Processing Plant Wastewater Research Articles

Utilization of andesite processing wastewater treatment sludge as admixture in concrete mix

The dried physicochemical sludge from the coagulation–flocculation treatment of an andesite processing plant wastewater was used as concrete admixture in powder form. Various physicochemical sludges obtained with various coagulant/flocculants (alum, FeCl3, and sepiolite) were experienced dry particulate (powder) form of the sludge was replaced at 0.5–1.5% w/w of the cement for 250kg/m3 cement dosage. The admixture doses were complied with local standard. Slump tests were conducted on fresh concrete, and compressive strengths were measured for 7 and 28days hardened concrete samples. Physical properties, namely freeze/thaw resistance, water absorption, capillary suction, void ratio and porosity were determined at the end of 28days for the hardened concrete samples. The concrete consistency (slump) was improved up to 16–18cm from 14.5cm by the admixture. The best compressive strength was achieved with 0.5% w/w for admixtures. The admixture sludges obtained with organic flocculants were worse than the other admixtures. The structural changes after freeze/thaw tests were very close to the reference concrete (concrete without admixture); only the capilary suction had increased. The results confirmed that up to 0.5% of physicochemical sludge can be replaced with cement in concrete for use in certain non-load bearing structures that require medium strength concrete.

Minimizing pump energy in a wastewater processing plant

This paper discusses energy savings in wastewater processing plant pump operations and proposes a pump system scheduling model to generate operational schedules to reduce energy consumption. A neural network algorithm is utilized to model pump energy consumption and fluid flow rate after pumping. The scheduling model is a mixed-integer nonlinear programming problem (MINLP). As solving a data-driven MINLP is challenging, a migrated particle swarm optimization algorithm is proposed. The modeling and optimization results show that the performance of the pump system can be significantly improved based on the computed schedules.

Recycling studies of marble processing waste: Composites based on commercial epoxy resin

Marble waste was obtained from marble processing plant wastewater with precipitation using different coagulants, such as sepiolite, zeolite, and pumice in dosages of 0.5–8 g/500 mL and mixed in 20 wt % with commercial epoxy resin. The effects of marble, coagulant type and dosage on the physicomechanical and thermal properties were investigated. The incorporation of marble processing waste particles increases the 10% decomposition temperature of pure epoxy by 5–50°C. Surface hardness, tensile strength, percentage elongation, and stress at maximum load of the composites were higher than those of pure resin, too. The composites reinforced with marble processing waste-pumice showed about 10% increase in elastic modulus, whereas the composite reinforced with marble processing waste-sepiolite or zeolite showed about 76.67–143.33% increase in elastic modulus over the pure epoxy matrix. Scanning electron microscopy (SEM) was used for characterization of surface and cross sections of the composites to verify the results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

On the Waste Water Processing Plant at the Closed Matsuo Mine

On the Waste Water Processing Plant at the Closed Matsuo Mine

Models for Optimization of Energy Consumption of Pumps in a Wastewater Processing Plant

In this paper, a data-mining approach for modeling pumps in the wastewater preliminary treatment process is discussed. Data-mining algorithms are utilized to develop pump performance models based on industrial data collected at a municipal wastewater processing plant. The performance of wastewater pumps is described by two parameters, pump energy consumption and water flow rate after the pumps. Two types of models, dynamic and steady state, are established to predict pump energy consumption and water flow rate. The first type of model is developed based on 5-min data and the second type is built based on 30-min data. The accuracy of the models has been validated.

Basic Principles of Treated Wastewater Reuse Planning in Ecologically Sensitive Areas

The present paper aims at planning the treated municipal wastewater reuse in fragile ecosystems of Messolonghion lagoon and Acheloos estuary, which are protected as a Natura wetland under the Ramsar Treaty. The need for environmental protection of the wetlands became necessary due to the continuing anthropogenic intervention, as well as to the climate changes that have been occurring in recent years. Relevant studies have shown that the lagoon of Messolonghion and Acheloos estuary are ecosystems that have been burdened by anthropogenic activities (pesticides, fertilizers, overexploitation of underground aquifers, intrusion and land use change), as well as by climatic changes (temperature, precipitation, sea level), which altogether have adversely affected the hydrodynamic and ecological balance of the entire ecosystem. The Messolonghion lagoon and Acheloos estuary are also the recipients of the wastewater processing plant effluents, operating locally, which have over-enriched the waters with macronutrients N, P and K, favouring eutrophication. The municipal wastewater reuse for crop irrigation grown in the protected area appears to be an environmentally acceptable solution for alleviating the natural water shortage, since it could save significant amounts of irrigation water as well as it could reduce the adverse effects of the treated effluents discharge into the aquatic ecosystem. This study describes the planning of the treated wastewater reuse in this ecologically sensitive area, on the basis of the geomorphologic and geotechnical characteristics, climatic factors, and crop irrigation water requirements grown in the area.

Treated Municipal Wastewater Irrigation Impact on Olive Trees (Olea Europaea L.) at Al-Tafilah, Jordan

Soil, olive leaves, and fruits, were sampled from an olive grove 200 ha, irrigated with treated municipal wastewater (TMWW), located at Al-Tafilah wastewater processing plant (WWPP), Jordan. Similar samples were also taken from plants not irrigated with TMWW (Control). The heavy metal and essential nutrients were determined in all samples, and the data were statistically processed. The following were found: Much smaller quantities of heavy metals than essential elements were accumulated in the leaves and fruits, the accumulation being independent of the TMWW heavy metal concentration, suggesting a selective uptake of the metals by the olive plants. Also the elemental interactions, which occurred in the olive fruits, contributed mainly essential nutrients and secondarily heavy metals. The trend of heavy metal transfer from soil to olive fruits, and leaves, was almost the same, showing a consistency of transfer.

Electrical conductivity measurements in sewage sludge pellets: Innovative techniques for environmental management

This paper presents research on the behaviour of electrical conductivity of sludge pellets resulting from the treatment of urban wastewater at the drying grounds of the El Trebal wastewater processing plant, located in the Mapocho river basin of the Metropolitana Region, Santiago, Chile. In the methodology used samples were taken that correspond to three horizons of the sewage sludge pile. The first horizon made up the upper portion of the pile (the surface), the second the central portion (mesophilous), and the third the lower one (thermophilous). Electrical conductivity measurements were taken in sewage sludge pellets under pressures on the order of 15–50 MPa with currents of 10 −15 A. Electrical conductivity measurements were also taken for different horizons, and innovative techniques and methodologies for sludge samples presented in the form of pellets are used for this purpose. Such pellets are easily reproduced with sufficient precision, and at the same time allow modifying other variables like mass, sample dimensions and compaction levels. The trends of the conductivity curves are similar for the sludge from the isolation surface horizon (H1) as well as for the mesophilous area horizon (H2). In the case of the thermophilous area horizon (H3), the electrical conductivity shows extremely high values when compared to horizons H1 and H2. This paper could be useful in establishing a general rule for taking electrical conductivity measurements in sewage sludge samples. Such a rule could bring accurate reproducible values, and be used for other types of dry wastes.

Enhanced biological treatment of a residual oil processing plant wastewater by a membrane-bioreactor for effluent quality improvement in a Hungarian refinery

A 160-day-long preliminary laboratory scale MBR treatment study and the performance test of a new 480 m3/day capacity full scale plant for quality improvement of effluent from a bitumen plant off-gas scrubbing followed by dissolved air flotation were conducted. Two testing periods were distinguished during the laboratory study, specifically the first with 100 days SRT and the second with 50 days SRT. To evaluate the possibility of the organic matter removal enhancement at the end of each testing period powdered activated carbon (PAC) treatment was carried out. The COD and oil & grease removal efficiency of the well acclimated MBR sludge was greater than 90% and 98%, respectively. The COD content of the treated wastewater during the full scale performance test period was reduced below 100 mg·L−1. To ensure an optimal treatment process, the organic loading rate should be kept in 1.5 – 3 kg COD m−3 d−1 range. and optimal biomass concentration of 10-15 g·L−1 should be ensured to reduce the cleaning frequency of the membrane ultrafilters. To avoid exceedance of compliance with respect to the discharge criteria, further treatment step(s) should be considered prior to any treated wastewater reuse.

A Case Study of Fish Processing Plant Wastewater Treatment

A Case Study of Fish Processing Plant Wastewater Treatment

Sulfide removal in wastewater from petrochemical industries by autotrophic denitrification

An alternative flowchart for the biological removal of hydrogen sulfide from oil-refining wastewater is presented; autotrophic denitrification in a multi-stage treatment plant was utilized. A pilot-scale plant was fed with a mixture of the following constituents: (a) original wastewater from an oil refining industry (b), the effluent of the existing nitrification-stage treatment plant and (c) sulfide in the form of Na 2S. Anoxic sulfide to sulfate oxidation, with nitrate as a terminal electron acceptor, proved very successful, as incoming concentrations of 110 mg S 2−/L were totally converted to SO 4 2−. At complete denitrification, the concentration of S 2− in the reactor effluent was less than 0.1 mg/L. Fluctuating S 2− concentration in the feed could be tolerated without any problems, as the accumulated sulfide in the effluent of the denitrification stage is oxidized aerobically in a subsequent activated-sludge treatment stage. This alternative new treatment scheme was further introduced at the refinery's wastewater processing plant. Thus, complete H 2S removal is now accomplished by the combination of the proposed biological method and the existing stripping with CO 2. As a result, stripping, and thus its cost, is reduced by 70%.

Recovery and utilization of useful by-products from egg processing wastewater by electrocoagulation

The efficacy of a laboratory electrocoagulation (EC) system for treating egg processing plant waste-water (WW) is reported. For simulated and industrial egg processing WW, chemical oxygen demand, turbidity, and total suspended solids (TSS) were reduced 92 to 97%, 97%, and 99%, respectively, after treatment with EC. The final TSS concentration and turbidity values were 30 mg/L and 5 formazin turbidity units (FTU), respectively, similar to that of potable water standards. The recovered by-product solids had a similar pattern of essential amino acids compared to that of liquid whole egg and were comparable to the Food Agriculture Organization's essential amino acid profile for an ideal protein. The relative protein digestibilities of the recovered solids and a commercial corn meal averaged 130 and 56%, respectively, compared to liquid whole egg (set at 100%). An economic analysis of EC indicated that this treatment is economically feasible in that a savings of approximately $425,000 per year is possible in addition to recovering the capital equipment costs after about 14 mo of operation. These findings demonstrate that EC can be successfully applied to treat egg processing plant WW, yielding a high quality water suitable for recycling and valuable by-products having a highly digestible protein and fat value.

Magnetization of activated sludge by an external magnetic field

Magnetization of acclimated activated sludge with the application of an external magnetic field was observed using a magnetic force microscope and can be expressed as the visual magnetic flux density graph. FeCl3 addition up to 0.1% (w/v) into the sludge, which was acclimated with synthetic sewage wastewater, enhanced the magnetization. Such magnetization was also observed in the activated sludge obtained from the practical wastewater treatment plants of a food processing plant and sewage wastewater. FeCl3 addition also enhanced the sludge magnetization. The possibility is suggested that this magnetization causes the flock to enlarge and enhance sedimentation of the activated sludge on application of an external magnetic field.

Recovery and Characterization of By-Products from Egg Processing Plant Wastewater Using Coagulants

The effectiveness of precipitation or coagulation technology to treat commercial egg processing plant wastewater, using such coagulants as lignosulfonate, bentonite, carboxymethylcellulose, and ferric chloride, was evaluated. For simulated and industrial waste-water, chemical oxygen demand, turbidity, and total solids were reduced over 90, 97, and 95%, respectively, for all coagulants tested. Protein and fat recoveries were over 95% for all coagulants. The optimal coagulant concentration for maximum by-product recovery depended on initial wastewater concentrations of protein, total solids, and fat. The dried by-products contained high concentrations of protein (30 to 50%) and fat (30 to 40%) and had similar essential amino acid profiles as standard proteins from the United Nations Food and Agricultural Organization (FAO). The relative protein digestibilities of each recovered solid (carboxymethycellulose, lignosulfonate, bentonite, and ferric chloride) and corn meal relative to a liquid whole egg standard were approximately 80, 90, 60, 30, and 56%, respectively. These compositional and in vitro digestibility studies suggest that the recovered by-products could be useful as livestock feed ingredients or for other applications.

Use of flow-injection sample-to-standard addition methods for quantification of metals leached by selective chemical extraction from sewage sludge

The flow injection sample-to-standard addition method (FI-SAM) proposed by Israel and Barnes and a modification of it was employed for determination of the extractable contents of chromium, lead, nickel and zinc in a sewage sludge sample obtained from an urban wastewater processing plant. The new calibration method was a modification of the one established by Israel and Barnes in which the sample was injected into a blank solution and two different standard solutions. The advantages of this modified calibration method were: (i) sample consumption was minimised in comparison with the `reverse' flow injection method since the sample was not used as carrier; (ii) a blank that was matrix matched to the sample was not required; (iii) a similar precision was observed in comparison with the original procedure. For studying FI-SAM calibration strategies, extractable metals obtained by using two known sequential extraction schemes (Tessier and BCR) were determined. Only fractions that required calibration with the standard addition method for metal determination were considered. FI-SAMs compensate for interference effects caused by concomittants co-extracted at each stage of the sequential extraction scheme from sewage sludge, for all metals studied except for chromium.

Application of microwave extraction for partitioning of heavy metals in sewage sludge

The four-stage Tessier sequential extraction method was used for metal fractionation in a sewage sludge sample collected from an urban wastewater processing plant. The original Tessier's method was modified, in each stage, using microwave heating in order to reduce the long operation time. Extraction conditions (heating time and power) were specifically optimised for Cu, Cr, Ni, Pb and Zn with the aim of finding extraction efficiencies similar to that of the original Tessier's method. Analytical results obtained by both the conventional and the microwave Tessier extraction methods were statistically compared ( p=0.05) for all the studied elements and no significant differences (recoveries between 98.3% and 100.8%) were found for Ni, Pb and Zn in the three first stages (i.e. exchangeable, carbonate-bound and Fe–Mn oxides-bound). However, in the fourth stage (i.e. organic matter-bound), a different behaviour was found when using microwave heating since Ni and Zn were extracted with same efficiency as compared with the conventional Tessier method (recoveries of 98.8% and 100.2% for Ni and Zn, respectively), Pb was excessively leached and Cr was not leached. For Cu, although different metal partitioning pattern were obtained by applying both extraction methods, the total extractable content obtained by the microwave extraction method was only about 7% lower than that obtained by the conventional Tessier extraction method. The precision of the proposed microwave extraction method (expressed as RSD) was lower than 5% for all metals.

Speciation of metals in sewage sludge for agricultural uses

A study carried out on sewage sludge samples collected at an urban waste-water processing plant located in Zaragoza (Spain) is reported. The concentrations of metals (Cd, Co, Cr, Cu, Ca, K, Fe, Mg, Mn, Ni, Na, Pb and Zn) and agronomic parameters were determined. The speciation of metals based on the sequential extraction scheme proposed by Tessier et al. is reported. Principal component analysis was applied to the results obtained and the correlation factors are discussed. The concentration of heavy metals is lower than that established by European legislation. Heavy metals are mainly associated with the mineral fraction and consequently they show a low availability index.

97/03328 Use of peat and its byproducts in ecologically safe technologies

Phytoextraction is an effective method to remediate heavy metal contaminated landscapes but is often applied for single metal contaminants. Plants used for phytoextraction may not always be able to grow in drier environments without irrigation. This study investigated if willows (Salix x reichardtii A. Kerner) can be used for phytoextraction of multiple metals in biosolids, an end-product of the wastewater treatment process, and if irrigation with reclaimed and freshwater influences the extraction process. A plantation of willows was established directly onto a tilled stockpile of metal-contaminated biosolids and irrigated with slightly saline reclaimed water (EC ∼2 dS/cm) at a wastewater processing plant in Victoria, Australia. Biomass was harvested annually and analysed for heavy metal content. Phytoextraction of cadmium, copper, nickel and zinc was benchmarked against freshwater irrigated willows. The minimum irrigation rate of 700 mm per growing season was sufficient for willows to grow and extract metals. Increasing irrigation rates produced no differences in total biomass and also no differences in the extraction of heavy metals. The reclaimed water reduced both the salinity and the acidity of the biosolids significantly within the first 12 months after irrigation commenced and after three seasons the salinity of the biosolids had dropped to <15% of initial values. A flushing treatment to remove excess salts was therefore not necessary. Irrigation had an impact on biosolids attributes such as salinity and pH, and that this had an influence on metal extraction. Reclaimed water irrigation reduced the biosolid pH and this was associated with reductions of the extraction of Ni and Zn, it did not influence the extraction of Cu and enhanced the phytoextraction of Cd, which was probably related to the high chloride content of the reclaimed water. Our results demonstrate that flood-irrigation with reclaimed water was a successful treatment to grow willows in a dry climate. However, the reclaimed water can also change biosolids properties, which will influence the effectiveness of willows to extract different metals.

Analytical assessment of two sequential extraction schemes for metal partitioning in sewage sludges.

Two sequential extraction schemes were employed for speciation of Cu, Cr, Pb, Ni and Zn in sewage sludges: the conventional Tessier scheme and the sequential extraction scheme proposed by the European Communities Bureau of Reference (BCR). Both sequential extraction schemes were compared in terms of operation time, matrix effects and extraction efficiency. Two sludge samples collected from an urban wastewater processing plant at different seasons were analysed by FAAS for total contents and for extractable metals present in each fraction. Partitioning patterns were obtained for each metal so that metal mobility could be predicted. Both sequential extraction schemes yielded similar performance when extraction efficiencies were compared but matrix effects caused by concomitants were less pronounced in the BCR scheme in comparison with the Tessier scheme.

Technical Notes: Crawfish Processing Plant Wastewater Characterization

ABSTRACT WASTEWATER from crawfish processing plants was characterized on a per kg of live crawfish processed basis. The range of parameters were: water usage, 3.06 to 6.46 L/kg; BOD5, 2.3 to 10.2 g/kg; Total Suspended Solids (TSS), 0.97 to 3.47 g/kg; Oil and Grease (O & G), 0.64 to 1.23 g/kg; pH 6.4 to 7.45; Dissolved Oxygen (DO), 0.36 to 1.04 and temperature, 24.8 to 27 C.