treatment facility sludge disposal essential component ultimate disposal final disposal dried sludge effective handling sludges volume enterprises role popular technique costeffective stabilization total volume frequently recycled facilitates dewatering dewatering drying sludge produced controllable sludge properly sludge operations sludge clarifying sludge businesses realize safe sustainable worldwide movements creative configurations building materials farming biogas final processing vital part severe penalties regulatory noncompliance sizable amount disease outbreaks improperly treated moisture level drastically lower aerobic digestion situation functions improperly controlled heavy metals special problem solid material systems operation larger picture successfully eliminated dangerous pollutants important parts sewage treatment sludge management surface water treated water sewage sludge environmental impact resource recovery organic contaminants public health organic debris municipal wastewater contemporary wastewater environmental planners biologically broken human health environmental sustainability sludge important wastewater management sewage sludge wastewater water treatment plant energy recovery dumped microorganisms organic matter biologically treated prior efficient wastewater management human health purchasing sedimentation biological treatment untreated sludge poses activated sludge process make sludge safer handle huge amounts occasionally hazardous substances circular economy conclusion producing highquality effluent normal stp produces causing ecological imbalances pollute soil groundwater soil conditioner importance belt filter presses pathogenic content anaerobic present significant threats urban populations develop