Developing countries are facing challenges due to rapid urbanization and insufficient sanitation facilities. However, valorizing treated fecal sludge as a fuel source presents an opportunity to recover energy and mitigate environmental impacts. This experimental study aimed to produce low-cost biofuel from dried fecal sludge and enhance its energy efficiency by incorporating locally available organic matters. Various organic materials like rice husk, cow dung, sawdust, and coal were carbonized and mixed with the sludge to enhance calorific value. Eight sludge and organic matter mixtures were formed into briquettes. The blend of 50% sludge and 50% coal yielded the highest calorific value of 14618 KJ/kg and a boiling time of 14 minutes. The second-highest result was for 50% sludge and 50% cow dung, with a calorific value of 14427 KJ/kg and a boiling time of 23 minutes. The study found that blending sludge with organic materials enhances energy output. Briquettes with 50% sludge and 50% coal cost 19.87 BDT/kg, while those with 50% sludge and 50% cow dung cost 14.37 BDT/kg, proving more economical. The latter blend emerged as the most efficient and cost-effective biofuel, offering a sustainable eco-friendly solution for Bangladesh’s rural energy market.

Bioremediation as a cleaning up technology is less predictable and efficient for application on site. An apparent gap is still evident between the laboratory results with pure culture or mixed culture of microorganisms and their biochemical capability including genes and enzymes involved, and the effectiveness at cleaning up the pollutants in soil and sediment on site. Associated issues include the characteristics of the site, ageing of the chemical pollutants and sequestration into soil as one, and activity and competitive of the degradative microorganisms under the actual contaminated conditions of natural environment. Because of these, the favorable conditions for the active growth of degradative microorganisms have not been investigated well enough with the available technology, so a simple inoculation of the pure culture effective under laboratory conditions cannot guarantee an expected efficiency and positive results at on site testing. In addition, the soil or sediment physical and chemical conditions under the natural environment play an important role in the removal or mineralization of organic pollutants, but inadequate attention has been given to these factors involved from ecology. It is the objectives here to bring the attention to the bioavailable concentration of the pollutants and also the active metabolism of the organisms in situ to advance and demonstrate the effective cleaning up of contaminated sites.

Manure effects on soil organic matter (SOM) and related physicochemical fertility indices wane rather fast in the tropics due mainly to the prevailing high temperatures. In texturally similar soils, SOM-mediated aggregation controls hydraulic properties including rainfall-to-field-capacity time (FCtime) and field capacity water content (FCwater) that relate to water/nutrients availability to crops. This study assessed the residual effects of poultry-droppings manure at 25, 50 and 75 t/ha on SOM and aggregation, P-fertility and hydraulic properties of sandy-loam Ultisols in southeastern Nigeria. Mulch-protected treatment plots were water-saturated weekly during the dry season. Sampling for immediate effects was done one month after treatment; that for residual effects in the subsequent rainy season, 7-8 months after treatment, when FCtime/FCwater was monitored at 3-24 h intervals after three rainfall events each ≥ 30 mm. A given monitoring time was designated FCtime if the corresponding FCwater was similar to that of the succeeding one. Immediate effects showed higher soil pH, SOM, aggregates’ mean-weight diameter and available P in 50 and 75 t/ha than unamended control, but similar sand-corrected water-stable aggregates and permeability indices among treatments. Residual effects toed similar trends except that aggregates’ mean-weight diameter was unaffected, while soil bulk density was lower and microporosity higher in 75 t/ha than the rest. Across the three sampling periods, FCtime averaged 42 and 26 h, respectively at ≤ 25 and ≥ 50 t/ha, while FCwater increased steadily (0.08-0.22 g/g) with manure rate. Beyond the season of application to droughty Ultisols, poultry-droppings manure at heavy rates (50-75 t/ha) can still be promoting their SOM and P-fertility but not macro-aggregation. Up to 75 t/ha of the manure may be required for similar residual effects on soil hydraulic properties (including FCtime and FCwater), with FCtime seemingly varying not just with SOM but also the associated rainfall’s characteristics.

Biosurfactants produced by native microorganisms have excellent surface activity and ideal environmental compatibility, and the mining of the biosurfactant-producing strains has become a key focus in the field of applied and environmental biotechnology. In this paper, we report a new lipopeptide-producing strain isolated from the production water of Daqing oilfield in China and identified as Bacillus Subtilis R1-2 based on 16S rRNA gene sequence analyses. A combination of ESI-MS and FT-IR analyses revealed that the strain R1-2 produced the surfactin family containing four members of the C12-surfactin, C13-surfactin, C14-surfactin and C15-surfactin, which is a representative family of the lipopeptide biosurfactants. The lipopeptide biosurfactant produced by the strain R1-2 exhibits excellent surface activity and good thermal stability over a temperature range between 20°C and 100°C and pH range between 3 and 14, and has a strong salt tolerance to NaCl concentration up to 140 g/L. In addition, the lipopeptide biosurfactant demonstrates significant properties in changing the contact angles of oil reservoir core slices from 86.2° to 39.0° and the wettability from strong oil-wet to strong water-wet, and therefore, resulted in a good oil removing ability with an efficiency of 64.84%, suggesting that the lipopeptide-producing strain R1-2 is promising in applications in environmental bioremediation and enhanced oil recovery.

Mycotoxins contaminations in feedstuffs are one of the principal concerns worldwide nowadays, related to the fact that they may evoke health problems in animals and consequently in humans. Biodetoxification of mycotoxins by application of beneficial microorganisms (lactic acid bacteria or yeasts) is one of the well-known, relatively low-cost, easy, efficient, safe, and green approaches for the reduction of mycotoxins presence in feeds. The use of beneficial microorganisms as feed additives to remove mycotoxins is widely practiced in the industrial production of animal feed. In this overview, we aim to summarize the great potential of beneficial microorganisms as bio-detoxificant, including a summary of various reported detoxification activities of lactic acid bacteria or yeasts against mycotoxins with relevance for feedstuff. The principal focus is the detoxification of mycotoxins in livestock, poultry, and aquatic feed using beneficial microorganisms. The mechanisms of the detoxification process and effective factors in this process are also covered. This review article could be useful for biotechnologists, investigators, and animal feed manufacturers who have challenges regarding the existence of mycotoxins in feed, and help them to find the best method for feed bio-decontamination.

Organic inputs to tillage-pulverised soils could, by facilitating soil structure reformation with time, enhance environmental quality. This study examined the aggregate stability responses of three texture-contrasting soils from the derived savannah of southeastern Nigeria to poultry-droppings (PD) manure over time. The soils from Nsukka, Ukehe and Adani with clay contents of 53, 100 and 260 g/kg had antecent organic matter concentrations of 18.77, 29.73 and 16.23 g/kg, respectively, with sandy Nsukka/Ukehe being more stable than loamy Adani. Pulverised soils were amended with PD at rates equivalent to 0, 10, 20, 40 and 70 t/ha, watered and open-incubated under glasshouse conditions. They were augmented to field capacity at three-day intervals and sub-sampled at 2, 4, 8, 12, and 20 weeks after incubation (WAI). Treatment effects were highly soil-dependent. For all three soils, water-stable aggregates, mean-weight diameter (MWD) of aggregates and sand-corrected water-stable aggregates were highest with 70 t/ha at 20 WAI which showed similar MWD of aggregates as 0 t/ha at 20 WAI. Also, 70 and 20 t/ha each at 20 WAI consistently had similar effects (Adani only). Treatment effects on soil bulk density were irregular, with the highest values mostly at 20 WAI across rates. Thus, soil bulk density related inversely with aggregate stability only during 2-12 WAI, owing to their concurrent increases with soil pH beyond 12 WAI. These soil structure indices were not influenced by PD-induced fluctuations in electrical condutivity which always peaked 4 WAI. Heavy and modest PD addition, respectively, to tillage-pulverised sandy and loamy tropical soils promote their re-aggregation after 20 weeks; however, such soils even without manuring could re-structure into aggregates of sizes as though PD-amended over this long interval. Rather than PD-induced salinisation, it is soil pH that influences macro-aggregation up till the 20th week, when soil pH should be ≤ 6.65 to avoid soil densification above 1.71 Mg/m3.

Extensive aeration is required for constructed wetlands (CWs) since dissolved oxygen is essential in nutrients and pathogen removal. On the other hand, plants typically used in CWs can release oxygen into the system, lowering the need for external aeration. Hence, this study tried to uncover the oxygenation rate of three species of plants in the CWs system with limited oxygen and their capability to treat wastewater. Canna sp., Heliconia sp.,and Typha sp. were used and compared to uptake nutrients and reduce coliform numbers in domestic wastewater using sub-surface CWs in low levels of initial oxygen. In the meantime, oxygen release from the plant root was monitored in real-time using an IoT-based module. On the detention time of 24 hours, CWs planted with Typha sp. were able to reduce 61% NH4+ and 71% PO43−.The system was also able to remove coliform with a magnitude of 1.39 log units. In addition, Typha sp. was observed to generate a higher oxygenation rate to the CWs system compared to the other two plants at 0.175%/h, on average. These observations suggested that Typha sp. had the best prospect to be used in a sub-surface CWs system with the least external aeration needed.

Pesticides have considerably increased agricultural output, but their overuse presents serious threats to human health, food safety, and the environment. Alarmingly, only around 1% of pesticides used reach their intended pests, with the remainder polluting soil, water, and air. This causes broad environmental contamination and negative consequences on non-target animals, including people. Top pesticide-consuming countries, including China, the United States, and Brazil, confront considerable issues due to residual pesticide buildup. Recent biotechnology developments provide intriguing pesticide mitigation strategies. Engineered Escherichia coli (E. coli) strains have developed as very efficient bioremediation agents. These genetically engineered microbes are intended to convert hazardous chemicals into harmless metabolites. E. coli strains are tailored for increased expression of pesticide-degrading genes using modern genetic and metabolic engineering, dramatically enhancing their ability to break down hazardous chemicals. Studies have shown that modified E. coli may degrade persistent pesticides such as Paraoxon and p-nitrophenol (PNP), turning them to harmless molecules. These bacteria may reach great densities, making them ideal for large-scale detoxifying operations. Furthermore, recombinant DNA technology enables the development of E. coli strains with several copies of degradation genes, which improves their bioremediation capacities. Despite these advances, obstacles persist, including biosafety issues and the need for regulatory supervision. Ongoing research is critical for addressing these concerns and developing safer, more sustainable agriculture techniques. Engineered E. coli strains represent a substantial advancement in pesticide mitigation, providing a feasible approach for reducing environmental pollution and protecting human health.

In the context of advancing "green" development and global environmental standards, there is a pressing need to focus on biological methods of wastewater treatment in Kazakhstan, particularly concerning oil pollution. This study aims to develop an optimal technological model to minimise destructive pollution of wastewater by oil products using algae and aquatic plants on the example of artificial bioponds within the Ozen field owned by "Ozenmunaigas" JSC in the Mangistau region. Through a comprehensive set of scientific methods including induction and deduction, abstraction, system analysis, synthesis, concretisation, formalisation, and generalisation, the study assesses the ecological state of water resources, identifies pollution dynamics, and evaluates the impact of algae and aquatic plants on oil-contaminated effluents. The research culminates in the development of an effective biotreatment technology to mitigate the negative effects of wastewater on water quality and enhance Kazakhstan's overall environmental landscape. Furthermore, the study explores innovative technological and management approaches to reduce pollutant concentrations, emphasizing the importance of ecosystem-based solutions and modern bio-treatment technologies. The findings hold practical significance for modernizing water treatment system, informing future preventive measures for water resource protection, and promoting the adoption of biological treatment as a viable alternative to traditional methods.