The theoretical analysis and modeling of nutrients in water catchments and in irrigation water is a significant issue in the design of industrial processes and devices. Besides, the amount of antibiotic resistant fecal coliform bacteria in wastewater treatment plants is important to monitor and control. In addition, the hazardous landfill leachate needs to be treated and handled properly to save the environment and public health. These three ideas are presented in this book. It includes six advanced and revised contributions, and it covers the following points of interest: (1) Nutrients and sediment loads in water catchments with heterogeneous land uses; (2) the effect of nitrogen release from bioplastic fertilizer (BpF) composites and slow release fertilizer control application; (3) prevalence of antibiotic resistant fecal coliform bacteria in wastewater treatment plants; (4) antibiotic resistant coliforms from the human gut to wastewater; (5) landfill leachate treatment by electrolysis and preparation of low cost activated carbon; and (6) treatment of scheduled waste landfill leachate and perspectives for this in Malaysia.