BioChar

Applications for Bioremediation of Contaminated Systems

Riti Thapar Kapoor, Maulin P. Shah, Riti Thapar Kapoor, Maulin P. Shah

• Éditeur: De Gruyter
• Année: 2022
• ISBN:
  9783110734065
• Édition: 1
• Sujet: Physical Sciences
• Sous-sujet: Chemistry

This book explores the production and applications of biochar. This material is used to remove contaminants from industrial effluent and to reutilize waste sludge in the production of biofuel/bioenergy. The treatment of wastewater and reuse of waste sludge in value added products manufacturing and environmental clean-up is explored. This book provides a roadmap for future strategies for pollution abatement and sustainable development.

Biochar as a remediation solution for pharmaceutical-contaminated wastewater

Wan Ting Tee

Billie Yan Zhang Hiew

Suchithra Thangalazhy-Gopakumar

Suyin Gan

Lai Yee Lee

Abstract

Water pollution caused by the discharge of pharmaceutical residues is a relatively recent environmental issue affecting clean water supply. The worldwide consumption of pharmaceutical products is continually increasing at rapid speed; hence, there is a need to control their concentration in the water resources. Recently, biochar has attracted significant exploration in wastewater treatment due to its abundant availability, facile production, and cost-effectiveness. Additionally, biochar has demonstrated great potential in removing pharmaceutical contaminants from water bodies indicating that it can be an effective, economical, and environmentally friendly resource for wastewater treatment. In this chapter, the main pollution point sources of pharmaceutical compounds are first discussed. Five most prevalent compounds in the current environment classified based on their therapeutic classes are evaluated along with their associated adverse health and environmental effects. The advantages and disadvantages of conventional and advanced removal technologies for pharmaceutical contaminants from the aquatic system are assessed. The chapter further reviews the synthesis methods of biochar as well as the mechanisms involved in the adsorption of pharmaceuticals, in detail. The current and future prospects of biochar in pharmaceuticals removal are also discussed in the context of biochar feasibility and challenges encountered.

Keywords: Adsorption, biochar, biomass, pharmaceutical, pyrolysis, wastewater,

1 Introduction

Industrialization has played a prominent role in the growth of global economy for the past few decades. Pharmaceutical industries in particular have contributed intensely to this development with an estimated annual production exceeding 20 million tons [1]. The production of pharmaceutical compounds is increasing exponentially to meet the growing demands for prevention and treatment of illnesses, and in sustaining the expansion of agricultural and aquacultural industries. Pharmaceutical products are commonly used in medical facilities, animal husbandry, drugs-manufacturing industries, aquafarming, and daily human life. The extensive utilization of pharmaceuticals worldwide, combined with inappropriate disposal methods as well as ineffective removal in existing wastewater treatment plants, have resulted in their existence in aquatic ecosystems [2].

The advancement of technology, especially in analytical measurement tools, has enabled the detection of pharmaceutical contaminants in aquatic environment, which are in trace concentrations, from nanograms per liter to micrograms per liter. In order to obtain an accurate detection of pharmaceutical samples in complex environment matrices, precise sample preparation and sensitive detection tools are required. Liquid or gas chromatography coupled with mass spectrometer provides the desired method to determine the pharmaceutical concentrations in aqueous systems. The evolution in measurement techniques further escalated the discovery of the ubiquitous presence of synthetic pharmaceuticals in marine life, thereby attracting attention of researchers from various fields to delve deeper into this issue.

The health and environmental impacts of pharmaceutical residues have become a major concern due to their presence in water sources, which eventually accumulate in human bodies through drinking water and food chain cycle. Pharmaceutical products are categorized into 24 therapeutic classes, whereby nonsteroidal anti-inflammatory drugs (NSAIDs), anticonvulsants, antibiotics, and lipid regulators are the four major classes reported in literature [3]. Pharmaceuticals are persistent and able to bioaccumulate in the environment due to their complex physicochemical properties. They cause detrimental effects on terrestrial and aquatic life such as extinction of species, delayed egg hatching, and reduction in reproduction rate [4, 5].

Several studies investigated the pathways of pharmaceutical pollutants to the ecosystem. Mompelat and Le Bot [3] explored the origins and routes of a variety of pharmaceutical residues. Households and non-domestic points such as hospitals, industries, and services are the major sources associated with the excretion from human beings and the improper disposal of drugs. The chemical compounds discharged from these point sources are usually directed to wastewater purification facilities and eventually released to the environment owing to the incapability of current removal technologies. Moreover, some countries discharged untreated waste streams to the water bodies directly, thus resulting in severe pollution issues [6, 7]. Other than that, animal farming and aquaculture are responsible for the direct discharge of pharmaceutical loaded waste. Landfills containing pharmaceutical waste materials from households and medical facilities can produce leachate, which may seep through soil into the groundwater. Hence, effective wastewater treatment is essential to prevent the pharmaceutical residues from impacting living organisms.

Current wastewater purification technologies are ineffective in eliminating the pharmaceutical residues. This deficiency has motivated researchers to investigate and develop advanced technologies to tackle this concerning issue. Among the investigated methods, adsorption using biochar is a promising alternative for the removal of pharmaceutical residues. Adsorption is a relatively simple and cost-effective process, while biochar is a relatively new adsorbent, thermochemically transformed from organic and inorganic wastes. The numerous microporous structures and great surface area allows the adsorption of pharmaceutical contaminants even at very low concentrations. The aim of this chapter is to provide a state-of-the-art review of this viable adsorbent in the removal of pharmaceutical contaminants from aqueous phase. The challenges and future prospects of biochar adsorption are included to address the current development and possible improvement of biochar to maximize its potential in the field of pharmaceuticals removal.

2 Background

The discovery of pharmaceuticals in the environment through published ar...