Cubic Meter Of Wastewater Research Articles

Assessment of carbon efficiency in wastewater treatment plants through Stochastic non-parametric data envelopment analysis (StoNED): Insights from Spanish facilities

Evaluating the carbon efficiency (CE) of wastewater treatment plants (WWTPs) is crucial for guiding these facilities towards carbon neutrality. Nevertheless, enhancing carbon performance ought not to be pursued to the detriment of pollutant removal efficiency. In this study, the CE of WWTPs is calculated as a composite index that integrates carbon emissions with the volume of pollutants removed from wastewater, including organic matter, suspended solids, nitrogen, and phosphorus. To achieve this, the Stochastic Non-parametric Envelopment of Data (StoNED) method is employed. This approach, distinct from the commonly used Data Envelopment Analysis (DEA), accounts for both empirical data and random variations in the estimation of CE, thereby enhancing the reliability of the CE evaluation. The study assesses the CE of 109 Spanish WWTPs, finding that none of them are fully carbon efficient. This involves that all plants have potential to reduce greenhouse gas emissions without sacrificing pollutant removal efficiency. The average CE of the WWTPs is 0.529, indicating a possible reduction in carbon emissions by approximately 0.076 kg of CO2 equivalent per cubic meter of wastewater treated. The analysis also reveals that neither the volume of wastewater treated nor the type of reactor used for secondary treatment has a significant impact on the CE of the facilities. The CE metric proposed in this study serves as an important decision-support tool for advancing towards the carbon neutrality of wastewater treatment processes. By providing a more comprehensive understanding of the environmental performance of WWTPs, it helps identifying areas for improvement and guiding policy and operational decisions.

A Review of AI-Driven Control Strategies in the Activated Sludge Process with Emphasis on Aeration Control

Recent concern over energy use in wastewater treatment plants (WWTPs) has spurred research on enhancing efficiency and identifying energy-saving technologies. Treating one cubic meter of wastewater consumes at least 0.18 kWh of electricity. About 50% of the energy consumed during this process is attributed to aeration, which varies based on treatment quality and facility size. To harness energy savings in WWTPs, the transition from traditional controls to artificial intelligence (AI)-based strategies has been observed. Research in this area has demonstrated significant improvements to the efficiency of wastewater treatment. This contribution offers an extensive review of the literature from the past decade. It aims to contribute to the ongoing discourse on improving the efficiency and the sustainability of WWTPs. It covers conventional and advanced control strategies, with a particular emphasis on AI-based control utilizing algorithms such as neural networks and fuzzy logic. The review includes four key areas of wastewater treatment AI research as follows: parameter forecasting, performance analysis, modeling development, and process optimization. It also points out potential disadvantages of using AI controls in WWTPs as well as research gaps such as the limited translation of AI strategies from research to real-world implementation and the challenges associated with implementing AI models outside of simulation environments.

Efficient bioremediation of distillery and dairy wastewaters: A three-stage biorefinery for high-quality aquaculture feed and bioenergy generation

The present study is motivated by the need to address the environmental issues related to dairy and ethanol plant wastewaters and to generate valuable products, including mycoprotein and bioenergy, through a novel three-phase fungi-based biorefinery. In the initial phase of the biorefining process, the cultivation conditions of Aspergillus oryzae were optimized. The objective was to maximize mycoprotein production using wastewater as a resource. The effluent generated during the first phase of the biorefinery underwent the second phase, where it was subjected to cultivation with Neurospora intermedia. In the third phase, the effluent obtained from the fungal growth underwent anaerobic digestion as a final treatment step, producing 306 NmL methane/g VS. This three-phase biorefinery contributed to a remarkable reduction in the chemical oxygen demand level of the wastewater by 56.8%, 11.6%, and 28.1% in each respective phase. Overall, the three-phase biorefinery process yielded promising results, generating 17.8 kg of mycoprotein and 5.0 Nm3 of biomethane per cubic meter of wastewater. The mycoprotein obtained through this process contains noteworthy quantities of essential amino acids, fatty acids, and minerals. These characteristics open up opportunities for substituting conventional feed in aquaculture with the produced mycoprotein.

Characterization of reciprocation membrane bioreactor on treatment performance, energy consumption and membrane fouling

Two reciprocating membranes (rMBR) with two frequencies of 0.46 Hz (rMBR-0.46) and 0.3 Hz (rMBR-0.3) were operated to compare the treatment performance and gross energy consumption with a conventional MBR. The average organic removal rates of MBR, rMBR-0.46 and rMBR-0.3 were maintained 295 ± 51; 823 ± 296; and 397 ± 129 mgCOD/gVSS.d, respectively. Nitrogen removal was enhanced in rMBR phases compared to conventional MBR phase due to anoxic membrane chamber. Further, fouling rate was found to be highest of 16.5 mbar/day (at conventional MBR phase), which was and much decreased to1.0 mbar/day (at rMBR-0.46 phase) and then 0.2 mbar/day (rMBR-0.3 phase). The reciprocation membrane also showed energy potential by saving 10.6% electricity for each treated cubic meter of wastewater compared to the conventional MBR.

Removal of chemical oxygen demand and ammonia nitrogen from high salinity tungsten smelting wastewater by one-step electrochemical oxidation: From bench-scale test, pilot-scale test, to industrial test

In recent years, electrochemical oxidation (EO) shows the characteristics of green and high efficiency in removing chemical oxygen demand (COD) and ammonia nitrogen (NH3–N) from wastewater, which has been favored by researchers. However, at present, most of current studies on EO remain in laboratory stage, reports about pilot-scale or even industrial tests with large treatment capacity are few, which slowing down the use of the advanced technology to practical application. In this study, bench-scale tests, pilot-scale tests (treatment capacity 200–500 L/h), and industrial tests (treatment capacity 100 m3/h) were carried out by EO technology in view of the characteristics of tungsten smelting wastewater (TSW) with high salinity (NaCl), COD, and NH3–N. Results showed that the removal of COD and NH3–N was a competitive reaction in the EO process, and COD could be removed more preferentially than NH3–N. When NH3–N content was low, the influent pH had a minimal effect on its removal, and when NH3–N content was high, increasing the influent pH was beneficial to its removal. Industrial tests showed that the one-step removal of COD and NH3–N in TSW met the standard, and the power consumption per cubic meter of wastewater was only 4.2 kW h, and the treatment cost was much lower than the two-step process of “breaking point chlorination to remove NH3–N and adding oxidant to remove COD”. This study has successfully realized industrial application of EO technology in TSW treatment for the first time and provided a successful case, which is helpful to accelerate the popularization and application of this technology in the field of high salinity organic ammonia nitrogen wastewater treatment.

Evaluating the performance of sequential batch reactor (SBR & ASBR) wastewater treatment plants, case study

The study aims to assess the operation efficiency of sequencing batch reactor (SBR) and advanced sequencing batch reactor (ASBR) wastewater treatment plants (WWTPs) in Egypt. After auditing more than 24 SBR and ASBR plants, four plants Al-Maamora [MAAM], Al-Negeela [NEGL], Khorshed No. 1 [KOR#1], Khorshed No. 2 [KOR#2] were selected for the current study according to its virtuous performance, good construction conditions and regulatory workflow. COD, BOD and TSS were measured in the influent and effluent samples according to APHA standard methods. Influent quantities and treatment power consumption were monthly recorded. The power consumed for removing a kilogram of BOD and/or treating a cubic meter of wastewater was taken as a comparative indicator among the included WWTPs and between SBR and ASBR technologies. The monthly average inflows were 427058, 189581, 1019876, and 144937 m3/month for MAAM, KOR#1, KOR#2, and NGEL and the monthly power consumption were 56553, 69763, 178,778 and 49545 kW/month respectively. The average removal percentage of the plants reached 92, 91.75, 92.5% for BOD, COD, and TSS respectively, the effluent concentrations of the intended parameters has met the regulatory standard. The average power consumption for removal of a kilogram BOD by SBR and ASBR was 0.932 and 1.58 kWh respectively. SBR and ASBR plants consumed average of 0.245 and 0.296 kWh to treat one cubic meter of wastewater complying with the Egyptian standard for discharge into the drainage canals as a reference values. The study concluded considering the ASBR technology for building new WWTPs or extending current plants, especially for the crowded cities.

Preparation of needle coke composite cathode and its treatment of RhB wastewater

A novel Fe-loaded needle coke composite electro-Fenton electrode was prepared, characterized, and investigated as the heterogeneous catalytic cathode for oxygen reduction and OH generation for the first time. The novel electro-Fenton system constructed with the cathode and DSA anode was employed to degrade rhodamine B (RhB) in an aqueous solution. Optimal conditions for electrode preparation for the treatment of RhB were obtained by single-factor experiments. The occurrence of the Fenton reaction was verified by hydroxyl radical quenching experiments, and the RhB degradation pathway was inferred by spectroscopic analysis. The decolorization rate of RhB of nearly 100% and the COD removal efficiency of 81.6% were achieved. RhB was degraded by N-de-ethylation, chromophore cleavage, opening-ring, and mineralization in the presence of reactive oxygen species, mainly OH. The cost of RhB simulated wastewater treatment was estimated at RMB 13 yuan per cubic meter of wastewater. As a cheap carbon cathode material, needle coke can catalyze the two-electron transfer of O2 to produce H2O2, reducing the material cost of the electrode, and also increasing the conductivity of the electrode, reducing the cost of water treatment. The needle coke composite electrode can serve as a cost-effective electro-Fenton cathode in the field of refractory organic wastewater treatment represented by dye wastewater.

Enhancing nitrogen removal and reducing aeration energy for wastewater treatment with intermittent Modified Ludzack-Ettinger process: A field demonstration

Previously an enhanced nitrogen removal process, i.e., intermittent Modified Ludzack-Ettinger (iMLE), was developed by incorporating intermittent aeration into the MLE process. In this research, a field demonstration of iMLE process on enhancing nitrogen removal was conducted in Shenzhen Guangming Wastewater Treatment Plant (WWTP) at a daily treatment capacity of 25,000 m3/d. Results indicated that, when operating the iMLE process with dissolved oxygen (DO) based control mode, its effluent chemical oxygen demand (COD) and ammonia concentrations were consistently less than 30 mg/L and 1.5 mg/L, respectively, similar to the original two-stage Anoxic/Oxic (A/O) process with continuous aeration. Even though the influent had insufficient organic matter (BOD5/TN = 2.5), the effluent TN concentration in the iMLE was still consistently below the new limit of 10 mg-N/L, with an average and removal rate of 6.1 ± 1.0 mg-N/L and 78%, respectively. This performance was similar to that in the two-stage A/O process equipped with step feed and external carbon addition. Without the addition of external carbon in the iMLE process, it saved approximately 0.16 Chinese yuan for one cubic meter of wastewater treated. In addition to eliminating external carbon addition, the iMLE process decreased the air consumption by 20–30%, which would also reduce operation cost. Therefore, the iMLE process operated with appropriate DO control could reduce chemical cost and aeration energy use synergistically, which provides a cost-effective approach for WWTP upgrade.

Photochemical treatments (UV/H2O2, UV/O3 and UV/H2O2/O3) and inverse osmosis in wastewater: Systematic review

Every year, the bodies of water receive millions of cubic meters of wastewater from municipal, industrial, agricultural or livestock discharges, treated in an inadequate way or without treatment. The objective of this study was to carry out a systematic review of the frequency of use and effectiveness of the main photochemical processes and the complementation with other treatments such as it is reverse osmosis, used in different types of wastewater effluents. We searched multiple electronic databases (2010-2021), using a stepwise searching approach, supplemented with hand searching. In vitro or in vivo English language publications, original studies, and reviews were included. The database was made up of a total of 100 articles that met the minimum selection criteria, of which 25 articles the maximum scores for analysis. These articles report the improvement in the elimination of pollutants when the treatments are used together and not individually, in relatively short times ranging from 30 minutes of radiation to 8 minutes of exposure to the treatments. Regarding the type of water that was treated, most of the articles report the decontamination of natural wastewater, that is, from the industry without treatment. The percentages calculated to identify research opportunities or gaps in relation to photochemical processes (UV/H2O2/O3). As proposed some authors, if any value of the percentage of pre-selected articles (PAA %) is less than the value of the percentage of failure (MAPAA %), a research opportunity is revealed not addressed by the literature. Based on the percentage results, it is observed that there are no gaps with respect to the photochemical processes or that there are possibly no updates reported in the literature yet.

Evaluation of Textile Wastewater Treatment Using Combined Methods: Factor Optimization via Split Plot RSM

The increase in the consumption of textile products as well as the use of dye compounds has increased the pollution of the effluent in these industries. Discharge of this wastewater without properly treating can cause groundwater pollution, poisoning and serious health effects. Dyed pollutants contain benzene rings and are more resistant to conventional biological treatment such as activated sludge. In this study, two combined processes in series were applied for the treatment of towel dyeing wastewater. An experimental design was used to optimize the process. In a batch reactor, the anodic oxidation process (AO) and the electro-Fenton (EF) were compared using four anodes and cathodes. The performance of AO method in dye removal and COD reduction was better than EF method. A good agreement is attained between the predicted value using experimental design and actual results. The correlation coefficient of dye removal, energy consumption, and COD was achieved 0.966, 0.997 and 0.900, respectively. The results showed that under optimum operating conditions of AO process (voltage=6.5 V, t= 6 min and pH =9.5) decreased 97% of dye index and 61% of COD amount. This condition was obtained by consuming 6.7 kWh of energy per cubic meter of wastewater (0.07 $/m3). The output of the optimal AO entered the Reverse Osmosis (RO) system, in the last step. TDS of effluent was reduced 98% in the membrane and also the COD decreased from 980 to 13 ppm under 6 bar pressure.

Economic Analysis of The Innovative Eco-Biofilter /Membrane Bioreactor (MBR) System for Community Wastewater Recycling

A prototype Eco-biofilter/MBR (Membrane Bioreactor) system has been developed and installed at a community in Chiang Rak Yai Sub-district, Sam Khok District, Pathum Thani Province, Thailand for community wastewater treatment and recycling. This research aims to investigate the performance of Eco-biofilter/MBR system, as well as the economic analysis of willingness to pay for wastewater treatment. A novel porous baked clay biofilter was also developed as an eco-friendly filter media to replace traditional plastic filter in order to reduce plastic pollution to water environment. The effluent quality from the system could meet the international standard for agricultural water reuse. The survey data for economic analysis were collected from the 281 households living in the studied area, analyzed by descriptive statistic and Contingent Valuation Method. The results show the fact that household’s land use has an inverse relationship while the water source use positively correlates to the value of willingness to pay for wastewater treatment at the statistical significance level of 0.05. The economic analysis of the innovative wastewater treatment system reveals the appropriate wastewater treatment fee at 7 THB per cubic meter of wastewater that is a breakeven point. In addition, the Eco-biofilter/MBR also shows many benefits both of direct and indirect benefits such as water reuse potential, opportunity economic value of treated effluent, and reducing medical expenses. The benefit to cost ratio is equal to 1.04.

EVALUATING FUTURE WATER QUALITY OF URBAN RIVERS IN HANOI UNDER EFFECT OF URBANIZATION AND CLIMATE CHANGE - THE APPLICATION OF WEAP MODEL FOR CAU BAY RIVER

Every day, up to 750,000 cubic meters of wastewater in Hanoi metropolitan areas is discharged directly into rivers and lake, of which only 10% is treated to the Vietnamese standards. According to the water drainage development master plan for the capital city of Hanoi until 2030, the government aim at dealing with flooding and improve environmental sanitation for local residents. With respect to the baseline and Master plan implementation scenarios, this study evaluates the future water quality of urban rivers in Hanoi under the effect of urbanization and climate change using Water Evaluation And Planning tool (WEAP) and take the Cau Bay catchment as the case study. The result shows that, without implementation of wastewater treatment plant, the water quality of Cau Bay River will be worse with the DO in dry season is 0.2-1.2 mg/l and BOD is 52.0-55.0 mg/l. With the implementation of Master plan, the level of DO and BOD would be 7.1-7.3 mg/l and 7.0-13.8 mg/l respectively in the dry season whereas the values are 3.7 mgO/l and 36.1-41.8 mg/l in the wet season. The degradation of wastewater during the wet season is results from the combine- overflow sewage system as designed in the master plan.

Renewable Energy Potential of Sewage in Zambia

This study was aimed at investigating the renewable energy potential of com- munal and municipal wastewater through methane production in biogas digesters and the use of the captured methane for energy production in biogas engines. It was conducted on biogas digesters receiving and pre-treating communal and municipal wastewater in the Zambian city of Livingstone. Wastewater inflow rates into biogas units including the wastewater turbidity, total dissolved solids (TDS), temperature, pH, conductivity and Chemical Oxygen Demand (COD) were measured during the study. And all the produced biogas was measured and combusted on-site during the course of the research. In order to know the methane content of the gas, the CO2 content in the biogas was measured with a CO2 indicator. The study showed that the predominant factor affecting the process of methane production from wastewater to the greatest extent is the COD concentration of the inflowing wastewater and not the system hydraulic retention times (HRT’s). The COD treatment levels of the tested systems ranged between 27 and 86 percent and the degree of breakdown primarily depended on the COD concentration of the influent wastewater. On renewable energy fuel production, about 3.54 kilograms of COD in each system produced a kilogram of methane. Communal wastewater was able to produce an average of 600 grams of methane per cubic meter of wastewater treated whilst municipal wastewater with less COD concentration was only able to produce about 64.5 grams of methane per cubic meter wastewater treated. With the use of a 45 kw Cummins 6 BT biogas engine, the respective wastewaters had potential to produce about 2.6 kWh and 0.1 kWh of electric energy per cubic meter of wastewater treated at a levelized cost of USD 9 cents per kilowatt-hour. Temperature also showed that it has significant effect on methane production as a degree temperature rise in the anaerobic system increased the methane production mass rate by 1.2 percent.

Developing a Closed-Loop Water Conservation System at Micro Level Through Circular Economy Approach

A closed loop system for micro-level conservation of fresh water at household user point has been developed in this work in a comprehensive circular economy (CE) framework encompassing technical, environmental and economic aspects in a concurrent manner. The system has been developed through field survey of households in an urban setting in Indian context and experimental investigation on membrane filtration and recirculation of grey water generated from domestic use like cooking, bathing, washing etc. Pollution load of the grey water utilized in the sample involved high alkalinity (pH = 9.00), total suspended solid (TSS = 536 mg/L), odour (TON 2). Membrane based filtration process has been developed to ensure that the reclaimed water is of acceptable quality as alkalinity decreases to 7.2, TSS reduces to 95 mg per litre and odour in terms of TON reduces to one. Economic feasibility of implementing such a system is assessed by cost benefit analysis. Estimated annualized total cost (capital and operating) for treating and reusing a cubic meter of waste water in this CE framework amounts to US $1.5 only. Preference score derived from utility estimates of conjoint analysis (CA) reveal that consumers have positive attitude to accept water conservation strategy in circular economy framework. The ideal composition of reclaimed grey water to be preferred is odourless (TON value near 1), low TSS (less than 102 mg/L) and neutral pH (nearly7.00) The study reveals that about half of fresh water demand per day per capita can be saved by developing a closed-loop production system at micro level, where grey water generated as waste from domestic use is not discharged as followed in traditional open-ended economic model. Instead of take-make-use-discharge, waste water is added in the production system as a resource. After applying an advanced cost-effective clean technology, grey water is kept in a material loop and usage creating further value for a longer period. Sustainable water system development by this holistic circular water conservation approach is no longer an option but a necessity to protect the life-sustaining valuable freshwater resource. Developing water conservation system in closed-loop model provides a novel solution as it will yield positive and significant utility and economic value in a very cost effective green design.

Greenhouse gas emissions from a sewage contact oxidation emergency treatment plant after destruction by an earthquake and tsunami

Emissions of greenhouse gases (GHGs) from a full-scale contact oxidation emergency sewage treatment plant (STP) in Japan that was damaged by an earthquake and a tsunami were measured. The open chamber (OC) and closed chamber (CC) methods were used to sample the gases emitted in the aeration tank and the settler, respectively. The dissolved gases were measured using the headspace method, and the major emissions sources in wastewater treatment were identified. The results indicated that the GHG emissions from the wastewater were 58.6 g-CO2/m3 (equivalent per cubic meter of wastewater). The CH4 emissions showed a strong negative correlation with the dissolved oxygen (DO) content. More than 98% of the GHGs were produced and stripped by the aeration tank. The CO2, CH4 and N2O emissions accounted for 73.0% (21,781 mL/m3), 17.1% (669 mL/m3) and 9.9% (10.9 mL/m3), respectively, of all GHG emissions. Approximately 1.06% of the incoming chemical oxygen demand (COD) was emitted as CH4, and 0.147% of the removed nitrogen was emitted as N2O.

Alternative solutions of industrial wastewater management in the textile industry

The investigation of cost-effective water treatment methods and techniques is considered an extremely important and vital objective. The aim of this study is to reach the optimum solution for the treatment of the effluent industrial wastewater from the textile industry sector in Egypt. In this work, the treatment methods and techniques under consideration were selected as being feasible and appropriate to achieve the required goal effectively. Misr Beida Dyers Company (MBDC), located at Kafer El Dawar Alexandria Governorate, has been chosen for the study. The company discharges 10–12 millions of cubic meters of wastewater annually into Abu Qir Bay, thus it is considered one of the major sources of industrial pollution in this zone. In this work, the selected procedure is to compare between two different designs for the wastewater treatment plants, whereby three alternative solutions (interventions) were proposed for each design namely: end-pipe-treatment on raw wastewater, with pollution prevention (PP) and with cleaner production (CP). Evidently, the selection of the best design approach is based on economics. To achieve this objective, a suitable cost-benefit analysis tool (CBA) has been adopted. Finally, looking at benchmarking results, it was observed that the specific rate of consumed items (water, electricity, fuel, chemicals, etc.) is rather high when compared with the recognized international standards (IS) in this respect. The unexpected rise in the abovementioned items coupled with a notable decline in the production of the plant under consideration in the period from 1994 to 2004 poses a big question mark and needs a prompt answer from the responsible authorities.

Assessing potential of nanofiltration for sulfuric acid plant effluent reclamation: Operational and economic aspects

Sulfuric acid plant wastewater is characterized by low pH and high concentrations of sulfate and metals, including arsenic, which is a toxic element that requires specific treatment. This study aimed to investigate the sulfuric acid plant wastewater treatment using NF by evaluating the main NF operational conditions (feed pH, applied pressure and permeate recovery rate) and the preliminary capital and operational cost. The results showed the NF potential to treat the wastewater. The retention of higher valence counterions to balance the retained co-ion loads was the most important mechanism observed. By combining the best operational conditions (feed pH = 2, applied pressure = 10 bar and permeate recovery rate = 45%), retention of 94% of sulfate, 98% of calcium, 85% of As III and 75% of As V was achieved and permeate could be reused in industry. The NF system had its CapEx estimated at US$ 551.250,00 and the OpEx ranged from 0.364 to 0.446 US dollars per cubic meter of wastewater for estimated membrane lifespan of 5–1 year. Savings of more than US$ 99,000 year−1 could be achieved with the industrial reuse of the permeate, which could reduce the water consumption by approximately 551,880 m3 year−1.

Iron-catalyzed wet air oxidation of biomethanated distillery wastewater for enhanced biogas recovery

In the present work, catalytic wet air oxidation (WAO) technique was applied to biomethanated spent wash from a local sugar factory. This wash water exhibited high biological oxygen demand (BOD5 = 8100 mg/L) and chemical oxygen demand (COD = 40,000 mg/L). The objectives of oxidative pre-treatment were two-fold, viz. efficient treatment of wash water and enhanced biogas recovery. For the catalytic oxidation process, two iron-based heterogeneous catalysts were employed, viz. Fe2O3 and Fe/C. To synthesize the Fe/C catalyst, activated carbon (AC) support was modified either by thermal treatment or chemical treatment with nitric acid; accordingly, the catalyst was named as Fe/AC-T or Fe/AC-N. In a batch slurry reactor, catalyst performance was investigated at T = 175 °C, PO2 = 0.69 MPa and ω = 33 mg/L (here, T, PO2 and ω denote temperature, oxygen partial pressure and catalyst loading) for 1 h. Based on the conversions of COD and total organic carbon (TOC) and the improvement in biodegradability index (BI), it was found that the activity of the catalysts reduced in the order: Fe/AC-N > Fe/AC-T > Fe2O3. The results were more encouraging (COD conversion = 87%, color reduction = 88% and BI value = 0.71) when carbon adsorption (5% w/v) followed WAO over Fe/AC-N. Clearly, our novel hybrid process for pre-treatment, viz. wet oxidation-carbon adsorption showed potential. Post biomethanation, around 1.2 Nm3 biogas (CH4 72%) was formed per cubic meter of the wastewater; without pre-treatment by catalytic WAO and carbon adsorption, the yield of biogas (CH4 11%) was just 1 Nm3 for every cubic meter of wastewater. After a last aerobic treatment step, 97% COD was removed and BI value was 0.84. Finally, a kinetic model was proposed to describe kinetics of COD reduction. In this way, a promising method was suggested for treating a complex wastewater.

KINETIKA PROSES AOPs UNTUK PENGHILANGAN WARNA AIR LIMBAH PRODUKSI BATIK

An experiment of Advanced Oxydation Processes (AOPs) was conducted in semi-pilot scale using ozon and hydrogen peroxide. The reaction of ozon and hydrogen peroxide produce an active hydroxil which can crack a long-chain organic compounds such as azo dyes. A wastewater contains colour substances coming from batik industries in Jababeka was treated by AOPs. The reaction rate was affected by ozon concentration supplied to the wastewater. The more ozon concentration, the colour removal became faster.The colour removal using AOPs could be illustrated by first-order chemical reaction equation.The constant of reaction was calculated from experiment as high as 0,38 per hour.The cost for treating the wastewater using AOPs was Rp.3.656,- for one cubic meter of wastewater. Key words: AOPs, Colour Removal, Hydrogen Peroxide, Ozon,

Management tool to assess, benchmark and support energy efficiency actions in more than 800 WWTP

Águas de Portugal (AdP) group was responsible, during 2014, for the treatment of 547 million cubic meters of wastewater, operating more than 1,000 wastewater treatment plants (WWTPs) in Portugal. Electrical energy (EE) consumption was evaluated in 219 gigawatt hours, representing the largest part of OPEX in these plants. Improving energy efficiency is an ongoing challenge for AdP, being a major challenge for such huge number of facilities as well as for the large number of different technologies applied. However, this scenario has allowed, during the last five years, a systematic analysis and benchmarking of the operational information, and has outputted an important management tool regarding EE consumption, based on real data from more than 800 WWTP. This tool is used to leverage consumptions and identify efficiency opportunities, and represents an operational asset, not only for future EE consumptions prediction, but also as a driver for energy efficiency plans and to the design of new WWTPs.