Page 375 - Industrial Wastewater Treatment, Recycling and Reuse

Phenolic Wastewater Treatment: Development and Applications of New Adsorbent Materials 347

Table 8.4 Macro- and microanalysis data for BP
Macroanalysis data (%) Microanalysis data (%)

Moisture content 3.31 C 42.60
Ash content 50.24 H 6.56
Volatile matter 40.82 N 1.58
Fixed carbon 5.63

In the adsorptive removal of 4-NP by ATW, the COD/BOD 5 ratio was
found to be 28.24, which indicates the nonbiodegradable nature of the waste.
1
The synthetic stock solution had an initial BOD value of 203.70 mg L ,
1
which decreased to 10.20 mg L after treatment with ATW indicating
95% BOD removal. The reduction in these values indicates the effective-
ness of the treatment technique. The initial COD was found to be
1
288 mg L , while the final COD was found to be 128 mg L 1 with %
COD removal of 55.55%. AES showed a very low content of C, H, and
N, explaining its low adsorptivity. The %C, %H, and %N content were
8.18, 0.12, and 0.94, respectively.

8.4 SINGLE-SOLUTE ADSORPTION STUDIES:
PERFORMANCE AND EVALUATION

A synthetic solution of phenol-containing wastewater was prepared. The
performance of some potential adsorbents such as BP, TW, ATW, AES,
and BMO were evaluated, compared with JSC (jute stick char), PPC (potato
peel char), AAJSC (acid-activated jute stick char), ANL (activated neem
leaf), and APPC (activated potato peel char), and an attempt was made to
understand the mechanism of adsorption in these different types of adsor-
bent. Desorption studies using various eluents in different concentrations
were investigated for the regeneration of the adsorbent. Efficiency was also
tested in several cycles.

8.4.1 Adsorption on Untreated Adsorbents

The untreated adsorbents showed low adsorption capacity. The studies on
utilization of these untreated adsorbents for the effect of several parameters
on adsorption were not extended further as such. In an attempt to increase
their efficiency, the acid-activated forms of the raw precursors were tested.
More extensive study has been done on the adsorption studies of activated
forms rather than the raw/untreated form of the adsorbent.