System water recirculation needs to be given the highest priority whenever and wherever possible by the industries. This means that the conventional wisdom of end-of- pipe treatment for pollutants discharge may not be sufficient. Additional in-plant water conservation efforts are becoming necessary to reduce the volume of effluents discharged and minimize solid waste for disposal. The development of process integration technique has been one of the most significant advances in waste minimisation in the past decades. Via in-plant material reuse/recycle, both raw material consumption and waste generation are reduced significantly. The book discusses methods for waste water recycling in the process, using water pinch technique by giving actual industrial example. Process integration without and with treatment of paper mill effluent is discussed in details by Authors. In addition saving in terms of money, by reduction of pollution discharge and fresh water consumption is also analyzed. This book will be useful for process engineers, environmental engineers, students, researchers, consultants, managers and other professionals working in the water recycling field.