Screening of three phenol-degrading bacteria for copper bioremoval of copper

Aim: Potential microbial isolates for bioremoval of copper were collected from phenolic and heavy metal-contaminated soils and screened in copper-containing medium for determining the maximum tolerance level for copper. Methodology: Bioremoval of copper was assessed using sodium diethyl dithiocarbamate assay. Physical and cultural conditions influencing copper bioremoval such as initial concentration, biomass dosage (inoculum volume), temperature and pH were optimised via one-factor-at-a-time. Results: The highest maximum tolerance level was displayed by Serratia sp. AQ5-03 at 600 mg l-1, while for Alcaligenes sp. AQ5-02 and Pseudomonas sp. AQ5-04 it was 500 mg l-1. The highest bioremoval for Alcaligenes sp. AQ5-02, Serratia sp. AQ5-03 and Pseudomonas sp. AQ5-04 was achieved at 20, 50 and 75 mg l-1, respectively. The optimum biomass dosage (inoculum volume) for both Serratia sp. AQ5-03 and Pseudomonas sp. AQ5-04 were 15%, whereas it was 10% for Alcaligenes sp. AQ5-02. The results also revealed that maximum bioremoval was achieved at pH 6 at an optimum temperature of 20°C for both Alcaligenes sp. AQ5-02 and Pseudomonas sp. AQ5-04, while Serratia sp. AQ5-03 showed optimum removal at pH 7 and at 30°C temperature. The maximum bioremoval efficiency for Alcaligenes sp. AQ5-02, Serratia sp. AQ5-03 and Pseudomonas sp were found to be 62, 57 and 70%, respectively. Interpretation: The results indicate that Alcaligenes sp. AQ5-02, Serratia sp. AQ5-03, Pseudomonas sp. AQ5-04 can be utilised as bioremoval agent since it possessed the highest bioremoval efficiency for copper remediation.

Study of capability of nanostructured zero-valent iron and graphene oxide for bioremoval of trinitrophenol from wastewater in a bubble column bioreactor

BACKGROUND: Bioremoval of phenolic compounds using fungi and bacteria has been studied extensively; nevertheless, trinitrophenol bioremediation using modified Oscillatoria cyanobacteria has been barely studied in the literature. RESULTS: Among the effective parameters of bioremediation, algal concentration (3.18 g·L−1 ), trinitrophenol concentration (1301 mg·L−1 ), and reaction time (3.75 d) were screened by statistical analysis. Oscillatoria cyanobacteria were modified by starch/nZVI and starch/graphene oxide in a bubble column bioreactor, and their bioremoval efficiency was investigated. Modifiers, namely, starch/zero-valent iron and starch/GO, increased trinitrophenol bioremoval efficiency by more than 10% and 12%, respectively, as compared to the use of Oscillatoria cyanobacteria alone. Conclusions: It was found that starch/nano zero-valent iron and starch/GO could be applied to improve the removal rate of phenolic compounds from the aqueous solution.

Role of brown-rot fungi in the bioremoval of azo dyes under different conditions

The present study is vital to the understanding of bioremediation of structurally different azo dyes by some unusual Brown-rot fungi. Bioremoval of each dye (20 mg l-1) was tested in two different culture media under static and shaking conditions by taking inocula from different fungi. Fungal strains showed varying dyes removal abilities, though considerable high in case of Acid Red (AR) 151(di-azo) as compared to Orange (Or) II (mono-azo). With an exception of Aspergillus tereus SA3, all the fungal isolates showed higher removal of dyes in SDB. Under static condition, the maximum decolorizing fungal strains were; Aspergillus flavus SA2 (67 percent) and Alternaria spp. SA4 (57 percent) in AR 151, while Penicillium spp. (34 and 33 percent) in Orange II, in SDB and STE, respectively. Bioremoval of dyes was considerably increased when experiments were shifted from static to shaking mode. It was specifically increased ( percent) in; AR 151 (255) with Penicillium spp., Or II with A. flavus SA2 (112) and Alternaria spp. (111). The primary mechanism of dyes removal proved to be fungal biosorption. However, reduction of dyes (onto fungal) with formation of their products (α. naphthol, sulphalinic acid and aniline) furthermore revealed that dyes (specifically azo) were actually biodegraded.

Removal Efficiency of the Heavy Metals Zn(II), Pb(II) and Cd(II) by Saprolegnia delica and Trichoderma viride at Different pH Values and Temperature Degrees

The removal efficiency of the heavy metals Zn, Pb and Cd by the zoosporic fungal species Saprolegnia delica and the terrestrial fungus Trichoderma viride, isolated from polluted water drainages in the Delta of Nile in Egypt, as affected by various ranges of pH values and different temperature degrees,was extensively investigated. The maximum removal efficiency of S. delica for Zn(II) and Cd(II) was obtained at pH 8 and for Pb(II) was at pH 6 whilst the removal efficiency of T. viride was found to be optimum at pH 6 for the three applied heavy metals. Regardless the median lethal doses of the three heavy metals, Zn recorded the highest bioaccumulation potency by S. delica at all pH values except at pH 4, followed by Pb whereas Cd showed the lowest removal potency by the fungal species and vice versa in case of T. viride. The optimum biomass dry weight production by S. delica was found when the fungus was grown in the medium treated with the heavy metal Pb at pH 6, followed by Zn at pH 8 and Cd at pH 8. The optimum biomass dry weight yield by T. viride amended with Zn,Pb and Cd was obtained at pH 6 for the three heavy metals with the maximum value at Zn. The highest yield of biomass dry weight was found when T. viride treated with Cd at all different pH values followed by Pb whilst Zn output was the lowest and this result was reversed in case of S. delica. The maximum removal efficiency and the biomass dry weight production for the three tested heavy metals was obtained at the incubation temperature 20degrees C in case of S. delica while it was 25degrees C for T. viride. Incubation of T. viride at higher temperatures (30degrees C and 35degrees C) enhanced the removal efficiency of Pb and Cd than low temperatures (15degrees C and 20degrees C) and vice versa in case of Zn removal. At all tested incubation temperatures, the maximum yield of biomass dry weight was attained at Zn treatment by the two tested fungal species. The bioaccumulation potency of S. delica for Zn was higher than that for Pb at all temperature degrees of incubation and Cd bioaccumulation was the lowest whereas T. viride showed the highest removal efficiency for Pb followed by Cd and Zn was the minor of the heavy metals.