Biological Treatment Methods Research Articles

Treatment and Recycling of Tungsten Beneficiation Wastewater: A Review

The large amount of wastewater containing various pollutants generated during the tungsten beneficiation process has become a bottleneck for the sustainable development of tungsten mining enterprises. Typical pollutants mainly include suspended solids (SSs), silicate ions, metal ions, and residual organic reagents. The direct discharge of untreated tungsten beneficiation wastewater can cause serious harm to the ecological environment, while recycling can significantly affect flotation indicators. In this paper, the sources and characteristics of typical pollutants were analyzed, and various purification techniques were outlined, including coagulation, adsorption, chemical precipitation, oxidation, and biological treatment methods. Among these techniques, coagulation is particularly effective for the removal of SSs, while adsorption and chemical precipitation are recommended for the removal of soluble ions. For residual organic reagents, oxidation methods have demonstrated high treatment efficiencies. The mainstream methods for wastewater recycling were summarized, including centralized recycling, as well as internal recycling at certain stages. For tungsten beneficiation such a complex process, where the quality of wastewater varies greatly between different stages, it is suitable to recycle the wastewater after appropriate treatment at a specific stage. Furthermore, this study provided a perspective on the future directions of tungsten beneficiation wastewater treatment, serving as a reference for related research and industrial practices.

A Review on the Effect of Wood Surface Modification on Paint Film Adhesion Properties

Wood surface treatment aims to improve or reduce the surface activity of wood by physical treatment, chemical treatment, biological activation treatment or other methods to achieve the purpose of surface modification. After wood surface modification, the paint film adhesion performance, gluing performance, surface wettability, surface free energy and surface visual properties would be affected. This article aims to explore the effects of different modification methods on the adhesion of wood coating films. Modification of the wood surface significantly improves the adhesion properties of the paint film, thereby extending the service life of the coating. Research showed that physical external force modification improved the hydrophilicity and wettability of wood by changing its surface structure and texture, thus enhancing the adhesion of the coating. Additionally, high-temperature heat treatment modification reduced the risk of coating cracking and peeling by eliminating stress and moisture within the wood. Chemical impregnation modification utilized the different properties of organic and inorganic substances to improve the stability and durability of wood. Organic impregnation effectively filled the wood cell wall and increased its density, while inorganic impregnation enhanced the adhesion of the coating by forming stable chemical bonds. Composite modification methods combined the advantages of the above technologies and significantly improved the comprehensive properties of wood through multiple modification treatments, showing superior adhesion and durability. Comprehensive analysis indicated that selecting the appropriate modification method was key for different wood types and application environments.

Tetracycline degradation for wastewater treatment based on ozone nanobubbles advanced oxidation processes (AOPs) – Focus on nanobubbles formation, degradation kinetics, mechanism and effects of water composition

Presence of pharmaceuticals, especially antibiotics, in industrial and domestic effluents causes serious damage to the environment. Classic wastewater treatment processes, in particular conventional biological treatment methods, are not sufficient to rapidly eliminate antibiotics. Typically, Advanced Oxidation Processes (AOPs) based on activation of hydrogen peroxide, ozone or persulfate for production of particular type of radical species or singlet oxygen are used. A one of cutting-edge technologies to increase effectiveness of AOPs based on ozone are nanobubbles based processes. Thus, this paper focuses on utilization of ozone in the form of nanobubbles for degradation of tetracycline (TC). The effects of several reaction parameters, such as antibiotic concentration, ozone intake, pH, presence of salts, were investigated. This study revealed that the presence of ozone nanobubbles had a substantial positive impact on the degradation of TC. This improvement may be attributed to the enhanced mass transfer and the production of reactive radicals that occur during the collapse of the nanobubbles. Identification of radical species revealed a significant contribution of hydroxyl radicals in the degradation of the antibiotic. AOP process based on O3 nanobubbles was most (•OH) and superoxide (O2–) effective with 100 % degradation efficiency of 100 mg/L TC within 20 min at 8 mg/L concentration of ozone. Based on identified by LC-MS intermediates a degradation mechanism has been described. Degradation of TC and intermediates transformations included methylation, hydroxylation, ring-opening steps as well as cleavage of C-N bonds. This research introduces a novel technique combining nanobubbles with advanced oxidation processes (AOPs), which is anticipated to provide enhanced efficiency and environmental sustainability.

Advanced technological integration for swine wastewater: Enhancing treatment with photo-Fenton and electrocoagulation

The increase in pork consumption and its reputation as one of the best sources of protein has led to growth in this industry, however, its production generates a significant amount of swine wastewater (SWW). Conventional biological treatment methods are typically used to treat SWW. However, their applicability in small and medium sized enterprises (SMEs) in the swine industry is limited due to their high space requirements. Therefore, advanced oxidation processes (AOPs) such as photofenton (PF) and electrocoagulation (EC) represent a potential alternative for SWW treatment due to their lower space requirements. The aim of this study was to treat SWW by integrating the PF process followed by EC as a technological couple to optimize the removal efficiency of pollutants present in SWW. Experiments were conducted in a 2 L batch reactor, examining the effects of hydrogen peroxide (H2O2) concentration (0.5, 2.5, 5.0 g L−1) and current density (10, 50, 90 A m−2) on pH, organic matter, nutrients, and germination index (GI). The results showed that the optimum process conditions correspond to 2.6 g L−1 H2O2 and a current density of 41 A m−2. Under these conditions, an effluent is obtained with pH values of 7.8, TSS of 385 mg L−1, COD of 254 mg L−1, BOD5 of 139.8 mg L−1, TN of 190.4 mg L−1 and GI of 117 %. The results showed that the effluent complies with the Colombian standards. From a cost perspective, the use of Photo-Fenton to treat wastewater under these conditions would be US$ 0.7 per liter.

Research on the Performance of New Microbial Fuel Cell Anodes

In recent years, with the vigorous development of the maritime transportation industry, the resulting problem of ship oil pollution has become increasingly prominent. Efficient and thorough treatment of oily wastewater is the key to solving such problems. Microbial fuel cell (MFC) technology is a promising biological treatment method due to its good degradation effect, no secondary pollution, and energy recovery. In this paper, the discarded corn cob materials in nature were selected for high-temperature carbonization at 350°C, and NaOH was used to modify the modified biochar. Then, the coating technology of Ti3C2 MXene, NbC, WC, TaC and other materials was used to modify the surface of biochar, and the biochar anode material was obtained to construct a double-chamber microbial fuel cell device. The properties of the modified anode biochar materials were studied.

Recent advancement in microplastic removal process from wastewater - A critical review

Microplastics, small sized plastic particles having size <5 mm are formed through primary process including production of beauty products, microbeads and microfibres as well as secondary process including mechanical weathering, friction, aberration and fragmentation of large plastics. The major sources of microplastics are land-based and ocean-based sources. Microplastic pollution is a serious concern due to the persistent, low biodegradability and bio-accumulative behaviour. Microplastics can bioaccumulate in the food chain and can cause ecological and human health risk. Hence, it is important to remove from the aquatic ecosystems. Microplastics are removed from aquatic systems and wastewater through a series of processes such as physical, chemical and biological treatments. In the present articles, >250 articles are reviewed to collect the information regarding the various physical, chemical and biological methods for the removal of microplastics. Also, the probable control strategies to combat with plastic pollution were assessed. It was concluded that recent water treatment methods are efficient in removing microplastic pollution. The efficiencies to remove microplastic from the water ranged between 74 %-99.2 %, 65 %-99.20 % and 77 %-100 % for physical, chemical and biological treatment methods, respectively. Among the three treatment methods, physical methods especially the filtration of water from biochar is the most efficient way (efficiency up to 100 %) to remove microplastics. It was also concluded that creating public awareness, promoting reusing, recycling and reducing, and application of bioplastics can control the production of microplastics from plastic wastes. This review will be useful to add current knowledge regarding the abatement of microplastic pollution, and finding novel solution to control microplastics. This review will also help the policymakers to implement most effective and cost-efficient method to remove microplastics, and to find out new methods to reduce, reuse and recycle plastic wastes.

Photocatalytic nanohybrid UV-light-driven PVDF/GO-NiFe@SiO2 membrane coupled with bentonite adsorption and ozonation process for a sustainable textile wastewater treatment

The textile industries face significant environmental challenges due to the presence of complex pollutant dyes in its wastewater, making it one of the world's major sources of industrial water pollution. Numerous studies have been employed to overcome this problem, including physical, chemical, and biological treatments. However, most of those methods still suffered to achieve higher dye removal performance. This study provides new insight regarding textile wastewater treatment containing indigo red as the main colorant by carrying out a hybrid process combining bentonite adsorption, ozonation, and photocatalytic membrane filtration. For the membrane, we propose a modified polyvinylidene fluoride (PVDF) membrane incorporated with graphene oxide (GO) and nickel-iron doped silica (NiFe@SiO2) photocatalyst, which is named PVDF/GO-NiFe@SiO2 membrane. The membrane was employed under different sets of filtrations (dark and under ultraviolet irradiation) to treat natural dye wastewater from textile industry effluent. Further improvement was achieved when UV light irradiation was subjected to the process. This sequential adsorption-ozonation-membrane process under UV exposure exhibited improved dye removal from 55.11 % to 97.22 %. The results show that the proposed hybrid process successfully improved the membranes' antifouling behavior, thus boosting the membranes' performance and durability. From a broader perspective, our work promotes new insights for the integration of other physical, chemical, and biological treatment methods to improve the performance and durability of membrane-based processes, particularly for dye wastewater treatment.

Biofilm Reactors: A Potential Alternative to Current Treatment Technology for Wastewater in Kathmandu Valley

Kathmandu Valley faces challenges managing its growing wastewater volume, compounded by the complex composition of unregulated industrial discharges. Releasing untreated wastewater poses a severe risk to public health and the environment. Existing wastewater treatment infrastructure, primarily reliant on conventional activated sludge processes (ASP) struggles to meet growing demands. These systems require substantial land area, are sensitive to influent variations, produce a high volume of sludge, and incur high operational and maintenance costs. Biofilms, naturally occurring assemblages of microorganisms adherent to surfaces and embedded within an extracellular polymeric matrix (EPS), present a compelling alternative for wastewater treatment due to their diverse pollutant removal capabilities. When implemented as biofilm reactors, they offer distinct advantages, including tolerance to fluctuations in wastewater composition, minimal land requirements, and reduced energy consumption. Notably, microbes residing within a biofilm are capable of biodegradation of persistent materials such as pharmaceuticals, metals, and plastics. Globally, biofilmmediated wastewater treatment has been implemented successfully, while a knowledge gap remains for the treatment of Kathmandu's wastewater. This review critically assesses biological wastewater treatment methods, providing insight into: a) suspended growth process with their configuration, application, and limitations, b) wastewater treatment infrastructures of Kathmandu Valley, and c) biofilm process with their configuration, factors influencing biofilm development and performance, application of specific microbial strains for enhanced treatment efficiency, and factors to be considered during implementation. Furthermore, the paper recommends: a) an extensive study of laboratory-scale biofilm reactors evaluating and optimizing their performance for local integration and b) investigating the role of diverse microbial communities to further enhance the treatment plant's operation. By prioritizing research and development towards biofilm technology, Kathmandu Valley can achieve efficient and environmentally friendly wastewater management.

Deep-sea microorganisms-driven V5+ and Cd2+ removal from vanadium smelting wastewater: Bacterial screening, performance and mechanism

The disorderly discharge of industrial wastewater containing heavy metals has caused serious water pollution and ecological environmental risks, ultimately threatening human life and health. Biological treatment methods have obvious advantages, but the existing microorganisms exhibit issues such as poor resistance, adaptability, colonization ability, and low activity. However, a wide variety of microorganisms in deep-sea hydrothermal vent areas are tolerant to heavy metals, possessing the potential for efficient treatment of heavy metal wastewater. Based on this, the study obtained a group of deep-sea microbial communities dominated by Burkholderia-Caballeronia-Paraburkholderia through shake flask experiments from the sediments of deep-sea hydrothermal vents, which can simultaneously achieve the synchronous removal of vanadium and cadmium heavy metals through bioreduction, biosorption, and biomineralization. Through SEM-EDS, XRD, XPS, and FT-IR analyses, it was found that V(V) was reduced to V(IV) through a reduction process and subsequently precipitated. Glucose oxidation accelerated this process. Cd(II) underwent biomineralization to form precipitates such as cadmium hydroxide and cadmium carbonate. Functional groups on the microbial cell surface, such as -CH2, C=O, N-H, -COOH, phosphate groups, amino groups, and M-O moieties, participated in the bioadsorption processes of V(V) and Cd(II) heavy metals. Under optimal conditions, namely a temperature of 40 °C, pH value of 7.5, inoculation amount of 10%, salinity of 4%, COD concentration of 600 mg/L, V5+ concentration of 300 mg/L, and Cd2+ concentration of 40 mg/L, the OD600 can reach its highest at 72 h, with the removal efficiency of V5+, Cd2+, and COD in simulated vanadium smelting wastewater reaching 86.32%, 59.13%, and 61.63%, respectively. This study provides theoretical insights and practical evidence for understanding the dynamic changes in microbial community structure under heavy metal stress, as well as the resistance mechanisms of microbial treatment of industrial heavy metal wastewater.

Performance of salt‐bridge microbial fuel cell (SB‐MFC) with various microorganism cultures on the generation of electricity from tofu wastewater

A suitable wastewater treatment system is required due to the high organic compound content in tofu wastewater, which can harm the environment. Biological treatment methods are effective for treating tofu wastewater due to its characteristics. Microbial fuel cells (MFCs) represent one such biological treatment option, effectively removing organic contaminants while generating low‐power electricity through bioenergetic reactions. In MFCs, microorganisms are used as biocatalysts to degrade the organic compounds present in wastewater. This study aimed to assess the efficacy of Salt‐bridge microbial fuel cells (SB‐MFC) using various acclimatized microbe cultures for reducing organic compounds and generating energy from tofu wastewater. Tofu wastewater was sterilized prior to introduction into the reactor. Additional microbes, including the native microbe consortium from tofu wastewater, Escherichia coli, Saccharomycopsis fibuligera, and a mixed culture of E. coli and S. fibuligera, were then introduced as biocatalysts. Carbon electrodes were utilized as both the anode and cathode. The results indicate that the mixed culture of E. coli and S. fibuligera significantly reduced COD and BOD5 levels, with removal rates of 82.74% and 76.53%, respectively, after 48 h. Furthermore, the culture generated a voltage of 676 mV, a current of 2.53 mA, a power density of 428 mWatt/m2, and 4.789×10‐2 kWh of energy. This study contributes to the advancement of SB‐MFC by utilizing wastewater and a combination of bacteria and yeast as biocatalysts.

Impact of dissolved organic nitrogen (DON) to the formation of disinfection byproducts (DBP) during water/wastewater treatment: A review

Disinfection byproduct (DBP) formation during water and wastewater treatment is a concern for public health and environmental preservation. Dissolved organic nitrogen (DON) serves as a recognized precursor to DBP formation, which can potentially jeopardize human health. This review article offers a comprehensive insight into DON's influence on DBP formation during water and wastewater treatment processes. It delves into DON's sources, properties, and concentrations in water and wastewater, underlining the variability dependent on water source and environmental conditions. The mechanisms of DBP formation from DON, encompassing formation pathways and influencing factors, are meticulously examined. Different treatment methods, like chlorination, ozonation, and UV disinfection, are carefully examined to see how they affect the formation of DON and DBP. Factors that sway DON's impact on DBP formation are also explored. The review also presents various DBP reduction techniques, spanning physical, chemical, and biological treatment methods, their efficacy in curtailing DON's influence, and their potential pros and cons. It addresses challenges, outlines future research directions, identifies knowledge gaps, and highlights the necessity for regulatory measures and policies, providing recommendations for prospective research avenues. It is clear from this in-depth review that more research is needed to understand how DON affects the formation of DBP entirely. It is also essential to protect human health and the environment and follow the rules first when treating wastewater. In conclusion, it analyzes DON's part in forming DBP in water and wastewater treatment. This emphasizes the need for ongoing research and mitigation strategies to protect public health and water quality.

Evaluation of the effluent concentrations of Karbala wastewater treatment plant using reliability analysis

Abstract The effective and consistent operation of wastewater treatment plant systems (WWTPs) is crucial for the sustainability of the environment and public health protection. The main objective of the present study is concentrated on assessing the reliability of the Karbala wastewater treatment plant’s (WWTP’s) performance. It investigates the plant’s efficiency through the weekly concentration values of three key water quality indicators, which are biochemical oxygen demand (BOD), total suspended solids (TSS), and chemical oxygen demand (COD) collected over 4 years of operation from 2020 to 2023. The methods employed were the coefficient of reliability (COR) method for plant performance in removing the effluent concentrations of 5-day biochemical oxygen demand, COD, and TSS. The analysis found that the COR values were generally close to 1 for all years, with the lowest value recorded at 0.71 in 2020, during the initial stabilization phase of the WWTP. The main finding was that the Karbala WWTP has been effective in pollutant removal. The present study is important because it supplies dependable data that wastewater treatment operators can use to assess their daily operations and gauge the success of biological treatment methods. It is worth noting that no study has been done on the reliability model for examining the quality of wastewater of the Karbala WWTP, and such a method of analysis is considered a new improvement for the evaluation of the plant to meet the Iraqi standards.

Investigating the addition of Fe for improving contaminant removal and regulating microbes in a simulated coastal wetland.

Contaminants from wastewater of aquaculture are increasing the risks of red tides in coastal areas. Such types of contaminants are difficult to remove by using conventional biological and ecological treatment methods because of the relatively low C/N ratios and the high salinity in coastal water ambience. Fe is considered a key element in natural chemical cycling and promotes the growth of animals and plants as well. The cycling of Fe ion combined with carbon, nitrogen, and phosphorus stimulates bacterial growth. As a result, it acts as a microbial carbon pump in coastal areas, such as natural wetlands, which have been activated and adapted to be salinity resistant and insufficient energy supply. Along these lines, in this work, constructed wetlands (CWs) with high ecological benefits and low cost of maintenance were used to treat aquaculture wastewater. The impact of Fe ion recycling on multiple contaminants was also systematically investigated. The two types of Fe dosage were pure ferrous ions and a mixture of iron powder and ferrous ions. After the application of a 3-day treatment, the dosage of iron powder/ferric ions (1:1 m/m) at a concentration of 15 mg L-1 showed a better effect, where the total nitrogen, total phosphorus, and chemical oxygen demand removal rates were increased by 2.95%, 2.16%, and 9.76%, respectively. From the microbial analysis, it was indicated that Fe ion affected the abundance and functions of the microbial communities in the CWs. The significant enrichment of Proteobacteria promoted the removal of multiple contaminants under saline stress and fixed carbon, and affected the whole microbe distribution and diversity in CWs. The implementation of such an environmentally friendly and economical approach arises as a promising candidate for the efficient removal of multiple contaminants from aquacultural wastewater in coastal zones.

Synthesis and characterization of X (X = Ni or Fe) modified BaTiO3 for effective degradation of Reactive Red 120 dye under UV-A light and its biological activity

For the sustainable advancement of industrial expansion that is environmentally conscious, harmful dyes must be removed from wastewater. Untreated effluents containing colors have the potential to harm the ecosystem and pose major health risks to people, animals, and aquatic life. Here, we have fabricated Ni or Fe modified with BaTiO3 materials and effectively utilized them for Reactive Red 120 (RR 120) dye degradation under UV-A light. The synthesized materials were characterized, and their structural, and photo-physical properties were reported. Phase segregation was not present in the XRD pattern, as evidenced by the absence of secondary phase peaks linked to iron, nickel, or oxides. Low metal ion concentrations may be the cause of this, and the presence of those elements was confirmed by XPS measurements. The Raman spectra of the BaTiO3/Ni and BaTiO3/Fe samples show a widened peak at 500 cm−1, which suggests that Ni or Fe are efficiently loaded onto the BaTiO3. RR 120 dye photodegradation under UV light conditions was effectively catalyzed by BaTiO3/Fe, as evidenced by its superior performance in the UV irradiation technique over both BaTiO3 and BaTiO3/Ni. Compared to bare BaTiO3, both metal-modified materials efficiently degraded the RR 120 dye. Acidic pH facilitated the degradation process, which makes sense given that the heterogeneous photo-Fenton reaction was the mechanism of degradation along with BaTiO3 sensitization. High-acidity sewage can be dangerous and carcinogenic, and conventional biological treatment methods are not appropriate for managing it. In the current investigation, it may be used to treat color effluents with extremely low pH levels. Additionally, the ability of the produced nanocomposites to inhibit the growth of twenty pathogens was examined, along with two fungi, fifteen Gram-negative Bacilli (GNB), one Gram-positive Bacilli (GPB), and two Gram-positive Cocci (GBC).

A Comprehensive Approach to Azo Dichlorotriazine Dye Treatment: Assessing the Impact of Physical, Chemical, and Biological Treatment Methods through Statistical Analysis of Experimental Data

This exploration investigates integrated treatment systems combining advanced oxidation processes (Fenton and photo-Fenton) with biological methods for the effective elimination of stubborn organic compounds in simulated textile wastewater composed of azo Dichlorotriazine dye. A comprehensive optimization of key process factors including catalyst dosage, hydrogen peroxide quantity, irradiation duration, etc. was systematically conducted for both Fenton and photo-Fenton processes to realize maximum COD and color removal. Under ideal conditions (0.4 g/L photocatalyst, 1 mL/L H2O2, and 75-Watt UV intensity for 60 min), the photo-Fenton process realized 80% COD elimination and complete decolorization, meeting industrial discharge limits without needing extra biological treatment. Statistical models correlating process parameters to treatment efficiency were developed, giving important design insights. For Fenton, effluent COD exceeded discharge thresholds, so a post-biological treatment using activated sludge was essential to comply with regulations. This integrated Fenton–biological scheme utilizes synergism between chemical and biological processes for enhanced overall treatment. Notable economic benefits were achieved by photo-Fenton over conventional UV-only and UV/H2O2 methods regarding energy consumption and operating costs. Overall, this pioneering work successfully proves integrated advanced oxidation–biological systems as a superior, sustainable alternative to traditional techniques for economically removing obstinate pollutants, such as azo Dichlorotriazine dye, as it is a simulated textile wastewater treatment used to satisfy environmental standards.

Photophysics of singlet oxygen generation in chitosan films with viburnum fruit extract (Viburnum opulus L.) under the influence of plasmons on a modified titanium surface

Subject of study. This study investigates the luminescence spectral and kinetic features of singlet oxygen generation in chitosan microfilms (10 µm thick) embedded with an extract of viburnum fruit (Viburnum opulus L.). These films were deposited on both glass and gold film (80 µm thick), with the gold film electrochemically deposited on a rough, modified titanium surface. Aim of study. The aim was to determine the primary photophysical patterns of singlet oxygen dynamics in chitosan films containing viburnum fruit extract, following pulsed monochromatic photoexcitation by a structured titanium surface coated with electrochemically deposited gold. Method. The films were investigated in the visible and near-infrared regions using fluorescence techniques. The luminescence lifetime of Viburnum opulus L. flavonoids in the nanosecond range was measured using multichannel photon counting with a picosecond diode. The lifetime of the flavonoid triplet states and singlet oxygen phosphorescence in the studied extract in the microsecond range under excitation by a pulsed xenon lamp were also recorded. Main results. Long-lived delayed annihilation fluorescence of Viburnum opulus L. flavonoid molecules in the 590 nm spectral region, along with luminescence at 1272 nm attributable to singlet molecular oxygen, were observed. A comprehensive kinetic analysis was performed, considering the rate constants of photophysical processes involving singlet oxygen in films with viburnum fruit extract on rough gold surfaces under conditions of sample saturation with molecular oxygen. Stable generation of singlet oxygen was achieved in the chitosan microfilms containing viburnum fruit extract. Practical significance. The findings of this study can be applied to biological methods for cancer treatment.

Strategies for biological treatment of waste water: A critical review

Global water demand is continuously growing due to rising population and associated industrial and agricultural activities. However, these factors are also polluting the existing water bodies and therefore, limiting the water supply. Increasing level of contaminants poses risk to human, wildlife and the environment. Widening gap between water demand and supply creates water stress. Therefore, treatment of waste water becomes imperative in order to ensure sustainable development of planet earth. Conventional methods utilizing physical, chemical and biological processes are generally adopted for this purpose. These methods are further modified so as to enhance the efficiency and economy of the treatment process as well as to make them more eco-friendly. None of the conventional or advance technology is individually sufficient for appropriate treatment of wastewater. Therefore, more efficient hybrid methods are required. The development of such hybrid methods needs detailed information about various treatment methods. This paper critically reviews the conventional and advanced biological methods used for waste water treatment. The main objective of this review is to present vital information about various biological treatment methods forming the basis for the development of sustainable hybrid methods for waste water treatment.

The Bioremediation of Industrial Effluents by Phanerochaete Chrysosporium: The COD, TOC Removal Efficiency and Biochemical Assessment for Dreissena Polymorpha

AbstractBioremediation is one of the cheapest and easy method for biological treatment for most kind of industial wastewater. Bioremediation potential of the Phanerochaete chrysosporium for industrial wastewater from Industrial Zone Wastewater plant in Mardin, Turkey, was evaluated. The chemical oxygen demand (COD) and total organic carbon (TOC) reduction efficiencies of P. chrysoporium of on wastewater studied using biomarkers such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), Thiobarbituric Acid (TBARS) and reduced glutathione (GSH) levels in Dreissena polymorpha. The level of TBARS, a marker of lipid peroxidation was found to be high because of wastewater exposure after treatment. TBARS levels decreased (from 20.2 to 31.6 and from 20.8 to 37.5). GSH levels (from 52.3 to 15.9), CAT levels (from, 119.7 to 15.3 and from 91.1 to 13.4) SOD levels (from 3.8 to 0.9 and from 3.4 to 1.2) and GPX activity (from 177.2 to 104.4 and 174.2 to 100.5) decreased in the wastewater exposure groups during 24 and 96th hour compared to the control groups. GSH levels, CAT, SOD and GPX activity increased after treatment by P. chrysosporium. Results indicate that industrial wastewater caused oxidative stress in Dreissena polymorpha. The findings revealed that the highest removal efficiency for COD and TOC, at 86.3 % and 80.3 % respectively, occurred in the 1/20 diluted medium. P. chrysosporium has proven to be effective in the bioremediation of wastewater from the Industrial Zone Changes in biochemical parameters before and after bioremediation showed that antioxidant parameters such as CAT, SOD, GPx activities and GSH and TBARS levels can be used as biomarker to evaluate bioremediation efficiency.

Promoting Water Sustainability through Degradation of 4-Nitrophenols by Spirodela polyrrhiza and Rhodococcus sp. Strain PKR-1 Association

The removal of chemicals from water sources that are harmful to humans and the environment can contribute to improving water quality. Biological treatment methods, such as bioaugmentation are an environmentally sustainable approach for pollutant removal. The 4-nitrophenol is the most hazardous nitrophenol chemical pollutant. In this study, a laboratory investigation was conducted on a flask scale to evaluate the rhizoaugmentation of 4-nitrophenol-polluted water. This was achieved by employing Rhodococcus sp. strain PKR-1, which was reintroduced into the roots of Spirodela polyrhiza. The selected strains were inoculated into the root at the rate of 104 to 106 colony-forming units (CFU) per plant. At high levels exhibited stability across five consecutive two-day degradation cycles, and full elimination of 4-nitrophenol was accomplished within these five repeated cycles. Therefore, the introduction of degraders into the root systems of aquatic plants has proven to be a successful method for treating effluents or aquatic resources contaminated with 4-nitrophenol.

The construction of a microalgal-bacterial biofilm reactor for enhanced swine wastewater treatment

Traditional biological wastewater treatment methods face challenges in treating swine wastewater with a low carbon-to‑nitrogen ratio. Microalgae show great potential in low-cost swine wastewater treatment for nutrient recovery. This study investigated the effects of altering the carbon/nitrogen/phosphorus (C:N:P) ratio in swine wastewater and immobilizing microalgae for enhancing treatment using Desmodesmus sp. A C:N:P proportion of 106:16:1 was determined to be optimal for treatment. The implementation of an inclined plate bioreactor facilitated microalgal adherence, forming a biofilm that improved treatment efficiency. The biofilm exhibited removal rates of 92 % for ammonia nitrogen (NH4+-N), 98 % for total phosphorus (TP), and 99 % for chemical oxygen demand (COD). The harvested biomass from the biofilm was 7.6 times higher than that from the suspended system with a high content (63 %) of fatty acids (C16:0, C18:0, C18:1n9c and C18:2n6c) suitable for biodiesel production. Proteobacteria were dominant in the biofilm, while Firmicutes and Bacteroidetes contributed to effective organic matter and nitrogen removal. These findings present a promising technology for cost-effective swine wastewater treatment and resource recovery.