Types Of Treatment Systems Research Articles

Modifying filamentous algae nutrient scrubbers for improved wastewater treatment and harvestability - comparison with microalgae

Algae have been well studied for their abilities to treat wastewater, and several types of treatment systems have been demonstrated at a range of scales. High Rate Algae Ponds (HRAP) are a microalgae-based system and Filamentous Algae Nutrient Scrubbers (FANS) a filamentous algae-based system. For FANS, nutrient removal rates are typically lower and more variable than HRAPs, while HRAPs have lower productivity and poor harvestability. This study investigated if modifying a FANS to mimic HRAPs (using high rate algae mesocosms HRAM), with respect to hydraulic retention time (HRT) and smaller footprint, overcomes FANS limitations, while increasing wastewater treatment and resource recovery compared to HRAPs. Biomass productivity on the FANS (10.5 ± 2.9 g m−2 d−1) and FANS with CO2 addition (19.0 ± 4.8 g m−2 d−1) were significantly higher (p < 0.01) compared to the HRAMs (6.7 ± 1.4 g m−2 d−1) and HRAMs with CO2 addition (8.1 ± 1.2 g m−2 d−1). Under phosphorus replete conditions, biomass production was significantly higher on FANS (44.8 ± 14.4 g m−2 d−1) than HRAMs (5.0 ± 0.6 g m−2 d−1). Effluent quality (nutrient removal) was significantly higher (p < 0.05) for FANS compared to HRAMS, regardless of treatment. For harvesting, FANS (2.9–41%) yielded significantly higher (p < 0.01) percentage solids with, and, without dewatering/gravity harvesting compared to the HRAM (0.04–0.11%). Modifying the operation of the FANS to mimic longer HRT of HRAMs resulted in higher areal biomass productivity and nutrient removal in the FANS than the HRAM, regardless of treatment. The use of filamentous algae on FANS greatly improved the percentage solids yield in the harvested biomass without the need for energy intensive harvesting techniques. Further investigations need to be undertaken to determine if benefits will be realised at fullscale.

Early warning of statewide COVID-19 Omicron wave by sentineled urbanized sewer network monitoring using digital PCR in a province capital city, of Gujarat, India

Wastewater-based epidemiology (WBE) has been implemented globally. However, there remains confusion about the number and frequency of samples to be collected, as well as which types of treatment systems can provide reliable specific details about the virus prevalence in specific areas or communities, enabling prompt management and intervention measures. More research is necessary to fully comprehend the possibility of deploying sentinel locations in sewer networks in larger geographic areas. The present study introduces the first report on wastewater-based surveillance in Gandhinagar City using digital PCR (d-PCR) as a SARS-Cov-2 quantification tool, which describes the viral load from five pumping stations in Gandhinagar from October 2021 to March 2022. Raw wastewater samples (n = 119) were received and analyzed weekly to detect SARS-CoV-2 RNA, 109 of which were positive for N1 or N2 genes. The monthly variation analysis in viral genome copies depicted the highest concentrations in January 2022 and February 2022 (p < 0.05; Wilcoxon signed rank test) coincided with the Omicron wave, which contributed mainly from Vavol and Jaspur pumping stations. Cross-correlation analysis indicated that WBE from five stations in Gandhinagar, i.e., capital city sewer networks, provided two-week lead times to the citywide and statewide active cases (time-series cross-correlation function [CCF]; 0.666 and 0.648, respectively), mainly from individual contributions of the urbanized Kudasan and Vavol stations (CCF; 0.729 and 0.647, respectively). These findings suggest that sewer pumping stations in urbanized neighborhoods can be used as sentinel sites for statewide clinical surveillance and that WBE surveillance using digital PCR can be an efficient monitoring and management tool.

Enhanced microwave and photocatalytic decomposition of synthetic lignin wastewater by TiO2 nanoparticles coated on activated carbon

The present investigation was carried out to Microwave (MW) and photocatalytic decomposition of synthetic lignin wastewater by using TiO2 nanoparticles and TiO2 coated activated carbon (AC). The materials were prepared and characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infra-red spectroscopy and BET surface area analyzer. Synthetic lignin wastewater was used as model pollutant and two types of treatment systems were employed such as photocatalytic and MW with photocatalytic reactors. Among the systems, the MW with photocatalytic reactor treatment was found to be more efficient than photocatalytic reactor.

Sports medicine market – growth factors and forecasts

Sports medicine bridges the gap between science, health and exercise. It involves a combination of physicians, physical therapists, athletic trainers and sports scientists to provide the best possible care for sports injuries and illnesses. The paper demonstrates the overall market review of sports medicine and its scope of expansion during the estimation timeframe. Firstly, the study centers around the key factors driving the sports medicine market over the analysis period. Secondly, with growing price competition and technological advancement in implants, the industry is projected to witness entry of new companies during the forecast period. The study also provides information about the various types of treatment systems that are accessible to treat sports-related injuries. Consequently, the growing popularity of sports and healthy lifestyle has enabled hospitals and clinics to open separate sports medicine section in the medical setting.

Natural treatment system models for wastewater management: a study from Hyderabad, India.

Wastewater generated on a global scale has become a significant source of water resources which necessitates appropriate management strategies. However, the complexities associated with wastewater are lack of economically viable treatment systems, especially in low- and middle-income countries. While many types of treatment systems are needed to serve the various local issues, we propose natural treatment systems (NTS) such as natural wetlands that are eco-friendly, cost-effective, and can be jointly driven by public bodies and communities. In order for it to be part of wastewater management, this study explores the NTS potential for removal of pollutants, cost-effectiveness, and reuse options for the 1.20 million m3/day of wastewater generated in Hyderabad, India. The pilot study includes hydro-geophysical characterization of natural wetland to determine pollutant removal efficiency and its effective utilization for treated wastewater in the peri-urban habitat. The results show the removal of organic content (76-78%), nutrients (77-97%), and microbes (99.5-99.9%) from the wetland-treated wastewater and its suitability for agriculture applications. Furthermore, the wetland efficiency integrated with engineered interventions led to the development of NTS models with different application scenarios: (i) constructed wetlands, (ii) minimized community wetlands, and (iii) single outlet system, suitable for urban, peri-urban and rural areas, respectively.

MUSIC for cost optimisation of stormwater treatment systems

A model of urban stormwater improvement conceptualisation (MUSIC) developed and widely used in Australia, estimates pollutant transport from catchments and stormwater treatment through different systems. MUSIC also provides life-cycle costing estimates for different treatment systems. Following a series of tests for several stormwater treatment systems' efficiencies around the world, MUSIC was further tested for a grass swale system in Taiwan. The tested model was then used for the cost optimisation of three different types of treatment systems: grass swale, bio-retention system and porous pavement. For each treatment system, cost verses expected pollutant removal efficiency curves are presented for the treatments of total suspended solids (TSS), total phosphorus (TP) and total nitrogen (TN). Eventually, different systems were compared in regards to costs in achieving the same removal efficiency. It is found that within lower cost range, bioretention system will provide highest removal efficiency for all the three pollutants considered in this study.

Toxicity assessment of chlorinated wastewater effluents by using transcriptome-based bioassays and Fourier transform mass spectrometry (FT-MS) analysis

Effects of chlorination on the toxicity of wastewater effluents treated by activated sludge (AS) and submerged membrane bioreactor (S-MBRB) systems to HepG2 human hepatoblastoma cells were investigated. In addition to the cytotoxicity and genotoxicity assays, the DNA microarray-based transcriptome analysis was performed to evaluate the change in types of biological impacts on HepG2 cells of the effluents by chlorination. Effluent organic matter (EfOM) and disinfection by-products (DBPs) were also characterized by using Fourier transform mass spectrometry (FT-MS). Although no significant induction of genotoxicity was observed by chlorination for both effluents, the chlorination elevated the cytotoxicity of AS effluent but reduced that of S-MBRB effluent. The FT-MS analyses revealed that more DBPs including nitrogenated DBPs (N-DBPs) were formed in the AS effluent than in the S-MBRB effluent by chlorination, supporting the increased cytotoxicity of AS effluent. The lower O/C ratio of S-MBRB EfOM suggests that a large number of organic molecules were detoxified by chlorination, which consequently decreased the cytotoxicity of S-MBRB effluent. Integration of all the results highlights that both cytotoxicity and biological impacts of chlorinated wastewater effluents were clearly dependent on the EfOM characteristics such as DBPs and O/C ratio, namely, on types of treatment systems.

Using fundamental hydrogeological equations to monitor the effects of clogging and media consolidation on the hydraulic regime of a vertical subsurface flow treatment system

The design of passive biological filters has evolved and current design practices are predominantly based on flow (either horizontal or vertical) through porous media. To date, no method has been developed to accurately estimate the effective life expectancy of these types of treatment systems, nor have non-intrusive methods to determine the extent of substratum clogging been perfected. This research presents the results of tracer studies on various stages of two hybrid-passive landfill leachate treatment systems: an aerated pretreatment system followed by two different types of vertical-flow through porous media treatment systems. The tracer studies were used to assess changes in the active volumes of the different stages of the leachate treatment systems over a 9-month period. An analytical method, employing the governing equations for flow through porous media, was used to quantify the changes in saturated hydraulic conductivity in the treatment system cells. The results from the analytical method were combined with the results from the tracer study to further the understanding of the flow and mixing within the treatment system cells.

Municipal wastewater treatment in Mexico: current status and opportunities for employing ecological treatment systems

The aim of this paper is to evaluate the current status of municipal wastewater (MWW) treatment in Mexico, as well as to assess opportunities for using ecological treatment systems, such as constructed wetlands. In 2008, Mexico had 2101 MWW treatment plants that treated only 84 m3/s of wastewater (208 m3/s of MWW were collected in sewer systems). Unfortunately, most treatment plants operate below capacity owing to a lack of maintenance and paucity of properly trained personnel. The main types of treatment systems applied in Mexico are activated sludge and waste stabilization ponds, which treat 44.3% and 18% of the MWW collected, respectively. As in many other developing nations around the world, there is a great need in Mexico for low-cost, low-maintenance wastewater treatment systems that are both economically and environmentally sustainable. In 2005, 24.3 million Mexicans lived in villages of less than 2500 inhabitants and 14.1 million lived in towns with 2500–15,000 inhabitants. An opportunity exists to extend the use of ecological treatment systems to these low population density areas and considerably increase the percentage of MWW that is treated in Mexico. Small-scale and medium-size constructed wetlands have been built successfully in some states, primarily during the past five years. Several barriers need to be overcome to increase the adoption and utilization of ecological wastewater technology in Mexico, including: a lack of knowledge about this technology, scarce technical information in Spanish, and the government's concentration on constructing MWW treatment plants solely in urban areas.

Biological treatment of salty wastewater

AbstractIndustrial wastewater containing high concentrations of salt can be treated in biological treatment systems. However, the high salt contents tend to add to the cost and sensitivity of the treatment system. Wastewater containing high concentrations of salt can be handled in the following types of treatment systems: Conventional activated sludge systems can handle up to 5% salt. Anaerobic systems can handle up to 1.5% salt. Specialized systems, such as fluid bed/SBR/Zeno‐Gem®, can handle up to 10% salt. Special bacteria can be used for treatment of wastewater containing up to 15% salt. This paper discusses three wastewater treatment projects that involved wastewater with high concentrations of salt, up to 10% salt. This paper also summarizes the information collected from literature searches conducted as part of the projects.