Explore the vast range of titles available.

Water recycling is of increasing concern due to the shortage of natural resources, calling for advanced methods to remove contaminants. Indeed, the transfer of contaminants to living organisms may lead to bioaccumulation and diseases. In particular, the overuse of antibiotics for human and animal health has led to antibiotic pollution in waters, sludges and crop soils, and, in turn, to the unintended development of multi-resistant bacteria, named antibiotic resistance. Here we review antibiotic properties, antibiotic occurrence in wastewater, and antibiotic removal. Remediation techniques include electrocoagulation, photocatalysis, Fenton process, sonocatalysis, ozonation, membrane filtration, adsorption and ionizing irradiation. Nanofilters and reverse osmosis showed the highest removal of antibiotics in a bioreactor, averaging at 95%. Recently developed methods such as photocatalysis, sonocatalysis and ozone oxidation show a removal of about 98%.

Increasing pollution of ecosystems is calling for sustainable methods to remove pollutants. In particular, electrodeionization has recently emerged as an efficient technique to remove ionic compounds from contaminated waters. Electrodeionization involves a continuous process of electrochemical water deionization using ion-specific membranes, mixed-bed resins and a direct current voltage. Electrodeionization is thus safer than classical treatments with acids, bases and other chemicals. Electrodeionization produces highly pure water, allows efficient ion removal and does not require chemicals for resin regeneration. Electrodeionization for water purification overcomes limitations of resin beds for ion exchange, particularly the release of ions as the beds exhaust. Applications include the removal of toxic chemicals, radioactive pollutants, heavy metal ions and corrosive anions; the regeneration of valuable metals; the deionization of water and the removal of nitrates. Continuous electrodeionization requires performance optimization and modification of the stack configuration. This article reviews principles and applications of ion removal, transport and reaction mechanisms, and factors controlling the efficiency.

Climate change issues are calling for the design of renewable sources of energy. In particular, biomass energy from algae is encouraging because production of algae at the commercial scale can be done successfully with various techniques. Here, we review the conversion of algal biomass into energy by fast, slow, microwave and catalytic pyrolysis. The article details algae classification; cultivation of macroalgae and microalgae; pyrolysis parameters; production of biochar, bio-oil and biogas; and types of pyrolysis.

Biogas production is rising in the context of fossil fuel decline and the future circular economy, yet raw biogas requires purification steps before use. Here, we review biogas upgrading using physical, chemical and biological methods such as water scrubbing, physical absorption, pressure swing adsorption, cryogenic separation, membrane separation, chemical scrubbing, chemoautotrophic methods, photosynthetic upgrading and desorption. We also discuss their techno-economic feasibility. We found that physical and chemical upgrading technologies are near-optimal, but still require high energy and resources. Biological methods are less explored despite their promising potential. High-pressure water scrubbing is more economic for small-sized plants, whereas potassium carbonate scrubbing provides the maximum net value for large-sized plants.

Actual agricultural practices produce about 998 million tonnes of agricultural waste per year. Therefore, converting lignocellulosic wastes into energy, chemicals, and other products is a major goal for the future circular economy. The major challenge of lignocellulosic biorefineries is to transform individual components of lignocellulosic biomass into valuable products. Here we review lignocellulosic biomasses such as coffee husk, wheat straw, rice straw, corn cob, and banana pseudostem. We present pretreatment technologies such as milling, microwave irradiation, acidic, alkaline, ionic liquid, organosolv, ozonolysis, steam explosion, ammonia fiber explosion, and CO2 explosion methods. These methods convert biomass into monomers and polymers. For that, the concoction pretreatment methods appear promising.

Food safety is a major concern in the context of rising population and decreasing earth resources. Food is often contaminated by bacteria, viruses, fungi and parasites, which induce disease such as hemolytic uremic, irritable bowel and Guillain–Barre syndromes. Detection of pathogenic microbes is therefore essential for food safety. Detection methods include biological methods, biosensors and methods based on spectroscopy, immunology and nucleic acids. Here, we review advanced detection techniques used to analyze toxic substances in food.

Artificial intelligence (AI) is currently making an appearance in the wastewater treatment industry because of its effectiveness, speed, and independence from human intervention. This in-depth analysis examines the underlying ideas of AI and how they apply to the field of wastewater treatment. This review explores cutting-edge AI technology, focusing on water quality monitoring, where AI-driven innovations have completely changed how water quality data is gathered and analysed. Also, it reviewed AI applications in adsorption, coagulation for removal of microorganism, heavy metals, organic and inorganic chemicals, dyes, and other emerging pollutants present in water and its process optimisation, prediction of capacity and efficiency, real-time monitoring, and better material selection in all conventional techniques. With a focus on intelligent electrode material selection, electrochemical process optimisation, and electrochemical system predictive maintenance, we examine the synergy of AI in electrochemical wastewater treatment. The paper also looks at AI applications in various areas of wastewater treatment, including advanced oxidation processes (AOPs), AI-based membrane material selection, and biological wastewater treatment. This includes cost–benefit analysis of AI deployment in wastewater treatment facilities, together with AI-driven financial optimisation and return on investment analysis, because economic factors are vital for technological acceptance. At the end of the article potential future possibilities for AI applications in this industry and analysing the difficulties encountered while integrating AI in wastewater treatment has been highlighted. Overall, incorporating AI into wastewater treatment procedures has a lot of potential to improve global sustainability, efficiency, and environmental protection.

Pharmaceutical compounds such antibiotics, anti-inflammatories, psychotropics, human drugs, hormones, anticonvulsants, antidepressants, veterinary drugs and steroids occur widely in wastewater and drinking water. This pollution by active compounds and their metabolites is expected to increase with rising global population. Therefore, advanced monitoring and remediation techniques are needed. Here we review analytical and removal techniques for pharmaceuticals. Techniques focus on titrimetric, electrochemical, chromatographic and electrophoresis for analysis, and on membrane bioreactors for removal.

Eggshell (ES)‐based photocatalysts have gained attention in recent years. They are less toxic, abundant, affordable, and efficient photocatalysts in treating dye‐polluted water. This work reports the deterioration of Congo red (CR) under visible light region using ES‐integrated graphitic carbon nitride (g‐C 3 N 4 ). The photocatalyst was prepared by thermal condensation by varying the mass ratios of ES powder. The material structure and the morphological characteristics are confirmed using FTIR, XRD, BET, UV‐DRS, UV‐Vis spectra, SEM, EDAX, and photoluminescence. By optical investigations, the band gap of bare ES was found to have a value of 5.04 eV. It was narrowed down to 2.57 eV at the optimum composition of ES/g‐C 3 N 4 . The effects of several reaction parameters, such as the initial concentration of dye, the amount of catalyst, and the pH level of the solution on the photodegradation rate were investigated. The degradation results revealed that the catalyst removed around 90.5% of the CR dye in 90 min at 498 nm when subjected to visible light. A pseudo‐first‐order model was concluded from the kinetic data analysis of the mineralization of CR dye using carbon nitride photocatalysts infused with eggshells. The photodegradation rate of 5% ES g‐C 3 N 4 was three times greater than that of pure g‐C 3 N 4 , indicating a decreased recombination rate of the electron‐hole pair.

Biotransformation of organic wastes into value-added products is gaining interest owing to waste management issues, exhaustion of fossil fuels and the demand for biodegradable plastics. Lactic acid is widely used for polymers, foods, beverages, medicines, cosmetics and clothing. However, the major obstacle in large-scale fermentation of lactic acid is achieving enhanced yield, productivity and optical purity with cheap resources. Therefore, we review methods and recovery techniques for production of microbial lactic acid using cheap fermentative substrates. New strategies allow to alleviate limitations associated with substrate inhibition, product inhibition, undesirable by-products, sensitivity to toxic compounds, inefficient utilization of mixed sugars and overuse of neutralizing agents. Efficient utilization of mixed sugars can be achieved with simultaneous saccharification and fermentation using mixed cultures, isolating carbon catabolic repression-negative strains and altering the metabolic pathway. Lactic acid productivity can be improved by co-culture, maintaining high cell density and periodically removing end-products accumulated in the fermentation medium. Inhibition by toxic compounds can be eliminated by using engineered feedstock which releases less inhibitors, by using inhibitor-tolerant microbes and by development of genetically engineered strains. Fed-batch fermentation was found to be better than other operation modes due to less substrate inhibition.