Minimization of sludge production by a side-stream reactor under anoxic conditions in a pilot plant

► An anoxic side-stream reactor (SSR) at −150 mV minimizes sludge production. ► Treating the whole sludge line in the SSR reduces the observed yield by 18.31%. ► The applied sludge loading rate is the key parameter for sludge minimization. ► Application of an SSR improves settleability and maintains removal efficiencies.