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A Review on Emerging Contaminants in Indian Waters and Their Treatment Technologies
2020
Riya Ann Mathew , S. Kanmani
Emerging contaminants (ECs) have been detected recently in many water bodies across India. Studies have found the presence of ECs in surface water, groundwater, stormwater, treated wastewater, treated industrial effluent, bottled water and snow from glaciers in Indo-Chinese border which contaminate water bodies. The surface water recharges the groundwater, thereby the ECs make their way to deep water aquifers. The soil also gets contaminated and plants can uptake ECs. These micropollutants can cause adverse ecological and human health effects. Antimicrobial resistance of bacteria to commonly used antibiotics has been observed in India. An exhaustive review of emerging contaminants in Indian waters and their treatment technologies has been carried out. Antibiotic-resistant genes can be easily transferred resulting in a plethora of antimicrobial-resistant bacteria which can cause devastating effects on human health. Conventional biological treatment is not capable of removing ECs completely. Advanced oxidation processes using ozonation and visible light active photocatalyst are a sustainable solution for the removal of most ECs. Hence, it is of utmost importance to monitor the presence of ECs in the water environment and develop treatment technologies for its removal.
Afficher plus [+] Moins [-]Optimization of Protease Production by Bacillus isronensis Strain KD3 Isolaed from Dairy Industry Effluent
2020
N. S. Patil and J. V. Kurhekar
Proteases have a broad range of applications in pharmaceuticals, detergents and food processing industries. Protease producing strains are used profusely in industrial applications and the bioremediation process of wastewaters. In the present research work, efficient protease producing strain was isolated from dairy industry effluent. Screening of protease activity by isolates was checked by growing them on milk agar (skimmed) by spot inoculation method and further estimation was performed using quantitative protease assay. The efficient protease producing strain was identified based on morphological as well as biochemical characteristics as per standard keys of Bergey’s Manual of Determinative Bacteriology, later confirmed by 16s rRNA sequencing and BLAST analysis as Bacillus isronensis strain KD3. The maximum protease was produced at 42°C; pH 7-8; 200 rpm; and 7% inoculum concentration after 48h of the incubation period.
Afficher plus [+] Moins [-]Biogas Investment Intention of Large-Scale Pig Farmers Under the EmissionTrading System
2020
Wenjie Yao
Based on the field research data of 424 large-scale pig farmers in Zhejiang Province, this paper takes the biogas fermentation as the main adoption behaviour of pollution treatment, and make the quantitative analysis on the biogas investment intention and its influencing factors on large-scale pig farmers under the emission trading system. The research shows that the emission trading system can encourage large-scale pig farmers to adopt biogas fermentation to deal with pollution and make environmental protection investment for waste resources utilization, which mainly depends on the pig breeding scale, the biogas digesters purchased or not, the benefit evaluation of biogas fermentation and the biogas fermentation technology service existed or not, rather than environmental awareness. Therefore, it is feasible to introduce the emission trading system into the agricultural non-point source pollution control with pig breeding pollution as the typical example. For the pig breeding industry, emission trading can be transformed from the traditional redistribution of environmental capacity to the redistribution of production scale.
Afficher plus [+] Moins [-]Changes in the Microbial Succession During Sewage Sludge Composting and its Correlation with Physico-Chemical Properties
2020
Chuang Ma, Bin Hu, FU-Yong Liu, Ai-Hua Gao, Ming-Bao Wei and Hong-Zhong Zhang
Sewage sludge composting is a process entailing a continuous succession of microorganisms. To understand the microbial mechanisms involved in sewage sludge composting, we performed an aerobic static composting of sewage sludge and sawdust (ratio = 3:1 m/m) in medium-scale bioreactor systems. The associated changes in physico-chemical parameters (i.e., temperature, organic matter, pH, ammonium nitrogen) were studied parallelly to those in the microbial (i.e., bacteria, fungi, archaea) succession. Additionally, we discussed correlations between these physico-chemical parameters and the microbial communities. The results showed that the pile temperature went through mesophilic phase, thermophilic phase, and cooling phase. The pile temperature reached a maximum of 78.68°C by day 3 and remained above 55°C for more than 6 days, complying with the harmless composting requirements. The organic matter content decreased gradually, the pH increased after a first decrease and the NH4 +-N content showed a consistent trend. The dominant bacteria during composting were Ureibacillus, Bacillus, Sphaerobacter, and Thermobifida, while the dominant fungi were unclassified_f_ Trichocomaceae, unclassified_d_Eukaryota, Hypocrea and Thysanophora; finally, the dominant archaea were Methanobrevibacter, Methanosaeta, Methanobacterium, and unclassified_k_norank. The composting stages were characterized by different microbial compositions. The mesophilic phase presented a relatively uniform proportion of bacterial genera, while the thermophilic and cooling phases were dominated by Ureibacillus and Bacillus, respectively. The fungus unclassified_f_Trichocomaceae played a major role during the mesophilic, thermophilic, and cooling phases, while unclassified_d_Eukaryota played a major role during the mesophilic and thermophilic phases. For what concerns the archaea, Methanobrevibacter played a major role in the mesophilic, thermophilic, and cooling phases, Methanosaeta during the mesophilic and thermophilic phases, and Methanobacterium during the thermophilic and cooling phases. Additionally, the bacterium Ureibacillus and the archaea Methanospirillum were positively correlated with temperature, while the bacteria norank_Pem15, norank_JG30-KF-CM45 and the archaea Methanosphaera were negatively correlated with temperature. The fungi Thysanophora, unclassified_d_ Eukaryota, and unclassified_p_Ascomycota were negatively correlated with pH. Moreover, the bacterium norank_c_1-20, the fungi Trichosporon, norank_o_Saccharomycetales, unclassified_o_Pleosporales, and the archaea Methanosaeta, Methanomethylovorans were positively correlated with organic matter. On the other hand, the bacteria Bacillus, Thermobifida, the fungus unclassified_f_Trichocomaceae, and the archaea Methanobrevibacter were negatively correlated with organic matter. Finally, the bacteria Bacillus, Thermobifida, the fungus unclassified_f_Trichocomaceae, and the archaea Methanobrevibacter were positively correlated with ammonium nitrogen, while the bacterium norank_c_1-20, the fungi Trichosporon, norank_o_Saccharomycetales, unclassified_o_Pleosporales, and the archaea Methanosaeta, Methanomethylovorans were negatively correlated with ammonium nitrogen. This paper provides new solid bases to understand changes in microbial composition and their correlation with physico-chemical parameters during sewage sludge composting.
Afficher plus [+] Moins [-]University-Industry Knowledge Collaboration in Chinese Water Pollution Abatement Technology Innovation System
2020
Guoxin Liu, Pengfei Zhang and Feng Zhang
University-industry knowledge collaboration is one of the keys to overcoming the current development bottleneck in water pollution abatement technology in China. To explore university-industry knowledge collaboration in Chinese water pollution abatement technology innovation system, characteristics and dynamic evolution law of knowledge collaboration were analyzed by using patent data from China for the period 2000-2018. Results show that university-industry knowledge collaboration continues to increase and experiences three development phases in Chinese water pollution abatement technology innovation system. University-industry knowledge collaboration in each province (city) keeps growing and the difference between provinces (cities) is decreasing, but the difference remains significant. The scale, scope, and depth of inter-regional university-industry knowledge collaboration continue to increase, but they are still not large enough. Although the scale and linking efficiency of university-industry knowledge collaboration improve significantly, the subgroups are too many and the agglomeration degree of networks is low.
Afficher plus [+] Moins [-]Use of Crystalline Silica Waste for Enhancement of Engineering Properties of Black Cotton Soil
2020
M. Selvaraj, M. Krithigaisrilatha, S. Syed Masoodhu and N. Natarajan
Construction of pavement layers on subgrade soil with excellent properties reduces the thickness of pavements and consequently reduces the initial cost of construction. However, construction of pavement on poor soil subgrade like black cotton soil is unavoidable due to several constraints. In such a situation, the enhancement of subgrade properties can be attained by the addition of foreign materials. The worldwide growing usage of cement has led to a larger collection of crystalline silica from the cement manufacturing plants. The disposal of the crystalline silica is extremely challenging and also causes an environmental impact. Hence this waste material can be used for enhancement of the strength of the weak soils. Chemical analysis has revealed that crystalline silica is rich in oxides such as silicon oxide, aluminium oxide and calcium oxide. In this study, the black cotton soil is blended with 8%, 12%, 16%, 18% and 20% crystalline silica by the weight of the dry soil. Laboratory tests, namely, standard proctor compaction test, California Bearing Ratio (CBR) test and Unconfined Compressive Strength (UCC) test were carried out to examine the performance of crystalline silica mixture in black cotton soil. The outcome suggests that a potential increase in crystalline silica content enhances the maximum dry density (MDD). The results also indicate there is a huge potential to use crystalline silica as an admixture to strengthen the black cotton soil. Moreover, the employment of crystalline silica might also benefit the environment and construction cost.
Afficher plus [+] Moins [-]Passivating Effect of Dewatered Sludge and Biochar on As-Contaminated Soil
2020
Luo, Ninglin | Wen, Jiajun | Li, Zhongwu | Huang, Mei | Yang, Ren
The pollution caused by As in soil menaces the health of humans. There are characteristics of waste utilization, low cost, and a wide range of materials by using dewatered sludge as the main component of soil repair agents. In this paper, dewatered sludge and biochar were used as repair agents for As pollution, which were rarely reported, and the related passivation experiments were carried out. Through the analysis of experimental data of the basic physical and chemical properties of contaminated soil, various characteristics of repair agent and As morphology were obtained, and the applicability and passivation effect of dewatered sludge-biochar compound repair agent and dewatered sludge as an individual repair agent on passivation of As pollution in soil was discussed. By comparing different passivation effects, the repairing effect increases with time, and the optimal repair time was 40 days; in the set experiment group, the best passivation effect of the individual repair agent was the S3 (dry sludge accounting for 20% of soil samples) experimental group, and the best effect of the compound repair agent was the S + B3 (dry sludge and biochar accounting for 10% and 2% of soil samples, respectively) group. As a repair agent, the dewatered sludge-biochar compound repair agent can be used to repair As-contaminated soil, which provides a new method for the recycling and waste utilization of dewatered sludge.
Afficher plus [+] Moins [-]Novel Electrochemical Sensor Based on Nylon 6,6-Modified Graphite HB Pencil Electrode for Chlorothalonil Determination by Differential Pulse Cathodic Stripping Voltammetry
2020
Thanalechumi, Paramalinggam | Yusoff, Abdull Rahim Mohd | Yusop, Zulkifli
Mercury-based electrode was the choice of electrode material for many years, and it has been extensively used in voltammetry studies. Nonetheless, alternative electrode materials are highly preferred in voltammetry studies due to the toxicity of mercury. This work introduces a novel green sensor, nylon 6,6-modified graphite HB pencil electrode (Nyl-MHBPE) as electrochemical method for chlorothalonil determination by differential pulse cathodic stripping voltammetry (DPCSV). The Nyl-MHBPE was significantly improved electroactivity towards the reduction of chlorothalonil, under the optimal conditions (at pH 8.0). It was clearly observed that nylon 6,6 revealed as an efficient modifier for enhancing stripping signal for voltammetric analysis. Moreover, the developed sensor showed great feature such as a remarkably low detection limit in nanomolar level (0.94 × 10⁻⁸ M) with a linear range from 1 to 26 × 10⁻⁷ M. It presented excellent repeatability with high sensitivity and selectivity. Besides, analysis of chlorothalonil in real water samples was successfully carried out with good recovery values (92.5–103%) and relative standard deviation (RSD) values < 2.2%. The performance of Nyl-MHBPE was also compared to bare pencil electrode (HBPE). Another significant feature of this work is that the conductivity properties of the Nyl-MHBPE were superior as compared to hanging mercury drop electrode (HMDE). The present study provides admirable merits that make the Nyl-MHBPE selected as a promising electrochemical sensor to perform routine analysis of chlorothalonil.
Afficher plus [+] Moins [-]Ingestion of Microplastic by Fish of Different Feeding Habits in Urbanized and Non-urbanized Streams in Southern Brazil
2020
Garcia, Thiago D. | Cardozo, Ana L. P. | Quirino, Bárbara A. | Yofukuji, Katia Y. | Ganassin, Maria J. M. | dos Santos, Natália C. L. | Fugi, Rosemara
Most studies that address microplastic (MP) ingestion by fish are conducted in marine environments; however, freshwater ecosystems such as rivers and streams are also important sources of these particles in coastal areas. Considering that increasing urbanization surrounding watersheds increases the sources of plastic pollution and that fish feeding behavior may influence the probability of ingestion of these particles, the aim of this study was to evaluate the ingestion of MP by fish of different feeding habits in urbanized and non-urbanized streams. The fish were captured in ten streams in Southern Brazil and the stomach contents of 294 individuals belonging to 13 species were analyzed. Individuals of ten species ingested MP of fiber type. From a generalized linear mixed model, we observed that the urbanized streams and the omnivorous habit showed a positive correlation with MP intake. Our results suggest that both types of streams present MP, but this pollutant is probably more prominent in heavily urbanized sites, which may represent important sources of MP for larger systems along the river basin. This evidences the importance of preserving riparian areas of small order streams as a means to reduce MP inputs into these ecosystems.
Afficher plus [+] Moins [-]Oxidative stress, hemato-immunological, and intestinal morphometry changes induced by ochratoxin A in APRI rabbits and the protective role of probiotics
2020
El-Deep, Mahmoud H. | Amber, Khairy A. | Elgendy, Salwa | Dawood, Mahmoud A. O. | Elwakeel, Enas M. | Paray, Bilal Ahamad
This work studied the protective effects of Aspergillus awamori against ochratoxin A (OTA)-induced toxicity in APRI maternal line rabbits. A total number of 48 APRI line weanling rabbits (5 weeks) were divided into 4 groups (12 rabbits each) and fed the basal diet, 30 ppb/kg diet of OTA, 1 g/kg diet of A. awamori, and a mixture of OTA and A. awamori for 8 weeks. OTA reduced the final body weight and weight gain as well as the intestinal villi length and thickness, whereas increased the feed intake and feed conversion ratio. Rabbits fed diets with OTA showed significantly reduced crude protein, lipids, and fibers apparent digestibility coefficients (P < 0.05). The red blood cells and hemoglobin were significantly decreased in the OTA group comparing with the other groups (P < 0.05). The blood total protein and albumin displayed significantly lower levels by OTA than the other groups. In contrast, glucose, aspartate aminotransferase (AST), alkaline phosphatase (ALP), urea, and creatinine levels were significantly increased by OTA (P < 0.05). Phagocytic activity (PA) and phagocytic index (PI) showed significantly (P < 0.05) decreased levels in OTA-contaminated group, while rabbits fed A. awamori significantly showed the highest PA and PI levels (P < 0.05). Dietary A. awamori kept the levels of PA and PI in rabbits fed OTA significantly higher than those fed without A. awamori (P < 0.05) and not significantly different from the control group (P > 0.05). Catalase (CAT) and superoxide dismutase (SOD) displayed significantly lower levels in the OTA group, while malondialdehyde (MDA) was significantly higher than the other groups (P < 0.05). Rabbits fed OTA-contaminated diets displayed significantly lower CAT and SOD and higher MDA than rabbits fed OTA combined with A. awamori (P < 0.05). Our results indicated that dietary A. awamori ameliorated the damage in APRI rabbits fed OTA through alleviation of oxidative stress and immunity.
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