Assessment of Co-compost Quality by Physico-chemical and Exploratory Data Analysis

Abstract

The dynamic parameters of the transformation of fresh cow dung (FCD), municipal solid waste (MSW), pond sediment (PST), tea pruning litter (TPL), tea waste (TWE), and water hyacinth (WHH) into a manure using a co‐composting process were investigated. Among the six different modes of compost, it was observed that the best quality of compost can be produced where the substrate was FCD/MSW/TPL/PST/TWE/WHH 1:1.5:1.5:2.5:2.5:1 with respect to Indian compost standard. Hierarchical agglomerative cluster analysis (HCA) for physical and chemical variables during composting yielded a dendrogram and formed two clusters, one of which includes temperature, amount of cadmium, chromium, copper, lead, MSW, nickel, phosphorus, and zinc and the other includes cation exchange capacity, FCD, germination index of chickpea, germination index of green gram, mercury, nitrogen, organic carbon (OC), pH, TPL, potassium, PST, TWE, and WHH. Principal component analysis (PCA) was applied to all the data sets, which resulted in nine, four, four, three, and two latent factors of the total variance in compost quality. Varifactors of PCA implied that the parameters responsible for metals and P were MSW and temperature variation, N was mainly related to PST and TWE whereas OC was influenced by TPL and FCD. Therefore, on application of HCA and PCA, a meaningful classification of the above‐mentioned parameters has been obtained. Thus, these results should be effective measures for future in using tea garden waste materials for the preparation of valued eco‐friendly compost.