Paint Wastewater Research Articles

Experimental and artificial neural network application on the optimization of paint effluent (PE) coagulation using novel Achatinoidea shell extract (ASE)

This study investigated the potentials of Achatinoidea shell extract (ASE) as a coagulant for the pretreatment of paint wastewater. ASE preparation was adapted from the modified method of Fernandez-Kim, with effective deacetylation of precursor by NaOH at 65°C for 2h. Bench scale jar test experiment was carried out using ASE for the removal of TDSP (total dissolved and suspended particles). The influence of operating parameters on the process efficiency was examined using both one factor at a time (OFAT) and central composite design (CCD) methods. Results indicated the process followed second order reaction with rate constant of 0.0001 (l/g.s) and period of 7.432s. Optimum performance of 99.22% was recorded at pH 4, 4g/l dosage and 45°C. There was significant agreement between results obtained by OFAT and CCD, which was validated by experimental and artificial neural network (ANN) methods. The process efficiency showed that paint effluents (PE) could effectively be treated at the conditions of the experiment.

Reuse paint wastewater in the manufacture of cement bricks and tiles

Waste management is one of the most important and serious issues facing many developing countries. The main purpose of this research involves reusing wastewater generated by the paint industry in the manufacture of cement bricks and tiles, in addition to improving some mechanical properties of the cement bricks and tiles. Since large quantities of water are needed to produce bricks and tiles, this project focuses on using wastewater rather than supply clean water in the production of bricks and tiles. Different samples have been prepared and tested to evaluate the effect of using wastewater on the properties of the bricks and tiles formed. The bricks and tiles samples were tested for water absorption, ignitability, toxicity, and corrosivity. The concentrations of sulfide and cyanides in all samples were determined and compared to the prescribed limit identified by the U.S. EPA. The bricks samples were also tested for compressive strength, where the tiles samples were tested for bending strength and abrasion resistance. The tests results showed that there are no negative effects of using wastewater generated from the paint industry in the manufacture of the cement bricks and tiles, as well as it improves the mechanical properties of the bricks and tiles.

Treatment of paint wastewater by coagulation process

The increase in industrial wastewater poses potential health and environmental problems. Faced with the stricter environmental regulations and the increasing exhaustion of water resources, the recycling of wastewater for reuse have become a priority. This study looks into the field of treatment of industrial paint wastewater by coagulation-flocculation process.

A Kinetic Investigation of the Pulverized Okra Pod Induced Coag-Flocculation in Treatment of Paint Wastewater

The effectiveness of locally available okra pod powder as natural coagulant under varying pH, dosage and settling time in the removal of turbidity from paint waste water at room temperature has been evaluated. The application of single angle Turbidimeter measurement was employed for the experiment. Such kinetic and functional parameter as coagulation rate constant (K), and coagulation period (τ1/2) , were determined. Statistical parameters such as coefficient of determination (R2), sum of squares due to error (SSE), and the root mean square error (RMSE), were used to evaluate the adequacy of the process. The highest value of 1.7×10﹣4L/mg.min for K is recorded at pH 4 and 100 mg/L dosage with τ1/2 of 14.91 min and the least value of K, 3.6×10﹣5L/mg.min is recorded at pH 8 and 300 mg/L doses with τ1/2 of 70.43 min respectively. The efficiency of turbidity removal of more than 80% and 95% was achieved at the end of 3 mins and 30 mins settling time respectively, indicating a system controlled by perikinetic method of coag-flocculation. The results exhibited the potential of pulverized okra pod for removal of suspended particle from paint wastewater.

Cactus opuntia (ficus-indica): an eco-friendly alternative coagulant in the treatment of paint effluent

In this study, the potentiality of Cactus opuntia (ficus-indica), as a coagulant for the treatment of simulated industrial water-based paint wastewater in terms of colour, chemical oxygen demand (COD) and turbidity was investigated. The coagulation ability was assessed for 1 L of effluent using the standard jar test apparatus by varying the operational variables like eluent type (water, NaCl and BaCl2), eluent concentration (1–5 N), coagulant dosage (1–6 g), coagulant volume (20–100 mL), initial pH (5–11) and initial effluent concentration (3100, 4224, 5650, 6258 and 7693 mg/L named as sample number 1–5, respectively). The results were maximum when 100 mL of 3 g of C. opuntia, eluted using 3 N NaCl was used as a coagulant to treat a litre of effluent. The favourable pH to run the treatment was confirmed as the actual pH of the sample (7.2–7.8). It was found that the removal efficiency increased as the pollution load swelled. The FTIR study revealed the presence of various functional groups, which are responsible for the coagulation process. The obtained results were compared with conventional coagulant ferric chloride. The results acknowledged that Cactus opuntia (ficus-indica) a natural, eco-friendly coagulant, could be a strong alternative to the conventional coagulant in the treatment of water-based paint wastewater.

Reduction of COD in water-based paint wastewater using three types of activated carbon

In this study, the reduction chemical oxygen demand (COD) in water-based paint wastewater using commercial activated carbon, activated date pits and rice husks was investigated. The process was studied in the batch mode with respect to the initial pH, contact time, and adsorbent dose. Adsorption equilibrium and kinetic data were determined for the three adsorbents and were fitted to several isotherm and kinetic models accordingly. The results indicated that activated rice husks (ARH) and activated date pits (ADP) were as effective as commercial activated charcoal (CAC) in the reduction of the effluent COD reaching a maximum of 83% using 180 g/L ARH and 76% using 120 g/L ADP. Kinetically, the results showed that reduction of COD onto both ADP and ARH was better fitted to pseudo-second-order model which involved particle/pore diffusion. In addition, equilibrium adsorption data for the reduction of COD effluent ADP and ARH was best represented by the Langmuir model.

Treatment of paint wastewater by radiation combined with coagulation and adsorption

In this study, attempts were made to examine the efficiency of radiation combined with coagulation with aluminium sulphate and adsorption using granular activated carbon (GAC) for treatment of paint wastewater and its reuse for different purpose. Parameters affecting microorganism disinfection such as radiation dose showed that complete disinfection was obtained at radiation dose 2 kGy. Factors affecting coagulation such as settling time, aluminium sulphate concentration were also studied, it was found that Al2(SO4)3.16H2O at concentration 10 g/L and pH 8 showed the better coagulation at 51 sec compared with other concentrations. A combined treatment of radiation followed by coagulation and adsorption by GAC of a dose (2 g/100 ml supernatant) showed a reduction in sulphate concentration 50%, COD 92% and BOD 98.5%. Also the obtained supernatant can be used for some irrigation purposes, whereas the coagulant was used as filler and showed the same physical parameters compared with the original one. Thus, this study might offer an effective way for wastewater treatment of paint industry.

Opportunities for In-mould Painting at TVS Motor Company Ltd

TVS Motor Company is the third largest manufacturer of two-wheelers in India and one of the top ten manufacturers in the world. The company manufactures 1.5 million two-wheelers for both its domestic and overseas requirements. The company's manufacturing process involves painting of plastic, metal and aluminium components to enhance their appearance and performance properties. The company currently uses a conventional post painting process for its moulded plastic panels. However the conventional post painting process causes a huge impact on the environment through flue gas emissions from baking ovens, solvent emission from paint booths and ovens, sludge generation from paint booths and wastewater generation from paint booths and pre-treatment processes. The volumes of waste and cost for part attached to the painting process for TVS Motor Company are detailed in this paper. Paint shop replacement technologies in relation to current in-mould decoration technologies such as pigmented plastics, in-mould film, co-injection moulding and in-mould spray painting (INSPIRE) are considered. Based on current specifications and requirements for painted plastic components, INSPIRE is found to be the most advantageous paint shop replacement technology for current TVS Motor Company Ltd production as it uses a thermoset, matching current specifications. A design of experiments is performed using a polyester skin and ABS substrate to optimise part coverage for a sample part. Using statistical analysis spray time and spray pressure are found to be the most important process parameters for paint coverage. Paint coverage could be greatly improved compared to that which has been previously reported.

Treatment and recycling facilities of highly polluted water-based paint wastewater

The study presented focuses on treatment and recycling facilities of highly polluted water-based paint wastewater from electronics industry, using coagulation-flocculation, Fenton’s oxidation and membrane processes. The treated water is sought after for recycling purposes within the painting unit and the water quality is negligible except suspended solids. The wastewater used in this study was characterized as highly polluted wastewater with high concentrations of COD (55,000–144,000 mg/l) and SS (9500–32,000 mg/l), alkaline and blackish colored. Coagulation-flocculation using alum and FeSO4 was investigated. 67% of COD removal was achieved at 1000 mg/l of alum dosage whereas coagulation with FeSO4 obtained 45% removal efficiency at 750 mg/l dosage. The Fenton’s oxidation process gave good results for the removals of COD and color. 81% of COD removal was achieved at a molar ratio of [H2O2]/[Fe+2] = 10 with 2 m H2O2. Waste sludge produced during the Fenton’s process was less than that of coagulation, but s...

Electrochemical treatment of simulated industrial paint wastewater in a continuous tubular reactor

Abstract The electrochemical treatment of industrial water-based paint wastewater was investigated in a continuous tubular reactor constructed from a stainless steel tube with a cylindrical carbon anode. Industrial wastewater was prepared by thinning a commercial paint down to 4.4% (w/v) with water, which is the solid material content of the wastewater generated in the paint manufacture. The effects of residence time on chemical oxygen demand (COD), color and turbidity removals and pH change was studied at 30 °C, 35 g/L electrolyte and 7496 mg/L COD feed concentrations with 66.8 mA/cm2 current density. The optimum residence time in the reactor was determined 6 h for a cost driven approach, enabling COD, color and turbidity removal as 44.3%, 86.2% and 87.1%, respectively, and a discharge pH value of 7.33. At 6 h of residence, 42 kWh energy was consumed per kg COD removed maintaining a mass transfer coefficient value of 3.62 × 10−6 m/s. In all runs, the polymer/water emulsion always broke into insoluble solid particles during the electrochemical treatment, which eventually precipitated.

Optimization of electrochemical treatment of industrial paint wastewater with response surface methodology

The electrochemical oxidation of water-based paint wastewater was investigated batch-wise in the presence of NaCl electrolyte with carbon electrodes for the first time in literature. The electrochemical treatment conditions were optimized using response surface methodology where potential difference, reaction temperature and electrolyte concentration were to be minimized while chemical oxygen demand (COD), color and turbidity removal percents and initial COD removal rate were maximized at 100% pollution load. The optimum conditions were satisfied at 35 g/L external electrolyte concentration, 30 °C reaction temperature and 8 V potential difference (64.37 mA/cm 2 current density) realizing 51.8% COD and complete color and turbidity removals, and 3010.74 mg/L h initial COD removal rate. According to these results, the electrochemical method could be a strong alterative to conventional physicochemical methods for the treatment of water-based paint wastewater.

Determination of poisonous metals in wastewater collected from paint manufacturing plant using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) system was developed for determination of toxic metals in wastewater collected from local paint manufacturing plant. The plasma was generated by focusing a pulsed Nd:YAG laser at 1064 nm on the solid residue from wastewater collected from paint industry. The concentration of different elements of environmental significance like, lead, copper, chromium, calcium, sulphur, magnesium, zinc, titanium, strontium, nickel, silicone, iron, aluminum, barium, sodium, potassium and zirconium, in paint wastewater were 6, 3, 4, 301, 72, 200, 20, 42, 4, 1, 35, 120, 133, 119, 173, 28 and 12 mg kg −1, respectively. The evaluation of potential and capabilities of LIBS as a rapid tool for paint industry effluent characterization is discussed in detail. Optimal experimental conditions were evaluated for improving the sensitivity of our LIBS system through parametric dependence study. The laser-induced breakdown spectroscopy (LIBS) results were compared with the results obtained using standard analytical technique such as inductively coupled plasma emission spectroscopy (ICP). The relative accuracy of our LIBS system for various elements as compared with ICP method is in the range of 0.03–0.6 at 2.5% error confidence. Limits of detection (LOD) of our LIBS system were also estimated for the above mentioned elements.

Treatability of water-based paint wastewater with Fenton process in different reactor types

Water-based paint wastewater which is formed during the coating step of metal surfaces performed with various spray processes include binders, pigments and additives. Binders and other additives may also affect the toxicity of the paint depending on the specific characteristics of the paint. This study deals with Water-based paint wastewater, which is hard to treat. Fenton oxidation process was principally used to treat the wastewater. Treatability runs were carried out by using rust (oxidized iron) particles obtained as a waste of the metal rolling process, as the Fenton’s catalyst. In order to change the variables such as dimensions of the column, packing material size, reactive dosage, pH value and reaction time, the experiments on the basis of packed columns and mixed reactors were carried out to increase the COD removal. COD eliminations with pH adjustment were about 20%. With the contribution of Fenton process in both column and mixed-reactor studies, the COD removal was improved by about 80%.

Application of reverse osmosis to automotive electrocoat paint wastewater recycling

Field and bench-scale reverse osmosis experiments on wastewater derived from automotive electrocoat paint operations are reported. Field experiments were performed continuously over a six-month interval using a reverse osmosis unit equipped with cellulose acetate membranes. An operating pressure of 3100 kPa (450 psi) and a temperature of 24–27°C was maintained. These RO experiments were unusual for two reasons. First, certain solutes in the feedwater were allowed to permeate through the membrane along with water. This was done to permit solute recycling and reuse. Since these solutes (ethyl, butyl and hexyl glycol ethers) were present in a 3% total concentration in the feedstream, their permeation through the membrane eliminated a flux reduction mechanism. This would arise from the increased upstream osmotic pressure if these solutes were concentrated. Second, the experiments were performed under conditions where colloidal lead was present. This caused limited membrane fouling which was controlled via weekly cleaning with dilute lactic acid. Some supporting bench-scale RO experiments were carried out to probe factors influencing this RO application.