INTRODUCTION

As legal frameworks and regulations have progressively tightened their restrictions, various industries and municipalities have responded by adding or expanding unit processes at their treatment plants. As a result of this evolution, the quantity and variety of wastewater sludge has increased, and in many cases, this sludge must be dewatered before final disposal or eventual reprocessing. Surprisingly, the costs associated with the processing and proper disposal of sludge, especially its dewatering, can approach almost half of the maintenance and operating costs in the treatment plant's budget. Therefore, while acknowledging that this is not an "easy" issue to address, it is extremely important to carefully evaluate and participate in the selection of the various alternatives.

It is precisely with this spirit of cooperation that we present today this modest beginning, a joint effort of James C. Young Environmental and Balestie & Balestie Ingenieros /CTI SA. It is our sincere conviction that the dissemination of advances, experiences and conclusions among equipment suppliers, industrial and municipal users, as well as other professionals in the sector, can only result in a marked benefit, both in the evaluation of alternatives and in the resolution of the various daily situations that arise in the operation, even if adequate, of this type of unit.

We want to express our recognition and gratitude to all the firms and specialists who have collaborated with technical material, observations and summarized comments from decades of experience, without which this digital booklet, among other things, would probably never have existed.

Finally, it is our wish that, gradually, it can provide genuine support to both field professionals and staff at research centers, specialists, technology laboratories, universities, and related institutions.