Common Effluent Treatment Plant Research Articles

A Novel Methylotrophic Bacterial Consortium for Treatment of Industrial Effluents

Considering the importance of methylotrophs in industrial wastewater treatment, focus of the present study was on utilization of a methylotrophic bacterial consortium as a microbial seed for biotreatment of a variety of industrial effluents. For this purpose, a mixed bacterial methylotrophic AC (Ankleshwar CETP) consortium comprising of Bordetella petrii AC1, Bacillus licheniformis AC4, Salmonella subterranea AC5, and Pseudomonas stutzeri AC8 was used. The AC consortium showed efficient biotreatment of four industrial effluents procured from fertilizer, chemical and pesticide industries, and common effluent treatment plant by lowering their chemical oxygen demand (COD) of 950-2000mg/l to below detection limit in 60-96h in 6-l batch reactor and 9-15days in 6-l continuous reactor. The operating variables of wastewater treatment, viz. COD, BOD, pH, MLSS, MLVSS, SVI, and F/M ratio of these effluents, were also maintained in the permissible range in both batch and continuous reactors. Therefore, formation of the AC consortium has led to the development of an efficient microbial seed capable of treating a variety of industrial effluents containing pollutants generated from their respective industries.

Modeling the performance of a tannery common effluent treatment plant using artificial neural networks

Modeling the performance of a tannery common effluent treatment plant using artificial neural networks

Insights into dewatering and characterization of the waste activated sludge

Abstract On-site filtration experiments were carried out at the local Common Effluent Treatment Plant (CETP) to measure the properties of the waste activated sludge (WAS). The consequences of several operational parameters such as effect of pressure, filtration media, coagulant addition, etc. were studied. To better understand the role of hydrodynamics as well as the biological content, a comparison was made between the activated sludge (AS) and WAS cake and its properties. In our findings, the cake obtained in case of WAS filtration was denser as compared to the cake from AS. In the former, it was found to be in the range of 2–2.5% w/v of WAS as compared to 0.25–0.5% w/v of AS. The addition of coagulant accelerated settling and in turn reduced the WAS filtration time by 10 fold. Important filtration parameters obtained for WAS were: cake resistance (α) = 1.5 × 1011 m/kg, cake porosity (e) = 0.86, cake compressibility (η) = 0.41, effective mean particle size (x) = 0.5 µm, capillary number (Nc) = 2.7 × 10–3, irreducible saturation (S∞) = 0.155 and threshold pressure (Pb) = 1 × 105 N/m2.

Evaluation of toxicity reduction in textile effluent by different treatment protocols involving marine diatom Odontella aurita on freshwater fish Labeo rohita

Raw textile effluent, collected from Common Effluent Treatment Plant (CETP), Perundurai, Tamil Nadu, was subjected to toxicity reduction employing varied laboratory treatment protocols viz. chemical (Advanced Oxidation Process), physical (Electrocoagulation), bacterial (Lyisinibacillus sphaericus), phycoremediation (Odontella aurita) and their combinations. Aquatic toxicity was tested using freshwater fish Labeo rohita and the variations in fish histopathological, biochemical, enzymology, hematological and immunological parameters were analyzed. The intermediatory dye metabolites and secondary amines produced during chemical (96hLC50=5%) and bacterial remediation (96hLC50=15%) had enhanced the stress factor and organ damage in the exposed fish. In phycoremediation, though the newly explored Odontella aurita could effectively absorb metal ions than other algal species and moderately reduce effluent physical parameters, but was less efficient in the removal of azo dyes from the effluent (96hLC50=50%). Subsequent physical remediation had removed these dyes and other effluent solid sludge, and had enabled the fish to survive acute toxicity (96h+). However, it was less efficient in removing the secondary metabolites produced during bacterial (96hLC50=20%) and chemical (96hLC50=25%) remediation. Secondary phycoremediation had effectively reduced effluent physical parameters, metal ions and the hydroxyl radicals left over after primary chemical remediation. Therefore, this combined chemical and phycoremediation processes had enabled the fish population survive short term chronic toxicity (168h+), with less organ damage and slightly enhanced immunological response. This treatment is certainly better than the methodology adopted by CETP, where the fish could survive only acute toxicity with higher organ damage.

Hexavalent chromium reduction potential of Cellulosimicrobium sp. isolated from common effluent treatment plant of tannery industries

Present study deals with the isolation and characterization of a bacterium capable for the effective reduction of Cr(VI) from tannery wastewater. Based on the 16S rRNA gene sequence analysis, this bacterium was identified as Cellulosimicrobium sp. (KX710177). During the Cr(VI) reduction experiment performed at 50, 100, 200,and 300mg/L of Cr(VI) concentrations, the bacterium showed 99.33% and 96.98% reduction at 50 and 100mg/L at 24 and 96h, respectively. However, at 200 and 300mg/L concentration of Cr(VI), only 84.62% and 62.28% reduction was achieved after 96h, respectively. The SEM analysis revealed that bacterial cells exposed to Cr(VI) showed increased cell size in comparison to unexposed cells, which might be due to either the precipitation or adsorption of reduced Cr(III) on bacterial cells. Further, the Energy Dispersive X-ray (EDX) analysis showed some chromium peaks for cells exposed to Cr(VI), which might be either due to the presence of precipitated reduced Cr(III) on cells or complexation of Cr(III) with cell surface molecules. The bacterium also showed resistance and sensitivity against the tested antibiotics with a wide range of MIC values ranging from 250 to 800mg/L for different heavy metals. Thus, this multi-drug and multi-metal resistant bacterium can be used as a potential agent for the effective bioremediation of metal contaminated sites.

Effect of ultrasonic pretreatment on secondary sludge and anaerobic biomass to enhance biogas production

Anaerobic digestion studies were carried out with tannery excess secondary sludge obtained from common effluent treatment plant. The excess sludge as a feed was disintegrated by ultrasonic homogenizer, to solubilize the intracellular compounds to overcome the rate-limiting hydrolysis step. The anaerobic biomass was subjected to diligent disintegration with the aim of increasing the maintenance energy requirements thereby enhancing its microbial activity. To achieve maximum gas production, the percentage treatment volume of feed and biomass were chosen as dynamic variables and the optimization of these variables was carried out by RSM technique. A 22 full factorial central composite design was used for experimental design and analysis. It was observed that the percentage treatment volume of biomass was found to be most significant variable that of feed and the interaction effects of these two variables found to be insignificant. Based on experimental results, quadratic model was arrived and the variables were optimized for maximum gas production. In addition, response surface for maximum gas production was obtained as a function of two dynamic variables for identification. In the present study, the influence of pretreatment was observed only in biogas production and COD removal, but the methane content remains unchanged.

Comparison of biochemical methane potential and methanogen morphology of different organic solid wastes co-digested anaerobically with treatment plant sludge

Abstract This paper describes biomethanation of tannery limed fleshing (TLF), fruits and vegetables (FVW), and sugarcane juice residue (SJR) with pre-fermented tannery-based common effluent treatment plant sludge (CETP), as an inoculum. The BMP, microbial morphology and other bioprocess efficiency parameters were evaluated using a laboratory scale batch reactor, with a substrate/inoculum ratio of 3:1 under a mesophilic anaerobic (35 ± 2 °C) condition and mixed at 100 rpm in orbit shaker. Maximum cumulative biogas yield was observed in FVW (2468.50 ± 0.44 Nm mL/d) followed by TLF and SJR comparatively to the inoculum. The specific methane yield observed ranged from 0.169 ± 0.05 to 0.478 ± 0.00 Nm L/g VS r for the wastes, against 0.204 ± 0.01 Nm L/g VS r for control treatment. The mixture of all the three wastes (CLFS) benefitted to yield more biogas compared to the mono-digestion. The highest VS r and sCOD r efficiency of 62.44 ± 0.32 and 93.46 ± 1.04% obtained in FVW compared to other wastes, coincides with the methanogenic microbial count and densities. A good correlation (R 2 = 0.82) was also observed between the experimental BMP and stoichiometric methane potential of the various organic solid wastes.

Investigation on potential reuse of textile sludge as fertiliser and for preparation of solid blocks

Sludge management practices are more important and becoming global challenge for effective reuse and safe disposal of sludge. Common effluent treatment plant is a cost effective option for treating textile wastewater from various units which is facing problem in sludge management. Reuse of chemical sludge for construction purposes is a suitable alternative for waste disposal. This study examines characterisation of chemical sludge and the suitability of chemical sludge for replacing cement (5%, 10%, 20%, 30%, 40% and 50%) in preparation of solid blocks. The preparation and testing of solid blocks were carried out as per ASTM and BIS standards. It is inferred from the results that the maximum of 30% chemical sludge used in solid blocks meets all requirements specified in ASTM non-load bearing and BIS load bearing standards. Experimental results of bio sludge revealed that the soil with 1% bio sludge addition was more suitable for the plant growth.

Impending heavy metal tolerance of fungus isolated from dye industrial sludge

In the present study, the fungal species were isolated from dye industrial sludge collected at common effluent treatment plant (CETP). The isolated strains were screened for metal tolerance index (MTI) and minimum inhibitory concentration (MIC) in potato dextrose agar plates amended with various concentrations, ranging from 20-100 ppm of Cu and Fe. The three fungal strains such as Aspergillus fumigatus, Aspergillus flavus and Rhizopus were isolated. The results of MIC revealed that all the three isolates were able to tolerate various concentrations of Cu and Fe. The strain Aspergillus flavus showed the higher tolerance index of Cu, when compared with other isolates. Similarly the strain Rhizopus was the most tolerant species and exhibit strong growth at high concentration of Fe. The fungus Aspergillus fumigatus exhibit the moderate tolerance of both the heavy metals. The isolated fungus was exhibiting strong growth and tolerance to metals, can be a viable species for bioremediation.

Biosorption of Chromium from Tannery Effluent Using Bacterial and Fungal Species

Tannery effluent was collected from Common Effluent Treatment Plant, Dindigul, Tamil Nadu and used for analysis for physico-chemical, heavy metals and biological properties. Soil samples were collected from the field and Aspergillus sp. and Pseudomonas sp. were isolated and pure cultured. The pH of the tannery waste water was around 8.50 and electrical conductivity was 2.89 dS/m indicating the alkalinity of the effluent. Total dissolved solids(TSS) was found to be 1460 mg/L and BOD showed 2346 mg/l. The AAS reading of chromium in the effluent indicated 205 mg/L which means the effluent can not be released into the environment without proper treatment. The metal tolerance capacity of the organisms was tested at different concentrations of chromium salts dissolved in tannery effluent viz., 25 to 200 ppm with 25 ppm of increment for each of the treatment. Pseudomonas sp.tested tolerated upto 100 ppm,while the Aspergillus sp could resist upto 75 ppm of chromium concentration. It was also found that the Pseudomonas sp. had potentially removed chromium from aqueous spiked solution with effluent, hence it could be a good biosorbent for the removal of chromium from tannery effluent contaminated agricultural fields.

Impending heavy metal tolerance of fungus isolated from dye industrial sludge

In the present study, the fungal species were isolated from dye industrial sludge collected at common effluent treatment plant (CETP). The isolated strains were screened for metal tolerance index (MTI) and minimum inhibitory concentration (MIC) in potato dextrose agar plates amended with various concentrations, ranging from 20-100 ppm of Cu and Fe. The three fungal strains such as Aspergillus fumigatus, Aspergillus flavus and Rhizopus were isolated. The results of MIC revealed that all the three isolates were able to tolerate various concentrations of Cu and Fe. The strain Aspergillus flavus showed the higher tolerance index of Cu, when compared with other isolates. Similarly the strain Rhizopus was the most tolerant species and exhibit strong growth at high concentration of Fe. The fungus Aspergillus fumigatus exhibit the moderate tolerance of both the heavy metals. The isolated fungus was exhibiting strong growth and tolerance to metals, can be a viable species for bioremediation.

Groundwater quality assessment in emerging industrial cluster of alluvial aquifer near Jaipur, India

Groundwater is the major source of drinking water on the earth’s surface. The threat to groundwater contamination is increasing day by day due to rapid increase in industrialization and urbanization. The present study aims at assessing the groundwater quality contamination threat around industrial cluster at Rajasthan State Industrial Development and Investment Corporation (RIICO) in Jaipur district of Rajasthan, India. The cluster does not have common effluent treatment plant, and very few units have their effluent treatment plants. Groundwater samples were collected around the industrial cluster and its vicinity and analyzed for major cations, anions and trace elements. The water quality data indicate that total dissolved solids exceed the drinking water standard set by the Bureau of Indian Standards in few samples, and trace elements of health significance are not detected in any sample. The soil analysis indicates that only the top surface near the point of disposal of the treated effluent is affected. In view of the thick alluvium of 60–80 m and the water table above 30 m, the effluents are retarded significantly before reaching the water table. The sodium adsorption ratio of water samples indicates its suitability for irrigation and falls in the category of fairly suitable to excellent. Piper plot reveals that dominant cations are Na+, K++ and Mg++ and dominant anions are \({\text{HCO}}_{3}^{ - }\) and \({\text{CO}}_{3}^{ - }\). The Gibbs plot indicates that rock–water interactions influence the groundwater quality. The study reveals that the groundwater quality from most of the sources meets the requirements of drinking water standards, and there is enough environmental space available for the expansion of industrial belt in this RIICO hub.

Effect of pH, inoculum dose and initial dye concentration on the removal of azo dye mixture under aerobic conditions

Biodegradation of mixture of three dyes namely, reactive brilliant red X-3B (RBRX-3B), direct blue-6 (DB-6) and direct black-19 (DB-19) in a batch shake flask was investigated in this study. Mixed microbial culture isolated from the sludge procured from a local common effluent treatment plant was used to degrade the dyes. Acclimatization of the bacterial culture was done prior to the experiment to obtain a culture with effective degradation ability. Batch kinetic studies were done and modelled using Monod and Michaelis-Menten models. The effects of process parameters, namely pH (5–9), inoculum dosage (5–15%) and initial dye concentration (20–100 mg l−1) on the biodegradation of dye mixture were studied systematically and optimized using response surface methodology (RSM). The maximum removal efficiencies obtained for RBRX-3B, DB-6 and DB-19 were 31.2%, 71.5% and 87.6% respectively. The model equations generated by RSM were found to be statistically significant and the optimized values of process parameters were experimentally validated. The error between experimental values and model prediction was found to be less than 10% for all the three dyes.

Development of simultaneous partial nitrification, anammox and denitrification (SNAD) in a non-aerated SBR

The objective of this work was to develop simultaneous partial nitrification, anammox and denitrification (SNAD) process in a twenty liter non-aerated sequencing batch reactor (SBR). Flocculent type activated sludge sourced from a tannery common effluent treatment plant was used as seed biomass. The SBR was operated for 161 days in 23 cycles with initial feed concentrations of NH4-N and COD as 250 ± 14.9 mg l−1 and 250 ± 4.6 mg l−1, respectively. The process was developed in a non-mixing condition in a dark room with no temperature control, but the temperature in SBR varied between 30 °C and 36 °C. The average HRT was 10.5 d with SBR cycle time of 7 d. The last three cycles gave the best average removals of NH4-N (94%), COD (92%) and TN (82%). The conversion ratio Y(NO2-N+ NO3-N)/(NH4-N) during the last 10 cycles remained below 0.11, confirming a stable SNAD process. Maximum specific substrate (NH4-N, COD and TN) utilization rates of SNAD biomass were determined as 185 mg NH4-N g−1 MLVSS d−1, 153 mg COD g−1 MLVSS d−1 and 172 mg N g−1 MLVSS d−1. These results contribute towards the application of SNAD process in shallow anoxic ponds/tanks/ditches in the absence of sunlight.

CAPTIVE POWER PLANT - A CASE STUDY OF CETP ICHALKARANJI, MAHARASHTRA

Water and wastewater treatment processes requires huge amount of energy in around 30to 80 % of industrial operation cost. As per this background the water companies needs to identify cost effective and sustainable ways of producing energy. The generated energy should reduce its dependence on fossil fuel and ensure security of power supply. It also helps to reducing the energy cost. Micro hydro power can be available at the doorstep of effluent treatment plant, which has been identified as the solution to a sustainable energy option for the water industry. Nevertheless, there is no option available in literature of hydropower application to water treatment plants. This research gives an overview of hydropower application options available to the water industry consist of water / sewage / Effluent treatment plant. Economics plays an important role in industrial world. The power plants are design on the basis of most economical condition not on the most efficient condition by considering profit and advantage. Effectiveness of the plant is measured financially. The main goal of design and operation of the plant is to bring the cost required for energy production keep minimum as possible. Among many factors, the efficiency of the plant is one of the factors that determine the energy cost. This project measures the feasibility of implementing hydroelectric turbine systems in wastewater treatment facilities in Maharashtra, India. Thus a treatment plant named, Ichalkaranji Textile C.E.T.P. Ltd., Ichalkaranji, District- Kolhapur, Maharashtra, India was selected for a case study analysis. Based on flow and head data, 26 kW of power could be produced, generating 3.8% of the facility’s electricity needs. Payback periods were calculated to determine hydropower feasibility for other common effluent treatment plants, and 70 % were potentially feasible based on flow but depending on head.

Draft Genome Sequence of Commercial Textile Dye-Decolorizing and -Degrading Bacillus subtilis Strain C3 Isolated in India.

Bacillus subtilis C3, a commercial textile dye-decolorizing and -degrading bacterium, was isolated from the common effluent treatment plant (CEPT) of the Jetpur textile dyeing and printing industrial sector situated in the district of Rajkot, Gujarat, India. Here, we present the annotated 4.18-Mb draft genome sequence of B. subtilis C3, providing information about the metabolic pathways involved in decolorization and degradation of several commercial textile azo dyes. Thus, we confirm B. subtilis C3 as a potential candidate for bioremediation of textile effluents.

Treatment of Common Effluent Treatment Plant Wastewater in a Sequential Anoxic-Oxic Batch Reactor by Developed Bacterial Consortium VN11.

A laboratory-scale anoxic-oxic sequential reactor system was seeded with acclimatized mixed microbial consortium for the treatment of common effluent treatment plant (CETP) wastewater having 7000-7400mgL(-1) of COD and 3000-3400mgL(-1) of BOD. Initially, CETP wastewater was treated under anoxic reactor at 5000mgL(-1) of MLSS concentrations, 5.26 ± 0.27kg COD m(-3)day(-1) of organic loading rate (OLR) and 36h of hydraulic retention time (HRT). Further, the effluent of anoxic reactor was treated in oxic reactor with an OLR of 6.6 ± 0.31kg COD m(-3)day(-1) and 18h HRT. Maximum color and COD removal were found to be 72 and 85% at total HRT of 2.25days under anoxic-oxic sequential reactor at 37 °C and pH 7.0. The UV-VIS, FTIR, NMR and GCMS studies showed that majority of peaks observed in untreated wastewater were either shifted or disappeared after sequential treatment. Phytotoxicity study with the seeds of Vigna radiata and Triticum aestivum showed more sensitivity toward the CETP wastewater, while the products obtained after sequential treatment does not have any inhibitory effects. The results demonstrated that the anoxic-oxic reactor fed with bacterial consortium VN11 could bring about efficient bioremediation of industrial wastewaters.

Bacterial Community Exploration through Ion Torrent Sequencing from Different Treatment Stages of CETP for Tannery

Bacterial Community Exploration through Ion Torrent Sequencing from Different Treatment Stages of CETP for Tannery In developing nations, the tannery industry is a major polluter. Only 20% of the chemicals consumed are utilized in the tanning process; the remainder is waste that pollutes the environment. The Common Effluent Treatment Plant (CETP) is a promising approach to treat industrial effluent. In this study, the physico-chemical parameter and the bacterial communities were analysed in different treatment stages of CETP effluent; raw effluent (RE), primary treated (PT), secondary treated (ST) and tertiary treated (TT). The physicochemical results revealed a decrease in the concentration of pollutants at each stage. It was hypothesised that in addition to chemical treatment, the bacterial community plays a key role in the reduction of chemical load and heavy metals. So, theV6 hyper-variable region of 16S rRNA gene was amplified and analysed using ion torrent PGM platform to explore the uncultivable bacterial community which are responsible for pollution reduction. The sequence data were evaluated using the MG-RAST server, which revealed proteobacteria (4.3-34.6%) as predominant in all CETP stages. Actinobacteria was dominant in ST (10.6%) and TT (5.1%) effluent and bacteroidetes dominated in PT (36.7%) and RE (51.9%). The results clearly showedthe taxonomic shifts in each stage of CETP, which aligned with physico-chemical changes. We conclude that the bacterial survivability and species richness in each stage could be used as bioindicators to monitor the level of pollution and appropriate functioning of a CETP.

Exposure of composite tannery effluent on snail, Pila globosa: A comparative assessment of toxic impacts of the untreated and membrane treated effluents

Effluent from tannery industries can significantly affect the aquatic environment due to the presence of a variety of recalcitrant components. The present study focuses on a comparative assessment of the toxic impacts of an untreated tannery effluent and membrane treated effluents using snail, Pila globosa as an aquatic model. Composite tannery effluent collected from a common effluent treatment plant was selected as the untreated effluent. To investigate the effect of treated effluents on the aquatic organism the effluent was treated by two ways, viz. a single stage microfiltration (MF) using ceramic membrane and a two-step process involving MF followed by reverse osmosis (RO). The whole body tissue, gonad and mantle of P. globosa were subjected to enzyme assays like superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GSH-GPx), glutathione S- transferase (GST), etc. for assessing toxic impact. Changes in the biochemical parameters like protein, carbohydrate and amino acid were observed including histological studies of gonad and mantle tissue upon treatment with tannery effluents. To examine potential DNA damage due to the exposure of the effluent, comet assay was conducted.The study revealed that with an exposure to the untreated effluent, activity of the antioxidant enzymes increased significantly while the protein and carbohydrate content reduced largely in the whole body tissue, gonad as well as mantle tissues of P. globosa. Histological study indicated considerable damage in the gonad and mantle tissues following exposure to the untreated effluent. Comet assay using hemolymph of P. globosa following exposure to tannery effluent, showed significant genotoxicity.Interestingly, compared to the untreated effluent, damaging effect was reduced in molluscs tissues when exposed to MF treated effluent and even lesser when exposed to MF+RO treated effluent. Apart from the reduced activities of oxidative stress enzymes, the protein, amino acid and carbohydrate content of molluscs exposed to both of the treated effluent were found close to that of control. Comet assay revealed no damage in the DNA for MF and MF+RO treated effluent indicating that the membrane based treatment procedure restores environmental condition to control level.

Treatment of cosmetic effluent in different configurations of ceramic UF membrane based bioreactor: Toxicity evaluation of the untreated and treated wastewater using catfish (Heteropneustes fossilis).

Extensive usage of pharmaceutical and personal care products (PPCPs) and their discharge through domestic sewage have been recently recognized as a new generation environmental concern which deserves more scientific attention over the classical environmental pollutants. The major issues of this type of effluent addressed in this study were its colour, triclosan and anionic surfactant (SDS) content. Samples of cosmetic effluent were collected from different beauty treatment salons and spas in and around Kolkata, India and treated in bioreactors containing a bacterial consortium isolated from activated sludge samples collected from a common effluent treatment plant. Members of the consortium were isolated and identified as Klebsiella sp., Pseudomonas sp., Salmonella sp. and Comamonas sp. The biotreated effluent was subjected to ultrafiltration (UF) involving indigenously prepared ceramic membranes in both side-stream and submerged mode. Analysis of the MBR treated effluent revealed 99.22%, 98.56% and 99.74% removal of colour, triclosan and surfactant respectively. Investigation of probable acute and chronic cyto-genotoxic potential of the untreated and treated effluents along with their possible participation in triggering oxidative stress was carried out with Heteropneustes fossilis (Bloch). Comet formation recorded in both liver and gill cells and micronucleus count in peripheral erythrocytes of individuals exposed to untreated effluent increased with duration of exposure and was significantly higher than those treated with UF permeates which in turn neared control levels. Results of this study revealed successful application of the isolated bacterial consortium in MBR process for efficient detoxification of cosmetic effluent thereby conferring the same suitable for discharge and/or reuse.