 14%, as in the conventional and with the venture arrangement, it was observed at 2% and 8% respectively. The sudden pressure drop and effective vena contracta generate the zone of un-stability for the synthesized cavities. This un-stable zone of pressure increases the rate of collapses as well as the new generation of cavities. The reduction of BOD and COD was also observed at its highest during the utilization of the orifice arrangement, which is 20% and 6%, respectively. By adopting the cavitation method and observing degradation of said factors in the wastewater, this procedure may be found to be more successful than the conventional treatment method. The method may be employed before the conventional treatment method, and the water that has been treated may also be utilized for secondary purposes, while before it may have been wasted.

Effectiveness of Algae in Wastewater Treatment Systems

Abstract: Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) play important role in determining the quality of wastewater. Hence it is necessary to calculate COD and BOD of water before setting up of wastewater treatment plant. Algae has been used for decades for various purposes. It is one of the important characteristics is to nitrogen, phosphorus etc., which are harmful for drinking and other purposes but they act as food for algae. Thus in this study COD and BOD analysis is done for sterilized and non-sterilized wastewater after and before treating it with algae in inverse fluidization under aerobic condition, for different time interval and found that percentage reduction in COD and BOD for sterilized wastewater gives greater value than non-sterilized water the reason for this difference being the decrease in the competition between algae and other micro-organism which are present in raw wastewater and COD % reduction is 65-70 % and BOD % reduction is 68.75- 70.5%.Organic and inorganic substances which are released into the environment as a result of domestic, agricultural and industrial water activities lead to pollution.

Sustainable approach for biodiesel production and wastewater treatment by cultivating Pleusrastrum insigne in wastewater

The globalized modern world has been confronted with some of the most challenging problems, most of which arise from human activities. Overexploitation of fossil fuels which leads to energy and environmental crisis, and loss of aquatic ecosystem due to improper disposal of household and industrial waste into water bodies constitute some of the biggest emerging global problems. In this study, an unconventional and sustainable approach to produce biodiesel was analyzed by growing Pleurastrum insigne in different wastewater. The growth of P. insigne in wastewater in turn resulted in up to 93.61% reduction in biological oxygen demand, 58.62% reduction in total phosphorus content, and up to 76.61% total nitrogen removal in the wastewater. The total lipid content of the organism was highest in wastewater sample 6 (30.47%). The fatty acid profile also showed a high percentage of C16 and C18 fatty acids which are desirable fatty acids for a high-grade fuel. Production of biodiesel conforming to international standards was predicted from P. insigne cultivated in wastewater confirming the effectiveness of combining wastewater treatment and biodiesel production. Novelty statement: Pleurastrum insigne has never been studied before for phytoremediation of wastewater and biodiesel production. This novel research highlighted the application of P. insigne in wastewater treatment and the viable scope in biodiesel production. This work aimed to provide a significant contribution in reducing the cost of production of biodiesel from microalgae while shedding new light on an eco-friendly approach to wastewater treatment.

Microbial Remediation of Textile Dye Acid Orange by a Novel Bacterial Consortium SPB92

Textile effluent generated during the dyeing process of textiles is a huge supplier to water toxicity all over the world. Textile dyes are the main toxic component found in the effluent sample which is difficult to treat. A bacterial consortium capable of decolourizing and degrading the textile dye acid orange is reported in this research article. The bacterial consortium was identified by 16 S rDNA sequence and phenotypic characteristics. It is composed of four strains i.e., Pseudomonas stutzeri (MW219251), Bacillus tequilensis (MW110471), Bacillus flexus (MW131645), Kocuria rosea (MW132411). The consortium was able to cause decolorization of azo dye acid orange (30 mg/L) in 23 h, when kept under static laboratory conditions. The optimal pH and temperature for color removal were pH 7.5 and 32°C, respectively. The decolorization of dye before and after was checked by UV-Visible absorption spectra. This gives evidence that decolorization was caused due to biodegradation. This was further assured by studying the reduction of biological oxygen demand (BOD5 (96%), chemical oxygen demand (COD) (79%), and TOC (total organic carbon) (54%) of the bacterial-treated water sample. The Fourier transform-infrared spectroscopy (FT-IR) spectroscopy and gas chromatography-mass spectroscopy (GC-MS) results confirmed the mineralization of the dye. The results indicate the effectiveness of the bacterial consortium SPB92 in the biodegradation of acid orange dye. This demonstrates that the consortium has immense potential and will serve as an important contributor to the treatment of textile wastewater.

Evaluation of Natural and Chemical Coagulants Performance in Treatment of Municipal Wastewater of Behshahr City

Municipal wastewater is one of the largest volumes of wastewater which contains various organic compounds from proteins and fats to carbohydrates and nucleic acids. Municipal wastewater of Behshahr city (Mazandaran, Iran) was evaluated using aluminum sulfate and iron chloride as chemical coagulants and pectin and sodium alginate as natural ones. Biological oxygen demand was investigated at different temperatures and coagulant concentrations. The fraction of full factorial statistical method and Qualitek-4 software were applied for designing experiments and analyzing the results to determine the optimal conditions for achieving the highest reduction in wastewater organic load and biological oxygen demand. In the case of biological oxygen demand, the optimal condition was achieved at 25°C, using 1, 0.02, 1.5 and 1 g/L of aluminum sulfate, sodium alginate, iron chloride and pectin, respectively. Under the optimal condition, the percentage of biological oxygen demand reduction was equal to 34.5%. Maximum BOD removal of 40.9% was obtained at 25°C using aluminum sulfate, sodium alginate, iron chloride, and pectin at concentrations of 0.6, 0.02, 1.5, and 6 g/L, respectively. The contribution of aluminum sulfate, sodium alginate, iron chloride, and pectin concentration in biological oxygen demand removal of the studied wastewater was 3.8%, 22.4%, 16.3%, and 14.4%, respectively. Coagulation temperature and aluminum sulfate concentration with approximately 42.7% and 3.8% contribution values were determined as the most and the least effective factors in biological oxygen demand reduction.

Effect of Process Parameters on the Adsorption of Chromium VI on a Packed Bed Column (PBC) using Vetiver (Vetiveria zizanioides)

The objective of this study is to evaluate the different process parameters on adsorption of chromium VI on a packed bed column using Vetiver (Vetiveria zizanioides) and to examine the effect of pH, Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) at a constant contact time of 10 minutes at a temperature of 40 ºC under two experimental conditions namely, tannery effluent with and without microwave treatment. The results revealed that microwave heating process had a higher impact on chromium (VI) adsorption than normal heating process. The pH values of microwave treated sample were found to be 6.65±0.65 when compared to normal heated sample where the pH was 4.62±0.72 when compared to the initial pH of effluent found to be 3.47±0.58. Further, a threefold reduction in BOD and COD values was observed in microwave treated vetiver sample which was around 86.73±1.43 and 107.90±2.82 mg/l respectively when compared to normal heated sample (250±1.45 and 200±2.65 mg/l respectively) and untreated effluent (780±2.53 and 920±3.86 mg/l respectively) which indicated the reduction of chromium VI present in the effluent water. It was also observed that the metal adsorption capacity of the vetiver powder and the adsorption characteristics were positively correlated with the FTIR and SEM analysis which confirmed the presence of chromium (VI) on the surface of vetiver.

Adsorptive removal of dairy industrial pollutants by chitosan zinc –oxide nanoadsorbent- A comparitive study of artificial neural network and quadratic Box-Behnken design

Aim: To investigate the effect of operational parameters on the adsorption of biological oxygen demand (BOD) and chemical oxygen demand (COD) on to Chitosan zinc oxide (CZnO) nanoadsorbent using cost-effective and eco-friendly nanoadsorbent based effluent treatment processes. Methodology: CZnO nanoadsorbent particle was synthesized using chemical precipitation method. The nano size <100 nm was achieved using high-speed cryo all mill, followed by the characterization using high-end instruments such as scanning electron microscope with elemental detection sensor (SEM-EDS), atomic force microscope (AFM), X-ray diffractometer (XRD) and Fourier transform inform infrared spectroscopy (FT-IR). Modeling and optimization of operational parameters were done with the artificial neural network (ANN) and Box-BehnkenDesign (BBD) statistical tools. Results: Optimized treatment combination for adsorption of BOD and COD were found at initial BOD and COD concentration of 100 and 200 mg l−1, pH of 7.0 and 2.0, adsorbent dosage of 1.25 mg l−1, contact time of 100 and 60 min. In these conditionsthe desirability values of 0.988 and 0.950 were found for BOD and COD adsorption. The maximum per cent reduction of BOD and COD by using CZnO nanoadsorbent was found to be 96.71 and 87.56. Two models such as Quadratic Box-Behnken and ANN were compared in term of sum of square errors (SSE), root mean square error (RMSE) and correlation coefficient (R2) values. Interpretation: The results obtained revel the well trained ANN model found to be more accurate in prediction of BOD and COD adsorption process parameters compared to BBD model.

Bacterial Population of Fish and Their Environment in Ponds Utilized for Natural Purification of Wastewater

Viable threats from waste-fed aquaculture have become a genuine subject of discussion presumably since the initiation of such fishery. An aquaculture-based sewage treatment system, blending fish as biological component was assessed in Bandipur, Titagarh, North 24 Parganas, West Bengal, India. The 5 MLD (million litres per day) system receiving domestic sewage flow comprised of anaerobic ponds (areas-0.7 ha, depths-2.5m), facultative ponds (areas-4.8 ha, depths-1.5m) and maturation ponds (areas-4.8 ha, depths-1m). The observation revealed substantial aptitude of the system for biological sewage treatment, with respect to reduction of ammonia nitrogen, BOD (Biological oxygen demand) and COD (Chemical Oxygen Demand). The TVC (Total Viable Count) and enteric bacterial counts were detected in higher numbers from water and fish. Some of the members customarily recovered in this study like Vibrio were established fish and human pathogens. Counts of faecal coliforms in fish culture ponds were found to outstrip the World Health Organization (WHO) standards of ≤103 faecal coliforms per 100 ml of water to be used in aquaculture. High concentrations of pathogenic bacteria were reported to be present in fish even at low numbers of indicatory bacteria. Estimated risk of bacteriological infection of fish for most of the times crossed the guide line proposed by international commission on the microbiological specification of foods (1995). Public health risks associated from fish and fishery products of Bandipur sewage fed farm clearly indicate infelicity of wastewater treatment along with inappropriateness of treated waste water to be reused in aquaculture.

Chromium-free and waterless vegetable-aluminium tanning system for sustainable leather manufacture

Intensifying researches in leather sector are focusing on eco-benign tanning chemicals with less environmental impact processing route. The present study aims to design an eco-acceptable shoe upper leather process that could potentially eliminate use of chrome from the leather industry. Possible conversion of Cr3+ to Cr6+ in suitable oxidant environment during leather manufacture is always a threat to the ecosystem. Water load for leather processing is very high, also becoming a precious resource that needs to be reduced for industrial applications. Further without water usage for a process, generation of wastewater could be averted. With this context, a combination tanning using wattle and aluminium has been developed in a pickle-less and waterless medium. The experimental leather possesses a shrinkage temperature of 84 °C with a fully loaded compact fibre structure indicating that tannin penetration is not affected in waterless medium. Experimental leathers exhibit better physical strength and comparable organoleptic characteristics. The process enjoys environmental benefits as it shows significant pollution load reduction in Biological Oxygen Demand (BOD), chemical oxygen demand (COD), Total Dissolved Solids (TDS) by 88, 89, and 97%, respectively. Hence, a viable option is made available to manufacture eco-acceptable leather without water usage and chrome salts in tanning.

Modelling and optimisation of chitosan anchored titanium dioxide nano-adsorbent for dairy industry effluent treatment

AbstractThe present study emphasised the efficiency of chitosan anchored titanium dioxide nano-adsorbent on dairy industry effluent treatment. Chitosan titanium dioxide nano-adsorbent was synthesised by using chemical precipitation method and characterised for its particle size, surface morphology and texture. A four-factor-three-level Box–Behnken design along with response surface methodology was used to optimise the adsorption process parameters. Linear, two factor interaction, quadratic and cubic model techniques were used to demonstrate the influence of each parameter and their interaction effects on the responses. The quadratic models derived from the experimental data were used to predict the maximum per cent reduction of biological oxygen demand (BOD) and chemical oxygen demand (COD). The optimised treatment combination for maximum per cent reduction in BOD (90.48%) and COD (82.10%) was found to be initial concentration of 100 mg L−1, pH of 7, dosage of 1.25 mg L−1 and contact time of 100 min.

Palm Oil Mill Effluent Treatment by Using Copperas as Physicochemical Treatment Agent

The palm oil mill industry in Malaysia are a huge agriculture industry which generates significant amount Palm Oil Mill Effluent (POME). POME is an oily wastewater which consist of various suspended components, the liquid are a combination of steriliser condensate and cooling water. The wastewater is very pollutant to human and environment, the coagulants applied to reduce the suspended materials in POME as following the stringent requirements of biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solid (TDS), total solid (TS) and turbidity as stated by the Department of environment. This paper analyses the use of ferrous sulphate heptahydrate as a coagulant as it was applied on the primary treatment and the results improvement upon physicochemical treatment parameters. Series of batch treatment for coagulation and flocculation with ferrous sulphate heptahydrate were conducted. Dosage and pH were conducted to determine the optimum conditions to apply the coagulants. The result of coagulants showed that ferrous sulphate heptahydrate have a good effect on BOD reduction at dosage 1500 mg/l pH of 3.4 before pH adjustment. There were eight different samples used for different concentration of coagulant, the sample of 250 ppm copperas feed till 1000 ppm feed has the COD result difference of 171 ppm. When the copperas feed increased the COD value will decreased gradually. For the second parameter, biological oxygen demands the BOD value are reduced successfully, the first sample with feed concentration 500 ppm of copperas has BOD value of 288 ppm. As we increase the feed of copperas to 2000 ppm the BOD value reduced to 13 ppm. Next the highest value of TSS reduction is at 2000 ppm of copperas feed, at the specific dosage the TSS reading was 7502 ppm

A novel strategy for microbial conversion of dairy wastewater into biofertilizer

Dairy industry generates copious amount of wastewater from its milk processing unit (1–10 m3 of wastewater per m3 of processed milk) which needs to be treated before getting discharged. The conventional treatment processes are tedious, energy intensive, and an additional burden for the dairy industry. This study attempts to develop an alternative strategy to convert the dairy wastewater into liquid biofertilizer. A tailor-made microbial consortium-based biofilm reactor with 8.64 m3 d−1 processing capacity, within 16 h of hydraulic retention time (HRT) at ambient temperature produced biofertilizer containing 96.01 mg L−1 ammonia from dairy wastewater at a flow rate of 360 L h−1 with associated 73.72% nitrate, 72.46% phosphate, 61.30% Biological Oxygen Demand (BOD) and 57.23% Chemical Oxygen Demand (COD) reduction. A similar system of 10.94 m3 d−1 processing capacity at 456 L h−1 flow rate produced 298.79 mg L−1 ammonia with nitrate, phosphate, BOD and COD reduction of 42.71%, 84.80%, 89.55% and 76.68% respectively. This liquid biofertilizer could enhance grain yield in maize (Zea mays var. Vijay) by 1.19-fold. It increased biomass yield in Sorghum Sudan grass (Sorghum sudanense) by 3.5-folds and Lemongrass (Cymbopogon citratus var. Dhanitri and var. Krishna) by 2.1 and 2.64 folds respectively. It enhanced gel content in Aloe vera (Aloe elongata var. Ghikuari) by 1.63-folds when compared to chemical fertilizer treatment. This single-step dairy wastewater treatment system requires ten times less energy with the development of a value-added product (biofertilizer). It could make the dairy wastewater management a revenue earning (USD 10.28 d−1 for 600 m3 d−1 processing capacity reactor), eco-friendly, zero discharge process preventing the use of freshwater and chemical fertilizer in agriculture, and saving 89.99% carbon dioxide equivalent (CO2 eq.) gas emission leading to environmental protection.

Utilization of prawn to reduce the value of BOD and COD of textile wastewater.

In the textile sector especially in the wet processing area, a large quantity of water is utilized together with specific chemicals for raw material processing. If the wastewater after the chemical treatment is directly discharged to the environment, it is hazardous for the living organism and also the aquatic life of nature. In this study, the cephalothorax and abdomen shell of the prawn was processed to obtain chitosan and the textile wastewater was treated with the obtained chitosan to reduce the value of biological oxygen demand (BOD) and chemical oxygen demand (COD). The reduction rate of BOD, COD was significant, and in the acceptable range of discharge water quality. In order to compare the performance of prawn shell treatment, similar untreated wastewater was treated separately by using the microorganism. The reduction of BOD and COD was analyzed differently for both microorganisms and prawn shell treatment which indicated the superiority in the reduction of BOD and COD of wastewater by using prawn shell treatment. The traditional process used in the purpose of wastewater treatment could be upgraded by using the naturally obtained chitosan which could also be easily applicable at a low cost. The used convenient procedure to obtain chitosan from prawn and to apply chitosan to reduce the value of BOD and COD could be efficacious in the new era to treat wastewater naturally, effectively.