What Hong Kong is doing is a good step but not ideal. The better approach is to expand anaerobic conversion to methane and generate electricity. That's what Oakland, CA and DC Water do. Previously DCWater produced 1200 tons per day of wet lime laden sludge. Now they produce 1/3 of the electricity that they need and have reduced the sludge volume significantly. Oakland apparently sells the excess electricity that they produce.
Published by Joseph Cotruvo, President at Joseph Cotruvo & Associates, Water , Environment and Public Health
What Hong Kong is doing is a good step but not ideal. The better approach is to expand anaerobic conversion to methane and generate electricity. That's what Oakland, CA and DC Water do. Previously DCWater produced 1200 tons per day of wet lime laden sludge. Now they produce 1/3 of the electricity that they need and have reduced the sludge volume significantly. Oakland apparently sells the excess electricity that they produce.