Table 1.

Advantages and disadvantages of anaerobic process [3, 15].

Advantages

Disadvantages

(i) Reduction of greenhouse gas emissions through methane recovery. (ii) High treatment efficiency for biodegradable sludge. (iii) Production of methane gas (potential source of fuel). (iv) A high degree of waste stabilization is possible. (v) Simplicity. (vi) Flexibility: anaerobic treatment can easily be applied on either a very large or a very small scale. (vii) Space saving (higher loading rates require smaller reactor volumes thereby saving on disposal cost). (viii) Less requirement of energy and oxygen. (ix) Inoffensive residual sludge may be used as soil conditioner. (x) Low nutrients and chemicals requirement.

(i) Long recovery time: it may take longer time for the system to return to normal operating conditions if shock loading happens. (ii) Low pathogen and nutrient removal. (iii) Long startup. (iv) Possible bad odors. (v) High sensitivity of methanogenic bacteria to a large number of chemical compounds. (vi) Small- and middle-scale anaerobic technology for the treatment of solid waste in middle- and low-income countries is still relatively new.