The removal kinetics and mechanism of active black removal by zero-valent iron were investigated. The experimental results showed that the rate of reactive black removal by zero-valent iron increased with the decreasing of pH and initial dye concentration, and increased with the increasing of temperature and ZVI dosage. SO42- promoted the removal rate of reactive black. Ca2+ had an inhibitory effect on the removal of reactive black in the early stage by zero-valent iron and promoted it in the later stage, while Mg2+, CO32-, ClO4-, NO3-, PO43- and HCO3- all inhibited the removal rate of reactive black by zero-valent iron. The activation energy was 26.38 KJ mol-1 by using the Arrhenius formula, indicating that this reaction was easy to occur. The degradation process was further analysed by UV-Vis, SEM and XRD, and the main reaction product was Fe2O3.

With human social and economic development, the problem of consumption and pollution of water resources greatly reduces the quality of human life. The research on the carrying capacity of the water environment can provide a theoretical basis and data support for coordinating the contradiction between man and nature and the green development of the urban economy. The driving force-pressure-stateresponse model evaluation index system, combined with entropy method to strike the index weight, using cloud theory calculated the level of 2004-2017 for each year of the Beijing water environmental carrying capacity. The results show that the water environment carrying capacity of Beijing has been rising in the past 14 years. It is the lowest in 2004 and tends to be stable after reaching a higher level in 2010. Despite Beijing’s water environment carrying capacity has increased, but overall still in the overload state.

The paper deals with the feasibility of arsenite removal by the adsorption from bentonite mineral. Groundwater arsenic contamination has been reported in different parts of the world including Jharkhand, Bihar and Uttar Pradesh. Tube wells in Holocene Newer Alluvium are characterized by grey to black coloured organic-rich argillaceous sediments which have arsenic-contaminated groundwater. The majority of arsenic present in the groundwater is in the form of As(III) which exists as uncharged species arsenic tri hydroxide at pH value of less than 9.2. Arsenite is removed by various techniques like coagulation microfiltration, fixed bed adsorption, bioremoval, ion exchange, membrane filtration, etc. Our studies have shown that locally available bentonites containing a unit of montmorillonites can remove the arsenic from an aqueous medium. On the treatment of 100 mL arsenite solution with 300 mesh sieves bentonites up to different intervals of time, it has been found that bentonites are good adsorbent of arsenite. The percentage removal of arsenite is up to 99 per cent with 3 g sodium derivative of bentonite for 1 hour. The removal efficiency, adsorption isotherm and kinetic studies show the suitability of bentonite minerals for arsenic removal following first-order kinetics. Freundlich and Langmuir isotherms are obeyed in the adsorption of arsenite by bentonite minerals. Adsorption of arsenic by bentonite minerals has proved to be a low-cost eco-friendly method. Sodium derivative of bentonite minerals has been found more efficient for removal of arsenite.

Cyanobacterial harmful algal blooms (cyanoHAB) have become more frequent and prominent in Atlantic Canada freshwater bodies over the last several years, especially in Nova Scotia (NS). Inspired by the trophic index of Vollenweider, a new index was developed with modification and adaptation for freshwater systems. Our model TRINDEX shows the effectiveness of estimation for the variation of cyanobacterial dominance in phytoplankton communities. TRINDEX can assist in determining the threshold for cyanobacterial bloom onset. Combinations of nutrients and pigments under TRINDEX were tested by a binary discrimination test to find the optimal range of threshold for cyanoHAB formation in freshwater lakes.

The data on growth and reproduction of composting earthworms may be beneficial for large scale earthworm production. The growth and reproduction of Perionyx excavatus were assessed in limited supplies of four experimental diets-cow dung alone and its mixture with acacia (Acacia auriculiformis) leaf litter, bamboo (Bambusa polymorpha) leaf litter and terrestrial weed Mikania micrantha under laboratory conditions to select suitable diet from our locally available resource for vermiculture. Growth performance of Perionyx excavatus was significantly (P<0.05) higher in cow dung (maximum weight mg worm-1 629 and growth rate mg worm-1 day-1 22.91). The rate of reproduction (0.3 cocoons worm-1 day-1 and 3.31 juveniles adult-1 week-1) was significantly higher (P<0.05) in acacia-cow dung mixture. The cocoon production was maximum on the 30th day in all experimental diets (cow dung, acacia-cow dung, bamboo-cow dung, mikania-cow dung). All the diets showed a maximum peak of juvenile production on the 45th day. The lowest rate of biomass increase as well as the rate of reproduction were observed in mikania-cow dung mixture. Present result indicates that cow dung and acacia leaf litter can be used as vermiculture substrate for P. excavatus.

Most of the textile and dying process industries in Tirupur region do not have proper wastewater treatment plants and they discharge the effluents in unlined channels and streams. Due to the issue, the groundwater in Tirupur is highly polluted. For analysing groundwater condition, groundwater modelling is used. For groundwater hydrologist, groundwater models are a vital tool. Nowadays, a lot of computer programs have been used for modelling groundwater. Visual MODFLOW software uses a finite difference method for solving the complexity. They can be used for simulating the behaviour of composite aquifers as well as the effects of irregular boundaries and different processes such as solute transport and groundwater flow. This paper evaluates the impact of industrial effluent in groundwater value in Tirupur region by five different scenarios.

India is the world’s largest user of groundwater, accounting for 25 per cent of the world’s extracted groundwater. Contamination of water bodies is the main problem for degrading the potable water quality in India. The contaminants, mainly cadmium, chromium, nickel, lead, zinc, copper, calcium, fluoride, nitrates, etc. have a significant impact on waters. There have been several advancements in technology for removal or reduction of these contaminants in water such as reverse osmosis, UV filtration, distillation and ion exchange. But these methods are not found to be eco-friendly and costeffective. This paper elaborates various techniques of organic nature that can be used to reduce/ remove the heavy metals from water bodies using orange peels as a bioadsorbent and detailed experimentation for the removal of lead ion concentration from water. In the present study, synthetic water with various heavy metals of known concentration was treated by a bioadsorbent (orange peels) by changing various parameters such as adsorbent particle size, dose, initial pH, etc. At pH 7, dose 0.5 g, and adsorbent particle size of 250 ?m, a drastic reduction in the concentration of lead from 10 ppm to 0.213 ppm in 50 mL synthetic sample was observed.

The impact of compost prepared from sewage sludge in addition/alteration to chemical fertilizer makes a unique direction for effective waste management with high crop productivity. The study aims to compare the quality, agronomic parameters of sugarcane amended by sewage sludge compost with that using optimum chemical fertilizer (NPK 150-50-90 kg/ha) in the two random fields near sewage treatment plant (STP) of our institute and also to predict the soil quality in that field before sowing and after ripening. Dimensional analysis, Brix, Pol, Purity, Sugar recovery and other necessary quality analysis were estimated for the sugarcane samples. Similarly, soil physico-chemical parameters such as pH, electrical conductivity, forms of nitrogen, organic carbon and other nutrients were also monitored. Obtained sugarcane purity of 89.2% from sludge derived compost (SDC) over the 82.8% using chemical fertilizer amendment leads to the sustainable management system. The % recovery of 12.23 of cane shows the optimum value for the compost amendment. The results scientifically reveal the suitability of sludge compost to the replacement of chemical fertilizers in terms of productivity and soil quality.

Jatropha biodiesel produced from Jatropha podagrica oil by alkaline-catalysed transesterification was blended with diesel in the ratios of 88:12 wt% (B88) and 12:88 wt% (B12). The fuel properties, consumption rate and exhaust gas emission characteristics of J. podagrica biodiesel, diesel and their blends were assessed. The results showed that J. podagrica seed oil have similar fatty acid profile with those of Jatropha curcas cultivated in Thailand and other South-East Asian countries. Blending of J. podagrica biodiesel and diesel enhanced the fuel properties of the blends, similar to those of the diesel. However, the B88 blend emitted lesser pollutants when compared to B12 and petrol diesel, making it very ideal for use as a promising alternative to the petrol diesel used in the mini tractor for farming activities. The results from the current study form a basis for further research on the use of B88 as a fuel source.

In this study, the efficiency of fungal consortia was evaluated on the degradation of rice straw by varying the initial carbon/nitrogen ratio of the compost piles. Consortia of three potent cellulose-degrading fungal strains: Aspergillus fumigatus, Aspergillus terreus and Aspergillus flavus were used as an inoculant to degrade rice straw in a 90-day composting process. The carbon/nitrogen ratio of the composting piles was varied by varying the proportion of bedding material in different treatments. The composts thus achieved were subjected to physic-chemical analysis and phytotoxicity assay using Solanum lycopersicum as test seeds. After 90 days of composting, compost from treatment 4 with initial carbon/nitrogen ratio 34 depicted maximum stability by achieving a final carbon/nitrogen ratio of 16.25. Compost from treatment 4 showed the highest Germination Index (%) followed by treatment 3 and treatment 2 as 94.32%, 88.88% and 79%, respectively on the growth of Solanum lycopersicum seeds. Results concluded that fungal consortia derived agro-waste compost with an initial carbon/nitrogen ratio 34 depicted the earliest maturity which is suggestive of its suitability for agricultural application.