Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fungal bioremediation of diuron-contaminated waters: evaluation of its
  degradation and the effect of amendable factors on its removal in a
  trickle-bed reactor under non-sterile conditions   The occurrence of the extensively used herbicide diuron in the environment
poses a severe threat to the ecosystem and human health. Four different
ligninolytic fungi were studied as biodegradation candidates for the removal of
diuron. Among them, T. versicolor was the most effective species, degrading
rapidly not only diuron (83%) but also the major metabolite 3,4-dichloroaniline
(100%), after 7-day incubation. During diuron degradation, five transformation
products (TPs) were found to be formed and the structures for three of them are
tentatively proposed. According to the identified TPs, a hydroxylated
intermediate 3-(3,4-dichlorophenyl)-1-hydroxymethyl-1-methylurea (DCPHMU) was
further metabolized into the N-dealkylated compounds
3-(3,4-dichlorophenyl)-1-methylurea (DCPMU) and 3,4-dichlorophenylurea (DCPU).
The discovery of DCPHMU suggests a relevant role of hydroxylation for
subsequent N-demethylation, helping to better understand the main reaction
mechanisms of diuron detoxification. Experiments also evidenced that
degradation reactions may occur intracellularly and be catalyzed by the
cytochrome P450 system. A response surface method, established by central
composite design, assisted in evaluating the effect of operational variables in
a trickle-bed bioreactor immobilized with T. versicolor on diuron removal. The
best performance was obtained at low recycling ratios and influent flow rates.
Furthermore, results indicate that the contact time between the contaminant and
immobilized fungi plays a crucial role in diuron removal. This study represents
a pioneering step forward amid techniques for bioremediation of
pesticides-contaminated waters using fungal reactors at a real scale.

1
The categories of this paper are: cs
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga