Assessment Of Environmental Degradation Due To Processing Of Cassava Into Garri Flakes

Abstract

The processing of cassava into garri is a multi-staged process that generates a large amount of effluent. This study was aimed at determining the impact of cassava processing into garri on the environment in Nsukka Metropolis. The soil, wastewater and sludge samples were collected from four different locations and subjected to physico-chemical analysis. The results obtained were subjected to descriptive statistical analysis and estimation of various measures of pollution indices. A detailed sanitary study of the processing plants was undertaken to ascertain their immediate and remote environmental impacts. The concentrations of hydrogen cyanide, total suspended solids and electrical conductivity were above the FEPA permissible limit and ranged from 8.6-42.8, 11900-40800 mg/l and 4006-5240 μS/cm respectively. Arsenic and mercury were above the FEPA permissible limit while the remaining heavy metals were within the permissible limits. Identified impacts from garri processing are: soil loss, litter generation, air pollution, water pollution, greenhouse gas emission, water demand and energy demand. The average pollution load index of the recipient soils ranged from moderately polluted (2.48) to highly polluted (4.56). Nemerow’s pollution index (NPI) indicated that soil samples from three of the locations were severely polluted (>3.0), while one was moderately polluted (2<PI<3). The geoaccumulation indices ranged from -0.03 (uncontaminated) to 2.59 (heavy contamination). The values of Er ranged from 5.63 to 91.8 for all metals investigated. The order of ecological risk of various metals based on their average values was: As>Cd>Cu>Cr>Pb>Ni with corresponding ecological risk values of 50.63 (moderate risk), 34.43 (low risk), 15.93 (low risk), 10.51 (low risk), 8.93 (low risk) and 5.63 (low risk).

Preliminary characterization and probabilistic risk assessment of microplastics and potentially toxic elements (PTEs) in garri (cassava flake), a common staple food consumed in West Africa

“…For the PTEs, the PCA and HCA generally showed three main clusters or components (PC 1, PC 2 and PC 3) accounting for 46.87 %, 33.06 % and 18.34 % of the total variance respectively based on eigen value greater than 1 (Figure 10). PC 1 or cluster B contain Cu, Zn and Fe, which source is geogenic [44] and anthropogenic particularly from the use of iron pan for frying the garri during production [55] or from atmospheric deposition during vending in markets [8]. PC 2 or cluster A contains Cr and Mn, which could be from the frying process using high energy/combustion sources such as firewood, coal and fuel oil burning [14,56]…”