A novel method to harvest Chlorella sp. via low cost bioflocculant: Influence of temperature with kinetic and thermodynamic functions

Richa Kothari; Vinayak V Pathak; Arya Pandey; Shamshad Ahmad; Chandni Srivastava; V V Tyagi

doi:10.1016/j.biortech.2016.11.050

A novel method to harvest Chlorella sp. via low cost bioflocculant: Influence of temperature with kinetic and thermodynamic functions

Bioresour Technol. 2017 Feb:225:84-89. doi: 10.1016/j.biortech.2016.11.050. Epub 2016 Nov 15.

Authors

Richa Kothari¹, Vinayak V Pathak², Arya Pandey², Shamshad Ahmad², Chandni Srivastava², V V Tyagi³

Affiliations

¹ Bioenergy and Wastewater Treatment Laboratory, Department of Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow (U.P.), India. Electronic address: kothariricha21@gmail.com.
² Bioenergy and Wastewater Treatment Laboratory, Department of Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow (U.P.), India.
³ Department of Energy Management, Shri Mata Vaishno Devi University, Katra (J&K), India.

PMID: 27886633
DOI: 10.1016/j.biortech.2016.11.050

Abstract

In this study, harvesting efficiency (HE) of bioflocculant (egg shell) was observed with variation in flocculent concentrations (0-100mgL^-1), temperature (30°C, 35°C 40°C, 45°C and 50°C) and variable contact time (0-50min). It was found maximum (≈95.6%) with 100mgL^-1 bioflocculant concentration whereas influence of temperature was also observed with optimized concentration of bioflocculant (100mgL^-1) at 40°C (≈98.1%) and 50°C (≈99.3%), in 30min of contact time. Significant changes in algal cell structures were also analyzed after exposure to various temperatures with microscopy, SEM (Scanning electron microscopy) and EDS (Energy dispersive X-ray spectroscopy) images with and without bioflocculant. The experimental data was found to be a good fit with pseudo-second order kinetic model. The thermodynamic functions such as ΔG (Gibbs free energy), ΔH (enthalpy), ΔS (entropy) were also determined. The negative value of ΔG and positive value of ΔH and ΔS shows the spontaneous and endothermic nature of flocculation process.

Keywords: Bioflocculant; Biomass harvesting; Kinetic models; Low-cost; Thermodynamic functions.

MeSH terms

Biotechnology / economics
Biotechnology / methods*
Chlorella / chemistry*
Chlorella / cytology
Chlorella / growth & development
Costs and Cost Analysis
Entropy
Flocculation
Kinetics
Microscopy, Electron, Scanning
Spectrometry, X-Ray Emission
Temperature
Thermodynamics