KIM HARRISBERG MIMI Ngalula never imagined cardboard boxes, cans and bottles would save her five children from hunger during lockdown, but over the past four months, digging through Johannesburg's trash cans has become her lifeline. Ngalula, a refugee from the Democratic Republic of Congo (DRC), is one of hundreds of people in the neighbourhood of Lorentzville who joined a project to exchange recyclables for a digital currency that they use to buy much-needed groceries. Run through local charity Love Our City Klean (LOCK), the project gives recyclers a card with a unique barcode that is used to load their recycling…