Bioaugmentation and phytoremediation wastewater treatment process as a viable alternative for pesticides removal: case of pentachlorophenol.

This study focused on the potential for pentachlorophenol removal by a biological process in secondary treated wastewater (STWW). The proposed process is a combined method of phytoremediation using a native plant, Polypogon maritimus and Lemna minor, and bioaugmentation using a fungus. The bioaugmentation process was performed by a fungal isolate capable of removing PCP, isolated from the compost. The identification of the fungus was performed by morphological, biochemical, and molecular methods. A biological treatment system by bioaugmentation and phytoremediation was set up to estimate the capacity of this process to eliminate a high concentration of PCP. physico-chemical parameters, such as pH, COD, and BOD were tested at experimentation times T0 (initial) and Tf (final). The concentration of PCP is controlled by the HPLC method. Thus, the growth of the fungus was determined by spectrophotometry and enumeration on the agar medium. The results obtained show that the isolated and selected fungus is identified by Penicillium Ilerdanum. The fungal strain used has a significant capacity for tolerance and elimination of PCP. The results of the physico-chemical parameters showed an improvement in the quality of wastewater after the treatment was carried out. The elimination of PCP came with a release of Common law- and an important decrease in the DOC value in the STWW. The results obtained show that the Polypogon treatment shows a significant elimination of PCP by a percentage of the order of 92.01% and 23.58 g. L- 1 chloride concentration. The macrophytes used showed a better ability to tolerate and eliminate PCP with an increase of chlorophyll and its longer sheets. Supplementary Information: The online version contains supplementary material available at 10.1007/s40201-023-00865-y.

Macrophyte and indigenous bacterial co-remediation process for pentachlorophenol removal from wastewater.

This study has contributed in the description of bioaugmentation-phytoremediation efficiency process using Typha angustifolia concerning PCP tolerance and removal from wastewater. Samples of wastewater were collected from industrial wastewater plants, namely row wastewater effluent "E.WW", primary wastewater "P.WW", secondary wastewater "S.WW", clarified wastewater "AC.WW". These effluents were spiked with PCP at different rate (100, 500, and 1000 mg.L-1), physical, chemical and biological properties were monitored. A second experiment was set up in order to check the efficiency of phytoremediation treatments of the different effluents artificially contaminated with 200 mg.L-1 PCP after 20 days lab scale experiment. An important PCP removal by indigenous bacteria was showed in S. WW with values from 1000 to 72.2 mg.L-1 from T0 (start of the experiment) to TF (end of the experiment), respectively. Phytoremediation process allowed a decrease of PCP rate from 200 to 6.4 mg.L-1, a decrease of chloride content from 14.0 to 4.0 mg.L-1 in S.WW samples was observed. Furthermore, a significant increase of bacterial number in S.WW and AC.WW to 1.700 × 106 and 1.450 × 106 CFU.mL-1, respectively was observed. In addition, the DGGE analysis showed that after bioaugmentation-phytoremediation treatments, the highest species richness and relative abundance in wastewater effluent was observed. Novelty statement Pentachlorophenol (PCP) is one of highly toxic of polychlorophenols and required to continuously monitor in environment. This paper presenting a sensitive method phytoremediation and bioaugmentation for PCP biotransformation in wastewater. The novelty is the choice of a macrophyte Typha angustifolia, which is still used for the elimination of heavy metals but it not used for pesticide and pollutant removal in wastewater. Also, there are different analysis that was performed in order to check phyto-technique process (DGGE and HPLC). On the other side, in this study, the phyto-techniques with Typha angustifolia positively affected intrinsic microorganisms in order to promote pollutant remediation. So, the intrinsic microorganisms in wastewater with the macrophyte presence have a great capacity to reduce this pollutant and improve the bioremediation process.

Study of the diversity of 16S-23S rDNA internal transcribed spacer (ITS) typing of Escherichia coli strains isolated from various biotopes in Tunisia.

We investigated the 16S-23S rRNA intergenic spacer region (ISR)-PCR and the phylogenetic PCR analyses of 150 Escherichia coli isolates as tools to explore their diversity, according to their sampling origins, and their relative dominance in these sampling sources. These genetic markers are used to explore phylogenetic and genetic relationships of these 150 E. coli isolates recovered from different environmental sources (water, food, animal, human and vegetables). These isolates are tested for their biochemical pattern and later genotyped through the 16S-23S rRNA intergenic spacer PCR amplification and their polymorphism investigation of PCR-amplified 16S-23S rDNA ITS. The main results of the pattern band profile revealed one to four DNA fragments. Distributing 150 E. coli isolates according to their ITS and using RS-PCR, revealed four genotypes and four subtypes. The DNA fragment size ranged from 450 to 550 bp. DNA band patterns analysis revealed considerable genetic diversity in interspecies. Thus, the 450 and 550 bp sizes of the common bands in all E. coli isolates are highly diversified. Genotype I appeared as the most frequent with 77.3% (116 isolates), genotype II with 12% (18 isolates); genotype III with 9.7% (14 isolates), and the IV rarely occurred with 4% (2 isolates). Distributing the E. coli phylogroups showed 84 isolates (56%) of group A, 35 isolates (23.3%) of group B1, 28 isolates (18.7%) of group B2 and only three isolates (2%) of group D.

Bacterial consortium biotransformation of pentachlorophenol contaminated wastewater.

The aims of this study were (i) to compare PCP removal (100 mg L-1) by two bacterial consortia B1 and B2 in sterile wastewater (STWW) and liquid mineral medium (MSM), (ii) PCP effect in biofilm formation and antimicrobial susceptibility. PCP removal was measured by high-performance liquid chromatography (HPLC) during 168 h at 30 °C. Biofilm formation was assessed with two approaches: Congo Red Agar and Microtiter-plate. Antimicrobial susceptibility was determined by the agar disc diffusion technique. The results showed that the PCP removal for consortium B1 and B2 after 168 h was 70 and 97.5% in STWW; 62.2 and 85.5% in MSM, respectively. In addition, PCP addition showed an increase in biofilm development especially for B2 consortium around 3.5 nm in 100 mg L-1 PCP. PCP added in the Muller Hinton (MH) medium and Gentamicin disc showed a clear increase in diameter of cell lysis around 2 to 4.5 cm.

Surfactant efficiency on pentachlorophenol-contaminated wastewater enhanced by Pseudomonas putida AJ 785569.

This study aims to evaluate the effect of three surfactants on the removal of PCP (800 mg L-1) from Secondary Treated Wastewater (STWW) by Pseudomonas putida AJ 785569. The effect of surfactants [sodium lauryl sulfate (SDS) as anionic, Tween 80 (TW80) as non-anionic and cetyltrimethylammonium bromide (CTAB) as cationic] is tested about the three following aspects: (1) bacterial growth, (2) bacterial biofilm formation or development and (3) PCP rate removal. The results showed that strain P. putida AJ 785569 could adsorb around 30 mg L-1 and remove 600 mg L-1 of PCP within 168 h of incubation. The SDS developed the growth of bacteria and the removal of PCP. This PCP removal in mineral salt medium (MSM) is around 760 mg L-1 (95% degradation) higher than the ones registered with CTAB and TW80 with a value 506.75 (63% degradation) and 364.1 mg L-1 (45% degradation), respectively. The obtained results of chloride concentration showed an important relation with PCP removal during incubation with an important value. Monitoring the development of bacterial biofilm, in MSM medium added with PCP (100 mg L-1) by strain P. putida AJ 785569, showed a significant increase in the optical density value from 0.9 to 4 at λ = 595 nm, a modification of strain P. putida AJ 785569's morphotype, density and color colonies.