Industrial Park Wastewater Treatment Plant Research Articles

Viral community distribution, assembly mechanism, and associated hosts in an industrial park wastewater treatment plant

Viruses manipulate bacterial community composition and impact wastewater treatment efficiency. Some viruses pose threats to the environment and human populations through infection. Improving the efficiency of wastewater treatment and ensuring the health of the effluent and receptor pools requires an understanding of how viral communities assemble and interact with hosts in wastewater treatment plants (WWTPs). We used metagenomic analysis to study the distribution, assembly mechanism, and sensitive hosts for the viral communities in raw water, anaerobic tanks, and returned activated sludge units of a large-scale industrial park WWTP. Uroviricota (53.42% ± 0.14%) and Nucleocytoviricota (26.1% ± 0.19%) were dominant in all units. Viral community composition significantly differed between units, as measured by β diversity (P = 0.005). Compared to raw water, the relative viral abundance decreased by 29.8% in the anaerobic tank but increased by 9.9% in the activated sludge. Viral community assembly in raw water and anaerobic tanks was predominantly driven by deterministic processes (MST <0.5) versus stochastic processes (MST >0.5) in the activated sludge, indicating that differences in diffusion limits may fundamentally alter the assembly mechanisms of viral communities between the solid and liquid-phase environments. Acidobacteria was identified as the sensitive host contributing to viral abundance, exhibiting strong interactions and a mutual dependence (degree = 59). These results demonstrate the occurrence and prevalence of viruses in WWTPs, their different assembly mechanism, and sensitive hosts. These observations require further study of the mechanisms of viral community succession, ecological function, and roles in the successive wastewater treatment units.

Molecular insights into the dissolved organic matter of leather wastewater in leather industrial park wastewater treatment plant

Leather wastewater (LW) effluent is characterized by complex organic matter, high salinity, and poor biodegradability. To meet the discharge standards, LW effluent is often mixed with municipal wastewater (MW) before being treated at a leather industrial park wastewater treatment plant (LIPWWTP). However, whether this method efficiently removes the dissolved organic matter (DOM) from LW effluent (LWDOM) remains debatable. In this study, the transformation of DOM during full-scale treatment was revealed using spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. LWDOM exhibited higher aromaticity and lower molecular weight than DOM in MW (MWDOM). The DOM properties in mixed wastewater (MixW) were similar to those in LWDOM and MWDOM. The MixW was treated using a flocculation/primary sedimentation tank (FL1/PST), anoxic/oxic (A/O) process, secondary sedimentation tank (SST), flocculation/sedimentation tank, denitrification filter (FL2/ST-DNF), and an ozonation contact reactor (O3). The FL1/PST unit preferentially removed the peptide-like compounds. The A/O-SST units had the highest removal efficiencies for dissolved organic carbon (DOC) (61.34 %) and soluble chemical oxygen demand (SCOD) (52.2 %). The FL2/ST-DNF treatment removed the lignin-like compounds. The final treatment showed poor DOM mineralization efficiency. The correlation between water quality indices, spectral indices, and molecular-level parameters indicated that lignin-like compounds were strongly correlated with spectral indices and CHOS compounds considerably contributed to the SCOD and DOC. Although the effluent SCOD met the discharge standard, some refractory DOM from LW remained in the effluent. This study illustrates the composition and transformation of DOM and provides theoretical guidance for improving the current treatment processes.

Occurrence and prevalence of antibiotic resistance genes and pathogens in an industrial park wastewater treatment plant

Antibiotic resistance genes (ARGs) and pathogens are emerging environmental pollutants that pose a threat to human health and ecosystem. Industrial park wastewater treatment plants (WWTPs) treat large amounts of comprehensive wastewater derived from industrial production and park human activity, which is possible a source of ARGs and pathogens. Therefore, this study investigated the occurrence and prevalence of ARGs, ARGs hosts and pathogens and assesses the ARGs health risk in the biological treatment process in a large-sale industrial park WWTP using metagenomic analysis and omics-based framework, respectively. Results show that the major ARG subtypes are multidrug resistance genes (MDRGs), macB, tetA(58), evgS, novA, msbA and bcrA and the ARGs main hosts were genus Acidovorax, Pseudomonas, Mesorhizobium. In particular, all determined ARGs genus level hosts are pathogens. The total removal percentage of ARGs, MDRGs and pathogens were 12.77 %, 12.96 % and 25.71 % respectively, suggesting that the present treatment could not efficiently remove these pollutants. The relative abundance of ARGs, MDRGs and pathogens varied along biological treatment process that ARGs and MDRGs were enriched in activated sludge and pathogens were enriched in both secondary sedimentation tank and activated sludge. Among 980 known ARGs, 23 ARGs (e.g., ermB, gadX and tetM) were assigned into risk Rank I with characters of enrichment in the human-associated environment, gene mobility and pathogenicity. The results indicate that industrial park WWTPs might serve as an important source of ARGs, MDRGs, and pathogens. These observations invite further study of the origination, development, dissemination and risk assessment of industrial park WWTPs ARGs and pathogens.

Study of hybrid performance of the methods applied for recycling Aq Qala-industrial park effluent

Aim: Currently, recycling of secondary effluent can be used sustainably as a new water source to minimize the water consumption in areas which are exposed to water crisis. Hence, it is necessary to appraise hybrid advanced treatment technologies performance and to determine the best alternative for reusing secondary effluent of industrial park in full-scale. Materials and Methods: The secondary effluent (biological-treated) of the centralized industrial park wastewater treatment plant (Aq Qala, Golestan province, Iran) is introduced into combined systems such as (1) sand filter (SF) and membrane bioreactor (MBR), (2) SF, MBR and granular activated carbon (GAC) (3) SF and GAC (4) SF, MBR, GAC, and reverse osmosis (RO), as the hybrid advanced scenarios. Results: The effluent of SF/MBR/GAC/RO showed the highest quality (>99% removal efficiency). In this scenario, pH, silica, manganese, iron, total suspended solids, turbidity, total coliform, and chemical oxygen demand (COD), alkalinity, hardness, total dissolved solids (TDS), chloride, and sulfate were determined 6.93 ± 0.19, 1.4 ± 0.6 mg/L, not detectable (ND), ND, <2 ± 0.2 mg/L, <1 Nephelometric Turbidity unit (NTU), ND and <2 ± 0.2 mg/L, 54.8 ± 1 2.5 mg/L, 50 ± 17 mg/L, 100 ± 14.89 mg/L, 68 ± 10.9 mg/L, and 44 ± 3.67 mg/L were observed in the range of product water standard for sensitive industries. Also, the maximum of efficiency of SF/MBR, SF/MBR/GAC, and SF/GAC systems was obtained 97.75% (as total coliforms), 62.65% (as COD), and 55.8% (as COD), respectively. Other parameters removed slight about 2% to 40%. However, hardness, alkalinity, and manganese concentrations not reduced after these systems (0% efficiency). Conclusions: The hybrid system of SF/MBR/GAC/RO was produced a clean and suitable water supply for the sensitive industries (e.g., intermediate-pressure boilers, cooling water, textile, etc.) of Aq Qala industrial park according to the environmental protection agency standards.

Estrogen toxicity reduction of industrial biochemical tailwater by electrolysis biofilters with ceramsite‑sulfur-siderite fillers

Biochemical tailwater of the industrial park wastewater treatment plant is facing the growing demand of advanced treatment and toxicity reduction. However, existing information on toxicity reduction of real industrial biochemical tailwater is still limited so far. Herein, the water quality of biochemical tailwater from an integrated industrial park in Taihu Lake Basin, China, was systematically investigated, and typical endocrine disrupting chemicals (EDCs) and estrogen toxicity were detected. Estrogen toxicity reduction by previously proposed electrolysis biofilters with ceramsite‑sulfur-siderite fillers was further verified. Results showed that total nitrogen (TN) and estrogen toxicity removal increased by 41.0 % and 30.3 % respectively under the optimal voltage of 4 V and electric loading of 24 h/d, and significantly positive correlation between estrogen toxicity reduction and TN removal (p < 0.05) was observed. The lowest effluent estrogen toxicity was 0.79–0.95 ngE2/L (in estradiol equivalent concentration) by the biofilter with ceramsite‑sulfur-siderite fillers, which was lower than the estrogen disruption effects mass concentration threshold of 1 ng/L. Electrical stimulation promoted the increase of the abundance of denitrifying bacteria Thauera and electroactive bacteria Hydrogenophaga, thus enhancing the removal of TN, furthermore, the abundance of Thiobacillus and Sulfuritalea were significantly correlated with the reduction of estrogen toxicity. The study highlights the potential of electrolysis biofilter in realizing the synergy of estrogen toxicity reduction and autotrophic denitrification of industrial biochemical tailwater, and paves the way for the application of electrolysis biofilter in the advanced purification of industrial biochemical tailwater.

Molecular Insights into the Dissolved Organic Matter of Leather Wastewater in Leather Industrial Park Wastewater Treatment Plant

Molecular Insights into the Dissolved Organic Matter of Leather Wastewater in Leather Industrial Park Wastewater Treatment Plant

Advanced treatment of secondary effluent organic matters (EfOM) from an industrial park wastewater treatment plant by Fenton oxidation combining with biological aerated filter

This study investigated the advanced treatment of secondary effluent organic matters (EfOM) from an industrial park wastewater treatment plant (IPWTP) by Fenton oxidation process and its combination with biological aerated filter (BAF). The constituents of EfOM were characterized by using fluorescence excitation-emission matrix, and the results showed that the major components included aromatic proteins, soluble microbial products, humic and fulvic acid-like substances, and compounds associated with fluorescent region of Ex 250–300 nm/Em 600–700 nm. The EfOM was strongly resistant to biodegradation (biochemical oxygen demand (BOD5):chemical oxygen demand (COD) ratio at 0.11), resulting in less than 15% dissolved organic carbon (DOC) removal efficiency by the BAF reactor. The advanced treatment of EfOM by Fenton oxidation process led to maximum ~50% mineralization efficiency of EfOM under the optimal conditions of 2.0 mM FeII, 10 mM H2O2, pH 3.0 and 3.0 h of the reaction time. Particularly, Fenton oxidation treatment effectively improved the biodegradability of EfOM in the IPWTP secondary effluents, e.g., increasing the BOD5:COD ratio from 0.11 to 0.42. A synergistic combination of Fenton oxidation process with the BAF reactor offered desirable mineralization efficiencies of EfOM (>70%) at lower dosages of Fenton's reagents. The present results suggest that Fenton oxidation process combining with the BAF reactor can be a promising strategy for the advanced treatment of EfOM in IPWTP secondary effluents. This study provides guidance for the characterization and advanced treatment of EfOM in IPWTP secondary effluents for practical purpose.

Separation and characterization of refractory colored dissolved effluent organic matter in a full-scale industrial park wastewater treatment plant.

Colored dissolved organic matter (DOM) is a significant indicator of refractory DOM in wastewaters, and fluorescent DOM is an essential part indicating colorants. However, little is known about the composition and contribution of colored DOM to wastewater. This study provided some insights on the persistent yellowish color in biological effluent through use of a multi-characterization approach, and evaluated the effect of two advanced treatments (O3 and granular active carbon (GAC)) in a full-scale wastewater treatment plant. The multi-characterization technique incorporated resin fractionation, excitation-emission matrix spectroscopy (EEM) combined with fluorescence regional integration (FRI), size-exclusion chromatography (SEC), and X-ray photoelectron spectroscopy (XPS) analysis. The fractionation results showed that hydrophobic acid (HPOA) and hydrophilic (HPI) substances are abundant in colorants, and HPI-type colorants are comparatively resistant or unable to be removed through GAC and O3 individually. FRI-based EEMs showed that F3 (fulvic acid-like organics) and F5 (humic acid-like organics) mainly account for the yellowish color, and their combined fractions of total colorants are 50%, 31%, and 48% in biological, biological + O3, and biological + GAC effluents, respectively. SEC for measurement of the apparent molecular weight revealed that these colorants may have molecular weights in the range 2-5 kDa. The XPS analysis indicated that these colorants possess ether or hydroxyl and nitro (C-O/C-N) chromophoric groups with conjugated aromatic structures. For C-O/C-N, O3 showed good removal efficiency overall. GAC showed exceptionally high efficiency for HPOA but very low efficacy toward HPI-type colorants in terms of C-O/C-N chromophoric functional group removal.

Enhancing biodegradability of industrial park wastewater by packing carriers and limited aeration in the hydrolysis process

This study aims to ameliorate effects of packing carriers, filling ratio, temperature and limited aeration on hydrolysis performance in a chemical industrial park wastewater treatment plant. Illumina-MiSeq sequencing was applied to compare microbial community structure between biofilm attached on carriers and activated sludge in a full-scale hydrolysis tank. Packing carriers intensified the plentifulness of microbial community, enriched hydrolytic bacteria (Betaproteobacteria, Gammaproteobacteria, Sphingobacteria, Clostridia, Bacteroidia), and enhanced biodegradability of organics in the wastewater. Rising carriers filling ratio increased first-order kinetic constant of hydrolysis from 0.015 to 0.080 h−1, and decreased fractions inert to hydrolysis. Rising temperature stimulated enzymatic activity for hydrolysis with activation energy of 80.22 kJ/mol. Limited aeration further enriched hydrolytic bacteria, inhibited sulfate-reducing bacteria and intensified biodegradability of organic substances. Variations of fluorescent organic substances and ammonia nitrogen release during hydrolysis confirmed that hydrolysis was strengthened by packing carriers, increasing filling ratio, enhancing temperature and introducing limited aeration. Packing carriers and limited aeration were techno-economic methods for enhancing hydrolysis performance in the chemical industrial park wastewater treatment plant by enriching hydrolytic bacteria and stimulating their activities.

Removal of hard COD from biological effluent of coking wastewater using synchronized oxidation-adsorption technology: Performance, mechanism, and full-scale application

Efficient removal of the non-biodegradable organics from the biological effluent of industrial wastewater is becoming more and more important with the increasing demand for stringent discharge regulation. In this study, a synchronized oxidation-adsorption (SOA) technology was proposed for the removal of hardly biodegradable COD (hard COD) from the biological effluent of coking wastewater, and its performance was verified in a full-scale coking industrial park wastewater treatment plant (Q = 5,000 m3/d). The SOA was performed by coupling oxidation by hydroxyl radical (molar ratio of Fe2+ to H2O2 of 1:1 and pH = 5.0 ± 0.2) and adsorption by in-situ-formed nano hydrolyzed Fe3+ particles (nano-FeOOH). The nano hydrolyzed Fe3+ particles formed during the SOA exhibited a much higher specific surface area (22.83 m2/g) than the particles (10.87 m2/g) formed during the polyferric sulfate coagulation (PFSC). In comparison to PFSC, SOA performed better in terms of average COD removal (39% vs 18%) from the biological effluent. Wastewater fractionation result showed that SOA performed better in the removal of the hydrophobic acid matters, which was supported by the experiment using fulvic acid as the model organics. Mechanism studies using both biological effluent and fulvic acid solution showed that more carboxylic substances were adsorbed by the in-situ-formed nano-hydrolyzed Fe3+ particles formed by SOA than by PFSC, which was likely due to the generation of carboxylic substances by hydroxyl radical oxidation. In the full-scale, the COD was reduced from 118.5–198.0 mg/L in the PFSC-pretreated effluent to 61.5–104.0 mg/L through SOA treatment. The SOA treatment characterized with a mild pH condition (pH 5) and low molar ratio of Fe2+ to H2O2 (1:1) is particularly suitable for the polishing purpose to remove limited amount of organic pollutants from wastewater before discharge.

Modeling performance of industrial park wastewater treatment plant by STOAT software

To control environmental pollution, the Wastewater Treatment Plant (WWTP) plays a vital role in treating wastewater to comply with quality standards before being discharged into the environment. However, not all WWTPs have worked optimally, so the periodic evaluations must be carried out to determine problems and what efforts can be made to improve WWTP processing quality. This study aims to evaluate the Jababeka 1 WWTP, which functions to treat wastewater in Industrial Area 1 and Industrial Area 7, which are in the Jababeka Industrial Estate (KIJ). Evaluation is carried out by comparing the actual processing efficiency with the related literature. Evaluation is also carried out by simulating the process and operation of WWTP using STOAT software. STOAT is one of the WWTP system modeling software mostly used to predict the wastewater treatment plant’s performance. The test results show that for the efficiency of Jababeka 1, WWTP removal for parameters BOD, COD, and TSS are 90%, 93.02%, and 96.12%. Based on the data obtained, modeling based on sensitivity analysis was also carried out using STOAT software to determine the most significant WWTP performance parameters. It was found that the wastewater discharge was the most critical parameter affecting the removal efficiency of TSS and BOD.

Is ozonation environmentally benign for reverse osmosis concentrate treatment? Four-level analysis on toxicity reduction based on organic matter fractionation

Ozonation is a promising option to treat reverse osmosis concentrate (ROC). However, a systematic understanding and assessment of ozonation on toxicity reduction is insufficient. In this study, ROC sampled from a typical industrial park wastewater treatment plant of China was fractionated into hydrophobic acid (HOA), hydrophobic base (HOB), hydrophobic neutral (HON), and hydrophilic fraction (HI). Systematic bioassays covering bacteria, algae, fish, and human cell lines were conducted to reveal the role of ozonation in toxicity variation of the four ROC fractions. HOA in the raw ROC exhibited the highest toxicity, followed by HON and HI. Ozonation significantly reduced total organic carbon (TOC) and UV254 values in HOA, HON, and HI and their toxicity except in HOB. Correlation analysis indicated that chemical data (TOC and UV254) of HOA and HON correlated well with their toxicities; however, poor correlations were observed for HOB and HI, suggesting that a battery of toxicity assays is necessary. This study indicates that TOC reduction during ozonation could not fully reflect the toxicity issue, and toxicity assessment is required in conjunction with the chemical data to evaluate the effectiveness of ozonation.

Determination of Kinetic Parameters in Integrated Fixed Film Activated Sludge for Amol's Industrial Park Wastewater Treatment Plant

In this study the performance of integrated fixed film activated sludge system (IFAS)  in Amol industrial wastewater treatment plant (Amol, Iran) in treatment of food industrial wastewater was investigated. In addition, kinetic coefficients were evaluated for the system. The capacity of this system was 1700 cubic meters per day; that includes different process comprising physical and biological treatment, disinfection, sludge thickening, digestion and dewatering. COD removal efficiency and kinetic coefficients including yield coefficient (Y), half saturation coefficient (Ks), maximum substrate utilization rate constant (k) and endogenous decay coefficient (kd) were evaluated. The obtained results demonstrated that except Ks other coefficient were in the normal range that was frequently reported for conventional activated sludge in the literature. The COD removal efficiency was about 98 to 99 percent. The results indicated that there is a direct relationship between the variation of kd and Ks with effluent substrate concentration; while, the relationship between rate constant (k) and effluent COD is reversed. Finally, the effect of increasing sludge retention time (SRT) on COD removal was also studied. It was concluded that COD removal increased with an increase active solid retention time to a certain point, behind that point there was no significant changes observed.

Toxicity evaluation of wastewater collected at different treatment stages from a pharmaceutical industrial park wastewater treatment plant

The toxicity of water-receiving bodies, the effluent and other treatment stages in wastewater treatment plants has recently been of interest to the public due to the lack of a regulated toxicity-based index for wastewater discharge in China. This study aimed to evaluate the conventional pollution parameters and toxicities of wastewaters collected at different treatment stages from a pharmaceutical industrial park wastewater treatment plant through dehydrogenase activity (DHA) and bioluminescent bacteria (Vibrio qinghaiensis) tests. The results of an analysis of conventional parameters indicated that the total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH3N), and total phosphorus (TP) were largely removed after various treatments. However, the TN, NH3N and COD still exceeded the regulated standards. The tested pharmaceutical park effluents were mainly polluted with organic pollutants and nitrogenous. The toxicity test results indicated that the toxicities could be markedly reduced after treatment, with the toxicities of two out of the six effluent samples at different treatment stages being greater than the influent toxicity. Spearman’s rank correlation coefficients indicated a significantly positive correlation between the toxicity values obtained using the DHA and Vibrio qinghaiensis tests. Compared with the DHA measurement, the Vibrio qinghaiensis test was faster and more sensitive. Meanwhile, the toxicity indicators were significantly and positively correlated with the TSS, TN, TP and COD concentrations. These results may aid the understanding of the toxicity of pharmaceutical industrial park wastewaters and toxicity removal using the treatment techniques that are currently utilized in China.

Advanced treatment of effluents from an industrial park wastewater treatment plant by ferrous ion activated persulfate oxidation process.

The advanced oxidation technology, ferrous ion (Fe(II)) activated persulfate (PS) producing sulfate radicals, was used for the advanced treatment of effluent from an integrated wastewater treatment plant in a papermaking industrial park. Separate and interactive effects of PS dosage, Fe(II)/PS ratio and initial pH on chemical oxygen demand (COD) removal were analyzed by the response surface methodology (RSM). The results showed that Fe(II)-PS system was effective in COD removal from the secondary effluent. PS dosage was the most dominant factor with positive influence on COD removal, followed by initial pH value. The optimum conditions with COD removal of 54.4% were obtained at PS/COD of 2.2, initial pH of 6.47 and Fe(II)/PS of 1.89. UV-visible spectrum analysis showed that after RSM optimization, Fe(II)-PS system effectively degraded large organic molecules into small ones, and decreased humification degree of the effluent. Three-dimensional fluorescence analysis demonstrated that aromatic protein and fulvic substances were fully decomposed by the Fe(II)-PS treatment.

An Engineering Practice of Industrial Wastewater Treatment with Fe/Cu Bimetallic Process

Fe/Cu bimetallic process was developed as a new industrial wastewater pretreatment method. It was difficult for an industrial park wastewater treatment plant in Shanghai to treat the wastewater with many refractory pollutants and match the improved discharge standards. The plant needed renovation and adopted Fe/Cu process as a core pretreatment technology. 60,000 tons of wastewater is treated in the plant every day and the average removal rate of COD, BOD, total phosphorous (TP) and color was 73%, 77%, 55% and 48% respectively before renovation. After renovation, the average removal rate of COD, BOD, total phosphorous (TP) and color was reached to 86%, 93%, 76% and 85%, respectively. The engineering practice shows that the removal rate of COD, color and TP in Fe/Cu tank reached 29.7%, 60% and 53.6%. The continuous operating data in two years shows that Fe/Cu process can effectively improve the biodegradability of wastewater and enhanced the subsequent biological treatment. The successful engineering practice indicts that the slag dropping quickly effectively avoid agglomeration and clogging of the Fe/Cu filler and the operating cost is very low.

Recycling the wastewater of the industrial park in Northern Taiwan using UF-RO system: in-situ pilot testing and cost analysis

In Taiwan, every industrial park equips a wastewater treatment plant (WWTP) to collect wastewater streaming from all the factories. These effluents, though showing high total dissolved solids (TDS) and fluctuating composition, would be a valuable water resource for industrial use after large scale purification, especially in the drought seasons. In this study, a pilot plant was installed for reclaiming the effluents from the industrial park WWTP through the membrane process. A modified spiral-wound ultrafiltration (UF) membrane with backwash function was utilized for the pretreatment of the reverse osmosis (RO) system. Evaluation results showed that the pilot plant was performing stably during the two-month operation. After the RO desalination, the quality of the reclaimed water basically met the requirement standards of intermediate-pressure boiler feedwater (150∼ 750psig) of the Environmental Protection Agency, United States (USEPA). The backwashable spiral wound UF membrane provided suitable water quality for RO influent (SDI < 4) and helped reduce the cost compared to using hollow-fibre UF membrane. The total cost of recycling one-ton effluent included US$ 0.35 for construction and US$ 0.45 for operation/maintenance.

Membrane processes for water reuse from the effluent of industrial park wastewater treatment plant: a study on flux and fouling of membrane

Both the relationship between the flux and the fouling mechanism of ultrafiltration (UF) membrane and the effects of pretreatment before reverse osmosis (RO) process on the treatment of the effluent of industrial park wastewater treatment plant (IPWTP) were investigated to examine the application of membrane processes on the water reuse treatment. For the former, the flux data was first fitted to the Hermia model to give the implication of the fouling mechanism. Then, the fouling mechanism was further identified with the aid of the SEM morphology of membrane surfaces. For the latter, the changes of both water characteristics (turbidity, TOC, conductivity, particle size distribution, and organic solute molecular weight) and membrane properties (surface zeta potential and surface morphology) before and after the treatment of membrane processes were measured. It was found that the major blocking mechanisms of UF membrane process at initial and final stage were standard blocking of pore (causing from colloid materials) and cake blocking of pore (causing from suspended particles), respectively. On the other hand, it was concluded that the permeate from 1 μm/UF/RO process was suitable for the reuse of cooling water and low pressure boiler water.