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Heavy metals pose a serious environmental threat on a global scale due to their toxicity towards livings. Therefore, removing harmful metals from the environment has become more challenging in recent years. The objective of this study is to isolate, examine, and characterize naturally existing bacteria that possess the ability to mitigate and detoxify heavy metals such as cadmium, mercury, and lead. The selected bacteria SMA3 actively demonstrated metal tolerance during screening and was then employed for biosorption study using a lab-scale technique. The bacterium belonged to Brevundimonas sp., according to 16 S rRNA analysis. To enhance the removal efficiency of SMA3, response surface methodology (RSM) was employed, resulting in the identification of optimized conditions (pH 7, temperature 30 °C and shaking speed 120 rpm) for achieving maximum removal percentage (69.5 % of Cd, 58.6 % of Hg, and 85.1 % of Pb) within 72 h. The structural changes induced by microbial treatment were demonstrated by comparing the findings of FESEM images and FTIR spectra confirming the disappearance of C ^ C, C]O peaks along with C]O, C–O–C, C–H, and O–H bond destabilization following bioaccumulation. Moreover, in terms of phytotoxicity evaluation, it was observed that the treated soil, containing both heavy metals and the selected potent bacterial strain, exhibited reduced toxicity, resulting in improved germination and growth parameters for the seeds of Solanum lycopersicum (tomato plant). Overall, the selected bacterial strain demonstrated its potential for effectively removing multiple metals from the metal contaminated environment.

The present study discusses the role of biochar in enhancing methane (biogas) production from organic solid waste (OSW) employing a co-culture of Pseudomonas aeruginosa and Methanosarcina mazei. The high porosity, alkalinity, and high ion-exchange capacity of biochar make it an efficient support material for microbial cell growth and proliferation. Here the effect of different doses of biochar on biogas production parameters, i.e., cumulative methane production, maximum methane production rate, and lag phases, are studied. The synergistic effect of biochar for its supplemental methane production via ammonia mitigation potential is also studied. The results illustrate a maximum methane yield of 109±0.42 mlCH4gCarboinitial with a maximum of 54.83±0.20% COD removal was achieved at 12.5 g/L biochar concentration. Also, there is a significant improvement in the lag phase from 13.2 ± 0.3 h at control (without biochar) to 8.8±.15 h at the same 12.5 g/L effective biochar concentration. The effect of ammonia addition revealed low methane production rates, which were subsequently reduced with the biochar amendment that conversely increased the methane production rates in each experimental batch. Thus the result showed that biochar addition could significantly affect methane production rates, ammonia inhibition potential and also showed increased volatile fatty acid generation.

In this study, the optimization of distinctive environmental factors such as pH, temperature, agitation-speed and atrazine-concentration on atrazine degradation by utilizing Bacillus badius ABP6 strain, has been done through response-surface-methodology (RSM). The optimum-conditions after analysis for the maximum atrazine degradation were: pH 7.05, temperature 30.4 °C, agitation-speed 145.7 rpm, and atrazine-concentration 200.9 ppm. The prescribed model was approved for high F-value (95.92), very low P-value (

Tannery industries discharge a large quantity of toxic substances like chromium, sodium sulphide, sodium carbonate, ammonium sulphate and chlorides in their effluent, which manifold soil pollution and affect on seed germination and plant growth. In this study, two investigational systems are attempted: i) tannery effluent was treated by aerobic bacteria Pseudomonas fluorescens and aquatic macrophyte Eichhornia crassipes and ii) the impact of treated and untreated effluent and soil on seed germination and plant growth were studied. The physicochemical properties such as color, pH, COD, BOD, total solids, suspended solids, dissolved solids, and chromium concentration were found decreased in effluent that treated with bacterial strain for 72 h and Water hyacinth for 20 days. These treated effluent also significantly enhanced chlorophyll content, and biomass production over other of wheat plant. The results revealed that effluent treated by microbes and plant has no negative impact on the seed germination and plant growth. Thus, it can be effectively used for irrigation.