**4. Conclusions**

Agro wastes or residues such as sugars, cellulose, minerals, and proteins are well off with nutrient composition and valuable bioactive compounds. Consequently, agro wastes having heterogeneity composition can be considered as "precursor" for other industrial processes instead of "wastes" keeping in mind sustainable development. Solid-state fermentation is a familiar approach for the production of microbial metabolites over agro waste with a low moisture content, with the advantages of a high yield concentration but only a proportionate minimum energy being needed. Various microbes have prospective to utilize the agro waste as raw materials for their growth through fermentation processes going for generation of biofuel as an alternative to faster depleting fossil fuel. The agro waste direct or active carbon generated from it can be suitable use for wastewater treatment. Vermicompost can be produced on the degradation of various agro wastes using numerous species of worms within 3–4 month time periods, which have advantages as (a) it can proceed as biofertilizers, reinstate soil nutrients, stabilizes the soil, and augmented the fertility of soil over an extended period; (b) it sorts out the social demands and recycles the waste; and (c) it is observed to be a beneficial endeavor as a circular economy. Vermicompost is found

to be better option as compared with the normal composting, commonly adopted in Asian countries, owing to its enhanced nutrient contents, i.e., nitrogen, phosphorus, and potassium content. The vermicomposting also has capability to enhance the soil structure and to improve its water-holding capacity. The vermicomposting is considered to be ideal organic manure for better growth and yield of agricultural product. The agro waste can be suitably used as lowcost adsorbent for wastewater treatment. One of the most ways to generate revenue from agro waste by converting into nanocellulose and activated carbon, which have a multidisciplinary applications per today's market demands. The agro waste can have different environmental approach that leads for waste to revenue generation.
