Continuous Biological Treatment of Ozone Pre-treated Membrane Concentrates of Deinking Wastewater Streams from Pulp and Paper Industry

The implementation of the European WFD （water framework directive） requires IWRM （integrated water resource management）, an important tool in managing available water resources in the presence of emerging constraints. Pressures caused by variability in water supply cycles, droughts, pollution, industrialization, increasing domestic and commercial demand, inadequate infrastructure, intense urbanization and population growth, and decrepit distribution networks have led to the increasing exploitation of industrial wastewater. Most industrial process has some negative impacts on the environment especially on a catchment scale i.e. water, air and soil quality. In the context of water resources and environmental protection measures, the term ＂sustainable development＂, a development that is compatible with the future gains and environmental protection, is regulated more and more by law. To comply with these emission-based limit values, so-called ＂end-of-pipe-techniques＂ are used. Experimental results show CBT （continuous biological treatment） processes present secondary measures to purify highly contaminated industrial wastewater.

Prediction of Dissolved Oxygen and Study of Engineered Nanoparticles to Improve Water Quality

The lack of fresh water is one of the greatest challenges of our time.Increasing population and arid regions due to the temperature change limit the use of clean water.In this paper,Streeter-Phelps equation was used to find the levels of DO(Dissolved Oxygen)and the oxygen deficit which are the main criteria for the water body quality.Reaeration constants and deoxygenation coefficients were used to find how the DO and BOD(Biological Oxygen Demand)of the water bodies converge to equilibrium.Some pollutants cannot be removed from water efficiently via traditional water treatment.EDTA derivatives,owing to their engineered chemical properties,are also studied to be the potential metal ion chelator for enhancement of water quality.These molecules were tested for their thermodynamic stabilities,reactivities,and polarizations,and these characteristics are found to be important factors in selecting the most suitable chelator for metal ion chelation which is used for water quality control.

The Ability of Some Aquatic and Terrestrial Plants to Purify Domestic Wastewater

The study aimed to evaluate the ability of some terrestrial and aquatic plants for wastewater purification.Aquatic plants can remove pollutants from wastewater by consuming and accumulating various contaminants in different parts of plants.Different aquatic and terrestrial plants(Rosa sinensis,Typha latifolia,Ocimm bacilicum,Azolla pinnata,and Salvinia molesta)which have the ability to decrease water pollution were utilized in this study.The capability offive different species of plants was investigated by measuring chemical oxygen demand(COD),biological oxygen demand(BOD),electrical conductivity(EC),total dissolved solids(TDS),and pH of the medium.In this research,some aquatic and terrestrial plants were transplanted in wastewater plastic pots containing domestic wastewater with different ratios of 50%and 100%.Then,after 30 days,the physiological and biochemical parameters of plants were calculated to observe the effect of wastewater on plants.Results revealed higher chlorophyll and carotenoids in typha plants treated with 100%wastewater.The highest percentage of elimination in BOD(65%),COD(27%),TDS(72%),EC(83%),and pH(6.8%)was noted with the use of typha and azolla.Intriguingly,total soluble sugars,total free amino acids,and total proteins were found maximum in the hibiscus plant as compared to the other plants under 100%and 50%domestic wastewater treatment,while typha and ocimum showed lower values of these parameters irrespective of wastewater treatments.Moreover,the COD,BOD,TDS,EC,and pH trend was higher in 100%wastewater as compared to 50%wastewater.Taking into account the accumulation capacity of the tested plants especially typha can be efficiently used for the treatment of domestic wastewater.

Quality of effluents from Hattar Industrial Estate

Of 6634 registered industries in Pakistan, 1228 are considered to be highly polluting. The major industries include textile, pharmaceutical, chemicals (organic and inorganic), food industries, ceramics, steel, oil mills and leather tanning which spread all over four provinces, with the larger number located in Sindh and Punjab, with smaller number in North Western Frontier Province (NWFP) and Baluchistan. Hattar Industrial Estate extending over 700 acres located in Haripur district of NWFP is a new industrial estate, which has been developed with proper planning for management of industrial effluents. The major industries located in Hattar are ghee industry, chemical (sulfuric acid, synthetic fiber) industry, textile industry and pharmaceuticals industry. These industries, although developed with proper planning are discharging their effluents in the nearby natural drains and ulti- mately collected in a big drain near Wah. The farmers in the vicinity are using these effluents for growing vegetables and cereal crops due to shortage of water. In view of this discussion, there is a dire need to determine if these effluents are hazardous for soil and plant growth. So, effluents from different industries, sewage and normal tap water samples were collected and analysed for pH, electrical conductivity (EC), total soluble salts (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen, cations and anions and heavy metals. The effluents of ghee and textile industries are highly alkaline. EC and TSS loads of ghee and textile industries are also above the National Environmental Quality Standards (NEQS), Pakistan. All the effluents had residual sodium carbonates (RSCs), carbonates and bicarbonates in amounts that cannot be used for irrigation. Total toxic metals load in all the effluents is also above the limit i.e. 2.0 mg/L. Copper in effluents of textile and sewage, manganese in ghee industry effluents and iron contents in all the effluents were higher than NEQS. BOD and COD values of all the industries are also above the NEQS. On the whole, these effluents cannot be used for irrigation without proper treatment otherwise that may cause toxicity to soil, plants and animals as well add to the problems of salinity and sododicity. Similarly, these effluents cannot be used for fish farming.

Spatial impact of organic matters from point sources on stream water quality

To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect dissolved oxygen(DO) concentration along a stream.An "upper-lower" boundary technique was applied to conduct sensitivity analysis to observe the responses of DO concentration to different DO-related parameters.The results show a non-linear discrepancy of biochemical oxygen demand(BOD) and DO concentration among different treatment scenarios,which indicates the higher the efficiency of the plant treatment,the shorter the time the stream needs to recover.The sensitivity analysis reveals that the larger the amount of the waste discharge,the more sensitive the BOD to the biological removal parameter.In addition,the DO is more sensitive to the biological removal parameter than to the reaeration parameter.

Aerobic Degradation Process in Palm Oil Mill— Issues, Challenges and Upsurging Its Efficiency through Bioremediation

Palm oil mill effluent (POME) is liquid waste produced from palm oil extraction process. Discharging it to the river without treatment is violation according to Malaysia Environment of Quality Act (EQA) 1974. In Malaysia, ponding system is a conventional treatment method for POME due to its economical and simple process. The treatment process mainly involves two main treatment phases;anaerobic and aerobic degradation. Anaerobic degradation has a proven track record in reducing pollutant properties in POME up to 85%. The real challenge is to increase the efficiency of aerobic process as the biological oxygen demand (BOD) discharge limit has been further reduced from 100 mg·L-1 to less than 20 mg·L-1. One of economical and feasible approach to increase the efficiency of aerobic phase is via bioremediation. This paper describes the limitation of aerobic degradation in ponding system, besides discussed on the important aspects that need to be optimized for a success implementation of bioremediation and its challenges.

Performance of Micelle-Clay Filters for Removing Pollutants and Bacteria from Tertiary Treated Wastewater

Filters filled with a micelle-clay complex mixed with sand were employed to investigate their purification capability of tertiary treated wastewater with loose UF-membranes. The UF membrane was hollow fiber with a molecular weight cutoff of 100 kD. The complex was prepared from the organic cation octadecyltrimethylammonium （ODTMA） and the negatively charged clay-mineral, montmoriIIonite. This complex has a very large surface area, which includes large hydrophobic domains and is positively charged, about half of the cation exchange capacity of the clay. Two sets of filtration experiments were carried out at flow rates of 1.2 and 50 mL/min, which correspond to flow velocities of 3.7 and 153 cm/h, respectively. In the first case, after a passage of 1 L, the turbidity, total suspended solids （TSS）, fecal coliforms （FC）, and total coliforms （TC） were reduced to zero from 14 NTU, 6 ppm, 350 and 10,000 counts per 100 mL, respectively. In the second case, the numbers of FC and TC were reduced from 50,000/100 mL to zero after the passage of 14 L. The values of COD and BOD were reduced several-fold. The conclusion is that the incorporation of micelle-clay filters in the sewage treatment system with loose tertiary capability is promising and warrants larger scale experiments for optimization of the overall system.

Application study of coupled model between reservoir organic pollutant BOD5-DO and temperature

The BOD5-DO (Biochemical Oxygen Demand in five days and Dissolved Oxygen) are important indexes that reflect the organic pollution extent of water,but the variation of the indexes is closely related with water temperature. The study on the coupled mathematical model reflecting the BOD5-DO with temperature is the key to reveal the mechanism of the migration and distribution of BOD5-DO in the water. The authors presented 1-D mathematical model for the three variables in vertical direction,and gave accurate solution for the equations under steady state,the relation among the variables and the method for solving BOD5-DO concentrations at different depth and temperature.

Treatment of spent wash water derived from shredded lettuce processing using a combination of electrocoagulation and germicidal ultraviolet light

Objective:Water recycling is a significant part of an overall water management system.The current study evaluated electrocoagulation,used in combination with ultraviolet light(at 254 nm),to reduce the organic content and enhance the microbiological quality,of wash water derived from shredded lettuce processing.Method:The composition of spent wash water derived from a commercial lettuce processing operation was used to prepare a simulated solution to be applied to validate the water recycling system.The simulated spent wash water was subjected to an electrocoagulation process followed by filtration and a tertiary ultraviolet(254 nm)treatment.The efficacy of the recycling treatment to decrease turbidity(nephelometric turbidity units,biological oxygen demand(BOD),chemical oxygen demand(COD)and decrease in introduced bacterial numbers.Results:Spent wash water sampled from a commercial processing line was found to be colloidal in nature(78±26 NTU)with low total solids content(544±87 mg/L),BOD(230±53 mg/L)and COD(309±53 mg/L).An electrocogaultion process performed for 10 min using 3.48 A/m2 current density at pH 6.5 and conductivity of>100μS/cm supported an 87%removal of turbidity,38%reduction in BOD along with 49%decrease in COD.The electrocoagulation process was also found to reduce the levels of Escherichia coli,Salmonella and Listeria monocytogenes by 1-2 log cfu.The tertiary UV treatment of water derived from the electro coagulation process,supported further reduction in model pathogens,although it was noted that the D values for inactivation were in the order of 1.01-1.60 mJ/cm^(2),which compares to 0.22-0.31 mJ/cm^(2) in saline.The apparent increase in bacterial resistance to ultraviolet was likely due to the UV absorbing low molecular weight constituents within wash water that provided protection against inactivation.Conclusion:In conclusion,the study demonstrated the feasibility of applying electrocoagulation and UV to rapidly treat spent lettuce wash water to facilitate in-process recycling within shredded lettuce processing operations.