scholarly journals Water reuse in the post-tanning process: minimizing environmental impact of leather production

2021 ◽  
Author(s):  
Rodrigo Miguel Klein ◽  
Éverton Hansen ◽  
Patrice Monteiro de Aquim
Keyword(s):  
Water Reuse ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Secondary Effluent ◽  
Oil And Grease ◽  
Organoleptic Properties ◽  
Liquid Effluent ◽  
Tanning Process

Abstract The post-tanning wastewater is very diversified, as the post-tanning stage should meet the desirable properties of the leather for the final product, with low standardization of the process (compared to beamhouse and tanning). This makes post-tanning effluent reuse less feasible, and reuse in the post-tanning stage still needs to be explored. This work aims to evaluate the reuse of liquid effluents in the post-tanning process. The work methodology consisted of (i) characterization of water streams (groundwater, liquid effluent after primary treatment, and liquid effluent after secondary treatment); (ii) pilot-scale post-tanning tests using groundwater, primary effluent, and secondary effluent; (iii) characterization of the residual baths from pilot-scale tests (pH, conductivity, total solids, chemical oxygen demand, biochemical oxygen demand, chloride, hardness and oil and grease); and (iv) testing the leather obtained for total sulfated ash and organoleptic properties. Results showed that the primary effluent and the secondary effluent could be reused in pilot-scale post-tanning tests. There was an increase in the conductivity of the residual baths when liquid effluents were reused, which confirms the accumulation of salts in the effluents after their reuse.

Anaerobic/aerobic treatment of greywater via UASB and MBR for unrestricted reuse

2014 ◽  
Vol 71 (4) ◽  
pp. 630-637 ◽  
Author(s):  
Hussein I. Abdel-Shafy ◽  
Ahmed Makki Al-Sulaiman ◽  
Mona S. M. Mansour
Keyword(s):  
Water Reuse ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Anaerobic Sludge ◽  
Oil And Grease ◽  
Treated Effluent ◽  
Water Head ◽  
Anaerobic Sludge Blanket ◽  
Kjeldahl Nitrogen

The aim of the present study was to investigate the efficiency of integrated up-flow anaerobic sludge blanket (UASB) as anaerobic system followed by membrane bioreactor (MBR) as aerobic system for the treatment of greywater for unrestricted reuse. Pilot-scale UASB and MBR units were installed and operated in the NRC, Egypt. Real raw greywater was subjected to UASB and the effluent was further treated with microfiltration MBR. The necessary trans-membrane pressure difference is applied by the water head above the membrane (gravity flow) without any energy input. The average characteristics of the raw greywater were 95, 392, 298, 10.45, 0.4, 118.5 and 28 mg/L for total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total phosphates, nitrates, oil and grease, and total Kjeldahl nitrogen (TKN), respectively. The pH was 6.71. The UASB treatment efficiency reached 19.3, 57.8, 67.5 and 83.7% for TSS, COD, BOD5 and oil and grease, respectively. When the UASB effluent was further treated with MBR, the overall removal rate achieved 97.7, 97.8, 97.4 and 95.8% for the same parameters successively. The characteristics of the final effluent reached 2.5, 8.5, 6.1, 0.95, 4.6 and 2.3 mg/L for TSS, COD, BOD, phosphates, oil and grease and TKN, respectively. This final treated effluent could cope with the unrestricted water reuse of local Egyptian guidelines.

scholarly journals Rotating belt sieves for primary treatment, chemically enhanced primary treatment and secondary solids separation

2017 ◽  
Vol 75 (11) ◽  
pp. 2598-2606 ◽  
Author(s):  
B. Rusten ◽  
S. S. Rathnaweera ◽  
E. Rismyhr ◽  
A. K. Sahu ◽  
J. Ntiako
Keyword(s):  
Removal Efficiency ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Biofilm Reactors ◽  
Fine Mesh ◽  
Coagulation And Flocculation ◽  
Successful Removal ◽  
Solids Separation ◽  
Chemically Enhanced Primary Treatment

Fine mesh rotating belt sieves (RBS) offer a very compact solution for removal of particles from wastewater. This paper shows examples from pilot-scale testing of primary treatment, chemically enhanced primary treatment (CEPT) and secondary solids separation of biofilm solids from moving bed biofilm reactors (MBBRs). Primary treatment using a 350 microns belt showed more than 40% removal of total suspended solids (TSS) and 30% removal of chemical oxygen demand (COD) at sieve rates as high as 160 m³/m²-h. Maximum sieve rate tested was 288 m³/m²-h and maximum particle load was 80 kg TSS/m²-h. When the filter mat on the belt increased from 10 to 55 g TSS/m², the removal efficiency for TSS increased from about 35 to 60%. CEPT is a simple and effective way of increasing the removal efficiency of RBS. Adding about 1 mg/L of cationic polymer and about 2 min of flocculation time, the removal of TSS typically increased from 40–50% without polymer to 60–70% with polymer. Using coagulation and flocculation ahead of the RBS, separation of biofilm solids was successful. Removal efficiencies of 90% TSS, 83% total P and 84% total COD were achieved with a 90 microns belt at a sieve rate of 41 m³/m²-h.

Treatment of petrochemical secondary effluent by an up-flow biological aerated filter (BAF)

2016 ◽  
Vol 73 (8) ◽  
pp. 2031-2038 ◽  
Author(s):  
L. Y. Fu ◽  
C. Y. Wu ◽  
Y. X. Zhou ◽  
J. E. Zuo ◽  
Y. Ding
Keyword(s):  
Removal Efficiency ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Gas Chromatography Mass Spectrometry ◽  
Secondary Effluent ◽  
Biological Aerated Filter ◽  
Total Removal ◽  
Aerated Filter ◽  
Final Effluent

In this study, petrochemical secondary effluent was treated by a 55 cm diameter pilot-scale biological aerated filter (BAF) with a media depth of 220 cm. Volcanic rock grains were filled as the BAF media. Median removal efficiency of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) was 29.35 and 57.98%, respectively. Moreover, the removal profile of the COD, NH3-N, total nitrogen and total organic carbon demonstrated that the filter height of 140 cm made up to 90% of the total removal efficiency of the final effluent. By gas chromatography–mass spectrometry, removal efficiencies of 2-chloromethyl-1,3-dioxolane, and benzonitrile, indene and naphthalene were obtained, ranging from 30.12 to 63.01%. The biomass and microbial activity of the microorganisms on the filter media were in general reduced with increasing filter height, which is consistent with the removal profile of the contaminants. The detected genera Defluviicoccus, Betaproteobacteria_unclassified and the Blastocatella constituted 1.86–6.75% of the identified gene, enhancing the COD and nitrogen removal in BAF for treating petrochemical secondary effluent.

Pilot study of SBR biological treatment and microfiltration for reclamation and reuse of municipal wastewater

2000 ◽  
Vol 42 (1-2) ◽  
pp. 263-268 ◽  
Author(s):  
R. Messalem ◽  
A. Brenner ◽  
S. Shandalov ◽  
Y. Leroux ◽  
P. Uzlaner ◽  
...  
Keyword(s):  
Water Reuse ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Groundwater Resources ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Fecal Coliforms ◽  
Wastewater Reclamation ◽  
Two Stage ◽  
Stage Scheme

In Israel the shortage of water and concern for the quality of groundwater resources have led to an awareness that a national wastewater reclamation program must be developed. Such a program could cover a major part of the agricultural water demand and could facilitate disposal of effluents without health hazards or environmental problems. A two-stage pilot-scale system comprising secondary sequencing batch reactor (SBR) treatment and tertiary microfiltration was operated for the treatment of Beer-Sheva municipal wastewater. The self-cleaning, continuous microfiltration system comprised a filter module made up of hollow fiber microporous membranes, with a pore size distribution of less than 0.1 μm, encapsulated into a bundle. The unit, which has a nominal filtration area of 4 m2, can treat 4–5 m3 of sewage per day, at a nominal rate of about 500 L/h. SBR treatment of the raw sewage produced an effluent with a biochemical oxygen demand (BOD) of <20 mg/L and total suspended solids (TSS) of <20 mg/L. Further treatment by microfiltration resulted in a BOD <5 mg/L, TSS <1 mg/L and turbidity <0.2 nephelometric turbidity units (NTU). Bacterial counts showed 6-log removal of coliforms and fecal coliforms. These results indicate that the two-stage scheme is capable of producing an effluent that meets or even surpasses the requirements for unrestricted water reuse for agriculture.

scholarly journals Preparation and Characterization of Eco-Friendly Ash Salts for Goat Skins Preservation

2019 ◽  
Vol 8 (11S) ◽  
pp. 184-190
Keyword(s):  
Suspended Solids ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Total Solid ◽  
Organoleptic Properties ◽  
Acacia Albida ◽  
Total Dissolved Solid ◽  
And Chemical Properties

Worldwide, mostly skin is preserved using NaCl which is polluting the environment by increasing soil salinity, affecting water body, releasing of more than 40 % TDS and 55 % Cl- . In the current study, plant derived ash salt from Acacia albida and Acacia bussei was used as salt-less and less salt formulations for curing goat skins, proving effective alternative to the conventional preservation with NaCl. Ash salt was prepared by burning the plants’ stems and leaves completely into ashes, soaked in water and then filtering; then boiling to evaporate water to get an ash salt. The ash salt demonstrated better antibacterial properties in preserving goat skins for 21st days without disintegration. Moisture contents were reduced to less than 30 %, nitrogen content and bacterial counts were sound and stood in a normal unaffected range and preserved skins were later processed and chrome tanned into crust upper leather. The physico-mechanical and chemical properties of all crust leathers were tested and the results met the standard requirements. The shrinkage temperatures (Ts) of all the prepared and preserved goat leathers were shown to be above 90 0C. Organoleptic properties were also analyzed and were shown much better. The pollution loads of soaking liquors were assessed and there was dramatic reduction in levels of total solid, total suspended solids, chloride, total dissolved solid, biochemical oxygen demand and chemical oxygen demand released along with the wastewater with the significant variations (P > 0.05).

Modelling and characterization of primary settlers in view of whole plant and resource recovery modelling

2015 ◽  
Vol 72 (12) ◽  
pp. 2251-2261 ◽  
Author(s):  
Giulia Bachis ◽  
Thibaud Maruéjouls ◽  
Sovanna Tik ◽  
Youri Amerlinck ◽  
Henryk Melcer ◽  
...  
Keyword(s):  
Model Development ◽  
Oxygen Demand ◽  
Resource Recovery ◽  
Primary Treatment ◽  
Model Parameters ◽  
Whole Plant ◽  
Chemically Enhanced Primary Treatment ◽  
Settling Velocity Distribution ◽  
Downstream Processes

Characterization and modelling of primary settlers have been neglected pretty much to date. However, whole plant and resource recovery modelling requires primary settler model development, as current models lack detail in describing the dynamics and the diversity of the removal process for different particulate fractions. This paper focuses on the improved modelling and experimental characterization of primary settlers. First, a new modelling concept based on particle settling velocity distribution is proposed which is then applied for the development of an improved primary settler model as well as for its characterization under addition of chemicals (chemically enhanced primary treatment, CEPT). This model is compared to two existing simple primary settler models (Otterpohl and Freund; Lessard and Beck), showing to be better than the first one and statistically comparable to the second one, but with easier calibration thanks to the ease with which wastewater characteristics can be translated into model parameters. Second, the changes in the activated sludge model (ASM)-based chemical oxygen demand fractionation between inlet and outlet induced by primary settling is investigated, showing that typical wastewater fractions are modified by primary treatment. As they clearly impact the downstream processes, both model improvements demonstrate the need for more detailed primary settler models in view of whole plant modelling.

Characterization of the potential impact of retention tank emptying on wastewater primary treatment: a new element for CSO management

2011 ◽  
Vol 64 (9) ◽  
pp. 1898-1905 ◽  
Author(s):  
T. Maruejouls ◽  
P. Lessard ◽  
B. Wipliez ◽  
G. Pelletier ◽  
P. A. Vanrolleghem
Keyword(s):  
Suspended Solids ◽  
Negative Impact ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Primary Treatment ◽  
Wash Water ◽  
Quebec City ◽  
Wide Variability ◽  
To Come

Theoretical studies have shown that discharges from retention tanks could have a negative impact on the WWTP's (Wastewater Treatment Plant) effluent. Characterization of such discharges is necessary to better understand these impacts. This study aims at: (1) characterizing water quality during emptying of a tank; and (2) characterizing the temporal variation of settling velocities of the waters released to the WWTP. Two full-scale sampling campaigns (18 rain events) have been realized in Quebec City and laboratory analyses have shown a wide variability of total suspended solids (TSS) and Chemical Oxygen Demand (COD) concentrations in the water released from the tank. Suspended solids seem to settle quickly because they are only found in large amounts during the first 15 min of pumping to the WWTP. These solids are hypothesized to come from the pumping in which solids remained after a previous event. When these solids are evacuated, low TSS containing waters are pumped from the retention tank. A second concentration peak occurs at the end of the emptying period when the tank is cleaned with wash water. Finally, settling velocity studies allowed characterizing combined sewer wastewaters by separating three main fractions of pollutants which correspond to the beginning, middle and end of emptying. In most cases, it is noticed that particle settling velocities increase as the pollutant load increases.

scholarly journals Pilot-scale study to investigate the impact of rotating belt filter upstream of a MBR for nitrogen removal

2019 ◽  
Vol 79 (3) ◽  
pp. 458-465
Author(s):  
V. A. Razafimanantsoa ◽  
D. Adyasari ◽  
A. K. Sahu ◽  
B. Rusten ◽  
T. Bilstad ◽  
...  
Keyword(s):  
Organic Matter ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Treated Wastewater ◽  
Transmembrane Pressure ◽  
Fine Mesh ◽  
The Impact

Abstract The goal of this study was to investigate what kind of impact the removal of particulate organic matter with 33μm rotating belt filter (RBF) (as a primary treatment) will have on the membrane bioreactor (MBR) performance. Two small MBR pilot plants were operated in parallel, where one train treated 2mm screened municipal wastewater (Train A) and the other train treated wastewater that had passed through a RBF with a 33μm filter cloth (Train B). The RBF was operated without a filter mat on the belt. About one third of the organic matter was removed by the fine mesh filter. The assessment of the overall performance showed that the two pilot plants achieved approximately the same removal efficiencies with regard to total suspended solids (TSS), chemical oxygen demand (COD), total phosphorus and total nitrogen. It was also observed that the system with 33μm RBF as a primary treatment produced more sludge, which could be used for biogas production, and required about 30% less aeration downstream. Transmembrane pressure was significantly lower for the train receiving 33μm primary treated wastewater compared to the control receiving 2mm screened wastewater.

scholarly journals Characterization of Car Wash Wastewater from Manually dispersed, Snow and Auto Car Wash Stations

2018 ◽  
Vol 7 (3.23) ◽  
pp. 45
Author(s):  
Muhammad Shahrul Shafendy Bin Ibrahim ◽  
Nor Haslina Hashim
Keyword(s):  
Suspended Solids ◽  
Oxygen Demand ◽  
Specific Pattern ◽  
Oil And Grease ◽  
Sulphate Chloride ◽  
Car Wash ◽  
Wastewater Samples ◽  
Cleaning Methods ◽  
Car Wash Wastewater

Although commonly perceived lightly in the eye of public, car wash wastewater should be taken more seriously as they have the tendency to be harmful and toxic not only towards the environment, but also humans. In this study, car wash wastewater samples were taken from three stations in Johor with different cleaning methods; manually-dispersed car wash (MCW), snow car wash (SCW) and auto car wash (ACW). At each station, samples were taken during the initial rinsing (IR), and final rinsing (FR) of the vehicles. The samples taken were analyzed for its pH, chemical oxygen demand (COD), biological oxygen demand (BOD), oil and grease (O&G), total suspended solids (TSS), anions (anionic surfactant, nitrate, sulphate, chloride, fluoride, orthophosphate) and heavy metals (iron, zinc, magnesium, chromium, manganese, copper, lead, silver). The results obtained shows that there appears to be no specific pattern to differentiate between the IR and FR samples due to the different washing methods, chemicals and equipment used. The level of contamination of the car wash wastewater was SCW>MCW>ACW. Overall, the result shows that some of the samples did not pass the standard discharge limit; pH, COD, BOD, O&G, TSS, AS and Fe. This shows that car wash wastewater produced in the cleaning activities should be given more concern and need to be treated before being released to the water body.  

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