If you don't maintain your engine oil properly, your car can develop a lot of issues, including engine sludge. Engine sludge — sometimes called oil sludge — is a thick, jelly-like substance ...

Sludge generated by Charlotte Water plants is recycled on more than 17,000 acres of private farmland in North and South ...

NAGOYA--Sludge generated through sewage treatment is set to be marketed by city officials here as the perfect fertilizer rich in nitrogen and phosphorus. Nitrogen is an indispensable ingredient ...