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Wang Q.,Northwest University, China | Li R.,Key Laboratory of Plant Nutrition and the Agri environment in Northwest China | Cai H.,Northwest University, China | Awasthi M.K.,Northwest University, China | And 5 more authors.
Ecological Engineering | Year: 2016

The aims of this study were to investigate the effect of added Ca-bentonite (CB) on nutrient transformation during pig manure (PM) composting and the related effects on Cu and Zn accumulation in crops. Five treatments representing different CB concentrations (0%, 2.5%, 5%, 7.5% and 10% of dry PM weight basis) were mixed with initial feed stock composting system. The end product with application of 5% (wet weight) was also studied in plant growth experiment using Chinese cabbage. The results showed 10% CB amendment could promote dissolved organic carbon (DOC) and organic matter (OM) degradation, improve the total nitrogen, total phosphorus, NO3--N, NH4+-N transformation and significantly enhance immobilization of Zn and Cu heavy metals. CB addition could reduce metal availability through adsorption and complexation of the Zn and Cu metals ions on inorganic components. The increase in pH and OM degradation was likely responsible for the reduction in exchangeable and bioavailable Cu and Zn in CB amended compost. Further pot experiments demonstrated that 5% CB-added compost application improved the yield of Chinese cabbage (Brassica rapa chinensis) with highest biomass (7.43 ± 1.2 g/pot) and significantly reduced the Cu and Zn contents in Chinese cabbage when compared with control. Finally results indicate 10% CB amendment prior to PM composting should be recommended, because the rate of addition was more effective in the immobilization of Cu and Zn concentration through the composting process. © 2015 Elsevier B.V.

Awasthi M.K.,Regional Office | Awasthi M.K.,Amicable Knowledge Solution University | Awasthi M.K.,Hong Kong Baptist University | Pandey A.K.,Madhya Pradesh Private Universities Regulatory Commission | And 4 more authors.
Bioresource Technology | Year: 2014

Influence of fungal consortium and different turning frequency on composting of organic fraction of municipal solid waste (OFMSW) was investigated to produce compost with higher agronomic value. Four piles of OFMSW were prepared: three piles were inoculated with fungal consortium containing 5. l each spore suspensions of Trichoderma viride, Aspergillus niger and Aspergillus flavus and with a turning frequency of weekly (Pile 1), twice a week (Pile 2) and daily (Pile 3), while Pile 4 with weekly turning and without fungal inoculation served as control. The fungal consortium with weekly (Pile 1) turning frequency significantly affected temperature, pH, TOC, TKN, C/N ratio and germination index. High degradation of organic matter and early maturity was observed in Pile 1. Results indicate that fungal consortium with weekly turning frequency of open windrows were more cost-effective in comparison with other technologies for efficient composting and yield safe end products. © 2014 Elsevier Ltd.

Awasthi M.K.,Amicable Knowledge Solution University | Awasthi M.K.,Rani Durgavati University | Pandey A.K.,Madhya Pradesh Private Universities Regulatory Commission | Bundela P.S.,Regional Office | Khan J.,Rani Durgavati University
Bioresource Technology | Year: 2015

The effect of various bulking waste such as wood shaving, agricultural and yard trimming waste combined with organic fraction of municipal solid waste (OFMSW) composting was investigated through assessing their influence on microbial enzymatic activities and quality of finished compost. All three piles of OFMSW with different bulking waste were inoculated with microbial consortium. The results revealed that OFMSW combined with wood shaving and microbial consortium (Phanerochaete chrysosporium, Trichoderma viride and Pseudomonas aeruginosa) were helpful tool to facilitate the enzymatic activity and shortened composting period within 4. weeks. Maximum enzymatic activity were observed in pile 1 and 3 during the first 3. weeks, while in pile 2 relatively very low. But phosphatase activity was relatively higher in all piles until the end of the process. Maturity parameters of compost quality also favored the pile 1 as the best formulation for OFMSW composting. © 2015 Elsevier Ltd.

Awasthi M.K.,Northwest University, China | Awasthi M.K.,Amicable Knowledge Solution University | Wang Q.,Northwest University, China | Huang H.,Northwest University, China | And 8 more authors.
Bioresource Technology | Year: 2016

This study aimed to evaluate the role of different amount of zeolite with low dosage of lime amendment on the greenhouse gas (GHGs) emission and maturity during the dewatered fresh sewage sludge (DFSS) composting. The evolution of CO2, CH4, NH3 and N2O and maturity indexes were monitored in five composting mixtures prepared from DFSS mixed with wheat straw, while 10%, 15% and 30% zeolite + 1% lime were supplemented (dry weight basis of DFSS) into the composting mass and compared with treatment only 1% lime amended and control without any amendment. The results showed that addition of higher dosage of zeolite + 1% lime drastically reduce the GHGs emissions and NH3 loss. Comparison of GHGs emissions and compost quality showed that zeolite amended treatments were superior than control and 1% lime amended treatments. Therefore, DFSS composting with 30% zeolite + 1% lime as consortium of additives were found to emit very less amount of GHGs and gave the highest maturity than other treatments. © 2016 Elsevier Ltd.

Li R.,Northwest University, China | Li R.,Louisiana State University | Wang J.J.,Louisiana State University | Zhou B.,Louisiana State University | And 6 more authors.
Bioresource Technology | Year: 2016

The present study deals with the preparation of a novel MgO-impregnated magnetic biochar (MMSB) for phosphate recovery from aqueous solution. The MMSB was evaluated against sugarcane harvest residue biochar (SB) and magnetic biochar without Mg (MSB). The results showed that increasing Mg content in MMSB greatly improved the phosphate adsorption compared to SB and MSB, with 20% Mg-impregnated MMSB (20MMSB) recovering more than 99.5% phosphate from aqueous solution. Phosphate adsorption capacity of 20MMSB was 121.25 mg P/g at pH 4 and only 37.53% of recovered phosphate was desorbed by 0.01 mol/L HCl solutions. XRD and FTIR analysis showed that phosphate sorption mechanisms involved predominately with surface electrostatic attraction and precipitation with impregnated MgO and surface inner-sphere complexation with Fe oxide. The 20MMSB exhibited both maximum phosphate sorption and strong magnetic separation ability. Overall, phosphate-loaded 20MMSB significantly enhanced plant growth and could be used as a potential substitute for phosphate-based fertilizer. © 2016 Elsevier Ltd.

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