Thesis for Master of Science
Ana Cláudia Gama, 2001,
“Degradação do ácido sulfanílico em
zonas húmidas artificias artificiais”,
Universidade de Aveiro,
2001
Supervisor:
S. Martins-Dias
Abstract
As
a result of the rapid deterioration in water quality due to industrial
development, water treatment has undergone a rapid growth in recent decades. The
current work is in the area of the treatment of industrial effluents.
The objective of this work is to develop an innovative process for the removal
and degradation of sulfanilic acid.
This work looks to develop technology that contributes to reduction, or
elimination, of sulfanilic acid in effluents, to recuperation and recycling of
water for subsequent reutilization in industry and to avoid the production of
further toxins.
The experimental work was developed using three beds, differing from one another
in the type of support matrix used: gravel and a sandy-clay soil with 2% and 12%
organic material. The different pilot units were fed with concentrations of
sulfanilic acid of up to 900 mg/l, obtaining removal efficiencies of 30, 80 and
90% for hydraulic loads of 140.8, 8.4 and 50 l/m2 with initial concentrations of
sulfanilic acid of 160, 900 and 900 mg/l respectively.
Intermediate products of the degradation of sulfanilic acid were also studied,
using HPLC and spectrophotometry, in the UV/visible range, of samples in a
hydroponic medium, so as to minimise interference. No organic intermediary was
detected. The quantity of sulphates measured in the effluents showed an equi-molar
relation with the quantity of sulfanilic acid degraded.
Kinetic analysis of the degradation of sulfanilic acid, in various experiments,
indicated a Michaelis-Menten type enzymatic reaction.
Reeds, ie, Phragmitis
spp., were the type of vegetation chosen, as it is one of the most abundant
in coastal zones.
The results obtained indicate that the optimum support matrix is a sandy-clay
soil.