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CHAPTER 8

Phenolic Wastewater Treatment:

Development and Applications of

New Adsorbent Materials

1
Laxmi Gayatri Sorokhaibam , M. Ahmaruzzaman 2
1
Chemical Engineering & Process Development Division, CSIR-National Chemical Laboratory, Pune, India
2
Department of Chemistry, National Institute of Technology, Silchar, India
8.1 INTRODUCTION

The principal objective of wastewater treatment has conventionally been
to dispose of industrial effluents without danger to human health or the envi-
ronment. There are a number of technologies already in place—both in
terms of physicochemical and biological processes for the treatment of var-
ious types of wastewaters—that have been discussed at length in this book.
However, it is evident that many of these conventional technologies have
limitations in terms of overall process economics; therefore, it becomes
imperative to devise solutions that are cost effective without compromising
process effectiveness. It is expected that the development of newer forms of
less expensive adsorbent materials, e.g., those derived from biomass, may
have potential to fulfill this objective. Such cost-effective alternatives would
enhance treatment abilities, especially for developing countries.
Typical physical characteristics of wastewater are gray color, stale odor, a
solids content of 0.1%, and 99.9% water content. The chemical composition
of wastewater consists of various organic and inorganic compounds as well as
numerous dissolved gases. There are a number of conventional and noncon-
ventional pollutants present in domestic and industrial wastewaters, and
these have been discussed in detail in Chapters 1 and 2. One particular class
of organic compounds that is of major concern in industrial wastewater
treatment due to its toxicity and hazardous nature is phenol and phenolic
compounds. They are hydroxyl derivatives of benzene that may occur in
domestic and industrial wastewaters. It is desirable to recover these chemicals
prior to discharge of waters. In any case, they have to be effectively removed
prior to discharge in order to prevent environmental pollution. The limit for
phenol in wastewaters for discharge is typically 0.1 mg L 1 (USEPA, 1985),

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