Journal of Hazardous, Toxic, and Radioactive Waste

Antibiotics, especially cephalosporins, have been identified as immense environmental pollutants for the generation of antibiotic-resistant gene and antibiotic-resistant bacteria due to its indiscriminate usage, enormous production and consumption, highest prescription, and longtime existence as bioactive in the environment. There are multiple sources identified for this environmental pollution and drug manufacturing units are top of the list because other sources of contamination release a lower amount of drugs through excretion but direct discharges to the environment from drug manufacturing possess a huge possibility to exert a selective pressure for antibiotic resistance. There are multiple ways of discharging environmental pollutants from a drug manufacturing unit. Man, material, and machine are all responsible for contaminating the environment from a drug manufacturing unit, which can lead to the risk of resistance to organisms, especially bacteria present in the environment, and can produce multiresistant bacteria. Some recent initiatives for degradation or removal have been published within the last couple of years featuring various aspects of antibiotics. However, a complete methodology for controlling and removal of antibiotics, especially cephalosporin antibiotic contaminants, from a manufacturing plant is still unavailable, and thus affects the management of cephalosporin discharges. This review highlights the potential sources of contamination from a cephalosporin manufacturing unit, current industrial practices, and the possible management procedure including methodologies for removal of these contaminants before exposure to the environment to control antibiotic resistance.

This study aimed to assess the biochemical methane potential (BMP) of microalgal substrates grown on high-strength beverage wastewater as a potential end-use application for biomass. Two microalgal species, Scenedesmus obliquus and Chlorella pyrenoidosa, were cultivated in standard Blue Green-11 (BG-11) media and high-strength beverage wastewater with a COD of around 5,000 mg L⁻¹. A BMP of 185.53 ± 2.66 mL CH₄ g⁻¹ VS_added was obtained from Scenedesmus grown in BG-11 media, which increased to 336.35 ± 26.56 mL CH₄ g⁻¹ VS_added after being grown in beverage wastewater. Similar increasing patterns were also observed in the case of Chlorella, where the BMP increased from 179.64 ± 4.14 to 245.51 ± 29.35 mL CH₄ g⁻¹ VS_added when changing the media from BG-11 to beverage wastewater. After lipid extraction, microalgae substrates yielded higher methane production, with 393.66 ± 41.08 and 421.86 ± 47.52 mL CH₄ g⁻¹ VS_added from Scenedesmus and Chlorella, respectively. Theoretical methane estimation from carbohydrate, protein, and lipid contents resulted in overestimating BMP. However, ANOVA statistics highlighted significant differences in experimental methane yields, and the modified Gompertz model validated the predicted BMP with the experimental values, with an R² above 0.94. Overall, this study outlines the potential for biomethane enhancement from microalgae grown in wastewater, with an extended energy recovery opportunity after lipid extraction.

The protection of wetlands plays a critical role in ecosystem health and human welfare. This research paper explores the role of major types of state action plans, including climate action plans (CAPs), hazard mitigation plans (HMPs), nonpoint source pollution management plans (NPSPs), long range transportation plans (LRTPs), and state wildlife action plans (SWAPs), to evaluate how well wetland conservation efforts have been integrated in these state-level plans in the 50 US states. A plan evaluation protocol with 15 indicators was developed to evaluate the plan integration across the 196 state-level action plans. The findings suggest that, even though various wetland conservation initiatives operate within the realm of environmental protection, a considerable number of these plans dedicate limited direct focus to wetland preservation. While the primary emphasis of these plans may not be explicitly on wetland conservation, the results unveil the degree of integration between wetland conservation and other state-level planning endeavors. The indicators show that the SWAPs obtained the highest grade among the five types of plans due to the closest natural connections of wildlife with wetland habitat. The LRTPs received the lowest score among all the plans, as expected, due to low scope of covering environmental issues. HMPs, NPSPs, and CAPs have considered wetland conservation as a useful mitigation tool in hazard risk reduction, water quality improvement, and climate adaptations, but large variations still exist among the different states. Additionally, among the indicators, coordination and policy development received relatively lower scores, suggesting that state agencies should work more proactively and collaboratively to improve wetland conservation. Incorporating wetland protection and restoration efforts in the state-level planning mechanisms is an important step toward achieving the national goal of no net loss of wetlands and improving the quantity and quality of wetlands in the United States.

Abstract

The sudden increase in phenol concentrations is frequently observed in coke-oven, petrochemical, and petroleum refinery waste streams due to changes in process parameters, posing challenges for the biological treatment processes due to the combined toxic effects of phenol with other inorganic pollutants present in the same wastewater. Owing to that fact, the versatility of the designed biological treatment system against multiple shock loading conditions needs to be analyzed before field-scale implementation. Therefore, this study aims to investigate the stability of a continuous hybrid moving bed biofilm reactor (MBBR) system against multiple and extreme phenol shock stress conditions and its impacts on the degradation of each pollutant (phenol, NH₄–N, ${\mathrm{SO}}_4^{2-}$, and NO₃–N) present in the wastewater under different metabolic conditions. The continuous hybrid system comprises three different MBBR units, such as anaerobic (CM₁), anoxic (CM₂), and aerobic (CM₃) units, connected in series and operated at 2.11 days. The system was exposed to 3,500, 4,000, and 5,000 mg/L of phenol shock loads in the presence of NH₄–N (300 mg/L) and ${\mathrm{SO}}_4^{2-}$ (200 mg/L) during Shock Phases I, II, and III, respectively. In Phase IV, the degradation performance of the system was further analyzed with 5,000 mg/L of phenol and two subsequent doses of NH₄–N (350 and 400 mg/L) to assess the system’s stability under multiple pollutant stress conditions. The system was completely recovered from the 3,500 and 4,000 mg/L of phenol stress conditions within a recovery period of 14 days, in Phases I and II. However, the ${\mathrm{SO}}_4^{2-}$ and NH₄–N removal was inhibited in CM₁ and CM₃ reactors, respectively, due to the exposure of the high concentration of phenol (5,000 mg/L). The performance of CM₁ and CM₂ was severely affected in Phase IV, even after stopping the feed. Nonetheless, CM₃ removed all the phenol from the wastewater in Phase IV, which reflects the dominance of heterotrophs. The hybrid MBBR system could withstand up to 4,000 mg/L of phenol shock load and achieved 100%, 97%, 69%, 93.51% of phenol, NH₄–N, ${\mathrm{SO}}_4^{2-}$, and NO₃–N removal during the recovery period, respectively.

Practical Applications

An abrupt change in pollutant concentration in waste streams is often observed, which becomes a stumbling block for secondary biological treatment processes due to the toxic effect. However, studies related to the treatment of multiple pollutants and achieving stable removal efficiency using a biological treatment system under multiple shock loading conditions are limited. This study shows the potential of a continuously operated hybrid MBBR system for simultaneous removal of heterogeneous pollutants (phenol, NH₄–N, NO₃–N, and ${\mathrm{SO}}_4^{2-}$) under various phenol and ammonia shock loading conditions. The results obtained from this lab-scale study could be helpful for the practitioners in designing integrated treatment systems to treat the real coke-oven and petroleum refinery effluent. The system achieved stable and higher removal efficiency for the multiple pollutants-bearing wastewater under various shock loading conditions.

Hydrochar (HC), a carbon (C)-rich solid material produced using a hydrothermal technique at relatively low temperatures and pressures, has gained little attention regarding its use as a nanocatalyst in multiple wastewater treatment technologies. These HC-based nanocatalysts, catalyst support materials, and nano-adsorbents have the advantage of being cost-effective and chemically stable, having a porous structure, semiconductive properties, and oxygen (O)-rich surface functionality. Laboratory-scale trials that have successfully used HC catalysts to accelerate the kinetics of advanced oxidation processes (AOPs) (photocatalysis, electrochemical oxidation, Fenton catalysis) are here reviewed in depth, with a special focus on the mechanisms involved. The potential of HC catalysts in energy and valuables recovery using anaerobic digestion, bioelectrochemical systems, metal air batteries, transesterification, isomerization, and reforming processes are highlighted. In addition, the synthesis of HC from waste biomass (a zero-cost C precursor) would reduce the cost of expensive electrocatalysts, reduce greenhouse gas (GHG) emissions, ensure C capture, offer a low-C economy with less of a C footprint, and enhance environmental sustainability. This review provides a unique and comprehensive sustainability related perspective on HC and HC-based nanocatalysts that can be used to positively impact the United Nations’ Sustainable Development Goals (SDGs), especially SDGs 3, 6, 7, 11, and 13. Finally, a circular economy approach that includes HC and HC catalyst use in wastewater treatment and waste management systems is discussed, along with future perspectives and challenges.

No long-term solution can evaluate the social and environmental requirements of communities near industries, especially in developing countries. The global landscape of technology, innovation, and industry has undergone significant transformation since the start of the Industrial Revolution, which has significantly altered the traditional socioeconomic structure of society, especially in urban regions. Industrialization has had positive and negative effects on society and the environment, which has left an enduring impact that includes improved employment prospects and economic growth. However, it brings adverse impacts, such as more pollution, greenhouse gas emissions, health risks, and changes in local communities and lifestyles. Threfore, efficient instruments and remedies must be used to mitigate the adverse effects of industrial activity and advances. Livability and environmental impact evaluations have become crucial tools for transforming the social and ecological spheres. Creating air pollution concentration models, particularly for industrial plumes, is a research need that is unresolved by the current environmental impact assessment (EIA) guidelines and procedures. Industries present severe risks to the population and ecosystems, because of the rapid changes in their mechanisms. In addition, no standardized method exists for assessing communities close to urban industrial clusters that encircle industrial development regions in the EIA and social impact assessment (SIA) evaluations. The national building codes (NBCs), urban and regional development plans formulation and implementation (URDPFI), and model building bylaws ignore this discrepancy. Several organizations have developed substitute models, such as California puff (CALPUFF) model from the USEPA and California Department of Pollution Monitoring, which outline risk assessment techniques for different models. Cambridge University’s Atmospheric Dispersion Modeling System-Urban (ADMS), from Cambridge Environmental Research Consultants, stands out as a widely used tool for evaluating pollution dispersion. Given the complexity of industrial emissions from several sources within a cluster of firms, a new strategy to lessen the effects of industrial plumes on the populations that live close to these zones is desperately needed. This means that communities must be categorized geographically according to different building heights and unique building regulations, which consider factors such as wind direction, atmospheric conditions, and separation from the sources of the emissions. This study used a cross-sectional methodology for a literature review of different issues that are due to the industrial plume rise heights in different domains.

Abstract

Microplastics (MPs) that are contained in water pose a great threat to the ecological environment, because they have the potential to biomagnify in the food chain, which negatively affects higher trophic level animals that include humans. In addition, they could adsorb several contaminants onto their surface due to their high adsorption capability, which poses a great risk of diseases in higher life forms. Microbial fuel cells (MFCs) can simultaneously treat MP-containing wastewater and produce value-added by-products in the form of bioelectricity; therefore, recent research is more focused on this area. This work explored the effect of MPs on chemical oxygen demand (COD) reduction, power production, and an electrochemical behavior study of the system with cyclic voltammetry (CV). The results of this work show that MPs in low concentrations (25–400 mg/L) in synthetic wastewater treatment had a more positive effect on COD reduction and power production than synthetic wastewater with no MPs and 1,000 mg/L MP.

Practical Applications

The mitigation of microplastic (MP)-containing wastewater has become very essential in today’s world. Apart from leading to water pollution, it poses significant environmental risks, such as ecosystem disruption and habitat degradation, by the accumulation of MPs in aquatic habitats, which bioaccumulate and enter the food chain. Then, they are ingested by smaller organisms and are passed onto larger ones, which adversely affects marine life. Contamination via MPs is not limited to marine ecosystems but is transferred to terrestrial ecosystems and harms terrestrial organisms, because MPs can absorb and concentrate other pollutants, such as pesticides and heavy metals, from neighboring environments. Therefore, in this work, a newer green approach has been taken to treat MP-containing wastewater and to evaluate its effect on the performance and electrochemistry of microbial fuel cells (MFCs). The results of this work show that among the cycles, Cycle 5 with 400 mg/L MP gave the highest power density of 1,971.86 mW/m², which makes it an energy-yielding process. The chemical oxygen demand (COD) removal efficiency of Cycle 2 (50 mg/L MP) was highest at 47 ± 0.5; however, Cycle 5 (400 mg/L MP) could reduce 33.3% ± 0.5% of the COD.

Abstract

This paper introduces a comprehensive approach to treating industrial laundry wastewater collected from a railway laundry, employing a novel unique sequential combination of coagulation–flocculation, neutralization, ultraviolet (UV)-H₂O₂ treatment, and biological processes. Typical characterization of laundry wastewater reveals high pH, suspended solids, dissolved organic content, and low biodegradability. The researched treatment sequence involved turbidity reduction (65%) using FeCl₃ and cationic polyelectrolyte coagulants followed by pH neutralization (7–8), UV-H₂O₂ treatment [83% and 23% chemical oxygen demand (COD) and biochemical oxygen demand (BOD) removal, respectively) and aerobic biological treatment (88% and 97% for COD and BOD removal, respectively). During the UV-H₂O₂ process, when the H₂O₂ dosage exceeded 30 mg·L⁻¹, inefficiency in COD removal was observed owing to the scavenging of hydroxyl radicals. With the increase in flow rate, the COD removal was reduced nominally. The effluent from the UV-H₂O₂ process was treated by an aerobic sequential batch reactor, demonstrating high efficacy in removing both BOD and COD. The biokinetics parameters, such as half-saturation coefficient (k_s), maximum specific rate of substrate utilization (k), yield coefficient (Y), decay rate (K_d), and maximum specific growth rate (µ_m) were determined, and they were observed to be 130 mg of COD·L⁻¹, 0.3 day⁻¹, 0.9 mg volatile suspended solids/mg COD, 0.055 day⁻¹, and 0.42 day⁻¹, respectively. Overall, a reduction of approximately 95% of COD and 97% of BOD was attained, rendering the wastewater suitable for safe disposal into inland surface waters. This showcases an effective and sustainable method for treating laundry wastewater.

Practical Applications

The present work deals with the characterization and treatment of industrial laundry wastewater. The typical laundry wastewater is mainly characterized by high suspended solids and chemical oxygen demand (COD) due to nonbiodegradable organics. The biodegradability index of the wastewater was very poor (0.15–0.25), which made it difficult to treat by conventional biological processes. Hence, a treatment chain consisting of coagulation–flocculation–sedimentation, neutralization, ultraviolet-H₂O₂ advanced oxidation process, and sequential batch reactor (SBR) was used. Alum coagulation at high pH, along with the addition of cationic polyelectrolyte, removed the suspended solids to a great extent. Sulfuric acid was found to be the most efficient to neutralize the wastewater after coagulation. In the UV-H₂O₂ process, the COD of the wastewater was reduced to < 250 mg·L⁻¹, below the discharge standard specified in the Central Pollution Control Board, India guidelines. However, the biochemical oxygen demand (BOD) was much higher compared to the discharge standard. The biodegradability index increased to 0.8, which indicated that nonbiodegradable organics were converted to biodegradable organics. The BOD of the wastewater was reduced to < 30 mg·L⁻¹ through SBR. The proposed wastewater treatment chain led to an overall 95% of COD and 97% of BOD removal.

Energy consumption reached 604 EJ in 2022 with 82% of it coming from fossil fuels and resulting in 39.3 billion tons of CO₂ emission, causing twin sustainability issues of energy security and global warming. This necessitates the energy transition from fossil fuels to renewables. Biomass, which is renewable and carbon neutral from a life cycle viewpoint, has attracted huge interest as a sustainable source for fuels and biochemicals. Agro-industry wastes, particularly nutshells, are available abundantly due to the large-scale consumption of nuts, of which walnut shells contain more than 35% lignin. Walnut shells were powdered, characterized, and subjected to organosolv extraction using ethanol as a solvent to extract lignin. The X-ray diffraction (XRD) pattern of walnut shell powder confirmed the presence of crystalline cellulose, combined thermogravimetric/differential scanning calorimetry indicated its thermal stability, and the particle size ranged from 200 to 400 nm while the ultimate analysis confirmed the absence of sulphur. Hierarchical Fe-Co-Zeolite Socony Mobil-5 (Fe-Co-ZSM-5) was synthesized by steam-assisted crystallization and its characterization by XRD confirmed the ZSM-5 structure while textural analysis confirmed its hierarchical nature. From the hydrothermal liquefaction (HTL) of the walnut shell-extracted lignin, conversion and bio-oil yield obtained in the presence of hierarchical Fe-Co-ZSM-5 of Si/(Fe + Co) ratio 60 were 6% and 53.2% higher than over hierarchical Fe-Co-ZSM-5 of Si/(Fe + Co) ratio 80 due to higher crystallinity and the amount of Fe and Co of the former. Hence, it is concluded that the Fe and Co in the tetrahedral framework of hierarchical ZSM-5 may be better active sites for the HTL compared with impregnated mesoporous support catalysts.