BOD Reduction Research Articles

The Efficacy of Seaweed Powder Application for Enhancing Wastewater Quality in the Cepuk Textile Industry of Nusa Penida

Introduction: The traditional textile art of Tenun Cepuk from Nusa Penida is highly valued for its intricate designs and cultural importance. Nevertheless, the environmental predicament posed by the textile industry's wastewater, particularly due to dye-related contamination, is substantial and necessitates sustainable remedies. Seaweed powder shows considerable promise as an adsorbent for addressing dye wastewater issues within the textile sector. An essential aspect of this endeavor is to explore the dynamic relationship between different thicknesses and contact durations, as it is pivotal in optimizing the adsorption capacity and effectiveness of seaweed powder for treating dye wastewater..Method: This research, utilizing an Experimental research design with a Posttest Only Control Group Design, is conducted to evaluate the influence of an intervention on the experimental group as compared to the control group. Euchema cottonii seaweed, sourced from Nusa Penida, is employed as the adsorbent. Different thicknesses of seaweed powder, namely 5 cm, 10 cm, and 15 cm, are added to tanks. Subsequently, wastewater samples from the Cepuk weaving process are introduced into each of the experimental tanks, alongside a control group. The process is allowed to continue for 24 and 72 hours as varying contact durations. The adsorption outcomes are then subjected to analysis, including parameters such as TSS, TDS, BOD5, and COD, at the Panureksa Denpasar Laboratory.Results: The application of seaweed powder as an adsorbent proves to be efficient in decreasing TDS, TSS, BOD5, and COD levels in Cepuk textile dye wastewater. The extent of reduction relies on the thickness of the adsorbent and the duration of contact. Increased thickness of the adsorbent results in a pronounced reduction in TDS, TSS, BOD5, and COD levels, leading to an improvement in the quality of wastewater and a safer environmental impact. Specifically, an adsorbent with a thickness of 15 cm effectively reduces TDS to permissible levels. Extended contact times also lead to a significant decrease in these levels..Conclusion: The application of seaweed powder is a viable method for reducing TDS, TSS, BOD5, and COD levels in textile dye wastewater. The thickness of the adsorbent and the duration of contact play a substantial role in improving the quality of the wastewater.

Biodegradation of olive mill wastewater by two bacterial strains

Wastewater from olive mill is a by-product of olive oil production, that is a serious environmental problem in many Mediterranean countries. The production of large quantities of waste in a short period of time together with the high organic load and high toxicity of the waste make it difficult to deal with the problem. Phenolic compounds are one of the main factors responsible for the toxicity of olive mill wastewater (OMW). In the present work, two selectively anaerobic bacteria, Sporolactobacillus spp. and Rhodopseudomonas spp. isolated from compost tea were used. These two strains were tested for their ability to reduce the BOD5 and COD levels and to degrade polyphenols responsible for the toxicity of OMW. The two strains were able to grow on a dilution of a natural OMW and largely degrade the polyphenols. The dilution depended on the initial COD value of the waste. After 90 days of treatment reduction over 70% was observed in all three parameters which were measured while in an additional sampling that carried out in the 150th day, the reduction of BOD5, COD and total phenols concentration, reached to 96.1%, 81.8% and 75.1% respectively. Additionally, an increase in the pH was observed, moving from acidic to slightly alkaline. All these features make the two strains attractive candidates for the development of a biotechnological process for the biodegradation of OMW.

Performance evaluation of gravity-driven bioreactor (GDB) for simultaneous treatment of black liquor and domestic wastewater.

A lab-scale gravity-driven bioreactor (GDB) was designed and constructed to evaluate the simultaneous treatment of black liquor and domestic wastewater. The GDB was operated with a mixture of black liquor and domestic wastewater at a ratio of 1:1 and maintained at an average organic loading rate of 1235mg-COD/L-Day. The wastewater was fed to the primary sedimentation tank at a flow rate of approximately 12mL/min and subsequently passed through serially connected anaerobic and aerobic chambers with the same flow rate. Each wastewater sample was allowed to undergo a hydraulic retention time of approximately 72h, ensuring effective treatment. The GDB was actively operated for nine samples (W1-W9) at a weekly frequency. The entire process was conducted within the workstation's ambient temperature range of 30-35°C to sustain microbial activity and treatment efficiency in an open environment. The performance of the GDB was evaluated in terms of various pollution indicators, including COD, BOD5, lignin removal, TDS, TSS, EC, PO43-, SO42-, microbial load (CFU/mL and MPN index), total nitrogen, and color reduction. The results showed that the GDB achieved promising treatment efficiencies: 84.5% for COD, 71.80% for BOD5, 82.8% for TDS, 100% for TSS, 74.71% for E.C., 67.25% for PO43-, 81% for SO42-, and 69.36% for TN. Additionally, about 80% reduction in lignin content and 57% color reduction were observed after the treatment. The GDB substantially reduced microbial load in CFU/mL (77.98%) and MPN (90%). This study marks the first to report on wastewater treatment from two different sources (black liquor and domestic wastewater) using a simple GDB design. Furthermore, it highlights the GDB's potential as a cost-effective, environmentally friendly, and efficient solution for wastewater treatment, with no need for supplementary chemical or physical agents and zero operational costs.

Adsorptive removal of biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) from greywater using activated carbon prepared from tropical almond and palm kernel shells

This study assesses the reduction of 5-day biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) of household greywater using palm kernel activated carbon (PKAC) and tropical almond activated carbon (TAAC) produced from locally available materials in a kiln at 800oC and activated using steam at a flowrate of 120 mL hr-1. Brunauer-Emmet-Teller (BET) surface area determination revealed that PKAC had a larger surface area than TAAC. Scanning electron microscope (SEM) imagery of the carbons also revealed amorphous and large internal shapes for TAAC while crystalline and closed packed shapes for PKAC. X-ray diffraction (XRD) analysis indicated that the major component present in the PKAC and TAAC was carbon and other allotropes of carbon. Batch results showed that reduction of BOD5 and COD was affected by particle size. The maximum percentage reduction of BOD5 and COD by PKAC was 76% and 65% respectively while reduction by TAAC was 62% and 52% respectively. The adsorption process was well described by the Freundlich adsorption isotherm. The studies showed that PKAC is a better adsorbent for reducing BOD5 and COD from domestic greywater as compared with TAAC. The PKAC is a potential low-cost adsorbent for BOD5 and COD removal from domestic greywater.

Unlocking the potential of lignocellulosic waste: A kinetic modeling approach for bio-coagulants in sewage water treatment

This study explores the potential of lignocellulosic materials, specifically sugarcane bagasse (SB) and coconut fibers (CNW), as coagulants and flocculants for sewage water treatment in combination with alum. The main aim is to evaluate the efficacy of alum:SB and alum:CNW combinations in improving water quality parameters, such as turbidity, EC, pH, TSS, TDS, DO, BOD, and COD, using modified methods (primary and secondary treatment). The results of the water quality parameters show significant reductions in turbidity of 95.32% and 90.94% for sewage waters treated with alum:SB and alum:CNW, respectively, as well as notable reductions in TDS (70.58%, 60.78%), TSS (98.63%, 97.27%), BOD (76.51%, 51.13%), and COD (95.07%, 76.47%). Moreover, bio-coagulants such as alum, SB, CNW, alum:SB, and alum:CNW were characterized by FT-IR. In comparison to other coagulants, the alum:SB treated sewage water was found to be efficient and have excellent coagulation activity (90%). The turbidity removal by both lignomaterials conformed to the WHO and BIS acceptable limits for finished water quality. Therefore, the highest turbidity reduction was achieved in alum:SB>alum:CNW treated sewage water. Statistical analysis also confirmed the effectiveness of alum:SB, highlighting its potential as a feasible option for sewage water treatment through factor and correlation analysis. The MANOVA (p < 0.05) result indicates that both bio-coagulants were significantly different. This study emphasizes the potential and eco-friendly method of using lignocellulosic bio-coagulants for the treatment of municipal sewage water.

The development of chrome free chestnut and Tetrakis Hydroxymethyl Phosphonium Sulfate based Eco-benign combination tanning system

The replacement of the conventional chromium tanning system with an eco-benign tanning systems has received great attention owing to stringent environmental regulations. In this specific study, a chrome-free combination tanning system based on chestnut and tetrakis (hydroxymethyl) phosphonium sulfate (THPS) was developed and presented as an effective alternative cleaner tanning technology. Processing of the tanning trials were carried out varying the percentages of chestnut as a tannage, followed by THPS as a re-tannage for process optimization. The leathers obtained were characterized for their thermal stability, grain surface properties using a scanning electron microscope, physical strength characteristics, comfort, and organoleptic properties. Finally, the environmental impact of the tanning systems was assessed through the comparative analysis of their spent liquors. The chestnut-THPS combination system tanned leathers using 20 % chestnut followed by 2 % THPS resulted in maximum shrinkage temperature of 95OC. The hydrothermal stability of the leathers tanned using this combination tanning system were found to be better than those tanned using chestnut and THPS tanning systems alone, respectively. The strength and comfort properties of the leathers produced using the developed combination tanning system were found to be on par with or better than those of conventionally tanned leathers, and the scanning electron microscopic study depicted that the grain surface of the leathers produced were observed to be free of surface deposition. The environmental impact assessment showed that the combination tanning system used resulted in a significant reduction in TS, TDS, TSS, and BOD in the wastewater. This research article has attempted and established the use of chestnut-THPS-based combination tanning systems as an effective, eco-friendly alternative tanning process technology.

Natural Aeration with Artificial System to Raw Water for Water Supply Process of Rajabhat Mahasarakham University, Maha Sarakham Province

This research aims to establish a gravity-based aeration system for raw water in the water supply process at Rajabhat Mahasarakham University. The objectives included evaluating the system's effectiveness for oxygen transfer and developing a suitable model for water supply applications. The study assessed various water quality parameters, including total suspended solids (TSS), biochemical oxygen demand (BOD5), and total coliform bacteria. In a series of six tests conducted at monthly intervals between 09:00 and 09:30 a.m., both inlet and outlet water were collected for a total of 12 samples. Results revealed that the gravity-based aeration system could reduce suspended solids by 54.87%. The average BOD5 of water at inlet and outlet was found to be 7.10 mg/L and 6.88 mg/L, respectively, indicating a 3.04% reduction in BOD5. Moreover, the gravity-based aeration system could reduce total coliform bacteria by 82.26%. To maximize the system's efficiency in eliminating total coliform bacteria, it is recommended to operate the system under optimal conditions and regularly clean the sediment tank when the system is shut down.&#x0D;

Continuous Treatment of Refractory Wastewater from Research and Teaching Laboratories via Supercritical Water Oxidation–Experimental Results and Modeling

Teaching and research laboratories generate wastes of various compositions and volumes, ranging from diluted aqueous solutions to concentrated ones, which, due to milder self-regulation waste-management policies, are carelessly discarded, with little attention given to the consequences for the environment and human health. In this sense, the current study proposes the application of the supercritical water oxidation (SCWO) process for the treatment of complex refractory wastewater generated in research and teaching laboratories of universities. The SCWO, which uses water in conditions above its critical point (T &gt; 647.1 K, p &gt; 22.1 MPa), is regarded as an environmentally neutral process, uniquely adequate for the degradation of highly toxic and bio-refractory organic compounds. Initially, the wastewater samples were characterized via headspace gas chromatography coupled with mass spectrometry. Then, using a continuous tubular reactor, the selected operational parameters were optimized by a Taguchi L9 experimental design, aiming to maximize the total organic carbon reduction. Under optimized conditions—that is, temperature of 823.15 K, feed flow rate of 10 mL min−1, oxidizing ratio of 1.5 (50% excess over the oxygen stoichiometric ratio), and sample concentration of 30%—TOC, COD, and BOD reductions of 99.9%. 91.5% and 99.2% were achieved, respectively. During the treatment process, only CO2, methane, and hydrogen were identified in the gaseous phase. Furthermore, the developed methodology was applied for the treatment of wastewater samples generated in another research laboratory and a TOC reduction of 99.5% was achieved, reinforcing the process’s robustness. A thermodynamic analysis of SCWO treatment of laboratory wastewater under isothermal conditions was performed, using the Gibbs energy minimization methodology with the aid of the GAMS® 23.9.5. (General Algebraic Modeling System) software and the CONOPT 4 solver. Therefore, the results showed that SCWO could be efficiently applied for the treatment of wastewater generated by different teaching and research laboratories without the production of harmful gases and the addition of hazardous chemicals.

Pemanfaatan Limbah Faba (Fly Ash Bottom Ash) Pltu Karangkandri Sebagai Adsorben Pengolahan Limbah Batik Di Desa Kutawaru Cilacap

In this modern era, many technologies are increasingly advanced and industrial developments are increasing, resulting in waste that can contaminate water. The purpose of this study was to determine the best adsorbents from fly ash and bottom ash and to determine the effect of filtration time on the decrease in content, color, BOD5, COD, TSS and pH in the Cilacap batik fabric industrial wastewater treatment process. The steps taken in this study were to find the best filtration time from variations of 60, 120, 180 minutes on fly ash and bottom ash adsorbents and to determine the best adsorbents from fly ash and bottom ash. The results of the color, BOD5, COD, TSS and pH tests showed that the most optimum adsorbent was fly ash, which produced the highest percentage reduction in color content at 60 minutes filtration time of 34.1%, the highest percentage reduction in BOD5 levels at 180 minutes of 69, 5%, the highest percent reduction in COD levels at 120 minutes was 71.5%, the highest percent reduction in TSS levels at 180 minutes was 69.1% and a neutral pH was produced. Analysis of the results of the most optimum time is the filtration time of 180 minutes where the results of filtration using bottom ash adsorbents show the highest percentage reduction in BOD5, COD, TSS levels of 55.4%, 55.3%, 20.4%.

Treatment of abattoir wastewater using &lt;i&gt;Moringa oleifera&lt;/i&gt; seed and snail shell in Rivers State, Nigeria

The practice of discharging abattoir wastewater into a receptacle without treatment is most likely to alter its physicochemical and microbiological properties. Against this background, this study is aimed at determining the efficacy of Moringa oleifera and snail shells as bio-coagulants for treatment of abattoir wastewater using the jar. The mean values of monitored physicochemical parameters were electrical conductivity (1227.7), total organic carbon (224.4%), biochemical oxygen demand (362.3 mg/l), chemical oxygen demand (1001.5g), total dissolved solids (462.5 mg/l), total suspended solids (1562.5) mg/l and turbidity (190.6 NTU). The mean total heterotrophic bacteria count (THBC) for untreated wastewater was 1.4 x 108 CFU/ml, total coliform count (TCC) was 5.6 x 105 CFU/ml, and total fungal count (TFC) was 1.6 x 102 CFU/ml. After treatment, the biocoagulants caused 82.5-84.2% reduction in EC, TOC (59-88.3%), BOD (90.8-93.7%), COD (94.4-95.3%), TDS (89.6-91.9%), TSS (93.3-94.5%) and turbidity (80.8-84.5%). The bio-coagulants were able to remove 92.2-95.4% of Zn, Pb (97-97.5%), Cr (97.2-98.8%) and Cd (86.7-89.3%). After treatment with the bio-coagulants, THBC dropped from 4.7 x 103-5.3 x 102 CFU/ml to 8-10 CFU/ml on day 6, TCC dropped from 4.2 x 102 – 6.7 x 10 CFU/ml to 5-7 CFU/ml on day 6 while TFC dropped from 1.1 x 102 - 1.5 x 10 CFU/ml to 2-4 CFU/ml on day 6, representing approximately 99.9% reduction in microbial load. Thus, the bio-coagulants were as good at removing pollutants in water as alum, but with the added advantages of being natural, cost-effective, and readily available.

The impact of concentration on the biotreatment of hair relaxers using Hydrocarbonoclastic Pseudomonas and Mucor Species from Ezu River, Awka, Nigeria

The contamination of an aquatic environment by hydrocarbons and other noxious compounds due to human activities may cause toxicity to microorganisms and may stimulate microbial activity especially at low concentrations while their persistence can be detrimental to the entire ecosystem. It is crucial therefore, to assess the risks of these pollutants for environmental policy. Diesel was used as carbon source in mineral salts medium for the isolation of petroleum degrading microorganisms from Ezu River using vapor transfer technique. Plates were incubated at 37 0C and 28 0C for bacterial and fungal cultures, respectively. Of the 23 bacterial and 4 fungal isolates recovered, Mucor species and Pseudomonas aeruginosa were the best hydrocarbon utilizing isolates obtained. The isolates were assessed for their ability to utilize both lye-containing and lye-free hair relaxers at different concentrations (0.2 – 1% w/v) in mineral salts medium for 14 days. The optical density (OD660nm), the biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and pH of the medium were monitored during incubation. The toxicity of the hair relaxers to Nitrobacter sp. was also assessed. Results showed that Pseudomonas aeruginosa utilized both lye-free(Lf) and lye-containing (Lc)hair relaxers at all concentrations as indicated by the high colony counts, reduction in BOD5 and COD during the incubation period. Mucor sp. grew better on higher concentrations Lc hair relaxer (1%&gt; 0.8%&gt; 0.6% w/v), but with minimal growth at lower concentrations of same relaxer (0.2%&lt; 0.4%&lt; 0.6% w/v). On the contrary, lye-free hair relaxer supported heavy growth of Mucor sp. at all concentrations tested. The growth of Nitrobacter sp. got inhibited by both types of hair relaxers between concentrations 0.6 and 1% w/v, with moderate growth at lower concentrations (0.2 – 0.4% w/v). The toxicity outcome of these hair relaxers to Nitrobacter species implies that the indiscriminate discharge of hair-relaxer-containing salon wastewater into the soil may affect the biogeochemical activities of the soil microbial communities. In addition, Pseudomonas aeruginosa and Mucor species recovered in this study can be used to attenuate sites contaminated by hair salon wastewater.

Improved remediation of amoxicillin-contaminated water by floating treatment wetlands intensified with biochar, nutrients, aeration, and antibiotic-degrading bacteria

ABSTRACTResidual antibiotics have become emerging contaminants of concern for their adverse impact on the ecosystem. Additionally, their accumulation in the environment is increasing antibiotic resistance among pathogens. This study assessed the impact of intensification of biochar, nutrients, aeration, and bacteria (BNAB) on the remediation potential of floating treatment wetlands (FTWs) to treat amoxicillin (AMX)-contaminated water. The FTWs were developed with saplings of Vetiveria zizanioides and intensified with biochar (1.5%), nutrients (25 mgL−1 N, 25 mgL−1 P, 20 mg L1 K), aeration (7 mg L−1), and AMX-degrading bacteria. The results showed that all the amendments enhanced the AMX degradation, while the maximum reduction in COD (89%), BOD (88%), TOC (87%), and AMX (97%) was shown by the combined application of all the amendments. The combined application also enhanced plant growth and persistence of the inoculated bacteria in the water, roots, and shoots. This approach can be employed for the low-cost, environment-friendly treatment, and recycling of antibiotic-contaminated wastewater, where BNAB intensification can further improve the bioremediation efficiency of FTWs in the case of heavily polluted waters.

Field site soil aquifer treatment shows enhanced wastewater quality: Evidence from vadose zone hydro-geophysical observations

Soil aquifer treatment (SAT) is an emerging, nature-based, economically viable wastewater treatment solution. Currently, most SAT experiments are done at the laboratory scale, which cannot generate the same conditions as natural field sites and limits the understanding of treatment efficiency. The current study carried out in situ SAT experiments in the Musi River basin in India, where wastewater irrigation is a common practice. SAT efficiency was determined using an integrated approach, including electrical resistivity tomography (ERT) surveys, soil investigations (grain size, permeability, and moisture measurements), and biochemical characterization of raw and SAT treated wastewater. The ERT scans of SAT column show lower order electrical resistivity 10-30 Ω-m with enhanced chargeability >5–6 mV/V attributed to the vadose zone, characterized by clay-rich soil and sandy soil up to 5–6 m depth. The increase in sand percentage (>70%) below 140–160 cm depth corroborates with the high moisture content (23.5%). The vadose zone permeability (K) 1.58 m/day and discharge (Q) 38.19 m3/day is used to determine the pollutants reduction efficiency of SAT column. Hydrogeological and biogeochemical observations reveal that the improved dissolved oxygen from <1.0 to 5–6 mg/L in the vadose zone catalyzes the oxidation of organic matter resulting in the reduction of BOD and COD up to 92% and 97%, respectively, and denitrification reducing NO3−− (0.55 kg/day). In addition, the precipitation and adsorption by kaolinite clay prompted the reduction of PO42− (0.26 kg/day). Furthermore, the oxic-vadose zone could not support the growth of coliforms and faecal coliforms, and the reduction observed was up to 99.99% in the SAT production well. Overall, the results indicated a positive outcome with SAT efficiency and framed the SAT sitting criteria for different geological environments.

Reduction of Oxidizable Pollutants in Waste Water from the Wadi El Bey River Basin Using Magnetic Nanoparticles as Removal Agents

Many of the current strategies for removing pollutants from water are based on nanomaterials and nanotechnology. Lower values of Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) in water results in reduction in the amount of oxidizable pollutants. We present a study on the reduction of COD and BOD5 in water from Wadi El Bey River (Tunisia), using magnetite nanoparticles (MNPs) and magnetic fields. The COD and BOD5 removal reached values higher than 50% after 60 min, with optimum efficiency at pH values of ≈8 and for MNPs concentrations of 1 g/L. The use of a permanent magnetic field (0.33 T) showed an increase of COD and BOD5 removal from 61% to 76% and from 63% to 78%, respectively. This enhancement is discussed in terms of the MNPs coagulation induced by the magnetic field and the adsorption of ionic species onto the MNPs surface due to Fe3O4 affinity.

Influence of loading rates and feeding conditions on hybrid constructed wetlands integrated with microbial fuel cells

The present study had as objective to evaluate the influence of different operation conditions on two treatment systems composed of anerobic biofilter (AF) and hybrid constructed wetlands (CWs). Both treatment lines had as the first treatment stages an 1450 L AF unit and a CW designed as a Floating Treatment Wetland. Then, a pump directed half of the wastewater flow for each of the treatment lines. One of the lines was composed of a Vertical Flow CW incorporated with microbial fuel cells (CW-MFC), called Configuration 1 (C1), whereas the other line consisted of a Vertical Flow CW (VFCW) and a Horizontal Flow CW (HFCW), named Configuration 2 (C2). The treatment system was fed with wastewater generated in a university campus and monitored for 13 months, with three operation conditions tested: 3 pulses per day with 50 L each (20.5 L/m2day); 4 pulses with 75 L each (41 L/m2day) and 6 pulses with 75 L each (61.6 L/m2day). In addition, the potential bioenergy generated was monitored. For the last operation condition, C1 efficiently reduced BOD5 (88.7%) and turbidity (84.4%). On the other hand, for the nutrients the treatment efficiencies were lower, with 40.3% (TP) and 46.6% (N−NH3). Overall, similar results were obtained with the C2, with mean removal efficiencies of BOD5 (87.3%), turbidity (93.1%), and lower TP (10.4%) reduction. The treatment performance presented similar tendencies even with the changes in loading rates and in hydraulic retention times. Regarding the voltage monitoring, a peak of 687 mV was obtained considering a mean loading rate of 15.6 gCOD/m2day, whereas the maximum power density was 0.25 mW/m. Future research should focus on reducing the internal resistance of the CW system, thus increasing the bioelectricity generated and in treating wastewater with higher organic matter content.

Stabilisation of Spent Wash by Polyhydroxybutyrate (PHB) Producing Microorganisms Isolated from Karad Region, Maharashtra

In recent years, there has been a significant increase in the needs of the overgrowing population. Naturally, industrial belts increased worldwide to satisfy the variety and quantity of needs. While producing the products, a huge quantity of waste is generated and added continuously to the environment, causing hazardous effects on the flora and fauna. Spent wash is one of the most important types of industrial waste since it is the liquid waste that is left over after making alcohol and it pollutes the environment. Despite effluent quality standards, untreated or partially treated sewage frequently enters water courses or soils. It is always overloaded with organic and inorganic substances. The stabilization of the effluent by microorganisms is reflected in the form of COD reduction. The present study attempted to isolate the PHB-producing organisms and use them to stabilize the spent wash. The locally isolated, characterized, and identified 11 PHB-producing microorganisms from the Karad region of Maharashtra were used to stabilize spent wash. They include Candida orthopsilosis, Bacillus subtilis, Bacillus cereus, Bacillus megaterium, Klebsiella grimontii, Citrobacter fruendii, and members of Staphylococcus and Rhodococcus. All potential organisms were reported to stabilize the spent wash. The degree of stabilization was measured in terms of the percent reduction of COD and BOD. The % reduction was reported at 95.31% and 81.39% of COD and BOD, respectively, by Klebsiella grimontii, followed by 92.18% and 80.46% reductions of COD and BOD, respectively, by Staphylococcus. These organisms are promising in the treatment of spent wash.

Optimal root oxygen release from two macrophytes Saururus cernuus L. and Pistia stratiotes L. varies with light and temperature in simulated constructed wetlands microcosms

Different environmental factors influence photosynthesis, transpiration, stomatal conductance, and oxygen released from macrophytes' roots. We measured several physiological parameters of Saururus cernuus L. (Lizard's Tail) and Pistia stratiotes L. (Water Cabbage) by exposing the plants to various controlled environmental conditions. The oxygen released from the plant roots was also used to treat the chemical and biological oxygen demand in wastewater in microcosms. This work determined that photosynthetic rate and oxygen release were dependent not only on the plant species but also on the light intensity exposed. The highest rate of photosynthesis differed considerably between the two plants, as S. cernuus required more light intensity than P. stratiotes. Maximum root oxygen release was at peak photosynthesis, thus correlated with light intensity. The temperature had an effect on stomatal conductance, photosynthesis rate, and transpiration rate was affected by the wind speed. For the highest stomatal conductance and photosynthesis, P. stratiotes required a higher temperature than S. cernuus. Stomatal conductance also influenced the oxygen released from plant roots. Furthermore, a relationship was determined between physiological processes and their potential to release oxygen from the roots where the reduction in COD and BOD measured at the end of the experiment was largely attributed to the oxygen that the macrophytes added to the substrate through their roots. The results of this study provide a good benchmark for plant scientists to predict the physiological processes of plants in response to different environmental conditions to control the negative impacts of harsh environmental conditions on plants' ability to release oxygen in their rhizosphere and to improve the efficiency of CW.

Development of microalgae and agrobost mutualism symbiotic technology in the aerobic treatment of sago refinery wastewater

Sago wastewater is 94% of the water produced from the sago processing that could pollute the environment. One of the biological treatments to solve this problem is the use of mutualism symbiotic between the microalgae Chlorella sp. and agrobost with the addition of 5.000 lux constant light. The purpose of this research was to develop symbiotic technology for microalgae and aerobic bacteria in the decomposition of liquid sago waste, in particular for optimizing the photosynthesis process. Furthermore, the reduction of BOD, COD, and organic content could be fast and effective. The research applied a Completely Randomized Design (CRD) with five treatments and three replications. The treatments were addition of 800 ml/l (7.595 log cell/ml) as much to sago waste at variation of concentrations (0% v/v,1% v/v, 2%v/v, 3% v/v, 4%v/v). Data were statistically analyzed using the Analysis of Variance, followed by Duncan’s New Multiple Range Test (DNMRT) at the level of 5%. The result showed that the addition of agrobost microorganisms significantly affected BOD, COD, DO, and pH of sago wastewater. The treatment selected from the results of this study was the P4 treatment with the highest reduction on day 7 with a BOD value of 116.06 mg/l, COD 200.90 mg/l, DO 6.62 mg/l, and pH 8.90.

Treatment of textile dyeing wastewater using a low-cost adsorbent

A cost-effective adsorbent was synthesized from Eichhornia Crassipes using phosphoric acid as an activating agent and it was applied for the decolourization of the Textile dyeing industry’s effluent (TDE). Physical, chemical and morphologic characteristics were investigated using characterization studies, BET and XRD techniques. Batch experiments were performed to determine the optimum dosage, temperature, time and pH. The ideal conditions for treating TDE were found to be 30 °C, 1 g/L dose, 90 min, and pH 7. Maximum decolourization of 92%, reduction of COD and BOD were found to be 66.77% and 83.94% respectively with 50 T TDE. As a result, the aquatic weed Eichhornia crassipes can be employed as an efficient adsorbent to remove dye from wastewater.

Hydroponic rhizofiltration of dairy wastewater by Coleus Scutellarioides &Portulaca Oleracea

Rhizofiltration through floating hydroponic process (FHP) is a cost effective and prospective technique for the treatment of liquid effluents. Coleus scutellarioides and Portulaca oleracea are effective macrophyte for phytoaccumulation because of their morphological and physiological properties. A limited study has been performed with macrophyte in treating dairy wastewater. An initiative has been taken with a table scale experimental study to evolve a bio-raft based Portulaca oleracea and Coleus scutellarioides for treatment of dairy effluent with non-aerated and aerated on raw dairy effluent. First time in research the Coleus scutellarioides and Portulaca oleracea have been grown hydroponically in combination with aeration. Amidst the treatment system, aerated Portulaca oleracea floating hydroponic process shows maximum removal efficiency in phytoaccumulation of raw dairy wastewater. The study outcomes exhibited a remarkable reduction in TSS (79.43 %), TDS (64.36 %), BOD (82.36 %), and COD (81.86 %) from aerated system. Study found that the nutrient contents such as total phosphorous (75.55 %), phosphate (74.24 %) and total nitrogen (74.67 %) are also accumulated by Portulaca oleracea efficiently. Nutrients accumulation attributed to the growth of Coleus scutellarioides and Portulaca oleracea. The study presents a low cost promising future for fostering a sustainable technology for treatment of dairy effluent.