Single Treatment Process Research Articles

Removal of contaminants in paper dyeing wastewater by Fenton and photo-Fenton processes with biological treatment

Due to the production of huge quantity of potentially toxic and recalcitrant pollutants, which cannot be completely decomposed with conventional biological wastewater treatment processes, in the paper industry, reliable treatment processes are highly required. This study conducted effective experiments of different series of processes to decompose persistent contaminants in the paper wastewater under controlled conditions of the used processes to meet the effluent quality standards of Korea Ministry of Environment in terms of CODMn (< 130 mg/L). For Biological treatment, Fenton, and photo-Fenton processes, various operational parameters were adjusted to determine the optimal conditions for CODMn value. Due to large quantity of refractory contaminants in the wastewater, single treatment process was not enough to meet the requirement of CODMn. Herein, we achieved the goal with two approaches: (1) secondary Fenton oxidation after biological and primary Fenton treatments, and (2) photo-Fenton treatment after biological treatment alone. The secondary Fenton oxidation process is an additional process operated under the same condition of the primary Fenton treatment to treat the effluent from the primary Fenton treatment. Ultimately, the residual CODMn concentrations of the secondary Fenton and single photo-Fenton treatment were 62.7 and 85.3 mg/L, respectively. However, the secondary Fenton required larger amounts of reagents and produced significant amounts of sludge, which require post-treatment, compared to single photo-Fenton treatment. Therefore, it suggests that the application of photo-Fenton was more efficient than the secondary Fenton in terms of economic feasibility and post-treatment requirement.

An Extensive Analysis of Combined Processes for Landfill Leachate Treatment

Sanitary landfilling is the predominant process for solid urban waste disposal, but it generates leachate that poses environmental, economic, and social concerns. Landfill leachate (LL) contains complex and refractory pollutants and toxic compounds that can vary depending on landfill maturity, age, and biochemical reactions, making its treatment challenging. Due to its unique characteristics and occurrence in remote locations, LL requires separate treatment from wastewater. Various conventional treatment processes involving biological, chemical, and physical processes have been used for LL treatment, but a single treatment process is insufficient to meet environmental standards. This review demonstrates that combined treatment processes are more effective and efficient for LL treatment compared to single processes. Among the various combinations, chemical–chemical and chemical–biological treatments are the most commonly used. Specifically, the integration of Fenton with adsorption and a membrane bioreactor (MBR) with nanofiltration (NF) processes shows promising results. The combined processes of MBR with NF, Fenton with adsorption, and PF with biological treatment show maximum removal efficiencies for COD, reaching 99 ± 1%, 99%, 98%, and 97%, respectively. Additionally, the combined Fenton with adsorption process and EC with SPF process enhance biodegradability as indicated by increased BOD5/COD ratios, from 0.084 to 0.82 and 0.35 to 0.75, respectively. The findings emphasize the importance of developing and implementing enhanced combined treatment processes for LL, with the aim of achieving efficient and comprehensive pollutant mineralization. Such processes have the potential to address the environmental concerns associated with LL and contribute to sustainable waste management practices.

Spatial Distribution and Risk Assessment of Antibiotics in 15 Pharmaceutical Plants in the Pearl River Delta.

Pharmaceutical plants are an essential source of antibiotics emitted into the aqueous environment. The monitoring of target antibiotics in pharmaceutical plants through various regions is vital to optimize contaminant release. The occurrence, distribution, removal, and ecological risk of 30 kinds of selected antibiotics in 15 pharmaceutical plants in the Pearl River Delta (PRD) were investigated in this study. Lincomycin (LIN) showed the highest concentration (up to 56,258.3 ng/L) in the pharmaceutical plant influents from Zhongshan city. Norfloxacin (NFX) showed a higher detection frequency than other antibiotics. In addition, the spatial distribution of antibiotics in pharmaceutical plants showed significant differences, with higher concentrations of total antibiotics found in pharmaceutical plant influents in Shenzhen City than those of different regions in PRD. The treatment processes adopted by pharmaceutical plants were commonly ineffective in removing antibiotics, with only 26.7% of antibiotics being effectively removed (average removal greater than 70%), while 55.6% of antibiotics had removal rates of below 60%. The anaerobic/anoxic/oxic (AAO)-membrane bioreactor (MBR) combined process exhibited better treatment performance than the single treatment process. Sulfamethoxazole (SMX), ofloxacin (OFL), erythromycin-H2O (ETM-H2O), sulfadiazine (SDZ), sulfamethazine (SMZ), norfloxacin (NFX), and ciprofloxacin (CIP) in pharmaceutical plant effluents posed high or moderate ecological risk and deserve particular attention.

Integrated sonophotocatalytic oxidation and SBR processes for the effective treatment of antibiotics with an emphasis on process optimization and microbial diversity

The presence of antibiotics in water and wastewater is a serious environmental concern of emerging interest globally. Their effective removal with a single treatment process is, however, challenging because of their widely varying characteristics, and requires innovative integration of treatment processes. In this study, sonophotocatalytic oxidation process was integrated with an aerobic sequencing batch reactor (SBR) for the comprehensive removal of a mixture of antibiotics. Initially, a Central Composite Design using Response Surface Methodology was used to optimise the operational parameters, viz. ultrasound (US) frequency, pH, and catalyst dosage, for the removal of Ciprofloxacin (CPX), Amoxicillin (AMX), and Tetracycline (TTC) in simulated wastewater. An optimised condition of 20 kHz US frequency, 6.59 initial pH, and 0.94 g L−1 catalyst dosage was observed for the maximum pollutant removal. These experimental conditions were subsequently used for combined sonophotocatalysis-aerobic SBR treatment. Three SBR systems representing a control system, pre-treated system, and untreated system, were used for the study. All three systems were able to achieve an average COD and NH4+-N removal of 85 % and 98 %, respectively. Results from the biological systems concluded that an enhanced CPX and TTC removal was observed in the pre-treated system, whereas maximum AMX removal was observed in the untreated SBR system. The metagenomic analysis confirmed the significant difference of microbial species with the addition of pretreated and untreated wastewater into the biological reactor, and pretreated system having higher number of species and greater biodiversity in comparison to untreated system.

Advancements in laundry wastewater treatment for reuse: a review

Laundry related activities produce huge quantity of wastewater that is very rich in lint, dyes, surfactants, and detergents. The large amount of laundry wastewater (LWW) is generated by extensive human activities. LWW needs to be treated in order to tackle the challenging problem of water pollution and to accomplish water sustainability. To achieve this success, LWW can be reused for several purposes such as irrigation, construction activities, vehicle washing etc. However, there are several challenges in the reclamation of LWW like effective handling of the wastewater and meeting the regulatory criteria. Based on the literature review it seems that a single treatment process is not sufficient to treat LWW up to acceptable reuse standards. To that end, different treatment chains have been proposed: i) hybrid processes combining membrane filtration with adsorption; ii) advanced oxidation process using ultraviolet (UV) and hydrogen peroxide (H2O2); iii) coagulation-flocculation combined with sand filtration; iv) combination of ozonation process, adsorption, and ultrafiltration (UF). This review paper discusses the selection of suitable treatment technology depends on several factors: i) a well-designed equipment, ii) cost-effectiveness of treatment method and iii) desired characteristics of the treated water. The review paper also presents solutions for treatment and reclamation of LWW.

Study hybrid Treatment Technologies using (MBBR with Electro-flotation) for Textile wastewater

A novel hybrid approach to the global development treatment technology was introduced in this research, by using two sustainable green technologies treatment methods as (MBBR) combined with the Electro-flotation process. To improve the removal efficiencies of persistent and non-biodegradable dissolved organic dyes (Methylene blue dye) by using Iron and Aluminum electrodes. The treatment system achieved high performance than that any single treatment process and without the need to add chemical reagents. The characteristics of wastewater from textile dyeing used in this study were simulated to the General Establishment of Cotton Textile Industry/Baghdad. In addition, one of the most sustainable and useful by-products is found to be producing H2 gas at a rate of 1:13L. As a result, in the continuous system the optimum removal efficiencies of color, COD, and BOD are 90.08%, 100%, 100% respectively, were achieved at (200V, 2cm electrodes distance, 5 minutes, pH=7, 8 number of electrodes, 30gm weight of media).

Efficient Removal of Azo Dye from Wastewater Using the Non-Toxic Potassium Ferrate Oxidation–Coagulation Process

The wastewater effluents from textile industries contain highly toxic metal complex dyes. For instance, azo dye has received significant attention owing to its toxicity and environmental stability. This study investigated the oxidation and coagulation processes to effectively remove azo dye from wastewater effluents. Potassium ferrate (K2FeO4) was selected as an oxidant because it has a high oxidation potential, is environmentally stable, and does not generate toxic byproducts. Moreover, it has a combination effect of coagulation and oxidation. Its performance was compared with a single oxidation process (using NaOCl) and a single coagulation process (using FeCl3·6H2O). Based on the jar test experiment, the optimized pH was estimated to be 3 and the optimal dosage was 56.4 mg/L for K2FeO4, and it removed nearly 100% of orange II azo dye (OD) and lissamine green B dye (LGB). However, its removal efficiency decreased when the pH increased to 12. In all processes, dye removal was completed in 5 min of the reaction. Overall, OD and LGB were effectively removed by K2FeO4, compared to the NaOCl and FeCl3·6H2O. This indicates that the combination of oxidation and coagulation of K2FeO4 outperformed the single treatment process without toxic byproduct production.

Improving the Properties of Laser-Welded Al-Zn-Mg-Cu Alloy Joints by Aging and Double-Sided Ultrasonic Impact Compound Treatment.

To improve the loose structure and serious porosity of (Al–Zn–Mg–Cu) 7075 aluminum alloy laser-welded joints, aging treatment, double-sided ultrasonic impact treatment (DSUIT), and a combination of aging and DSUIT (A–DSUIT) were used to treat joints. In this experiment, the mechanism of A–DSUIT on the microstructure and properties of welded joints was analyzed. The microstructure of the welded joints was observed using optical microscopy, scanning electron microscopy, and electron backscatter diffraction (EBSD). The hardness and tensile properties of the welded components under the different processes were examined via Vickers hardness test and a universal tensile testing machine. The results showed that, after the aging treatment, the dendritic structure of the welded joints transformed into an equiaxed crystal structure. Moreover, the residual tensile stress generated in the welding process was weakened, and the hardness and tensile strength were significantly improved. After DSUIT, a plastic deformation layer of a certain thickness was generated from the surface downward, and the residual compressive stress was introduced to a certain depth of the joint. However, the weld zone unaffected by DSUIT still exhibited residual tensile stress. The inner microhardness of the joint surface improved; the impact surface hardness was the largest and gradually decreased inward to the weld zone base metal hardness, with a small improvement in the tensile strength. Compared with the single treatment process, the microstructural and mechanical properties of the welded joint after A–DSUIT were comprehensively improved. The microhardness and tensile strength of the welded joint reached 200 HV and 615 MPa, respectively, for an increase of 45.8% and 61.8%, respectively. Observation of the fractures of the tensile specimens under the different treatment processes showed that the fractures before the aging treatment were mainly ductile fractures while those after were mainly brittle fractures. After DSUIT of the welded joints, a clear and dense plastic deformation layer was observed in the fracture of the tensile specimens and effectively improved the tensile properties of the welded joints. Under the EBSD characterization, the larger the residual compressive stress near the ultrasonic impact surface, the smaller the grain diameter and misorientation angle, and the lower the texture strength. Finally, after A–DSUIT, the hardness and tensile properties improved the most.

Combined electrocoagulation processes as a novel approach for enhanced pollutants removal: A state-of-the-art review

A novel approach using the integration of electrocoagulation, with one or more treatment processes has been recently practiced to improve the removal of colloidal and non-biodegradable pollutants. Several treatment processes including adsorption, chemical coagulation, magnetic field, reverse osmosis, and membrane filtration have been combined with electrocoagulation treatment step to improve pollutants removal efficiency. These combined systems showed the potential to improve the performance of the treatment process. This paper presents a state-of-the-art review for the recent processes available in the literature that combine treatment electrocoagulation with one of the previously mentioned treatment processes. It is found that the removal efficiency of any combined processes is higher than that of any single treatment process and the combined process has up to 20% higher removal efficiency compared to electrocoagulation alone. However, most reported studies were conducted at bench-scale level with synthetic wastewater instead of real wastewater. The main aspects of these combined systems including process mechanism, kinetic models, cost and the scale up of combined processes were discussed and summarized. Finally, several concluding remarks were drawn in view of the literature investigations and the gaps that suggest more studies and insights for future development were addressed.

Treatment of leachates in hightech systems

Leachates are complex wastewaters, which often contain high concentrations of ammoniwnions, refractory organic compounds as well as heavy metals. The composition of the leachateis a function of the kind of waste that has been deposited at the landfill. Furthermore,substances created during microbial and abiotic degradation processes of the waste will beeluted from the landfill. It is therefore difficult to determine the chemical composition of aleachate especially in regard to organic substances. Leachates from different landfills differ incomposition. No single treatment process is therefore suitable for all leachates. The processhas to be optimised for the specific leachate, which will be treated.

Combined process of electrocoagulation and photocatalytic degradation for the treatment of olive washing wastewater.

In this study, an electrocoagulation reactor (ECR) and photocatalytic reactor (PCR) were tested to understand the performance of combined electrocoagulation and photocatalytic-degradation of olive washing wastewater (OWW). The effects of initial pH (6.0, 6.9, 8.0, 9.0), applied voltage (10.0, 12.5, 15.0 V), and operating time (30, 60, 90, 120 min) were investigated in the electrocoagulation reactor when aluminum electrodes were used as both anode and cathode. The pH, conductivity, color, chemical oxygen demand (COD), and phenol were measured versus time to determine the efficiency of the ECR and PCR process. It was observed that electrocoagulation as a single treatment process supplied the COD removal of 62.5%, color removal of 98.1%, and total phenol removal of 87% at optimum conditions as pH 6.9, applied voltage of 12.5 V, and operating time of 120 min. Moreover, final pH and conductivity were 7.7 and 980 μS/cm, respectively. On the other hand, the effect of semiconductor catalyst type (TiO2 and ZnO) and loading (1, 2, 3 g/L) were tested using PCR as a stand-alone technique. It was found that photocatalytic degradation as a single treatment process when using 1 g/L ZnO achieved the COD removal of 46%, color removal of 99% with a total phenol removal of 41% at optimum conditions. Final pH and conductivity were 6.2 and 915 μS/cm, respectively. Among semiconductor catalysts, TiO2 and ZnO performed identical efficiencies for both COD and total phenol removal. Moreover, combination in which electrochemical degradation was employed as a pre-treatment to the photocatalytic degradation process obtained high COD removal of 88% and total phenol, as well as color removal of 100% for the OWW. The electrochemical treatment alone was not effective, but in combination with the photocatalytic process, led to a high-quality effluent. Finally, sludge collected from the electrocoagulation process was characterized by attenuated total reflection Fourier transform infrared and X-ray powder diffraction analyses.

Treating high-strength saline piggery wastewater using the heterotrophic cultivation of Acutodesmus obliquus

This study combined an algae treatment with post-ozonation for the robust treatment of piggery effluent in which high levels of organic constituents, inorganic nutrients, color, and salts remained. Due to a nearly complete light limitation resulting from a high level of color, the algae treatment was conducted with continuous O2 supplementation instead of using the combination of high lighting and CO2 injection. The microalga Acutodesmus obliquus KGE-17 showed tolerance to high salinity (up to 5.2% as chloride) and was capable of utilizing dissolved organics (1923mg-COD/(g-cell)(day)) under the heterotrophic growth conditions. The use of A. obliquus for remediation of piggery effluent also resulted in an operational simplicity in the simultaneous removal of nitrogen and phosphorus in a single treatment process, in contrast to conventional biological nutrient removal processes. Subsequent ozonation was successful in decolorizing the algae-treated wastewater and in improving the biodegradability of residual organics in post-treatment processes.

Evaluating integrated strategies for robust treatment of high saline piggery wastewater

In this study, we integrated physicochemical and biological strategies for the robust treatment of piggery effluent in which high levels of organic constituents, inorganic nutrients, color, and salts remained. Piggery effluent that was stabilized in an anaerobic digester was sequentially coagulated, micro-filtered, and air-stripped prior to biological treatment with mixotrophic algal species that showed tolerance to high salinity (up to 4.8% as Cl−). The algae treatment was conducted with continuous O2 supplementation instead of using the combination of high lighting and CO2 injection. The microalga Scenedesmus quadricauda employed as a bio-agent was capable of assimilating both nitrogen (222 mg N g cell−1 d−1) and phosphorus (9.3 mg P g cell−1 d−1) and utilizing dissolved organics (2053 mg COD g cell−1 d−1) as a carbon source in a single treatment process under the heterotrophic growth conditions. The heterotrophic growth of S. quadricauda proceeded rapidly by directly incorporating organic substrate in the oxidative assimilation process, which coincided with the high productivity of algal biomass, accounting for 2.4 g cell L−1 d−1. The algae-treated wastewater was subsequently ozonated to comply with discharge permits that limit color in the effluent, which also resulted in improved biodegradability of residual organics. The integrated treatment scheme proposed in this study also achieved 89% removal of COD, 88% removal of TN, and 60% removal of TP. The advantage of using the hybrid configuration suggests that this would be a promising strategy in full-scale treatment facilities for piggery effluent.

Review on Slow Sand Filtration in Removing Microbial Contamination and Particles from Drinking Water

The improvement of water quality is closely associated with man-environment relationships. There should be a dialogue between all actors and the community when undertaking water and sanitation activities. For positive results and better sustainability, the community should be involved and participate at all stages of water development and environmental sanitation schemes. A combination of safe drinking water, adequate sanitation and hygiene practices like hand washing is a pre-requisite for morbidity and mortality rate reduction, especially among under five years old children in developing countries. To reduce the incidence and prevalence of diarrhoeal diseases, improvements in the availability, quantity, and quality of water, improved sanitation, and general personal and environmental hygiene are required. The majority of people in developing countries do not have access to piped drinking water and must carry; transport and store water within their homes and in the process the quality of water may deteriorate. Therefore, slow sand filtration has been recognized as an appropriate technology for drinking water treatment in rural areas, and is recognized as a suitable filtration technology for removing water borne pathogens and reducing turbidity. It is capable of improving the physical, chemical, and microbiological quality of water in a single treatment process without the addition of chemicals, and can produce an effluent low in turbidity and free of bacteria, parasites and viruses.

A three step approach for removing organic matter from South African water sources and treatment plants

The high variability in the levels and composition of natural organic matter (NOM) in South-African water sources in different regions means that no single treatment process can be prescribed for each water treatment plant operating in the country. In order to remove NOM from water in a water treatment train, the composition of the NOM in the source water must be taken into account, especially as it may not necessarily be uniform since the composition is dependent on local environmental situation. The primary objective of this study was to characterise the NOM present in South African source waters through an extensive sampling of representative water types across the country and then develop a rapid NOM characterisation protocol. Water samples were thus collected from eight different water treatment plants located throughout the country at different sites of their water treatment trains. Raw water samples, the intermediate samples before filtration and water samples before disinfection were collected at these drinking water treatment plants. The fluorescence excitation–emission matrices (FEEMs), biodegradable dissolved organic carbon (BDOC), ultraviolet (UV) characterisation (200–900nm) and dissolved organic carbon (DOC) analysis were used to characterise the NOM in the water samples. The FEEM and UV results revealed that the samples were composed mainly of humic substances with a high UV-254 absorbance, while some samples had marine humic substances and non-humic substances. The sample’s DOC results were within the range of 3.25–21.44mgC/L, which was indicative of the varying nature of the NOM composition in the regions where samples were obtained. The BDOC fraction of the NOM, on the other hand, ranged from 20% to 65%, depending on the geographical location of the sampling site. It is evident from the results obtained that the NOM composition varied per sampling site which would eventually have a bearing on its treatability. The various water treatment processes employed at the different treatment plants were able to effectively reduce NOM, as evidenced by a percentage DOC removal of between 11% and 85%. The highest DOC removal was achieved at the treatment plants that had highly humic and coloured raw water sources.

Removal of high concentrations of NH3 by a combined photoreactor and biotrickling filter system

Average emission levels as high as 800 ppmv NH3 have often been found during the anaerobic fermentation process. At these levels, NH3 is regarded as an environmental toxic compound. High concentrations of NH3 gas are difficult to treat in a single treatment process, suggesting that, in terms of economic cost and treatment performance, a coupled system may be a feasible technological alternative. In the coupled TiO2 photocatalytic–biological treatment system evaluated here, the optimal gas retention time for NH3 removal – in terms of removal efficiency and capital cost – was 26 s. High gas temperatures, high NH3 concentrations, and low oxygen contents were unfavorable conditions for NH3 removal by the photoreactor. The coupled system successfully removed concentrated NH3 gas (R % > 97 %) under disrupted and shutdown conditions. The photoreactor component of the system successfully fulfilled its role as a pretreatment process and enhanced the performance of the biotrickling filter at a high inlet NH3 load (2,277 g-N m−3 day−1). Potential ammonia-oxidizing bacteria, including Bacillus cereus, Pseudomonas aeruginosa, and Stenotrophomonas sp., were isolated under the high inlet NH3 load condition. These microbial strains have a potential as biological agents in the removal of high concentrations of NH3 in waste gas or wastewater.

Electrochemical Treatment of Simulated Copper CMP Wastewater Using Boron Doped Diamond Thin Film Electrodes—A Feasibility Study

The overall goal of this research was to develop a single treatment process that will economically treat wastewater generated during chemical-mechanical planarization (CMP) processing of integrated circuits. Present treatment technologies require multiple steps, are expensive, and generate secondary waste streams requiring further treatment or disposal. This research investigated the feasibility of electrochemical treatment of CMP wastewater using boron doped diamond (BDD) film electrodes. BDD electrodes were selected for their absence of catalytic activity for water electrolysis and their high stability under anodic polarization. Cyclic voltammetry and constant potential batch deposition experiments were performed to study removal of Cu/sup 2+/ ions at BDD cathodes. Galvanostatic oxidation experiments were performed to study removal of citrate and benzotriazole from aqueous solutions. For all conditions tested, Cu/sup 2+/ removal was mass transfer limited. Average Faradaic current efficiencies for removing Cu/sup 2+/ from solutions with initial concentrations between 15 and 50 mg/L ranged from 43% to 87%. The oxidation experiments showed that citrate could be completely oxidized to CO/sub 2/ and that its rate of oxidation was independent of the current density under the conditions tested. In contrast, rates of benzotriazole oxidation were proportional to the current density. Based on the results, a novel, flow-through electrochemical reactor capable of simultaneously removing metal ions and organic additives in a single pass has been proposed.

Treatment and reuse of textile wastewater by overland flow

This paper presents the findings of a laboratory scale study utilizing land treatment of textile wastewater after pretreatment by physico-chemical and biological processes. The textile industry is a growing industry in Malaysia. It contributes about 22% of the total volume of industrial wastewater generated in the country. The wastewater contains various types of pollutants from desizing, scouring, bleaching and dyeing processes. A single treatment process was found to be unsatisfactory for treating the wastewater. For example, the wastewater cannot be treated effectively by biological processes such as the activated sludge process because dyes may contain heavy metals such as chromium and lead that are toxic to microbes. Some are also refractory in nature. A combination of physico-chemical, biological and land treatment processes was attempted in this study. The treatment regime proposed would allow water reuse. The treated wastewater also complied with the regulatory effluent discharge requirements. Alum was added at a rate of 416 mg/1 of wastewater as flocculant and lime at 213 mg/1 as precipitant. Settling of floes was assisted by addition of polyelectrolyte at 11 mg/1. An activated sludge process comprising a 30 1 aeration tank and a 20 cm ID conical settling tank was used in the study. Oxygen was supplied to the aeration tank via eight diffusers connected to air pumps. The process was maintained for 5 weeks to establish appropriate biological populations in the aeration tank. Sludge from a domestic wastewater treatment plant was used as the seeding material in the process. The biological system was operated with a loading rate of 0.9 kg COD/m 3 and maintained at a pH between 7.0–8.5. The sludge recycles rate was 20% and nutrient addition was maintained at optimum level of BOD:N:P of 100:5:1. The nutrient addition was found to be necessary for the operation of the activated sludge system. Overland flow was effected by using two units of artificial grass beds of 62 × 25 × 5 cm 3 each planted with Axonopus affinis and Panicum maximum. The beds were positioned at a 10° angle and operated with alternate resting periods of about 5 h under direct sunlight before another application of pretreated wastewater was carried out. The rate of land application was 1.053 cm/d. Sample of effluent from the irrigation bed was taken over 12 h after the wastewater application. The raw wastewater has high BOD, COD, SS and pH. The average pH level was 10.9 with average BOD, COD and SS values of 324, 2009 and 95 mg/1, respectively. The combined pretreatment process could improve the quality of the wastewater, i.e., BOD, COD and SS reductions averaged at 48, 488 and 27 mg/1, respectively. The BOD level was lower than the discharge limit for Class B rivers (i.e., 50 mg/1) but the COD is higher than the regulatory limit of 100 mg/1. Further reductions of BOD and COD to average values of 12 and 89 mg/1, respectively, were achieved after the land treatment. The overall performance of the treatment system indicated that land irrigation is suitable for the treatment of textile wastewater. The treated effluent has a potential for reuse in agriculture and fisheries.