An investigation on removal of ciprofloxacin and norfloxacin by phycoremediation with an emphasis on acute toxicity and biochemical composition.

Ciprofloxacin (CIP) and norfloxacin (NOR) belong to the class of emerging contaminants that are frequently detected in the aquatic environment as a binary mixture, responsible for the development of antibiotic-resistant genes and antibiotic-resistant bacteria. This study aims to investigate five different algal species Chlorella vulgaris (Cv), Chlorella pyrenoidosa (Cp), Scenedesmus obliquus (So), Tetradesmus sp (T) and Monoraphidium sp (M) for their tolerance and removal of binary mixture. The effects on biochemical composition in the algal species concerning the binary mixture and its removal efficiency are first reported in this study. The acute toxicity (96 h EC50) values are in the order of So > Cp > T > M > Cv, Chlorella vulgaris is the most sensitive algal species with 17.73 ± 0.24 mg/L and Scenedesmus obliquus is the least sensitive algal species with 39.19 ± 0.79 mg/L. The removal efficiency of the binary mixture was found to be in the order of So > Cp > T > M > Cv, Scenedesmus obliquus removed CIP (52.4%) and NOR (87.5%) with biodegradation as the major contributing removal mechanism. Furthermore, less toxic biotransformed products were detected in Scenedesmus obliquus and the biochemical characterization revealed that the growth-stimulating effect is higher with lipid (35%), carbohydrate (18%), and protein (33%) providing an advantage in the production of valuable biomass.

A pilot-scale study on the removal of binary mixture (ciprofloxacin and norfloxacin) by Scenedesmus obliquus: Optimization, biotransformation, and biofuel profile.

Ciprofloxacin (CIP) and norfloxacin (NOR) belong to the organic contaminants of emerging concern (OCECs) that are frequently detected in wastewater matrices at ng/L to mg/L concentrations. This study investigates the potential of Scenedesmus obliquus in the treatment of CIP and NOR as a binary mixture from raw wastewater. Optimization of inoculum was done to find the required cell density concentration that has less inhibition and high removal. The optimum inoculum (cell density: 200 × 105 cells/mL and OD680: 1.0) has shown 75% removal with no inhibition of growth. A pilot scale study was conducted in controlled environment using high-rate algal pond to investigate the contribution of abiotic and biotic removal. Abiotic removal is negligible in comparison with the biotic contribution of removal. The order of removal efficiency is observed as COD (88%) > NOR (84.8%) > CIP (84.6%) > NH4+ (71.7%) with biodegradation as the major removal mechanism. Biotransformed products of CIP + NOR were identified inside the Scenedesmus obliquus. During the pilot-scale study, Biomass (3.70 ± 0.07 g/L) was harvested with carbohydrates (17.85 ± 0.1%), lipids (38.36 ± 0.13%), and proteins (28.18 ± 1.63%). Lipid productivity in binary mixture was 2.6 times higher than the lipid production in control condition. Transesterification of these lipids yielded good biofuel composition of 32.72% of saturated fatty acids and 21.7% of unsaturated fatty acids.

Treatment algorithm for post sternotomy wound infection - our experience.

INTRODUCTION: Median sternotomy is the most commonly used approach in open cardiac surgery. As in any other surgery, surgical site infections are a known phenomenon, but morbidity depends on the depth of infection. Superficial wound infections can be managed conservatively; however, deep sternal wound infections need an aggressive approach to prevent disastrous consequence like mediastinitis. Hence, this study was conducted with the aim to classify sternotomy wound infection and to develop a treatment algorithm for superficial and deep sternotomy wound infections. MATERIAL AND METHODS: Between January 2016 to August 2021, 25 patients who had sternotomy wound infections were studied. These wound infections were classified as superficial or deep sternal wound infections. RESULTS: Superficial wound infections underwent treatment with diluted vinegar dressings and deep infections underwent treatment with bilateral pectoralis major muscle advancement flaps. Patients were followed up till the wounds healed completely without complications. Patient characteristics, comorbidities, duration of treatment and outcomes of treatment were analyzed. Superficial sternal wound infection patients responded favorably to diluted vinegar dressings and deep sternal wound infection patients to pectoralis major muscle advancement flaps. Average time duration of healing for superficial and deep wound infections was 66.2 days and 18 days respectively. None of the patients had an increased severity of infection or re-dehiscence following treatment and during follow-up. CONCLUSION: Relatively conservative approach using diluted vinegar (1% acetic acid) dressing for superficial sternal wound infections was efficacious, whereas aggressive debridement and bilateral pectoralis major advancement muscle flaps for deep sternal wound infections are necessary for favorable outcomes. However, more studies are needed to ascertain this treatment algorithm.

Zero waste discharge in tannery industries - An achievable reality? A recent review.

In the recent times, more attention is on industrial waste management due to the unaffordable space for dump yards and landfills and the increased charges for waste dumping. Even though the vegan revolution and plant-based meat products are booming, the traditional slaughterhouses and the wastes produced by them continue to be a concern. Waste valorisation is an established procedure striving to create a closed chain process in industries where there is no refuse. Although a highly polluting industry, slaughterhouse industry wastes have been recycled to economically viable leather since ancient times. However, the tannery industry is causing pollution in par with or even more than the slaughterhouses. Effective management of the liquid and solid wastes from the tannery is of utmost concern because of its toxicity. The hazardous wastes generated enter the food chain, causing long term impacts in the ecosystem. Several leather waste transformation processes are widely used in the industries, and they are yielding good products of economic value. However careful exploration into the processes and products of waste valorisation are often ignored as long as the transformed waste product is of higher value than the waste. The most efficient and environmentally friendly waste management technique should convert the refuse into a value-added utilization without any toxic leftovers. Zero waste concept is an extension of the zero liquid discharge concept, where the solid waste is also treated and reused to such an extent that there is no residue to be sent to the landfill. This review initially presents the existing methods for the de-toxification of tannery wastes and examines the possibility of solid waste management within the tannery industry to attain zero waste discharge.

A pilot-scale study of the integrated phycoremediation-photolytic ozonation based municipal solid waste leachate treatment process.

Municipal solid waste (MSW) leachate is a highly polluted liquid that accumulates in the landfill and contains a high concentration of toxic pollutants which can pollute the surrounding surface water and groundwater as well, if not treated properly. In this study, an integrated approach of phycoremediation with photolytic ozonation was employed for the leachate collected from the MSW dumpsite which has high Chemical Oxygen Demand (COD) and ammonium (NH4+) levels. Photolytic ozonation treatment was employed as a pre-treatment step under operating parameters of pH: 9.0; Ozone dosage: 5 g/h; UV-C: λ = 254 nm; and contact time: 60 min, in which the COD and NH4+ in the leachate was reduced up to 81% and 95%, respectively. The selected algae Chlorella vulgaris (C.vulgaris) was employed in a lab-scale study to optimize the inoculum conditions in the photolytic ozonated leachate (POL). The specific growth rate of C.vulgaris was observed as 0.14/d in the POL at the optimized condition (inoculum size of 25% (T25)) during the study period of 11 days. High-rate algal pond (HRAP) was employed for the pilot-scale study in controlled environmental conditions as in the T25 experimental run for the assessment of POL treatment and biomass production. C.vulgaris reduced the concentration of pollutants COD, NH4+, and heavy metals (Cu, Fe) in the POL up to 93%, 94%, and 71%, respectively, with the dry biomass productivity of 0.727 g/L/d which is 3 times higher than the biomass productivity of C.vulgaris in freshwater conditions. The biochemical composition (carbohydrates, proteins, and lipids) of the harvested biomass has higher lipid production with lipid productivity of 120 mg/L/d which can be used as a feedstock for the production of value-a dded products.

Efficacy of pedicled anterolateral thigh flap for reconstruction of regional defects - a record analysis.

BACKGROUND: The anterolateral thigh (ALT) flap was described as the fasciocutaneous flap. It can be harvested as a pedicled and/or free flap. Majority of the free flaps are harvested as a fasciocutaneous flap. Their use in head and neck reconstruction and limb trauma is well established. Apart from these advantages, this flap has various applications which are less utilized. ALT flap can be used as a myocutaneous flap along with vastus lateralis muscle. When muscle and fasciocutaneous flaps are required, both can be harvested as a chimeric flap which can cover two different regions of the wound. Moreover, harvest of the pedicled flap procedure is less time-consuming than that of a free flap. Since it has a long vascular pedicle, when used as pedicled flap, it can reach up to the gluteal region. To evaluate these less applied advantages of pedicled ALT flap, our study was undertaken. This study aimed to evaluate the efficiency of ALT flap in terms of the surface area of coverage, arc of rotation and the advantages of including vastus lateralis muscle as part of the flap. METHODS: A retrospective record analysis of all pedicled ALT flap reconstruction of trochanteric, upper thigh, gluteal and flank regions from 2016 to 2018 was undertaken; 7 patients with 8 defects were included. RESULTS: All the flaps healed successfully. There was no major necrosis of the flap and minor complications like wound gapping were found in three patients. CONCLUSION: The ALT-vastus lateralis flap dimensions can be very large and can be easily harvested in a very short time. Vastus lateralis muscle harvested can be used to fill the defect or can be used as chimera to cover the defect. The use of muscle over long standing infective pressure sores can sterilize the wound bed and help in preventing recurrence. The vascularity of this flap is robust and highly reliable. Even after a maximum arc of rotation (up to 170°) all the flaps survived without any major complications.

Phycoremediation integrated approach for the removal of pharmaceuticals and personal care products from wastewater - A review.

Pharmaceuticals and personal care products (PPCPs) are of emerging concerns because of their large usage, persistent nature which promised their continuous disposal into the environment, as these pollutants are stable enough to pass through wastewater treatment plants causing hazardous effects on all the organisms through bioaccumulation, biomagnification, and bioconcentration. The available technologies are not capable of eliminating all the PPCPs along with their degraded products but phycoremediation has the advantage over these technologies by biodegrading the pollutants without developing resistant genes. Even though phycoremediation has many advantages, industries have found difficulty in adapting this technology as a single-stage treatment process. To overcome these drawbacks recent research studies have focused on developing technology that integrated phycoremediation with the commonly employed treatment processes that are in operation for treating the PPCPs effectively. This review paper focuses on such research approaches that focused on integrating phycoremediation with other technologies such as activated sludge process (ASP), advanced oxidation process (AOP), Up-flow anaerobic sludge blanket reactor (UASBR), UV irradiation, and constructed wetland (CW) with the advantages and limitations of each integration processes. Furthermore, augmenting phycoremediation by co-metabolic mechanism with the addition of sodium chloride, sodium acetate, and glucose for the removal of PPCPs has been highlighted in this review paper.

Moriarty's sign - predictor of skin graft take.

BACKGROUND: Resurfacing wound beds with split skin graft is the most common procedure in plastic surgery. Association of more pain in the donor site than in the recipient site has been used as a predictor of successful graft take by Stark in 1962 who termed it Moriartys sign. PURPOSE: The aim of the study was: 1) to predict the successful take of skin graft by eliciting Moriartys sign; 2) to decide the day of first graft inspection based on Moriartys sign. METHODS: The authors hereby present a prospective study in 100 patients who underwent wound resurfacing with split thickness skin graft at the Department of Plastic Surgery in a tertiary care center between January 2014 and June 2015. The area with more pain, absence of pain or equivocal response at the graft donor site was recorded on the visual analog scale for 10 days. RESULTS: In this study, 80 patients had positive Moriartys sign, 12 patients had equivocal responses and 8 patients showed a negative sign. Patients with positive Moriartys sign underwent their first graft inspection on 10th postoperative day and showed 100% graft take. Twelve patients with equivocal response underwent first graft inspection on 5th day and had 70-80% graft take.  In 8 patients, with negative Moriartys sign first graft inspection done on 3rd day, the graft take was < 50%. CONCLUSION: The study demonstrates that Moriartys sign is a reliable clinical predictor of split thickness skin graft take and may be useful as a guide to determine the day of first graft inspection. It is an effective method even for junior members of the surgical and nursing team to monitor parameters in relation to this sign. It can be practiced in a smaller group of hospitals, too. Hence, the authors recommend to integrate this clinical assessment in routine practice.

Effect of culture conditions on biomass yield of acclimatized microalgae in ozone pre-treated tannery effluent: A simultaneous exploration of bioremediation and lipid accumulation potential.

Microalgae has huge potential towards biological nutrient removal, but the challenges are remains in maximizing the biomass yield and so nutrient/pollutant removal efficiency. In this study, a response surface methodology-central composite design was applied to investigate the significant process variables (temperature, light intensity, inoculum density and light period) and its interaction effect on biomass yield of effluent acclimatized microalgae Nannochloropsis oculata, Chlorella vulgaris and Chlorella sorokiniana in ozone pre-treated tannery effluent (OPTE). At optimum culture condition N. oculata, C. vulgaris, and C. sorokiniana have yielded 0.67 g/L, 0.85 g/L, and 1.06 g/L biomass. Besides, correlation and regression analysis revealed the strong correlation between microalgal growth and nutrient removal rate. Among the species, C. sorokiniana has shown better remediation potential, at 27.5 °C, 150 µmol m-2 s-1 light intensity, 30% (v/v) inoculum, 16 h light period with the specific growth rate of 0.559 day-1 and nutrient/pollutant removal efficiency of 90% C, 90% N, 100% P, 82% COD, and 100% chromium. But, N. oculata has revealed the better lipid accumulation potential (40%) in OPTE. Thus, the present study established the appropriate strains and conditions required for OPTE treatment along with the value-added biomass production in large scale.

Biodegradable and non-biodegradable fraction of municipal solid waste for multifaceted applications through a closed loop integrated refinery platform: Paving a path towards circular economy.

An increase in population, rapid urbanization and industrialization has accelerated the rate of municipal solid waste generation. The current disposal of solid waste is a burgeoning issue and it's in immediate need to shift the existing disposal processes to a sustainable manner. Circular economy (CE) is a conceptual model which is been used for better use of resources and minimization of waste in a closed loop approach which could be appropriate for waste management. In this context, the present review illustrates the effective use of biodegradable and non-biodegradable fraction of solid waste in a closed loop integrated refinery platforms for the recovery of bioenergy resources and for the production of value added products. The biodegradable fraction of solid waste could be treated by advanced biological processes with the simultaneous production of bioenergy such as biohydrogen, biomethane, bioelectricity, etc., and other value added products like butanol, ethanol, methanol etc. The scheme illustrates the closed loop approach, the bioenergy generated from the biodegradable fraction of solid waste could be used for the operation of internal combustion engines and the energy could be further used for processing the waste. The non-biodegradable fraction of solid waste could be used for construction and pavement processes. Overall the study emphasizes the paradigm shift of solid waste management concepts from linear economy to a circular economy following the "Zero Waste" concept. The study also explains the circular economy policies practiced for solid waste management that stimulates the economy of the country and identify the pathways to maximize the local resources. In addition the review addresses the advanced information and communication technologies to unfold the issues and challenges faced in the solid waste management. The smart governance of managing waste using the "Internet of Things" (IoT) is one of the great precursors of technological development that could lead innovations in waste management.

An integrated approach for tannery effluent treatment with ozonation and phycoremediation: A feasibility study.

For the exploration of an effective and economical method to treat composite raw tannery effluent, the integrated approach of Ozonation and phycoremediation was followed. In a lab-scale Ozone reactor, the highest performance index was attained, when it was operated at a low O3 flowrate (2 g/h) condition. The tannery effluent partially treated by Ozonation (≈60% COD removed in 90 min) with the ozone consumption of 1.5 g of O3/g of COD, at pH 7.6, coupled with phycoremediation had improved the tannery effluent characteristics to a considerable extent. Overall, the maximum reduction in pollutant concentration attained with the combined treatment was 84% for COD, 60% for colour, 100% for odour, 90% for inorganic carbon, 82% for NH4+- N, 100% for PO4-P, 97% for chromium and 10% for TDS. In phycoremediation, microalgae Nannochloropsis oculata had shown an enhanced growth (µ = 0.255 day-1) with a maximum cell density of 5.2 × 107 cells/mL, dry biomass of 0.86 g L-1 and cell division rate of 0.369 day-1. Elemental analysis of biomass validated the chromium remediation along with other elements such as calcium, magnesium, sodium, potassium, zinc, and iron from the tannery effluent. Therefore, the phycoremediation integrated ozone process can be considered as a feasible treatment method for tannery effluent along with value-added biomass production.

Insights on the current status of occurrence and removal of antibiotics in wastewater by advanced oxidation processes.

Antibiotics are considered as the significant group of pharmaceuticals which causes a serious hazard to the environment and human health in recent years. Due to the inefficient treatment technologies, conventional wastewater treatment plants (WWTPs) are unable to remove many antibiotics from wastewater. This review encapsulates the current status of antibiotics occurrence in influent and effluent of WWTPs globally. Specifically, ß-lactams, fluoroquinolones, macrolides, sulfonamides, tetracyclines classes of antibiotics are found to be high in wastewater. An overview of physicochemical properties, generation classifications of antibiotics, and different advanced oxidation processes (AOPs) available for the removal of emerging pollutants are presented. Besides, the removal efficiency of diverse antibiotics by various AOPs are discussed. The combination such as UV/H2O2, UV/H2O2/Fe2+ and ozonation are reported for maximum removal of antibiotics. However, when compared to simulated wastewater, limitations are persisted for the removal of antibiotics in real wastewater, owing to its difficulty in assessing and observing the compound under mixed nature. AOPs assisted degradation mechanism for ciprofloxacin antibiotic in wastewater is presented and the necessity of research on antibiotic removal is highlighted.

Phycoremediation of paddy-soaked wastewater by indigenous microalgae in open and closed culture system.

Phycoremediation; biotransformation of nutrients and or pollutants by microalgae, supports sustainable wastewater treatment, coupled with biomass production, resulting in enhanced cost savings, waste minimization, and energy conservation. A major challenge in this technique involves cultivation system to be adopted, mode of treatment and harvesting methods. Three different algal cultivation systems; polybags (PB), photobioreactors (PBR) and race way ponds (RWP) were employed for culturing an indigenous microalga, Scenedesmus obliquus in rice mill paddy-soaked wastewater (PSW). The maximum biomass productivity (BP) of 340 ±â€¯2 mg/L/d was observed in PBR with an ammonical nitrogen (NH3-N) removal (RN) of 96.12 ±â€¯0.21% and the phosphates (PO4-P) removal (RP) of 97.58 ±â€¯0.18%. Highest lipids (L)∼12% (% biomass), protein (P)∼40% and carbohydrates (C)∼20%) were gained in PBR culture system, followed by RWP and PB.

Green microalgae for combined sewage and tannery effluent treatment: Performance and lipid accumulation potential.

Microalgae have considerable interest owing to its phycoremediation potential and raw material for sustainable biofuel production. In this study, the performance of green algae Chlorella vulgaris (NRMCF0128) and Pseudochlorella pringsheimii (VIT_SDSS) was evaluated for the remediation of combined sewage and tannery effluent under different dilutions. Significant reduction in pollutant concentration was observed in the effluent: >65% for NH3-N, 100% for PO4-P, >63% for COD & >80% for total chromium, at higher dilutions (up to 30%) of tannery effluent (T) for both species. EDAX analysis confirms the intracellular accumulation of heavy metal chromium and other elements such as aluminum, zinc, and iron by both microalgae. In addition, the maximum yield of biomass achieved was 3.51 g/L (for 30% Tannery effluent) and 2.84 g/L (for 20% Tannery effluent) for Chlorella vulgaris &Pseudochlorella pringsheimii, respectively. Between the two species, Pseudochlorella pringsheimii has shown high lipid accumulation potential of 25.4% compared to Chlorella vulgaris (9.3%) at 20% Tannery effluent. Hence, it is evident that the green microalgae Pseudochlorella pringsheimii is promising for the sustainable treatment of combined sewage and tannery effluent along with biofuel production.

Ni2+ and Co2+ adsorption using Tectona grandis biochar: kinetics, equilibrium and desorption studies.

In this research, the potential of a relatively new adsorbent prepared from Tectona grandis leaves by pyrolysis for heavy metal removal from aqueous solution was studied. Adsorption behavior of the pyrolytic biochar was investigated with respect to Ni2+ and Co2+ removal with its affinity examined through batch studies and the mechanism elucidated using different empirical isotherm and kinetic models. A significantly higher efficiency of 92.46% and 91.21% was achieved at a weakly acidic pH of 6 and 5, dose of 3 g L-1 and 2 g L-1 for Ni2+ and Co2+ removal, respectively. Pseudo-second-order kinetics and Langmuir isotherm model best represented the adsorption process for both Ni2+ and Co2+. Thermodynamic analysis proved the endothermic and spontaneous nature of the process. Desorption studies revealed hydrochloric acid to have a high potential toward eluting the adsorbed metal ions. The well-organized microporous structure, the significant surface area value along with the presence of relative functional groups together with its high adsorption capacity for Ni2+ and Co2+, revealed the significant adsorptive potential of biochar of teak leaves powder for metal ion removal.

Continuous biosorption of nickel from aqueous solution using Chrysanthemum indicum derived biochar in a fixed-bed column.

The biosorption capability of Chrysanthemum indicum to remove nickel ions from aqueous solution in a fixed-bed column was examined in this study. Native C. indicum flower waste was improved for its biosorptive potential by pyrolysis to obtain its biochar form and, thereby, both raw (CIF-R) and biochar (CIF-BC) forms of the flower were used for Ni(II) removal. Fixed bed column studies were conducted to examine the influence of bed height (1.0-3.0 cm), flow rate (1.0-5.0 mL min-1) and initial metal ion concentration (25-75 mg L-1). The breakthrough curves (Cout/Cin vs time) were modelled using different dynamic adsorption models, viz. Adams-Bohart, Thomas and Yoon-Nelson model. Interpretation of the data revealed a favorable correlation with the Thomas model with higher R2 values and closer model-predicted and experimental biosorption capacity values. The equilibrium uptake capacity of CIF-R and CIF-BC for Ni(II) were found to be 14.02 and 29.44 mg g-1, respectively. Further, the column was regenerated using HCl as eluent, to desorb the adsorbed Ni(II) ions. The experimental results implied and affirmed the suitability of the biosorbents for nickel ion biosorption with its nature being favorable, efficient, and environmentally friendly.

Ni (II) adsorption onto Chrysanthemum indicum: Influencing factors, isotherms, kinetics, and thermodynamics.

The study explores the adsorption potential of Chrysanthemum indicum biomass for nickel ion removal from aqueous solution. C. indicum flowers in raw (CIF-I) and biochar (CIF-II) forms were used as adsorbents in this study. Batch experiments were conducted to ascertain the optimum conditions of solution pH, adsorbent dosage, contact time, and temperature for varying initial Ni(II) ion concentrations. Surface area, surface morphology, and functionality of the adsorbents were characterized by Brunauer, Emmett, and Teller (BET) surface analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). Adsorption kinetics were modeled using pseudo-first order, pseudo-second order, Elovich, intraparticle diffusion, Bangham's, and Boyd's plot. The equilibrium data were modeled using Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) isotherm models. Experimental data provided the best fit to pseudo-second-order kinetic model and Langmuir isotherm model for the adsorption of Ni(II) ion on both CIF-I and CIF-II with maximum adsorption capacities of 23.97 and 44.02 mg g(-1), respectively. Thermodynamic analysis of the data proved the process to be spontaneous and endothermic in nature. Desorption studies were conducted to evaluate the possibility of reusing the adsorbents. Findings of the present study provide substantial evidence for the use of C. indicum flower as an eco-friendly and potential adsorbent for the removal of Ni(II) ions from aqueous solution.

Adsorption capacity of Curcuma longa for the removal of basic green 1 dye--equilibrium, kinetics and thermodynamic study.

In the present study, Curcuma longa (turmeric plant) was used as an adsorbent to remove Basic Green 1 (BG) dye. Batch study was carried out to evaluate the adsorption potential of C. longa and influencing factors such as pH (4-10), adsorbent dose (0.2-5 g l-1), initial dye concentration (50-250 mg l-1) and temperature (30-50°C) on dye removal were analysed. The characterisation of adsorbent was carried out using fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Brunauer, Emmett and Teller (BET) method. Isotherm models that included Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich, and kinetic models such as pseudo first order, pseudo second-order, Elovich and intraparticle diffusion models were studied. A maximum removal percentage (82.76%) of BG dye from aqueous solution was obtained with optimum conditions of pH 7, 1g l-1 adsorbent dose and 30°C temperature, for 100 mg l-1 initial dye concentration. The equilibrium and kinetic study revealed that the experimental data fitted suitably the Freundlich isotherm and Pseudo second order kinetic model. Thermodynamic analysis proved that adsorption system in this study was spontaneous, feasible and endothermic in nature.

Evaluation of photosynthetic efficacy and CO2 removal of microalgae grown in an enriched bicarbonate medium.

Bicarbonate species in the aqueous phase is the primary source for CO2 for the growth of microalgae. The potential of carbon dioxide (CO2) fixation by Chlorella pyrenoidosa in enriched bicarbonate medium was evaluated. In the present study, effects of parameters such as pH, sodium bicarbonate concentration and inoculum size were assessed for the removal of CO2 by C. pyrenoidosa under mixotrophic condition. Central composite design tool from response surface methodology was used to validate statistical methods in order to study the influence of these parameters. The obtained results reveal that the maximum removal of CO2 was attained at pH 8 with sodium bicarbonate concentration of 3.33 g/l, and inoculum size of 30 %. The experimental results were statistically significant with R 2 value of 0.9527 and 0.960 for CO2 removal and accumulation of chlorophyll content, respectively. Among the various interactions, interactive effects between the parameters pH and inoculum size was statistically significant (P < 0.05) for CO2 removal and chlorophyll accumulation. Based on the studies, the application of C. pyrenoidosa as a potential source for carbon dioxide removal at alkaline pH from bicarbonate source is highlighted.