scholarly journals Deacidification through calcium carbonate dosing in combination with ultrafiltration

2021 ◽  
Author(s):  
Yair G. Morales ◽  
Pia Lipp
Keyword(s):  
Calcium Carbonate ◽  
Large Scale ◽  
Ph Value ◽  
Pilot Scale ◽  
Transmembrane Pressure ◽  
Treatment Technology ◽  
Critical Flux ◽  
Appropriate Treatment ◽  
Acidic Waters ◽  
Process Combination

Abstract Soft acidic waters are often treated for drinking water purposes by using limestone filters to attain chemical equilibrium. The present study investigated the process parameters of a relatively new process combination in which powdered calcium carbonate (CaCO3) was added prior to an ultrafiltration (UF). In order to reach the targeted pH value (≥7.8), dosing concentration, type of material and retention time were evaluated in pilot-scale experiments. The deacidification followed the same kinetics as for limestone filtration and yielded similar filtrate characteristics with dosing concentrations of 20 and 40 g/L CaCO3. No significant increase in transmembrane pressure was observed during the operation of a pilot-scale UF module at low flux (34 L m−2 h−1). Critical flux was determined in a lab scale to evaluate the potential impact of CaCO3 particles on the UF operation. Stepping-flux experiments revealed the presence of fouling only at high-dosing concentrations, resulting in a critical flux of 55 L m−2 h−1. At a higher flux, a CaCO3-fouling layer was formed, which decreased the membrane's permeability by 20% over 5 h. Considering that effective air-enhanced backwash and acidic chemical cleanings will be implemented in large-scale applications, the investigated process combination promises to be an appropriate treatment technology for turbid and soft acidic waters.

Characterization of seawater reverse osmosis fouled membranes from large scale commercial desalination plant

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Reverse Osmosis ◽  
Large Scale ◽  
Retention Rate ◽  
Local Level ◽  
Microscopic Analysis ◽  
Transmembrane Pressure ◽  
Hydraulic Permeability ◽  
Seawater Reverse Osmosis ◽  
A Chain

The objective of this work is to study the ageing state of a used reverse osmosis (RO) membrane taken in Algeria from the Benisaf Water Company seawater desalination unit. The study consists of an autopsy procedure used to perform a chain of analyses on a membrane sheet. Wear of the membrane is characterized by a degradation of its performance due to a significant increase in hydraulic permeability (25%) and pressure drop as well as a decrease in salt retention (10% to 30%). In most cases the effects of ageing are little or poorly known at the local level and global measurements such as (flux, transmembrane pressure, permeate flow, retention rate, etc.) do not allow characterization. Therefore, a used RO (reverse osmosis) membrane was selected at the site to perform the membrane autopsy tests. These tests make it possible to analyze and identify the cause as well as to understand the links between performance degradation observed at the macroscopic scale and at the scale at which ageing takes place. External and internal visual observations allow seeing the state of degradation. Microscopic analysis of the used membranes surface shows the importance of fouling. In addition, quantification and identification analyses determine a high fouling rate in the used membrane whose foulants is of inorganic and organic nature. Moreover, the analyses proved the presence of a biofilm composed of protein.

An Assessment of a Low-Cost Wastewater Disposal System after Twenty-Five Years of Operation

1987 ◽  
Vol 19 (5-6) ◽  
pp. 701-710 ◽  
Author(s):  
B. L. Reidy ◽  
G. W. Samson
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Wastewater Disposal ◽  
Industrial Base ◽  
Industrial Wastewaters ◽  
The Past ◽  
Gasification Process ◽  
Appropriate Treatment ◽  
Environmentally Safe ◽  
Coal Resource

A low-cost wastewater disposal system was commissioned in 1959 to treat domestic and industrial wastewaters generated in the Latrobe River valley in the province of Gippsland, within the State of Victoria, Australia (Figure 1). The Latrobe Valley is the centre for large-scale generation of electricity and for the production of pulp and paper. In addition other industries have utilized the brown coal resource of the region e.g. gasification process and char production. Consequently, industrial wastewaters have been dominant in the disposal system for the past twenty-five years. The mixed industrial-domestic wastewaters were to be transported some eighty kilometres to be treated and disposed of by irrigation to land. Several important lessons have been learnt during twenty-five years of operating this system. Firstly the composition of the mixed waste stream has varied significantly with the passage of time and the development of the industrial base in the Valley, so that what was appropriate treatment in 1959 is not necessarily acceptable in 1985. Secondly the magnitude of adverse environmental impacts engendered by this low-cost disposal procedure was not imagined when the proposal was implemented. As a consequence, clean-up procedures which could remedy the adverse effects of twenty-five years of impact are likely to be costly. The question then may be asked - when the total costs including rehabilitation are considered, is there really a low-cost solution for environmentally safe disposal of complex wastewater streams?

Technological aspects of wastewater management in coastal tourist areas

1999 ◽  
Vol 39 (8) ◽  
pp. 177-184 ◽  
Author(s):  
Derin Orhon ◽  
Seval Sözen ◽  
Erdem Görgün ◽  
Emine Ubay Çokgör ◽  
Nazik Artan
Keyword(s):  
Technology Selection ◽  
Specific Reference ◽  
Wastewater Management ◽  
Residential Areas ◽  
Treatment Technology ◽  
Environmentally Sensitive Areas ◽  
Appropriate Treatment ◽  
Treatment Technologies ◽  
Impact On Treatment ◽  
New Applications

Coastal tourist areas should be classified as environmentally sensitive areas. Effective nutrient control should be implemented to safeguard the quality of receiving waters in these areas. In this context, the applicable discharge limitations are reviewed with specific reference to European directives and criteria developed for small coastal residential areas in Turkey are reported; wastewater characterization and its impact on treatment technology selection is reviewed; appropriate treatment technologies are evaluated in terms of selecting new applications and upgrading and retrofitting existing systems.

scholarly journals Synthesis of Polyaniline Coating on the Modified Fiber Ball and Application for Cr(VI) Removal

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiao Li Ma ◽  
Guang Tao Fei ◽  
Shao Hui Xu
Keyword(s):  
Waste Water ◽  
Large Scale ◽  
Ph Value ◽  
Low Cost ◽  
Strong Acid ◽  
Removal Capacity ◽  
Secondary Pollution ◽  
Potential Possibility ◽  
Fiber Ball ◽  
Maximum Removal

Abstract In this study, polyaniline (PANI) is prepared by means of chemical oxidization polymerization and directly loaded on the modified fiber ball (m-FB) to obtain macroscale polyaniline/modified fiber ball (PANI/m-FB) composite, and then its removal ability of Cr(VI) is investigated. The effects of different parameters such as contact time, pH value and initial concentration on Cr(VI) removal efficiency are discussed. The experimental results illustrate that the favorable pH value is 5.0 and the maximum removal capacity is measured to be 293.13 mg g−1. Besides, PANI/m-FB composites can be regenerated and reused after being treated with strong acid. The kinetic study indicates that the adsorption procedure is mainly controlled by chemical adsorption. More importantly, the macroscale of composites can avoid secondary pollution efficiently. Benefiting from the low cost, easy preparation in large scale, environmentally friendly, excellent recycling performance as well as high removal ability, PANI/m-FB composites exhibit a potential possibility to remove Cr(VI) from industrial waste water. Graphic Abstract The polyaniline (PANI) was coated on modified fiber ball (m-FB) to remove Cr(VI) in waste water, and this kind of PANI/m-FB composites can avoid secondary pollution efficiently due to its macrostructure. Furthermore, the removal capacity can reach to 291.13 mg/g and can be multiple reused.

Pilot-Scale Demonstration of DARAMEND Enhanced Bioremediation of Sediment Contaminated with Polycyclic Aromatic Hydrocarbons in Hamilton Harbour

1996 ◽  
Vol 31 (3) ◽  
pp. 433-452 ◽  
Author(s):  
Paul Bucens ◽  
Alan Seech ◽  
Igor Marvan
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Pilot Scale ◽  
Hydrocarbon Contamination ◽  
Active Management ◽  
Treatment Technology ◽  
Technology Program ◽  
Hamilton Harbour ◽  
Polycyclic Aromatic ◽  
Enhanced Bioremediation

Abstract In 1992, GRACE Dearborn, Inc. was contracted by Environment Canada to conduct a field-scale demonstration of the DARAMEND bioremediation technology under the auspices of the Great Lakes Cleanup Fund's Contaminated Sediment Treatment Technology Program. The demonstration on approximately 150 tonnes of sediment dredged from Hamilton Harbour was completed by January 1994. Two distinct batches of sediment were treated. One batch of 90 tonnes of sediment, dredged directly from the harbour without any pretreatment, is the focus of this paper. Sediment was received in October 1992 and was treated through to December 1993. Treatment was conducted in an high-density polyethylene-lined treatment cell that was covered by a steel framed greenhouse. The treatment involved amending, tilling and closely controlling the sediment water content. In approximately 300 days of treatment, the level of total polycyclic aromatic hydrocarbon contamination was reduced from approximately 1,000 µg/g to 100 µg/g, corresponding to a destruction and removal efficiency of approximately 90%. Notably, the high molecular weight polycyclic aromatic hydrocarbons (containing 4 to 6 benzene rings) were effectively degraded to concentrations below the Ministry of the Environment and Energy’s Soil Placement Guideline for controlled fill (MOEE 1992). The trend in the data suggest that following addition of DARAMEND amendment and several months of active management, the polycyclic aromatic hydrocarbons would continue to biodegrade as a result of the DARAMEND amendment even without active management of the sediment.

scholarly journals ENVIRONMENTAL POLLUTION BY WASTEWATER FROM BROWN COAL PROCESSING ¬ A REMEDIATION CASE STUDY IN GERMANY

2014 ◽  
Vol 22 (1) ◽  
pp. 71-83 ◽  
Author(s):  
Arndt Wiessner ◽  
Jochen A. Müller ◽  
Peter Kuschk ◽  
Uwe Kappelmeyer ◽  
Matthias Kästner ◽  
...  
Keyword(s):  
Environmental Pollution ◽  
Large Scale ◽  
Pilot Scale ◽  
Wastewater Disposal ◽  
Interdisciplinary Approaches ◽  
Phenolic Wastewater ◽  
Term Monitoring

The large scale of the contamination by the former carbo-chemical industry in Germany requires new and often interdisciplinary approaches for performing an economically sustainable remediation. For example, a highly toxic and dark-colored phenolic wastewater from a lignite pyrolysis factory was filled into a former open-cast pit, forming a large wastewater disposal pond. This caused an extensive environmental pollution, calling for an ecologically and economically acceptable strategy for remediation. Laboratory-scale investigations and pilot-scale tests were carried out. The result was the development of a strategy for an implementation of full-scale enhanced in situ natural attenuation on the basis of separate habitats in a meromictic pond. Long-term monitoring of the chemical and biological dynamics of the pond demonstrates the metamorphosis of a former highly polluted industrial waste deposition into a nature-integrated ecosystem with reduced danger for the environment, and confirmed the strategy for the chosen remediation management.

Water recycling at the Millennium Dome

2001 ◽  
Vol 43 (10) ◽  
pp. 287-294 ◽  
Author(s):  
S. Hills ◽  
A. Smith ◽  
P. Hardy ◽  
R. Birks
Keyword(s):  
Large Scale ◽  
Pilot Scale ◽  
Water Recycling ◽  
Water Usage ◽  
Customer Perception ◽  
Recycling System ◽  
Optimum Configuration ◽  
Treatment Technologies ◽  
System Information ◽  
System Water

Thames Water is working with the New Millennium Experience Company to provide a water recycling system for the Millennium Dome which will supply 500m3/d of reclaimed water for WC and urinal flushing. The system will treat water from three sources:rainwater - from the Dome roofgreywater - from handbasins in the toilet blocksgroundwater - from beneath the Dome site The treatment technologies will range from “natural” reedbeds for the rainwater, to more sophisticated options, including biological aerated filters and membranes for the greywater and groundwater. Pilot scale trials were used to design the optimum configuration. In addition to the recycling system, water efficient devices will be installed in three of the core toilet blocks as part of a programme of research into the effectiveness of conservation measures. Data on water usage and customer behaviour will be collected via a comprehensive metering system. Information from the Dome project on the economics and efficiency of on-site recycling at large scale and data on water efficient devices, customer perception and behaviour will be of great value to the water industry. For Thames Water, the project provides vital input to the development of future water resource strategies.

scholarly journals Classification of brown earths based on field and laboratory properties: Problematic issues and proposition of their solution

2019 ◽  
Vol 52 (2) ◽  
pp. 225
Author(s):  
Karolina Woźnica ◽  
Agnieszka Józefowska ◽  
Justyna Sokołowska ◽  
Ryszard Mazurek ◽  
Tomasz Zaleski
Keyword(s):  
Calcium Carbonate ◽  
Main Parameter ◽  
Ph Value ◽  
Soil Classification ◽  
Base Saturation ◽  
Carbonate Content ◽  
Field Guide ◽  
Content Determination

<p class="Default">In this paper, the current problems associated with the classification of brown earths, are presented. According to the Polish Soil Classification (PSC) (1989, 2011), base saturation is the main parameter for identifying eutrophic and dystrophic brown soils. In practice, however, it is not possible to determine the base saturation value in the field. Therefore, the aim of this study was to estimate the base saturation using a regression equation and create a field guide for brown earths, based on the pH value, measured using a Hellige indicator, and the calcium carbonate content. Determination of the pH ranges enabled the classification of brown earth types in the field. These results suggest that pH can be used as a proxy for base saturation especially in the field. A change in the hierarchy of soil (sub)types is proposed for the new Polish Soil Classification.</p>

Scalable Sulfonate-Coated Cotton Fibers as Facile Recyclable and Biodegradable Adsorbents for Highly Efficient Removal of Cationic Dyes

2021 ◽  
Author(s):  
Linhua Li ◽  
Baojie Dou ◽  
Jianwu Lan ◽  
Jiaojiao Shang ◽  
Yafang Wang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Large Scale ◽  
Ph Value ◽  
Cationic Dyes ◽  
Cotton Fibers ◽  
Wastewater Remediation ◽  
Efficient Removal ◽  
Adsorption Sites ◽  
Highly Efficient ◽  
Coated Cotton

Abstract Adsorbents with superior adsorption capacity and facile recyclability are viewed as promising materials for dye wastewater treatment. In this work, a novel sulfonate decorated cotton fiber as a biodegradable and recyclable adsorbent was fabricated for highly efficient removal of cationic dyes. Herein, the poly(sodium p-styrenesulfonate-co-N-methylol acrylamide) (P(SSNa-co-NMAM)) with SSNa units as adsorption sites and NMAM units as thermal-crosslinking points was synthesized for modification of cotton fibers in a large scale at high temperature (160 oC). The various characterization investigations confirmed the successful construction of the P(SSNa-co-NMAM) coated cotton fibers (PCF). As expected, the as-obtained adsorbent presented outstanding adsorption performance toward cationic dyes in the both static and dynamic states, even in the synthetic effluent. The adsorption processes of cationic dyes onto the PCF were well fitted by the Langmuir isotherm model and Pseudo-second-order kinetics, respectively. The thermodynamics study showed that the adsorption reaction of the cationic dyes onto PCF was a spontaneous and endothermic process. The maximum adsorption capacities of PCF toward MEB, RhB and MG were 3976.10, 2879.80 and 3071.55 mg/g, respectively. The responsible adsorption of dyes ontothe PCF was electrostatic interaction. Moreover, the adsorption capacity of PCF toward cationic dyes was slight influenced by pH value of solution, because of the stable feature of sulfonate moiety in acid and alkali. In addition, the as-prepared PCF exhibited satisfactory recyclability and reusability. Given the aforementioned results, the as-obtained PCF is a promising adsorbent with great potential for practical application in the dye-contaminated wastewater remediation.

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