Enzymes are biological molecules produced by living entities for carrying out biological processes. The application of enzymes for waste treatment has been gaining pace commercially to solve concerns related to agricultural residues, wastewater, replacement of synthetic processes with natural ones, etc. The application of enzymes for waste management has been an environmentally reliable and sustainable process. Treatment of waste with enzymes such as xylanase, proteases, hydrolases, cellulose, peroxidases, chitinases, laccases, etc. has been studied to be effective. These enzymes act upon the waste products and transform them into biodegradable forms that can be recycled, reused and converted to value-added products. They have wide applications and utility as it has been an effective approach, economically cheaper and sustainable techniques. Application of such enzymes for waste management would be beneficial for reducing the quantity of waste, diminishing the negative effects of waste and pollution on the environment, and would be beneficial in bio-converting the waste products into alternate sources of energy. The current chapter focuses on different types of enzymes, their applications for waste management, and their limitations. This chapter also emphasizes the usage of some prominent microorganisms, their secreted enzymes and their proposed mechanisms of action involved with the degradation of the waste products.

Nanoscience is a rapidly growing science stream that has been one of the cost-effective and energy-efficient approaches with wide applications. Water pollution is a major issue that is increasing continuously due to anthropogenic activities and several organic and inorganic contaminants. To overcome this issue, nanoparticles (NPs) have been successfully used to treat water. These NPs possess many beneficial applications in many fields like agriculture, cosmetics, photoconductors, environmental biotechnology, glass and alloy production, solar cells, nanomedicine and drug deliveries, biosensors, food industries, etc. The properties comprising high surface area, greater chemical reactivity, and mechanical properties play a vital role in imparting such beneficiary properties. As a result, there has been an increasing demand for the synthesis of NPs. However, excess usage of NPs further creates toxic by-products. Therefore, scientists and researchers are now focussing on the biogenic synthesis of NPs. The biological routes of NP synthesis have been crucial because they are eco-friendly and environmentally safe. This chapter highlights the usage of different approaches and biogenic sources for the production of NPs. It also discusses the recent advancement in the use of biogenic NPs with respect to applications for wastewater treatment.

: This article reports on polymer (PLLA, poly(L-lactic acid)) nanosheets incorporated with Fe-ion nanoparticles, aiming at using the latter nanoparticles as source to release Fe ions to facilitate burn wound healing when such nanosheets are applied on skin as biomedical tissue. Laser ablation in liquid phase was used to produce Fe-containing nanoparticles that after incorporation into PLLA nanosheets would release Fe ions when in immersed in water. Such nanoparticles prepared in chloroform are shown by XPS to be based on iron chloride and oxide phases. After incorporation into PLLA nanosheets, the ion –release test demonstrated that Fe ions could be released successfully into water at pH 7.4, which implies that such polymer nanosheets show promise for biomedical applications as potential patches for healing burn wounds. Incorporation with two different metal ions (Fe and Zn) is shown to be efficient and both types of ions were demonstrated to be released simultaneously and with comparable release rates.