Sludge Production and Disposal for Small Cold Climate Bio-Treatment Plants

Ultimate disposal of wastewater sludge has long been a problem which to a large degree has been ignored. Haney (1971) stated that: "Until process sludge can be handled with minimum environmental impact, we cannot claim to have a viable wastewater treatment process". The relationship of sludge disposal to total treatment processes is emphasized by the fact that sludge handling and disposal represents up to 50 percent of the total treatment capital and operating costs (Burd, 1968). Processing of wastewater sludge will, no doubt, receive increased attention in the future because of environmental concerns for our air, land and water. The present technology for processing wastewater treatment plant sludge is well established and includes conditioning, dewatering, and disposal. Many of these processes are highly sophisticated and relatively expensive. Most of the more advanced processes are unsuitable for small wastewater treatment facilities in Alaska.The work upon which this report is based was supported in part by funds (Proj. A-033-ALAS) provided by the United States Department of the Interior, Office of Water Resources Research, as authorized under the Water Resources Act of 1964, as amended

Interpretation of the characteristics of ocean-dumped sewage sludge related to remote sensing

Wastewater sludge characteristics in general, and characteristics of wastewater sludges generated by the City of Philadelphia in particular, were addressed. The types and sources of wastewater sludges, a description of sludge treatment and disposal processes, examination of sludge generation and management for the City of Philadelphia, and definition of characteristics for typical east coast sludges undergoing ocean disposal were discussed. Specific differences exist between the characteristics of primary and secondary wastewater sludges, especially with the nature and size distribution of the solids particles. The sludges from the City of Philadelphia monitored during remote sensing experiments were mixtures of various sludge types and lacked distinguishing characteristics. In particular, the anaerobic digestion process exerted the most significant influence on sludge characteristics for the City of Philadelphia. The sludges generated by the City of Philadelphia were found to be typical and harbor no unique features

The Comparison of parasite eggs and protozoan cysts of urban raw wastewater and efficiency of various wastewater treatment systems to remove them

One of the most important quality characteristics associated with wastewater reuse in agriculture is the microbial quality. This study aimed to determine the efficiencies of Ghasreshirin (constructed wetland), Islamabadgharb and Gilangharb wastewater treatment plants (stabilization ponds), Sarpolezahab and Paveh (extended aeration activated sludge) and Kermanshah (conventional activated sludge) in the removal of protozoan cysts and parasitic eggs. This study was carried out during six months and samples were collected at weekly intervals from influent and effluent of the wastewater plants. In order to determine the concentration of ova, 288 samples were analyzed by Mc Master Slide according to Bailenger method. No parasite eggs or protozoan cysts were detected in the effluents of the constructed wetland or stabilization ponds systems. The extended aeration activated sludge system of Sarpolezahab removed 99-100% of parasite eggs and ≥99% of protozoan cysts. The respective values for extended aeration activated sludge system of Paveh were 97.5-100% and ≥99%. However, the conventional activated sludge of Kermanshah removed 97-99% and 99-100% of parasite eggs and protozoan cysts, respectively. According to the results, removal efficiency for cysts and parasite eggs in natural systems (constructed wetland and stabilization ponds) is better than mechanical systems (extended aeration activated sludge and conventional activated sludge). The effluent quality of all systems in terms of nematode eggs is consisted to Engelberg index (nematode eggs count: 1 ≥ counts per liter)

An evaluation of metal removal during wastewater treatment: The potential to achieve more stringent final effluent standards

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2011 Taylor & Francis.Metals are of particular importance in relation to water quality, and concern regarding the impact of these contaminants on biodiversity is being encapsulated within the latest water-related legislation such as the Water Framework Directive in Europe and criteria revisions to the Clean Water Act in the United States. This review undertakes an evaluation of the potential of 2-stage wastewater treatment consisting of primary sedimentation and biological treatment in the form of activated sludge processes, to meet more stringent discharge consents that are likely to be introduced as a consequence. The legislation, sources of metals, and mechanisms responsible for their removal are discussed, to elucidate possible pathways by which the performance of conventional processes may be optimized or enhanced. Improvements in effluent quality, achievable by reducing concentrations of suspended solids or biochemical oxygen demand, may also reduce metal concentrations although meeting possible requirements for the removal of copper my be challenging

Operation of an activated sludge plant for fellmongery wastewater treatment : a thesis submitted in partial fulfilment of the requirements of the degree of Master of Technology in Environmental Engineering at Massey University, Palmerston North, New Zealand

Activated sludge is one of the most common wastewater-treatment processes used to reduce pollutant loads on the receiving environment. For efficient operation, there must be an effective process control and operation strategy in place to ensure that process problems are avoided. This research is a case study into the process control and operation of an activated sludge plant used for fellmongery wastewater treatment. Analysis of the pretreated fellmongery wastewater showed that it is characterised by high total and volatile suspended solids concentrations, and high organic nitrogen concentrations. The plant was experiencing frequent problems that were attributed to the high influent suspended solids load coupled with ineffective solids management. Operation of bench-scale simulations showed that solids retention time (SRT) control at 5 or 10 days will produce acceptable effluent suspended solids concentrations and soluble chemical oxygen demand (COD) removal. Soluble COD removal for both 5 and 10 days was high at 85 and 80 % respectively at a hydraulic retention time of 6.4 days. Effluent suspended solids concentrations were 100 and 157 g/m 3 respectively. A steady state control model was developed based on, mass balances of biochemical oxygen demand (BOD) and volatile suspended solids (VSS), process performance equations, and the solids retention time (SRT). The model used three control points, the clarifier underflow pump, the clarifier influent pump and the waste sludge pump. The model was incorporated into an off-line Activated Sludge Operation Program (ASOP) to provide a user-friendly interface between the plant and operator. The main output from ASOP includes values for the three control points and suggestions to help avoid problems. A process control and operation strategy was developed using ASOP, the knowledge gained in this research, and an operation manual developed from accepted operation practises

Treatment of food processing industrial wastewater using two stages anaerobic system

The wastewater produced by food manufacturing industry is known for its high concentration of COD and suspended solid. In wastewater treatment, anaerobic process is favorable due to its low cost, biogas production, low sludge production and more. In this study, upflow anaerobic sludge bed (UASB) and hybrid-UASB (HUASB) reactors, were combined with anaerobic filter (AF) bioreactors forming two stages system to treat food processing industry wastewater. This study was focused on the performance of UASB-AF (R1) and HUASB-AF (R2) treatment systems and the granules development. Seed sludge was deposited into HUASB column up to a third of the height. Palm oil shells were then packed into the HUASB (above seed sludge) as well as AF reactors to promote growth of microorganisms. The R1 and R2 systems were operated simultaneously, fed with raw food manufacturing wastewater taken from Azhar Food Manufacturing Factory. Parameters measured to evaluate the performance of the process were pH, COD, NH3-N, oil and grease and total phosphorus. The highest average COD removal efficiency, at 99%, were detected in R1 and R2 systems, both at OLR 10.56 g COD/L.d. Moreover, the presence of aggregated bio particles with diameter ranges from 2.934 to 5.00 mm were observed in both UASB and HUASB reactors. The highest percentage of 2.934 to 5.00 mm diameter granules were 7.6 % and 10.7% in the UASB and HUASB respectively. In addition, the highest removal rate coefficient, k values for UASB and HUASB were 2.1981 and 3.3950, occurred at OLR 8.59 and 10.56 g COD/L.d, respectively. Overall, the k values have proved that HUASB reactor had performed better than UASB reactor

Statistically-Based Comparison of the Removal Efficiencies and Resilience Capacities between Conventional and Natural Wastewater Treatment Systems: A Peak Load Scenario

Emerging global threats, such as climate change, urbanization and water depletion, are driving forces for finding a feasible substitute for low cost-effective conventional activated sludge (AS) technology. On the other hand, given their low cost and easy operation, nature-based systems such as constructed wetlands (CWs) and waste stabilization ponds (WSPs) appear to be viable options. To examine these systems, a 210-day experiment with 31 days of peak load scenario was performed. Particularly, we conducted a deliberate strategy of experimentation, which includes applying a preliminary study, preliminary models, hypothetical tests and power analysis to compare their removal efficiencies and resilience capacities. In contrast to comparable high removal efficiencies of organic matter-around 90%-both natural systems showed moderate nutrient removal efficiencies, which inferred the necessity for further treatment to ensure their compliance with environmental standards. During the peak period, the pond treatment systems appeared to be the most robust as they indicated a higher strength to withstanding the organic matter and nitrogen shock load and were able to recover within a short period. However, high demand of land-2.5 times larger than that of AS-is a major concern of the applicability of WSPs despite their lower operation and maintenance (O&M) costs. It is also worth noting that initial efforts on systematic experimentation appeared to have an essential impact on ensuring statistically and practically meaningful results in this comparison study

Estimation of Costs of Phosphorus Removal In Wastewater Treatment Facilities: Adaptation of Existing Facilities

As part of a wider enquiry into the feasibility of offset banking schemes as a means to implement pollutant trading within Georgia watersheds, this is the second of two reports addressing the issue of estimating costs for upgrades in the performance of phosphorus removal in point-source wastewater treatment facilities. Earlier, preliminary results are presented in Jiang et al (2004) (Working Paper # 2004-010 of the Georgia Water Planning and Policy Center). The present study is much more detailed and employs an advanced software package (WEST®, Hemmis nv, Kortrijk, Belgium) for simulating a variety of treatment plant designs operating under typical Georgia conditions. Specifically, upgrades in performance, in a single step, from a plant working at an effluent limit of less than 2.0 mg/l phosphorus to one working with limits variously ranging between less than 1.0 mg/l to less than 0.05 mg/l phosphorus are simulated and the resulting costs of the upgrade estimated.Five capacities of plant are considered, from 1 MGD to 100 MGD. Three strategic, alternative designs for the facility are considered: the basic activated sludge (AS) process with chemical addition, the Anoxic/Oxic (A/O) arrangement of the AS process, and the Anaerobic/Aerobic/Oxic (A/A/O) arrangement of the AS process. Upgrades in performance are consistent with the logical alternatives for adapting these options. Cost comparisons are made primarily on the basis of the incremental cost of the upgrade, i.e., from the base-case, reference plant to that performing at the higher level, as expressed through the incremental Total Annual Economic Cost (TAEC; in $) and the marginal unit cost of phosphorus removal, expressed in ($/kg).For the most stringent upgrade, for example, to a plant generating an effluent with less than 0.05 mg/l phosphorus, these marginal costs -- the cost of the additional phosphorus removed as a result of the upgrade -- amount to something of the order of 150-425 $/kg, with the upper bound being associated with the smallest plant configuration (1 MGD). Working Paper Number 2005-001

Fate of selected drugs in the wastewater treatment plants (WWTPs) for domestic sewage

The wide diffusion of Emerging Organic Micropollutants (EOMs) in the environment is receiving increasing attention due to their potential toxicological effects on living organisms. So far, the Wastewater Treatment Plants (WWTPs) have not been designed with the purpose to remove these contaminants; therefore, they can represent the major source of release into the environment both through the effluent and the wasted sludge. The fate of EOMs in the WWTPs is still not completely known; further investigations are therefore needed to assess if it is possible to exploit the existing treatment units to reduce EOM concentrations or which processes must be implemented to this purpose. Among the wide class of EOMs, the present study focused on the following drugs of abuse: amphetamine (AM), methamphetamine (MET), 11-nor-Δ9-THC-9carboxy (THC-COOH) and benzoylecgonine (BEG). Presence and removal efficiency of these drugs in the activated sludge tank of a WWTP for domestic sewage was investigated through analyses at both full-scale and laboratory scale. Determinations conducted in the full-scale WWTP highlighted that, among the searched drugs, AM was found to be the most abundant in the influent and effluent of the biological oxidation tank, while 11-nor-Δ9-THC-9carboxy was present at the lowest concentration. Some removal took place in the units prior to the oxidation tank, although the main reduction was observed to occur in the biological oxidation reactor. All the drugs showed a wide variability of the measured concentrations during the week and the day. Taking into account results from both full-scale observations and batch tests, removals in the biological reactor were found within the following ranges: 33–84% for AM, 33–97% for MET, 33–57% for BEG and 29–83% for THC-COOH. These removals were due to a combination of adsorption and biodegradation mainly, while volatilization did not play a significant role. Other processes, e.g. hydrolysis, were likely to occur. © 2017 Springer-Verlag Berlin Heidelber

Treatment and removal strategies for estrogens from wastewater

Natural and synthetic steroidal estrogens (estrone, 17β-estradiol and 17α-ethinylestradiol) are endocrine disrupters, that are discharged consistently from the sewage treatment works into surface waters, thereby causing endocrine disrupting effects to aquatic organisms at trace concentrations (nanogram per litre). Several years of research have been focused on their fate, behaviour and removal in the environment but primarily in the sewage treatment works which acts as a sink for these compounds. This review attempts to summarize the factors involved in the removal of these chemicals from the sewage treatment works. Biological processes, and to a limited extent physio-chemical properties, play a vital role in the endocrinal deactivation of which these compounds. The efficiency of these processes is highly dependent on operating parameters (such as sludge retention time, redox potential, etc) that govern the secondary treatment process of a functional sewage treatment works. Although advanced treatment technologies are available, cost and operational considerations do not make them a sustainable solution