Effect of adding wood chips on sewage sludge dewatering in a pilot-scale plate-and-frame filter press process

RSC Advances ◽  
2014 ◽  
Vol 4 (47) ◽  
pp. 24762-24768 ◽  
Author(s):  
An Ding ◽  
Fangshu Qu ◽  
Heng Liang ◽  
Shaodong Guo ◽  
Yuhui Ren ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Wood Chip ◽  
Pilot Scale ◽  
Filter Press ◽  
Wood Chips ◽  
Physical Conditioning ◽  
Sludge Dewatering ◽  
Sludge Cake ◽  
Dewatered Sludge

Schematic mechanism of the effect of adding wood chips on sludge dewatering: (a) sludge without conditioning; (b) sludge with chemical conditioning; (c) sludge with chemical and physical conditioning; and (d) a physical image of a dewatered sludge cake with wood chip conditioning.

scholarly journals Full-scale performance of selected starch-based biodegradable polymers in sludge dewatering and recommendation for applications

2017 ◽  
Vol 77 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Kuangxin Zhou ◽  
Johan Stüber ◽  
Rabea-Luisa Schubert ◽  
Christian Kabbe ◽  
Matthias Barjenbruch
Keyword(s):  
Biodegradable Polymers ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Full Scale ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Operational Parameters ◽  
Sludge Dewatering ◽  
Dewatered Sludge ◽  
Green Polymers

Abstract Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the use of starch-based polymers for full-scale dewatering of municipal sewage sludge. The laboratory-scale and pilot-scale trials paved the way for full-scale trials at three WWTPs in Germany. The general feasibility of applying starch-based ‘green’ polymers in full-scale centrifugation was demonstrated. Depending on the sludge type and the process used, the substitution potential was up to 70%. Substitution of 20–30% of the polyacrylamide (PAM)-based polymer was shown to achieve similar total solids (TS) of the dewatered sludge. Optimization of operational parameters as well as machinery set up in WWTPs is recommended in order to improve the shear stability force of sludge flocs and to achieve higher substitution potential. This study suggests that starch-based biodegradable polymers have great potential as alternatives to synthetic polymers in sludge dewatering.

Characteristics of Sewage Sludge Affecting Dewatering by Belt Press Filter

1990 ◽  
Vol 22 (12) ◽  
pp. 143-152 ◽  
Author(s):  
M. Hashimoto ◽  
M. Hiraoka
Keyword(s):  
Sewage Sludge ◽  
Moisture Content ◽  
Charge Density ◽  
Suspended Solids ◽  
Factors Affecting ◽  
Solids Concentration ◽  
Sludge Cake ◽  
Extension Degree ◽  
Dewatered Sludge ◽  
Belt Press

Dewatering characteristics of sewage sludge were determined by conditioning the sludge with the most effective cationic polyelectrolyte studied, and dewatering using a belt press filter. The characteristics of sludges (16 mixed, and 8 anaerobically digested) were measured for 33 factors affecting dewaterability. The correlations of sludge factors with sludge dewaterability were investigated. The results revealed the following. A factor affecting the gravitational filterability of conditioned sludge is the suspended solids concentration of raw sludge. A factor affecting the moisture content of dewatered sludge cake is viscosity of the sludge adjusted to 4.0 % of suspended solids concentration. Factors affecting the viscosity are the intrinsic viscosity of alkaline extracts, the ratio of (VSS-Fiber)/SS : Ash/SS : Fiber/SS, and the charge density of sludge particles. A factor affecting the extension degree of dewatered sludge cake is the charge density of sludge particles. Factors affecting the amount of residual solids on the filter cloths are the charge density of sludge particles and the fibrous substances content of sludge. As for polyelectrolytes, a highly cationized polyelectrolyte is effective to lower the moisture content, the extension degree and the amount of residual solids on filter cloths. And a factor affecting the required dosage of a polyelectrolyte is anionic substances content in the liquid of raw sludge.

The Effect of Shear on Conditioning: Chemical Requirements during Mechanical Sludge Dewatering

1990 ◽  
Vol 22 (12) ◽  
pp. 117-124 ◽  
Author(s):  
John T. Novak ◽  
Daniel P. Lynch
Keyword(s):  
Filter Press ◽  
Sludge Dewatering ◽  
Sludge Cake ◽  
Laboratory Procedures

In this study it is shown that the shear occurring in a sludge cake during dewatering can create an increase in polymer demand. Comparisons between a laboratory mixing unit and a pilot filter press indicate that polymer requirements for mechanical dewatering equipment can be predicted using laboratory procedures.

Evaluation of novel drum chipper technology: pilot-scale production of short wood chips

TAPPI Journal ◽  
2019 ◽  
Vol 18 (10) ◽  
pp. 585-592
Author(s):  
JESSICA GARD TIMMERFORS ◽  
LEIF J. JÖNSSON
Keyword(s):  
Wood Chip ◽  
Pilot Scale ◽  
Wood Chips ◽  
Scale Production ◽  
Pilot Scale Production ◽  
Average Wood ◽  
Pulping Liquors

Impregnation of wood chips with acidic pulping liquors is improved when using short chip lengths. If the average wood chip length is too short, conventional chipping technology will generate excess small material, such as pin chips and fines. The possibility of using newly developed drum chipping technology to produce shortlength wood chips was evaluated with a pilot drum chipper operating at different drum velocities and in-feed angles. With a drum velocity of 30 m/s, the average wood chip lengths and the combined fractions of pin chips and fines were 24 mm and 3.3%, 22 mm and 4.2%, and 17 mm and 8.5%. The highest fractions of total accept chips (large and small accepts), 89% to 90% without screening, were observed for drum velocities of 30–34 m/s and average wood chips lengths of 21–22 mm. The results indicate the potential of drum chipping technology for producing short wood chips with relatively high fractions of accept chips and tolerable fractions of pin chips and fines.

Distribution and speciation of heavy metals in two different sludge composite conditioning and deep dewatering processes

RSC Advances ◽  
2015 ◽  
Vol 5 (124) ◽  
pp. 102332-102339 ◽  
Author(s):  
Chao Li ◽  
Shinan Zhang ◽  
Jiakuan Yang ◽  
Yafei Shi ◽  
Wenbo Yu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Red Mud ◽  
Pilot Scale ◽  
Sludge Dewatering

Pilot-scale sewage sludge dewatering experiments were conducted using two composite conditioners: FeCl3 + lime (Fe-lime) and Fenton's reagents + red mud (Fenton-RM).

A Comparative Study of Full-Scale Sludge Dewatering Equipment

1993 ◽  
Vol 28 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Ina Andreasen ◽  
Bente Nielsen
Keyword(s):  
Comparative Study ◽  
Wastewater Treatment Plants ◽  
Membrane Filter ◽  
Filter Press ◽  
Full Scale ◽  
Sludge Dewatering ◽  
Dewatered Sludge ◽  
Solids Content ◽  
Very High ◽  
P Removal

A comparative study of 4 different types of full-scale sludge dewatering units was performed in 1990 by I. Krüger AS in co-operation with the equipment suppliers. The purpose of the study was to examine the capability of the dewatering equipment on the “new” sludge types from wastewater treatment plants with N and P removal. The achieved results have formed the basis of a financial evaluation comprising construction and operating costs. The objective of the evaluation is to compare the total costs involved in sludge dewatering and disposal. The relatively cheap types of dewatering units (belt filter press, solid bowl centrifuge) produce dewatered sludge with a lower dry solids content than the more expensive equipment (press centrifuge, membrane filter press). The latter types should consequently primarily be applied where the dewatered sludge has to meet special requirements and in situations in which disposal costs are very high.

scholarly journals Evaluation of passive reduction of nitrate from greenhouse effluent by planted bioreactors

2017 ◽  
Vol 17 (6) ◽  
pp. 1764-1773 ◽  
Author(s):  
S. Fatehi Pouladi ◽  
B. C. Anderson ◽  
B. Wootton ◽  
L. Rozema
Keyword(s):  
Nutrient Removal ◽  
Nitrate Reduction ◽  
Wood Chip ◽  
Pilot Scale ◽  
The Other ◽  
Wood Chips ◽  
Carbon Limitation ◽  
Typha Angustifolia ◽  
Nutrient Treatment ◽  
Distinct Increase

Abstract A number of pilot-scale gravel and wood-chip hybrid bioreactors planted with select species, together with unplanted units, were evaluated for their nutrient removal capabilities from the typical greenhouse effluent with high levels of nitrate and salts. Two levels of nutrient solution (high and low loading: HL/LL) were prepared to simulate the typical characteristics of the greenhouse effluent. The wood-chip bioreactor with Typha angustifolia exhibited the highest consistent nutrient treatment with an average nitrate reduction in the LL phase of 88.4% (28.2 g N m−3 media day−1) and phosphate reduction of 34.4%. The nitrate reduction in this bioreactor was the highest among the values reported in the literature. The near-complete denitrification developed provided a nitrate-limiting environment as evidenced by an average 21.5% sulfate reduction. The distinct increase in the outflow organic carbon (as BOD5) from the wood chips in the bioreactor planted with T. angustifolia appeared to be the key explanation for the efficient denitrification, while the other vegetated bioreactors resulted in 19.0%–36.5% nitrate reduction and low outflow BOD5 near the end of the experiment, indicating carbon limitation in these bioreactors.

Comparison of lime and alum as oily sludge conditioners

1997 ◽  
Vol 36 (12) ◽  
pp. 117-124 ◽  
Author(s):  
Tay Joo Hwa ◽  
S. Jeyaseelan
Keyword(s):  
Specific Resistance ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oily Sludge ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Sludge Cake ◽  
Solids Content ◽  
Optimum Chemical

Chemical conditioning improves sludge dewatering. Choice of chemical conditioners is very much dependent on the characteristics of the sludges and the type of dewatering devices. Lime, alum, ferric chloride and polyelectrolytes are commonly used chemical conditioners. Anaerobic digested sludge samples collected from a sewage treatment plant with different oil contents varying from 1.8% to 8.0% by weight have been examined in the laboratory to find out their specific resistance, capillary suction time and filter yield. Lime and alum were used separately as conditioners. Different dosages of conditioner varying from 2% to 12% by weight were used to determine the optimum chemical dosage for varying oil contents. Lime dosages of about 6% were found to yield favourable characteristics. Addition of alum decreases the specific resistances and capillary suction times of oily sludges rapidly up to 4% dosages. Alum dosages beyond 4% only increase the solids content in the sludge cake and increase the sludge volume to be handled. A correlation between CST and specific resistance to filtration was established. CST can be measured easily and quickly in the laboratories. Using the CST and the correlation a quick prediction on dewaterability can be established.

scholarly journals Wood Chip Drying through the Using of a Mobile Rotary Dryer

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1590 ◽  
Author(s):  
Angelo Del Giudice ◽  
Andrea Acampora ◽  
Enrico Santangelo ◽  
Luigi Pari ◽  
Simone Bergonzoli ◽  
...  
Keyword(s):  
Moisture Content ◽  
Power Plants ◽  
Black Locust ◽  
Thermal Power ◽  
Initial Moisture Content ◽  
Wood Chip ◽  
Wood Chips ◽  
Cocurrent Flow ◽  
Drying Process ◽  
Rotary Dryer

Drying is a critical point for the exploitation of biomass for energy production. High moisture content negatively affects the efficiency of power generation in combustion and gasification systems. Different types of dryers are available however; it is known that rotary dryers have low cost of maintenance and consume 15% and 30% less in terms of specific energy. The study analyzed the drying process of woody residues using a new prototype of mobile rotary dryer cocurrent flow. Woodchip of poplar (Populus spp.), black locust (Robinia pseudoacacia L.), and grapevine (Vitis vinifera L.) pruning were dried in a rotary drier. The drying cycle lasted 8 h for poplar, 6 h for black locust, and 6 h for pruning of grapevine. The initial biomass had a moisture content of around 50% for the poplar and around 30% for grapevine and black locust. The study showed that some characteristics of the biomass (e.g., initial moisture content, particle size distribution, bulk density) influence the technical parameters (i.e., airflow temperature, rate, and speed) of the drying process and, hence, the energy demand. At the end of the drying process, 17% of water was removed for poplar wood chips and 31% for grapevine and black locust wood chips. To achieve this, result the three-biomass required 1.61 (poplar), 0.86 (grapevine), and 1.12 MJ kgdry solids−1 (black locust), with an efficiency of thermal drying (η) respectively of 37%, 12%, and 27%. In the future, the results obtained suggest an increase in the efficiency of the thermal insulation of the mobile dryer, and the application of the mobile dryer in a small farm, for the recovery of exhaust gases from thermal power plants.

Sign in / Sign up

Export Citation Format

Share Document