Published

2022-07-14

Application of a Mathematical Model for Sludge Reduction in Pharmaceutical Wastewater

Aplicación de un modelo matemático para la reducción de lodos de aguas residuales farmacéuticas

Keywords:

response surface model, sludge reduction, sludge dissolution rate, pharmaceutical wastewater (en)
modelo de superficie de respuesta, reducción de lodos, tasa de disolución de lodos, aguas residuales farmacéuticas (es)

Downloads

Authors

  • Yongqiang Zhu School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai.201418, China
  • Shengqi Yang Shanghai Institute of Technology
  • Min Zhu Fengxian Environmental Monitoring Station of Shanghai

Excess sludge treatment is indispensable in sewage treatment plants. This study aims to reduce the excess material from activated sludge and establish a mathematical model. Sludge dissolution rates were calculated by measuring the total chemical oxygen demand (TCOD) and the soluble COD (SCOD) with regard to water quality before and after pretreatment. Then, sludge reduction effects were obtained by means of the suspended solid (SS) changes. The major impact factors on sludge dissolution rates were evaluated, such as pH, temperature, potassium ferrate amount, and reaction time, among others. The response surface method of the Design-Expert V8.0.6.1 software was adopted to analyze the sludge dissolution rate, which represents the sludge reduction effect. By regulating the different constraint factors, the Design-Expert model showed that the sludge dissolution rate reached the highest value of 54,36% at a temperature of 21,58 oC and a pH of 4, as well with a potassium ferrate dosage of 1 mg/g SS and a reaction time of 4,07 hours with constant stirring. A mathematical model for the sludge dissolution rate that considers temperature, pH, potassium ferrate dosage, reaction time, and stirring condition was established, and the simulated R2 value of 0,72 indicated a relatively acceptable fitting effect.

El tratamiento de lodos sobrantes es indispensable en las plantas de tratamiento de aguas residuales. Este estudio tiene como objetivo reducir el exceso de material en lodos activados y establecer un modelo matemático. Las tasas de disolución de lodo se calcularon midiendo la demanda química total de oxígeno (DQO) y la DQO soluble (DQOS) con respecto a la calidad del agua antes y después del pretratamiento. Luego se obtuvieron los efectos de reducción de lodos por los cambios en sólidos suspendidos (SS). Se evaluaron los principales factores de impacto en las tasas de disolución de lodos, tales como pH, temperatura, cantidad de ferrato potásico y tiempo de reacción, entre otros. Se adoptó el método de superficie de respuesta del software Design-Expert V8.0.6.1 para analizar la velocidad de disolución del lodo, que representa el efecto de reducción del lodo. Mediante la regulación de los diferentes factores de restricción, el modelo Design-Expert mostró que la velocidad de disolución del lodo alcanzó el valor más alto de 54,36 % a una temperatura de 21,58 oC y un pH de 4, así como con una dosis de ferrato de potasio de 1 mg/g SS y un tiempo de reacción de 4,07 horas con agitación constante. Se estableció un modelo matemático para la velocidad de disolución del lodo que considera la temperatura, el pH, la dosis de ferrato de potasio, el tiempo de reacción y la condición de agitación. El valor R2 simulado de 0,72 indicó un efecto de ajuste relativamente aceptable.

Downloads

Download data is not yet available.

References

Capela, D., Ratola, N., Alves, A., and Homem, V. (2017). Volatile methylsiloxanes through wastewater treatment plants - A review of levels and implications. Environment International, 102, 9-29. https://doi.org/10.1016/j.envint.2017.03.005

Chakraborty, T., Balusani, D., Smith, S., Santore, D., Walton, J., Nakhla, G., and Ray, M. B. (2020). Reusability of recovered iron coagulant from primary municipal sludge and its impact on chemically enhanced primary treatment. Separation and Purification Technology, 231, 115894. https://doi.org/10.1016/j.seppur.2019.115894

Chen, M., Blanc, D., Gautier, M., Mehu, J., and Gourdon, R. (2013). Environmental and technical assessments of the potential utilization of sewage sludge ashes (SSAs) as secondary raw materials in construction. Waste Management, 33(5), 1268-1275. https://doi.org/10.1016/j.wasman.2013.01.004

Fang, C., Huang, R., Dykstra, C. M., Jiang, R., Pavlostathis, S. G., and Tang, Y. (2020). Energy and nutrient recovery from sewage sludge and manure via anaerobic digestion with hydrothermal pretreatment. Environmental Science & Technology, 54(2), 1147-1156. https://doi.org/10.1021/acs.est.9b03269

Fei, Y.-H., Zhao, D., Liu, Y., Zhang, W., Tang, Y.-Y., Huang, X., Wu, Q., Wang, Y.-X., Xiao, T., and Liu, C. (2019). Feasibility of sewage sludge derived hydrochars for agricultural application: Nutrients (N, P, K) and potentially toxic elements (Zn, Cu, Pb, Ni, Cd). Chemosphere, 236, 124841. https://doi.org/10.1016/j.chemosphere.2019.124841

Feria-Díaz, J. J., Polo-Corrales, L., and Hernández-Ramos, E. J. (2016). Evaluation of coagulation sludge from raw water treated with Moringa oleifera for agricultural use. Ingeniería e Investigación, 36(2), 14-20. https://doi.org/10.15446/ing.investig.v36n2.56986

Hong, J., and Li, X. (2011). Environmental assessment of sewage sludge as secondary raw material in cement production--a case study in China. Waste Management, 31(6), 1364-1371. https://doi.org/10.1016/j.wasman.2010.12.020

Hu, Y., and Gao, Z. (2020). Sewage sludge in microwave oven: A sustainable synthetic approach toward carbon dots for fluorescent sensing of para-Nitrophenol. Journal of Hazardous Materials, 382, 121048. https://doi.org/10.1016/j.jhazmat.2019.121048

Kavitha, S., Karthika, P., Rajesh Banu, J., Yeom, I. T., and Adish Kumar, S. (2015). Enhancement of waste activated sludge reduction potential by amalgamated solar photo-Fenton treatment. Desalination and Water Treatment, 57(28), 13144-13156. https://doi.org/10.1080/19443994.2015.1055810

Kelessidis, A., and Stasinakis, A. S. (2012). Comparative study of the methods used for treatment and final disposal of sewage sludge in European countries. Waste Management, 32(6), 1186-1195. https://doi.org/10.1016/j.wasman.2012.01.012

Mazeed, A., Lothe, N. B., Kumar, A., Sharma, S. K., Srivastav, S., and Verma, R. K. (2020). Evaluation of phytoaccumulation potential of toxic metals from sewage sludge by high-value aromatic plant geranium. Journal of Environmental Biology, 41(4), 761-769. https://doi.org/10.22438/jeb/41/4/MRN-1210

Pabón, S. L., and Gelvez, J. H. S. (2009). Starting-up and operating a full-scale activated sludge system for slaughterhouse wastewater. Ingeniería e Investigación, 29(2), 53-58. https://doi.org/10.15446/ing.investig.v29n2.15161

Poot, V., Hoekstra, M., Geleijnse, M. A. A., van Loosdrecht, M. C. M., and Pérez, J. (2016). Effects of the residual ammonium concentration on NOB repression during partial nitritation with granular sludge. Water Research, 106, 518-530. https://doi.org10.1016/j.watres.2016.10.028

Wang, Z., Yu, H., Ma, J., Zheng, X., and Wu, Z. (2013). Recent advances in membrane bio-technologies for sludge reduction and treatment. Biotechnology Advances, 31(8), 1187-1199. https://doi.org/10.1016/j.biotechadv.2013.02.004

Wilson, C. A., and Novak, J. T. (2009). Hydrolysis of macromolecular components of primary and secondary wastewater sludge by thermal hydrolytic pretreatment. Water Research, 43(18), 4489-4498. https://doi.org/10.1016/j.watres.2009.07.022

Wu, P., Pi, K., Shi, Y., Li, P., Wang, Z., Zhang, H., Liu, D., and Gerson, A. R. (2020). Dewaterability and energy consumption model construction by comparison of electro-dewatering for industry sludges and river sediments. Environmental Research, 184, 109335. https://doi.org/10.1016/j.envres.2020.109335

Xia, H., Wu, Y., Chen, X., Huang, K., and Chen, J. (2019). Effects of antibiotic residuals in dewatered sludge on the behavior of ammonia oxidizers during vermicomposting maturation process. Chemosphere, 218, 810-817. https://doi.org/10.1016/j.chemosphere.2018.11.167

Xiao, K., Chen, Y., Jiang, X., Seow, W. Y., He, C., Yin, Y., and Zhou, Y. (2017). Comparison of different treatment methods for protein solubilisation from waste activated sludge. Water Research, 122, 492-502. https://doi.org/10.1016/j.watres.2017.06.024

Yuan, Y., Yu, Y., Xi, H., Zhou, Y., and He, X. (2019). Comparison of four test methods for toxicity evaluation of typical toxicants in petrochemical wastewater on activated sludge. Science of the Total Environment, 685, 273-279. https://doi.org/10.1016/j.scitotenv.2019.05.389

Zeng, Q., Zan, F., Hao, T., Biswal, B. K., Lin, S., van Loosdrecht, M. C. M., and Chen, G. (2019). Electrochemical pretreatment for stabilization of waste activated sludge: Simultaneously enhancing dewaterability, inactivating pathogens and mitigating hydrogen sulfide. Water Research, 166, 115035. https://doi.org/10.1016/j.watres.2019.115035

Zhang, W., Tang, M., Li, D., Yang, P., Xu, S., and Wang, D. (2021). Effects of alkalinity on interaction between EPS and hydroxy-aluminum with different speciation in wastewater sludge conditioning with aluminum based inorganic polymer flocculant. Journal of Environmental Sciences, 100, 257-268. https://doi.org/10.1016/j.jes.2020.05.016

Zheng, M., Li, Y., Ping, Q., and Wang, L. (2019). MP-UV/CaO2 as a pretreatment method for the removal of carbamazepine and primidone in waste activated sludge and improving the solubilization of sludge. Water Research, 151, 158-169. https://doi.org/10.1016/j.watres.2018.11.086

Zittel, R., da Silva, C. P., Domingues, C. E., Seremeta, D. C. H., da Cunha, K. M., and de Campos, S. X. (2020). Availability of nutrients, removal of nicotine, heavy metals and pathogens in compounds obtained from smuggled cigarette tobacco compost associated with industrial sewage sludge. Science of the Total Environment, 699, 134377. https://doi.org/10.1016/j.scitotenv.2019.134377

License

Copyright (c) 2022 Yongqiang Zhu , Shengqi Yang, Min Zhu

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

The authors or holders of the copyright for each article hereby confer exclusive, limited and free authorization on the Universidad Nacional de Colombia's journal Ingeniería e Investigación concerning the aforementioned article which, once it has been evaluated and approved, will be submitted for publication, in line with the following items:

1.    The version which has been corrected according to the evaluators' suggestions will be remitted and it will be made clear whether the aforementioned article is an unedited document regarding which the rights to be authorized are held and total responsibility will be assumed by the authors for the content of the work being submitted to Ingeniería e Investigación, the Universidad Nacional de Colombia and third-parties;

2.    The authorization conferred on the journal will come into force from the date on which it is included in the respective volume and issue of Ingeniería e Investigación in the Open Journal Systems and on the journal's main page (https://revistas.unal.edu.co/index.php/ingeinv), as well as in different databases and indices in which the publication is indexed;

3.    The authors authorize the Universidad Nacional de Colombia's journal Ingeniería e Investigación to publish the document in whatever required format (printed, digital, electronic or whatsoever known or yet to be discovered form) and authorize Ingeniería e Investigación to include the work in any indices and/or search engines deemed necessary for promoting its diffusion;

4.    The authors accept that such authorization is given free of charge and they, therefore, waive any right to receive remuneration from the publication, distribution, public communication and any use whatsoever referred to in the terms of this authorization.