Disintegration of biological sludge. A comparison between ozone oxidation and ultrasonic pretreatment

The effects of ozone oxidation and ultrasonic pretreatment on anaerobic sludge bio-processing have been studied. Ultrasound (9690 kJ/kg total solids (TS) of specific energy) and ozone (0.1 g O3/kg TS) were applied to sludge samples preceding anaerobic sludge digestion for disintegration purpose. Organic matter reduction and methane production were measured, as well as physicochemical characteristics (pH, alkalinity, and particles size) and dewatering characteristics of sludge during semi-batch anaerobic digestion. For each treatment, 5 days of sludge retention time were applied on mesophilic conditions for 30 days operation period. The highest volatile solids reduction was obtained with ozone oxidation. Moreover, disintegrated sludge with ozone oxidation and ultrasonic pretreatment provided 55% and 49% higher methane production comparing to the raw sludge, respectively. In terms of dewatering characteristics of digested sludge, ultrasonic treatment led to an increase in the sludge's resistance to dewatering. This negative effect was not observed in ozone oxidation. © 2019 Technical University of Wroclaw. All rights reserved.105Y337; Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAKThe authors express sincere appreciation to the Scientific and Technological Research Council of Turkey (TUBITAK) for supporting the study under award #105Y337: Sludge Disintegration using Advanced Oxidation Processes

DISINTEGRATION OF BIOLOGICAL SLUDGE. A COMPARISON BETWEEN OZONE

The effects of ozone oxidation and ultrasonic pretreatment on anaerobic sludge bio-processing have been studied. Ultrasound (9690 kJ/kg total solids (TS) of specific energy) and ozone (0.1 g O-3/kg TS) were applied to sludge samples preceding anaerobic sludge digestion for disintegration purpose. Organic matter reduction and methane production were measured, as well as physicochemical characteristics (pH, alkalinity, and particles size) and dewatering characteristics of sludge during semi-batch anaerobic digestion. For each treatment, 5 days of sludge retention time were applied on mesophilic conditions for 30 days operation period. The highest volatile solids reduction was obtained with ozone oxidation. Moreover, disintegrated sludge with ozone oxidation and ultrasonic pretreatment provided 55% and 49% higher methane production comparing to the raw sludge, respectively. In terms of dewatering characteristics of digested sludge, ultrasonic treatment led to an increase in the sludge's resistance to dewatering. This negative effect was not observed in ozone oxidation.C1 [Erden, Gulbin] Pamukkale Univ, Dept Environm Engn, Kinikli Campus, TR-20070 Denizli, Turkey.[Filibeli, Ayse] Dokuz Eylul Univ, Dept Environm Engn, Tinaztepe Campus, TR-35160 Buca Izmir, Turkey

Use of drainability and filterability simulations for evaluation of oxidative treatment and polymer conditioning of sludge

In the traditional view of sludge structure, a two-phase system is visualized. The solid phase is often illustrated as consisting of uniform, spherical, negatively charged particles. This simplistic picture limits the understanding of both conditioning and dewatering. Specifically, it limits us to only two strategies for destabilization: charge neutralization (using cationic coagulant species with either uniform or patch effects), and bridging (using polymeric flocculants). In fact, the situation is more complex in many respects. In this paper, we compared chemical conditioning of anaerobically digested biosolids using (1) conventional polymeric flocculation, and (2) treatment by chemical oxidants. Since these strategies may alter dewatering behavior by very different mechanisms, we report comparisons using a lab-scale simulator of belt press dewatering, including separate steps for the drainage and filtration processes. This allows greater insight into the effects of these conditioning methods and how they might be properly employed.</jats:p

Control of pollution in organized industrial districts: A case study from Turkey

At Manisa Organized Industrial District (OID) chosen as pilot study area, a detailed wastewater profile and pollution control study has been realized. A pretreatment strategy was determined and a wastewater management plan was prepared. Existing central treatment plant was studied and cost items were determined. These evaluations were compared with the redesign options generated from our own wastewater management plan. Same treatment units and their combinations were successively designed for variable flow rates between 100-50,000 m(3)/d. Thus data for new OIDs of similar nature as Manisa, an optimized treatment scheme as well as its approximate cost varying with the wastewater inflow was generated. Proposals for preparing environmental criteria to be considered and applied in newly establishing or planned OIDs are summarized. Copyright (C) 1996 IAWQ

ULTRASONIC PRE-TREATMENT OF WASTEWATER SLUDGE FROM A MEAT PROCESSING

This investigation deals with ultrasonic disintegration of sludge taken from a meat processing wastewater treatment plant. Different specific energy inputs ranging between 0 and 100 MJ/kg Total Solids (TS) were used in the study. The effect of ultrasonic pre-treatment on anaerobic biodegradability and filterability characteristics of sludge were evaluated using lab-scale experiments. 30 MJ/kg TS of supplied energy is efficient for cell lyses. Ultrasonic pre-treatment significantly enhanced the biodegradability of sludge. Biochemical methane potential test results also supported this result. For 30 MJ/kg TS, 2.4 times higher methane production was achieved compared to raw sludge. Sludge's supernatant characteristics were also affected by the ultrasonic pre-treatment. For 30 MJ/kg TS, oil content, total nitrogen and total phosphorus in the sludge supernatant increased by 3.8 times, 58 times, and 12 times, respectively. The other result is that ultrasonic treatment adversely affected filterability characteristics of sludge even for very low specific energy levels