Bioremediaion Research Papers - Academia.edu (original) (raw)

Remediating crude oil polluted soil in developing countries by environment-friendly approach has attracted scientific interest. Sampled crude oil and poultry dung were obtained from oil pit and farm in Warri, Delta State. 500 g/kg of... more

Remediating crude oil polluted soil in developing countries by environment-friendly approach has attracted scientific interest. Sampled crude oil and poultry dung were obtained from oil pit and farm in Warri, Delta State. 500 g/kg of crude oil polluted soil was weighed into four different containers labeled A, B, C and D; the soil was amended with the application of sundried poultry manure at various weights of 50, 75 and 100 g/kg respectively leaving sample D without amendment as control for a period of 42 days. Isolation and identification process of bacteria strains were carried out using standard spread plate method on nutrient agar. Ten bacteria isolates were obtained from the amended and control soil in this research. Genus from pseudomonas and staphylococcus has the highest representation of three species each. The rate of degradation in the sample was determined by gravimetric analysis. The total petroleum hydrocarbon (TPH) present in sample D (control) initially was 4550.08 mg/kg. Samples A, B and C after remediation period reduced to the value of 3410.61, 2664.90 and 1598.95 mg/kg, respectively. The total hydrocarbon utilizing bacteria (HUB) increased gradually in the sample A, B, C and D to 7 × 10-4 , 7.9 10-4 , 8.0 × 10-4 and 5.0 × 10-4 respectively. The total heterotrophic bacteria count (THB) increased from 10 x 10-5 at zero week to 8.3 × 10-5 , 8.5 10-5 , 8.6 × 10-5 and 7.3 × 10-5 in the samples respectively. Physiochemical analysis of nitrogen increased from 0.04 to 0.17 mg/kg and phosphorous also increased from 1.72 to 6.73 mg/kg after the period of 42 days. This approach showed increased remediating effect of poultry dung on crude oil polluted soil.

The main element of PbRS (passive (bio)remediation systems) are sorbents, which act as natural filters retaining heavy metals and carriers of microorganisms involved in water treatment. Thus, the effectiveness of PbRS is determined by the... more

The main element of PbRS (passive (bio)remediation systems) are sorbents, which act as natural filters retaining heavy metals and carriers of microorganisms involved in water treatment. Thus, the effectiveness of PbRS is determined by the quality of the (ad)sorbents, which should be stable under various environmental conditions, have a wide range of applications and be non-toxic to (micro)organisms used in these systems. Our previous studies showed that bog iron ores (BIOs) meet these requirements. However, further investigation of the physical and chemical parameters of BIOs under environmental conditions is required before their large-scale application in PbRS. The aim of this study was (i) to investigate the ability of granulated BIOs (gBIOs) to remove arsenic from various types of contaminated waters, and (ii) to estimate the application potential of gBIOs in technologies dedicated to water treatment. These studies were conducted on synthetic solutions of arsenic and environmental samples of arsenic contaminated water using a set of adsorption columns filled with gBIOs. The experiments performed in a static system revealed that gBIOs are appropriate arsenic and zinc adsorbent. Dynamic adsorption studies confirmed these results and showed, that the actual sorption efficiency of gBIOs depends on the adsorbate concentration and is directly proportional to them. Desorption analysis showed that As-loaded gBIOs are characterized by high chemical stability and they may be reused for the (ad)sorption of other elements, i.e., zinc. It was also shown that gBIOs may be used for remediation of both highly oxygenated waters and groundwater or settling ponds, where the oxygen level is low, as both forms of inorganic arsenic (arsenate and arsenite) were effectively removed. Arsenic concentration after treatment was <100 µg/L, which is below the limit for industrial water.

Functionalization of the extracellular polymers (EPS) of a marine bacterium Pseudomonas aeruginosa N6P6 was carried out for cadmium (Cd) bioadsorption from an aqueous solution which led to the synthesis of cadmium sulfide (CdS)... more

Functionalization of the extracellular polymers (EPS) of a marine bacterium Pseudomonas aeruginosa N6P6 was carried out for cadmium (Cd) bioadsorption from an aqueous solution which led to the synthesis of cadmium sulfide (CdS) nanoparti-cles (NPs). Characterization of pristine, functionalized and Cd-treated functionalized EPS was accomplished by ATR-FTIR spectroscopy which illustrated Cd binding with the sulfhydryl (–SH) group. The XRD pattern confirmed the presence of CdS NPs on the functionalized EPS with diffraction peaks at 2θ = 27.45° and 32.66° indexed to (111) and (220) planes of cubic phase CdS. Maximum Cd adsorption was observed by the functionalized EPS which removed 88.86 ± 0.65% of Cd at pH 6.6 in 48 h. However, pristine EPS and bacterial cell biomass removed 83.61 ± 0.50% and 29.75 ± 0.73% of Cd respectively from aqueous solution. The experimental data of Cd adsorption thermodynamics by functionalized EPS fitted in Langmuir isotherm model. CdS NPs synthesis by functionalized EPS was evident by UV–Vis spectrum with a characteristic peak at 462 nm and Transmission electron microscopy with an average diameter of 8–10 nm. This work delivers an environment-friendly approach for efficient Cd removal from aqueous solution in the form of CdS NPs synthesis.

Cork boiling wastewater pollutants were fractionated by sequential use of four ultrafiltration membranes and five fractions were obtained: four retentates (>100, 50–100, 20–50 and 10–20 kDa) and one permeate (<10 kDa); which were used to... more

Cork boiling wastewater pollutants were fractionated by sequential use of four ultrafiltration membranes and five fractions were obtained: four retentates (>100, 50–100, 20–50 and 10–20 kDa) and one permeate (<10 kDa); which were used to study the correlation of molecular size with biodegradability and toxicity before and after ozonation. The results show that molecular size is correlated with organic load and restrains biodegradability. The fraction with >100 kDa corresponds to 56% of the organic load and the one with <10 kDa only 8%. The biodegradability of fractions increased 182% with fractions molecular size reduction from >100 to < 10 kDa and the chemical oxygen demand (COD) was from 3436 to 386 mg L−1. For biodegradability enhancement the best outcome of ozonation was obtained with compounds having molecular size >20 kDa and range from 5% up to 175% for applied ozone doses to COD ratios between 0.15 and 0.38.

This work reports new fragments of DNA sequences related to microbes able to degrade phenol into acetate under strict anaerobic conditions. For this purpose, anaerobic digesting sludge was acclimatised to degrade phenol, then heat treated... more

This work reports new fragments of DNA sequences related to microbes able to degrade phenol into acetate under strict anaerobic conditions. For this purpose, anaerobic digesting sludge was acclimatised to degrade phenol, then heat treated and in turn used as fermentative sludge. The resulting microbial community was able to convert phenol into acetate under anaerobic conditions (kinetic constants: 0.396 ± 0.01 and 0.345 ± 0.04 mg of compound L-1 day-1 , respectively). Microscopic, chemical and molecular analyses revealed that only bacteria were present in the final sludge and thus methanogens were eliminated. The bacteria were mainly Gram-negative sporeforming rods, belonging to the Deltaproteobacteria class and had a tendency for aggregation. These are also phenotypically related to organisms thriving at extreme environments. Cloning, temperature gradient gel electrophoresis (TGGE) and probe matching of a short 16S DNA fragment revealed that these new microbes are evolutionary related to, and share 90% of similarities with, Desulfovibrio sp.

A submerged biologicalaeratedfilter (BAF) partiallyaerated was used to study the removal of lowconcentrations of ammonia nitrogen (0.3 g N/m3 to 30.5 g N/m3) typically found in nutrient enriched river and lake waters, and treated... more

A submerged biologicalaeratedfilter (BAF) partiallyaerated was used to study the removal of lowconcentrations of ammonia nitrogen (0.3 g N/m3 to 30.5 g N/m3) typically found in nutrient enriched river and lake waters, and treated effluents. Four series of experiments were performed with a synthetic wastewater at ammonia loading rates between 6 g N/m3 d and 903 g N/m3 d and C/N ratios from 2 to 20. The results showed that ammonia removal rates reached higher values (172 g N/m3 d to 564 g N/m3 d) for C/N = 2 and lower values (13.6 g N/m3 d to 34.6 g N/m3 d) for C/N = 20. Between 50% and 70% of the ammonia was removed in the upper section of the BAF, where the dissolved oxygen (DO) concentration was over 2.1 g O2/m3 and the biofilm depth ranged from 0.4 to 0.6 mm. At the bottom section of the reactor, simultaneous removal of ammonia and nitrate was observed at the DO concentrations in the range 0.4 g O2/m3 to 0.8 g O2/m3. There was no removal of ammonia nitrogen for loads below 15 g N/m3.d. The results indicate that the removal of nitrogen in partiallyaerated BAF may not only be explained by the conventional mechanisms of nitrification/denitrification.

Arthrobactersp.SPGutilized2-nitrobenzoateasitssolesourceofcarbonandenergyanddegradeditwithaccumulationofstoichiometricamountsofnitriteions.Salicylateandcatecholweredetectedasmetabolitesofthe2-nitrobenzoatedegradationusinghighperformanceliqu... more

Arthrobactersp.SPGutilized2-nitrobenzoateasitssolesourceofcarbonandenergyanddegradeditwithaccumulationofstoichiometricamountsofnitriteions.Salicylateandcatecholweredetectedasmetabolitesofthe2-nitrobenzoatedegradationusinghighperformanceliquidchromatographyandgaschromatography–massspectrometry.Enzymeactivitiesfor2-nitrobenzoate-2-monooxygenase,salicylatehydroxylase,andcatechol-1,2-dioxygenaseweredetectedinthecrudeextractsofthe2-nitrobenzoate-inducedcellsofstrainSPG.The2-nitrobenzoate-monooxygenaseactivityresultedinformationofsalicylateandnitritefrom2-nitrobenzoate,whereassalicylatehydroxylasecatalyzedtheconversionofsalicylatetocatechol.Thering-cleavingenzyme,catechol-1,2-dioxygenasecleavedcatecholtocis,cis-muconicacid.CellsofstrainSPGwereabletodegrade2-nitrobenzoateinsterileaswellasnon-sterilesoilmicrocosms.TheresultsofmicrocosmstudiesshowedthatstrainSPGdegradedmorethan90%of2-nitrobenzoatewithin10–12days.ThisstudyclearlyshowsthatArthrobactersp.SPGdegraded2-nitrobenzoateviaanewpathwaywithformationofsalicylateandcatecholasmetabolites.Arthrobactersp.SPGmaybeusedforbioremediationof2-nitrobenzoate-contaminatedsitesduetoitsabilitytodegrade2-nitrobenzoateinsoil.

Nitrate removal from water has been accomplished by heterotrophic biofilms using organic carbon as a source of reducing power. To overcome the natural limitation in organic carbon in water, a poly-ε-caprolactone based biofilm carrier that... more

Nitrate removal from water has been accomplished by heterotrophic biofilms using organic carbon as a source of reducing power. To overcome the natural limitation in organic carbon in water, a poly-ε-caprolactone based biofilm carrier that serves simultaneously as a biofilm carrier and as a source of organic carbon was developed and tested in the present work. The feasibility of the new biofilm carrier for nitrate removal from water was evaluated in a packed bed reactor. The combination of size and structure provided a carrier element having high surface area and void volume, 1,170 m2/m3 and 67 %, respectively. A maximum denitrification rate of 4.4 mg N–NO3 −/(L.h) (9.2 mg N–NO3 −/(m2.h)) was achieved in the packed bed reactor at 20 °C and pH 7.0. Main advantages of the biofilm carrier developed in the present work are its mechanical stability in water even after biofilm formation and controlled release of organic carbon by enzymatic reactions. The proposed biotechnology to remove nitrate from groundwater is robust and easy to operate.