Sewage Pollution Research Articles

The synergistic effect of N-doped TiO2-SiO2 nanocatalysts and peroxydisulfate towards improving Bisphenol A photodegradation efficiency

TiO2-based photocatalysts have attracted tremendous attention for the degradation of hazardous organic pollutants in sewage. In this work, a series of N-doped TiO2-SiO2 with varying N contents (10N-TS5, 20N- TS5, 30N-TS5) were successfully synthesized via sol-gel method. The physical properties of the catalyst are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive emission spectroscopy (EDX), UV-visible absorption spectroscopy, and specific surface area (BET) measurements. The photocatalytic activities of as-prepared catalysts were assessed by degrading 10 mg. L-1 Bisphenol A (BPA) under simulated natural light irradiation. The results indicate that the N doping in the TiO2-SiO2 nanostructures can reduce the crystal sizes, improve the BET surface areas, and narrow the band gap energy, thereby enhancing the photocatalytic activity of the materials. The 10N-TS5 exhibits the best photoactivity, which degrades 90.7 % of BPA for 240 min irradiation. Noteworthy, the presence of 2 mM peroxydisulfate (PDS, S2O82-) in the 10N-TS5 reaction system removes completely 10ppm BPA for only 50 min illumination with the rate constant of 10.9×10-2 min-1, 7.8 times higher than that of 10N-TS5 suspension without PDS agent. The N-doped TiO2-SiO2 photocatalyst coupling with PDS provides a promising pathway for environmental remediation.

Three “R” Concept in Waste Management for Sustainable Environment

The dawn of the 21st century has thrown several challenges to mankind. The most dangerous among the challenges is the maintenance of a sustainable environment. While anthropogenic activities are considered as the predominant cause for environmental pollution, the solution also lies with human beings only. Here comes the role of the Three “R” concept which has been widely adopted across the globe. The Three “R” concept talks about Reducing the waste, Reusing the waste, and Recycling the waste and products to the extent possible. Today, a developing country like India generates a huge amount of solid waste, sewage, electronic waste, and gaseous pollutants. When we adopt this Three “R” Concept, the ill effects of the pollution caused by these agents can be effectively mitigated. Indeed, the various pollution control bodies of the governments are vigorously propagating the Three “R“ concept among the highly polluting industries to bring down the carbon emission to the sustainable level. Indeed, this is one of the United Nations Sustainable Development Goals (UNSDG). This new paradigm will definitely yield the desired result in developing and maintaining a sustainable environment which ensures the availability of pristine natural resources for the generations to come. The Higher Educational Institutions (HEI) play an important role in sustainability promotion in society. Waste management is one of the challenges educational institutions have to face in accomplishing the sustainability goals. KARE adopts the Three “R” Concepts in managing the solid, liquid, biochemical, and e-waste resulting in the development of a sustainable and eco-friendly environment on the campus. This poster details the recycling of solid, liquid, biochemical, and e-waste on Kalasalingam University campus. The solid wastes generated are converted into wealth and reused in the form of Vermicompost which is eco-friendly, the liquid waste is reused after treatment, paper and e-waste are recycled or reused through vendors. Further, the bio-medical/biochemical wastes are disposed of as per the government norms. Keyword: Reduce, Reuse, Recycle, Sustainable Development Goals (SDG), Eco-friendly

Regulation, quantification and application of the effect of functional groups on anion selectivity in capacitive deionization

Capacitive deionization (CDI) has been widely studied as a highly efficient method for the removal of charged pollutants in sewage. However, the control of ion selectivity has always been challenging, limiting the application of this approach. In this article, the regulation of different acid/base functional group distributions on the selectivity of four anions are comprehensively discussed. The effects are quantified through simulations and statistical analysis. Finally, optimized CDI is used for the simultaneous denitrification and dephosphorization of municipal wastewater. The results show that carboxyl groups significantly promote the selectivity of dihydrogen phosphate and that amino groups promote the selectivity of sulfate and dihydrogen phosphate. Density functional theory is used to calculate the influence of the functional groups on the anion adsorption energy. Compared with other anions, the energy released is improved when carboxyl groups are included in the adsorption of dihydrogen phosphate. The increase in the released energy is highest when amino groups participate in the adsorption of sulfate and is second-highest when they participate in the adsorption of dihydrogen phosphate. Statistical analysis shows that the valence and hydration energy of the anion and the effect of the functional groups on anion adsorption are significantly related to anion adsorption (P < 0.05), and the correlation coefficient of the model is 0.7253. A CDI stack for the removal of phosphorus and nitrogen under high background ion concentrations is constructed and applied, and it is shown that the treated wastewater meets higher discharge standards. Moreover, the method reaches nearly 80% water production under optimized operating modes. This study reveals the importance of functional groups in ion-selective regulation and provides a potential method for high-standard wastewater treatment.

Study the pollution with sewage water in for the Al-Hussainiya area in Karbala Governorate – Iraq

The research dealt with the study of some determinants of sewage pollution and evaluation of some of the trocars of Al-Hussainiya district, all the way to Lake Al-Razzaza In Karbala Governorate. Wastewater is the water that comes out of homes after being used for various purposes such as washing dishes, washing clothes. This study aims to determine the effect of sewage water on the quality of Lake Razzaza by analyzing the results of the characteristics of biological and physical indicators, where wastewater recorded values within the permissible environmental determinants of indicators Acidic function (pH) and (PO4-3), while the indicators recorded a higher value than the environmental determinants (BOD), (COD), and (TSS).

An efficient differential sensing strategy for phenolic pollutants based on a nanozyme with polyphenol oxidase activity.

To realize the efficient differential sensing of phenolic pollutants in sewage, a novel sensing strategy was successfully developed based on a nanozyme (GMP-Cu) with polyphenol oxidase activity. Phenolic pollutants can be oxidized using GMP-Cu, and the oxidation products reacts subsequently with 4-aminoantipyrine to produce a quinone-imine compound. The absorption spectra of final quinone-imine products that resulted from different phenolic pollutants showed obvious differences, which were due to the interaction difference between GMP-Cu and phenolic pollutants, as well as the different molecular structures of the quinone-imine products from different phenolic pollutants. Based on the difference in the absorption spectra, a novel differential sensing strategy was developed. A genetic algorithm was used to select the characteristic wavelengths at different enzymatic reaction times. Hierarchical cluster analysis and PLS-DA algorithms were utilized for the discriminant sensing of seven representative phenolic pollutants, including hydroquinone, resorcinol, catechol, resorcinol, phenol, p-chlorophenol, and 2,4-dichlorophenol. A scientific wavelength selection algorithm and a recognition algorithm resulted in the successful identification of phenolic pollutants in sewage with a discriminant accuracy of 100%, and differentiation of the phenolic pollutants regardless of their concentration. These results indicated that a sensing strategy can be used as an effective tool for the efficient identification and differentiation of phenolic pollutants in sewage.

Water and Air Pollution as an Emerging Problem for Pakistan: A Review

Currently, the development of human societies is greatly affected because of global environmental problems. Pakistan is also on the list of the most affected countries facing a number of environmental issues that affect not only people health but also the economy. The present work examines with focus on secondary data and information gathered from various literature on water and air pollution. Both water and air pollution are very complex issues and their connection to measuring the exact level of pollution is an extremely difficult one. Therefore, in this review, the main sources influencing pollution risks in Pakistan are human urbanization, surface water pollution, industrial sewage pollution, air pollution, and soil pollution. This study will help to develop suitable strategies and rules for Pakistan environmental protection in the near future. Finally, the aim of this article is to raise awareness of environmental pollution, including water pollution, air pollution, and their effect on human health, animals, and agricultural activities.

Reuse of sludge waste in Electro-Fenton:Performance and life cycle assessment

To address aggravating environmental and energy problems, the harmless treatment and resource utilization of waste has become an inevitable choice. In this study, we report a highly efficient and low-carbon reuse approach of coagulation sludge waste based catalysts for electro-Fenton(EF) process to treat wastewater. The results showed that the relative amount of iron element in flocs increase gradually along with the growth in coagulant dosage, the main composition of floc is iron-HA complex and the interaction force acting between them was weak complexation. According to evaluation by electrochemical characterization, the selectivity of sludge electrodes for hydrogen peroxide in Oxygen Reduction Reaction (ORR) process was more than 40%. Without add additional Fe2+, the as-prepared cathode material is able to achieves 98.7% bisphenol A (BPA) pollutant removal from wastewater within 130 min treatment due to its highly active two-electron reduction of oxygen (O2). Based on life cycle assessment (LCA) results, compared to traditional sludge disposal, the raw sludge used for EF could reduce fossil resource consumption by 73.7% and carbon emissions by more than 97.1%. The coagulation sludge applied in the field of EF in this paper proposes a novel and reliable way of collaborative treatment of sludge and sewage pollutants, and has certain guiding significance in environmental treatment and sludge recycling.

Batch and continuous fixed-bed column adsorption of tetracycline by biochar/MOFs derivative covered with κ-carrageenan/calcium alginate hydrogels

Due to the high dependence on tetracycline in the daily production and life of human beings, its abuse problem is serious, which affects the safety of the ecological environment. How to effectively remove residual tetracycline in the environment is an urgent problem to be solved. In this study, HKUST-1 was successfully composited with rice husk and wheat straw biochar by hydrothermal method, and then combined with κ-carrageenan and calcium alginate by cross-linking replacement method to prepare a novel modified biochar composite gel. Through a series of static adsorption experiments, the adsorption of TC on the two modified biochar composite gels reached equilibrium within 24 h and was dominated by chemical adsorption, and the maximum adsorption capacities for TC could reach 313.00 and 396.09 mg·g−1, respectively. The adsorption mechanism of TC on the modified biochar composite gels is mainly hydrogen bonding, electrostatic attraction, metal-organic complexation and π-π interaction. At the same time, the dynamic adsorption process was simulated through a fixed-bed column experiment, and the results showed that the modified biochar composite gels as a new type of adsorption material can be effectively applied to the removal of organic pollutants in actual sewage, providing basic support for future practical application research.

DOM tracking and prediction of rural domestic sewage with UV–vis and EEM in the Yangtze River Delta, China

Compared with the urban sewage treatment plants, the operation of rural decentralized sewage facilities is trapped by the absence of professionals, thus having to be run dependently on the self-adaptive operation of the facilities, which makes timely monitoring particularly important. In this study, organic pollutants in rural domestic sewage and urban domestic sewage are analyzed using ultraviolet-visible (UV-vis) absorption spectroscopy, fluorescence excitation-emission matrix (EEM) and Fourier transform infrared reflectance (FTIR). Compared with the UV-vis absorption spectrum, EEM can not only make up the deficiency in the detection of some easily degradable organics in sewage, but also reveal the transformation of different components, thus indicating timely the treatment progress of rural sewage. Linear fitting of COD and spectrum shows that UV254 combined with fluorescence excitation-emission at Ex/Em = 250/330nm might be more suitable for the prediction of COD in rural water than the UV254 alone. This is of great significance for guiding the self-adaptive operation of rural domestic sewage facilities, improving their stability and efficiency, so as to improve the rural living environment.

Sewage-associated plastic waste washed up on beaches can act as a reservoir for faecal bacteria, potential human pathogens, and genes for antimicrobial resistance

Sewage-associated plastic wastes, such as wet wipes and cotton bud sticks, commonly wash up on beaches; however, it is unclear whether this represents a public health risk. In this study, sewage-associated plastic waste, and naturally occurring substrates (seaweed and sand), were collected from ten beaches along the Firth of Forth estuary (Scotland, UK) and analysed using selective media for the faecal indicator organisms (FIOs) E. coli and intestinal enterococci (IE), and potential human pathogens (Vibrio spp.). Minimum inhibitory concentration (MIC) analysis was used to determine antibiotic resistance in selected strains. FIOs and Vibrio were more often associated with wet wipes and cotton bud sticks than with seaweed, and there was evidence of resistance to several antibiotics. This work demonstrates that plastics associated with sewage pollution can facilitate the survival and dissemination of FIOs and Vibrio and thus, could present an as yet unquantified potential risk to human health at the beach.

CrAssphage as an indicator of groundwater-borne pollution in coastal ecosystems

Novel approaches for monitoring coastal water quality changes and identifying associated contaminant source(s) are of growing importance as climate change and population redistribution to coastal zones continue to impact coastal systems. CrAssphage, a virus found in the human gut and shed with fecal matter, is currently gaining popularity as an indicator of human fecal contamination in surface water and groundwater. Here we demonstrate that DNA assays targeting crAssphage genetic fragments can be used to detect pollution from nearshore onsite wastewater treatment systems discharging to the ocean via submarine groundwater discharge. We integrated this novel viral monitoring tool into a field study that characterized the physical hydrogeology (hydraulic gradients, hydraulic conductivity, and seepage fluxes) and surface water and groundwater quality at a study site on the north shore of Nova Scotia, Canada. Increased use of onsite wastewater treatment systems during the summer cottage season coincided with widespread detections of crAssphage in submarine groundwater discharge (4/4 samples) and coastal surface waters (3/8 samples). Conversely, classical fecal pollution indicators based on bacterial targets (Escherichia coli and human-specific Bacteroidales genetic marker (HF183)) were sparsely detected in the samples in the coastal environment (2/12 E. coli samples, 0/12 HF183 samples), likely due to greater attenuation of bacterial contaminants within the subsurface environments. Results from this first application of crAssphage in coastal groundwater contribute to a growing body of research reporting the application of this emerging tracer in various environments impacted by sewage pollution sources.

Identification of enteroviruses along Lake Victoria shoreline - a potential indicator of sewage pollution.

E n t e r i c v i r u s e s a r e m a i n l y t r a n s m i t t e d b y t h e f a e c a l - o r a l r o u t e a n d h a v e b e e n l i n k e d t o s e v e r a l d i s e a s e s i n c l u d i n g g a s t r o e n t e r i t i s a n d r e s p i r a t o r y i n f e c t i o n s . T h e i r p r e s e n c e i n s u r f a c e w a t e r s h a s b e e n exacerbated by p o l l u t i o n f r o m a v a r i e t y o f p o i n t s o u r c e s s u c h a s s e w a g e d i s c h a r g e . W e s t u d i e d t h e occurrence o f e n t e r o v i r u s e s i n w a t e r s a m p l e s f r o m L a k e V i c t o r i a i n K e n y a t o i n v e s t i g a t e i f t h e r e w a s a l i n k b e t w e e n s e w a g e p o l l u t i o n a n d d e t e c t i o n o f e n t e r o v i r u s e s ( E V s ) t o b u i l d a b a s e l i n e f o r a n enteric viruses monitoring platform for this region. We analysed 216 samples collected over 6 months from six different locations along the Homa Bay Pier. The six sampling locations comprised of three sites (P3, P5, P6) located <500 m from a local sewage treatment plant and pit latrines while three other sites (P1, P2, P4) were located at approximately 0.5 to 3 Km. EVs were concentrated using glass wool adsorption elution protocol and identified using the nested reverse transcription-polymerase chain reaction. The odds ratio was performed to determine whether the location of the sources of sewage pollution near the lake was associated with the EVs contamination. Five out of 108 (5 %) samples collected from the sites (P3, P5 and P6 were EV positive, while 2 % (2/108) of samples from P1, P2 and P4 were EV positive. The presence of the EVs was associated with the distance from the possible sources of faecal contamination (odds ratio 20.28 and 4.86, confidence interval 2.42, and 0.95) for pit latrines and the sewage treatment plant respectively. The result from this study indicates that sewage discharge at the shoreline of Lake Victoria may have been the source of EVs contamination. Data from this study could significantly contribute to informing risk management on sewage pollution in Lake Victoria and it is important to continue monitoring this lake for potentially pathogenic enteric viruses.

An evolving marine environment and its driving forces of algal blooms in the Southern Yellow Sea of China

Continuing global warming and intensification of human activities have substantially disturbed the balance of coastal marine ecosystems, potentially creating favorable conditions for algal blooms. Using serial remote sensing data and various national and provincial statistics, we investigated the spatial and temporal variations of the environmental driving forces for algal blooms in the Southern Yellow Sea between 2003 and 2017. The findings suggest that (1) Continual warming was observed in the Southern Yellow Sea. The study area evidenced more than three times the warming speed (0.41 °C/decade) of the global oceans (0.12 °C/decade) during the same period. There was an apparent warming zone in the region where macroalgal blooms tended to spread, with a heating of 1.0–1.5 °C (May–June). (2) Nutrient loadings have diverse patterns, characterized by fast-growing aquaculture activities and declining nutrients from land-based agriculture fertilizers and sewage discharge (based on published national and provincial statistics). (3) Growing expansion of algal blooms in the Southern Yellow Sea was confirmed by the relative increases in average May–June chlorophyll-a concentration of 46.7% and floating biomass area from 3.3% in 2003 to 13.4% in 2017. (4) While spatial correlation analysis showed a positive influence of the ocean surface temperature on chlorophyll-a, their relatively moderate (r = 0.40, p < 0.15) and declining correlations suggest that nutrient enrichment could be comparatively more influential on macroalgal blooms. Nutrient loading from the discharge of wastewater sourced from coastal aquaculture and organic residuals from land-sourcing sewage and industrial pollution, even though declining as reported, is still upholding a high level of nutrient enrichment in the study area. In addition, the fixed facilities for seaweed mariculture in the region provide vast breeding surfaces for algae. Consequently, the Southern Yellow Sea has become an ideal marine area for algal blooms.

Are Farmers Willing to Pay for Centralized Mode Provision of Rural Domestic Sewage Treatment? A Large-Scale Assessment in North China

Evaluation of farmers’ willingness to participate (WTPP) and willingness to pay (WTP) for the centralized mode provision (CMP) of rural domestic sewage treatment (RDST) is imperative to improve the rural environment as well as to alleviate government financial pressures. This study adopted the contingent valuation method as well as face-to-face interview questionnaires to assess rural residents’ provision mode preferences, WTPP, and WTP for the CMP of RDST in China. Based on 761 samples collected from Shandong, Jilin, and Gansu provinces of China, we applied econometric models to estimate farmers’ WTPP and WTP for the CMP of RDST and explore the potential influencing factors, respectively. Results show that 1) 81.87% of the farmers would be willing to contribute to CMP of RDST; 2) farmers’ perceptions of the necessity of RDST, pollution of rural domestic sewage, and government propaganda significantly and positively affect their WTP; and 3) the expected WTP for CMP of RDST with the total respondents and the respondents with positive WTPP were estimated to be 7.59 USD/year and 10.10 USD/year (for a total of 20 years), accounting for 16.28 and 21.65% of construction costs, respectively. Based on these outcomes, it could be further estimated that the aggregate value was between 179.05 million USD/year and 238.26 million USD/year which implied that the farmers’ WTP may be a potentially non-negligible funding source for the CMP of RDST. The enhancement of environmental awareness of farmers and strengthening of propaganda should be the next priority of the Chinese government. Priority should also be assigned to villages closer to towns when the government formulates relevant strategies and policies. The results of this study provide references for policy formulation related to broadening the funding sources in RDST and exploring farmer payment mechanisms and implications for other developing countries.

Are there correlations between the levels of fluctuating asymmetry in Pelophylax ridibundus (Anura: Ranidae) meristic morphological traits and morphological parameters used for assessing their physical fitness (health status)?

The degree of developmental stability of individuals and populations is most often estimated by their level of fluctuating asymmetry (FA) - the random deviations from perfect symmetry. In our previous work, we recorded high levels of FA (FAMI index: frequency of asymmetric manifestation of an individual) in Pelophylax ridibundus populations that inhabit biotopes at Sazliyka River, south Bulgaria with high levels of anthropogenic pollution (domestic sewage pollution). At the same time, in the biotopes located in the upper reaches of the river (less disrupted habitats), the populations showed low levels of FA. Currently, we present the results of the study of the values of several morphological parameters: snout-vent length (SVL), body weight (BW), and body condition factor (CF) in the same populations of P. ridibundus. In addition, we evaluate the correlation between the values of these morphological parameters and the values of fluctuating asymmetry (the FAMI index), using the Kendall rank correlation analysis. The analysis of the relationships between the parameters characterizing the physical fitness of frogs and the indicator of developmental stability - the FAMI index - did not establish statistically significant correlations in the analyses in the whole groups of P. ridibundus from each site and in the correlations between sexes. We believe that the approaches to the study of developmental stability (analysis of fluctuating asymmetry levels) and those related to the assessment of physical fitness (health status) of frogs should be applied independently of each other.

A Longitudinal Study of Bacteriophages as Indicators of Norovirus Contamination of Mussels (Mytilus edulis) and Their Overlying Waters

Sewage pollution leads to the contamination of bivalve shellfish by pathogenic microorganisms. Bacterial indicators support the management of risks associated with the consumption of shellfish; however, they often fail to indicate adequately the potential hazard to human health posed by certain human enteric viruses. Bacteriophages have been proposed as alternative indicators that may more effectively predict the presence of enteric viral pathogens. This study explored the relationships between bacterial indicators (Escherichia coli (E. coli), faecal coliforms (FC) and intestinal enterococci (IE)), phages (somatic (SOMPH), F-specific RNA (F + PH) and human-specific Bacteroides GB-124 phages (GB124PH)) and Norovirus (NoV) (GI/GII) in mussels (Mytilus edulis) and their overlying waters. The bioaccumulation of these indicators and Norovirus in shellfish matrices (e.g., flesh, digestive gland) was investigated bimonthly over a 12-month period in an English estuary. The findings revealed a marked seasonality in the distribution of all organisms, with the highest levels occurring during the autumn/winter months. The levels of all phages in shellfish and their overlying waters correlated better with the levels of Norovirus than with those of bacterial indicators. Somatic coliphages were the indicator that exhibited the strongest correlations with NoV (rho = 0.929). This study suggests that relatively low-cost culture-based phage enumeration appears to offer a more accurate indication of the likely presence of Norovirus in mussels than traditional bacterial indicators.

Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki catchment, Addis Ababa, Ethiopia

In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for the dry and wet season. Spatiotemporal variation in bacterial hazards across the catchment was up to 6 log10 units. Cooccurrence of sewage pollution marker gene HF183 in all river samples testing positive for the Vibrio cholerae marker gene ompW, and high levels of these two genes in untreated wastewater, identified human sewage as the likely source of Vibrio cholerae hazards in the catchment. Levels of the marker genes rodA for E. coli, HF183 for human host associated Bacteroides, ciaB for Arcobacter, and ompW for Vibrio cholerae were all higher in the dry season than in the wet season. Marker gene gyrB for Pseudomonas aeruginosa was not detected in the samples. From the sequencing data, notable bacterial genera in the dry season included wastewater pollution indicators Arcobacter and Aeromonas, whereas soil erosion may explain the greater prominence of Legionella, Vicinamibacter, and Sphingomonas during the wet season. Except for the most upstream location, all faecal coliform (FC) counts exceeded WHO standards of 1000 CFU/100 mL for unrestricted irrigation. Concerningly, 0.6–20% of FC had ESBL producing antimicrobial resistance traits. In conclusion, multiple bacterial hazards were of concern for river water users in the Akaki catchment, and elevated in the dry season, when the river water is being used for irrigation of vegetable fields that supply the markets of Addis Ababa. This reflects inadequate treatment and limited dilution of urban wastewater by the natural river flows during periods of low rainfall.

Assessment of Sewage Molecular Markers in Port Dickson Coast and Kim Kim River with Sediment Linear Alkylbenzenes

The present study aimed to determine linear alkylbenzenes (LABs) concentrations as organic molecular marker for sewage pollution in the sediment samples collected from Coast of Port Dickson and Kim Kim River, Peninsular Malaysia. The adverse effects of anthropogenic inputs into the rivers and coastal environment could be detected by molecular organic markers such as LABs. The sediments were processed; their sources were identified and tested by gas chromatography-mass spectrometry (GC-MS). The significance of the differences among sampling stations for LAB concentrations and distribution at p < 0.05 was performed by analysis of variance and Post Hoc Tests, LSD procedures (ANOVA) and Pearson correlation coefficient. LABs indices which include internal to external (I/E) congeners, long to short chains L/S and homologs C13/C12 were used to identify the sewage treatment and degradation levels. Results of this study are statistically uncovered that the range of ΣLABs concentration in the investigated locations was between 112.0; 88.3 and 256.0; 119.0 ng·g−1 dw, respectively. There was significant difference (p < 0.05) of LAB homologs with high percentage of C13-LAB homologs along sampling locations. The calculated LAB ratios (I/E) were within the range between 2.0; 1.7 and 4.1, 2.0, demonstrated that, the treated effluents from primary and secondary sources were discharged to the study areas. The degradation of LABs was 40–64% and 34–38% in the studied locations. The findings of this study suggested the powerfully indicators of LABs in tracing anthropogenic sewage contamination and the necessity of continuing wastewater treatment system improvement.

Contrasting sewage, emerging and persistent organic pollutants in sediment cores from the River Thames estuary, London, England, UK

Sedimentary organic pollution in the urban reaches of the Thames estuary is changing from fossil fuel hydrocarbons to emerging synthetic chemicals. De-industrialisation of London was assessed in three cores from Chiswick (Ait/Eyot) mud island using pharmaceuticals, faecal sterols, hydrocarbons (TPH, PAH), Black Carbon (BC) and organotins (TBT). These ranked in the order; BC 7590-30219 mg/kg, mean 16,000 mg/kg > TPH 770–4301, mean 1316 mg/kg > Σ16PAH 6.93–107.64, mean 36.46 mg/kg > coprostanol 0.0091–0.42 mg/kg, mean of 0.146 mg/kg > pharmaceuticals 2.4–84.8 μg/kg, mean 25 μg/kg. Hydrocarbons co-varied down-profile revealing rise (1940s), peak (1950s -1960s) and fall (1980s) and an overall 3 to 25-fold decrease. In contrast, antibiotics, anti-inflammatory (ibuprofen, paracetamol) and hormone (17β-estradiol) increased 3 to 50-fold toward surface paralleling increasing use (1970s-2018). The anti-epileptics, carbamazepine and epoxcarbamazepine showed appreciable down-core mobility. Faecal sterols confirmed non-systematic incorporation of treated sewage. Comparison to UK sediment quality guidelines indicate exceedance of AL2 for PAH whereas TBT was below AL1.

Research on the Non-Point Source Pollution Characteristics of Important Drinking Water Sources

In recent years, freshwater resource contamination by non-point source pollution has become particularly prominent in China. To control non-point source (NPS) pollution, it is important to estimate NPS pollution exports, identify sources of pollution, and analyze the pollution characteristics. As such, in this study, we established the modified export coefficient model based on rainfall and terrain to investigate the pollution sources and characteristics of non-point source total nitrogen (TN) and total phosphorus (TP) throughout the Huangqian Reservoir watershed—which serves as an important potable water source for the main tributary of the lower Yellow River. The results showed that: (1) In 2018, the non-point source total nitrogen (TN) and total phosphorus (TP) loads in the Huangqian Reservoir basin were 707.09 t and 114.42 t, respectively. The contribution ratios to TN export were, from high to low, rural life (33.58%), farmland (32.68%), other land use types (20.08%), and livestock and poultry breeding (13.67%). The contribution ratios to TP export were, from high to low, rural life (61.19%), livestock and poultry breeding (21.65%), farmland (12.79%), and other land use types (4.38%). The non-point source pollution primarily originated from the rural life of the water source protection zone. (2) Non-point source TN and TP pollution loads and load intensities showed significantly different spatial distribution patterns throughout the water source protection area. Specifically, their load intensities and loads were the largest in the second-class protected zone, which is the key source area of non-point source pollution. (3) When considering whether to invest in agricultural land fertilizer control or rural domestic sewage, waste, and livestock manure pollution control, the latter is demonstrably more effective. Thus, in addition to putting low-grade control on agricultural fertilizer loss, to rapidly and effectively improve potable water quality, non-point source pollution should, to a larger extent, also be controlled through measures such as establishing household biogas digesters, introducing village sewage treatment plants, and improving the recovery rate of rural domestic garbage. The research results discussed herein provide a theoretical basis for formulating a reasonable and effective protection plan for the Huangqian Reservoir water source and can potentially be used to do the same for other similar freshwater resources.