Sludge

We investigated the co-digestion of domestic sewage sludge (SS) with food waste (FW) under different mixing ratios. Five mixtures of different SS:FW ratios (100:0; 80:20; 50:50; 20:80 and 0:100) having the same TS content were subjected to anaerobic digestion at mesophilic conditions. The amount of biogas generated during the codigestion process was monitored and fitted to the modified Gompertz model. Cumulative biogas production profile exhibited a sigmoid growth pattern. SS:FW ratio of 80:20 acquired higher yield of biogas and methane. Other ratios of FW failed to promote production of biogas due to lower pH environment that caused the death of bacteria. The obtained modified Gompertz model parameters indicate that the methane production rate is 0.811 L day-1 for a feed utilizing sludge only. Utilizing a feed with SS:FW ratio of 80:20 increased the methane production rate to 0.872 L day-1. Treated Organic Matter (TOM) showed enhanced nutrients content in terms of TN and TP, and low heavy metal contents and low total fecal coliform counts (TFCC).

Rapid industrializations and urbanizations were produces very huge amounts of waste water and effluents during various unit operations and the processes. It seems to huge burden to manage to supply the sufficient quantity of water and also very difficult to manage the waste water and its effluents, and it may lead to increasing of cost and maintenance of the ETP's. In this contest this present study attempt was done for reduction of total water consumption and to recovery of Nickel and Copper metals from the waste water effluents coming from electroplating industry were analyzed by Nickel Recovery Units and Copper Recovery Units, The metals, which are casted from aluminum wheel. The recovery units, which has a rinse bath-1, rinse bath-2, drag out bath, copper plating bath and cartridge filter, carbon filter , copper recovery. It was found that, after following of Nickel & Copper recovery systems, total water consumption is drastically reduced, sludge generation also reduced and also effluent generation in both the cases of nickel and copper were also reduced Cite this Article: M.V. Raju, L.

Carbide sludge (10.4-11.5 tonnes day -1) is generated from the reaction of calcium carbide (900 kg) and water (6,000 L) in the production of acetylene (2400 m 3), in three selected acetylene manufacturing plants. The sludge (of pH 12.2 and containing Cu, Ph, Fe, Mn, Ni and Zn ions whose concentrations exceed the Department of Environment limits for industrial wastewater) was treated by vacuum filtration as a substitute for the ponding system, which is environmentally less acceptable. A similar system by flocculation was also developed. The filtration system represents an improvement over the ponding method, as shown by a pH of 7 for the clear filtrate; the solid cake, which contains 98% of the metals, can be conveniently disposed at an integrated scheduled waste treatment centre.

http://wmr.sagepub.com/content/20/6/536.short

Los barros o polvos generados por los sistemas de tratamiento de humos de los convertidores al oxígeno, presentan dificultades para el reciclado debido a su contenido de cinc, particularmente en la fracción fina. Se plantean en este trabajo las diversas tecnologías utilizadas y los obstáculos que se deben superar para mejorar los índices de reciclado de este subproducto, con especial mención a las experiencias de plantas latinoamericanas. Las soluciones que se han propuesto varían en cuanto al tipo de aglomeración utilizada (sínter, briquetas, pélets, granulado) como en los equipos metalúrgicos en que se reciclan (en plantas de sínter, altos hornos, convertidores, hornos de solera rotativa y hornos de cubilote).

This paper presents the geoengineering properties of the alum water treatment residues derived from the production of potable water at three different municipal works, including the effects of catchment geology; chemical additives; and thixotropic hardening phenomena,with reducingwater content (increasing solids content) from the viscous slurry state to the semisolid state. The geoengineering behavior was akin to that of high-plasticity organic clays, with low values of bulk and dry density and high compressibility, although the consolidation rate was low (hydraulic conductivity of the order of 10^-4 to 10^-6 m/day). The data presented in this paper can be used to determine the level of dewatering necessary for more efficient landfill disposal, including the anticipated amounts and rates of settlement and the factor of safety against geotechnical instability of the residue slopes for the short- and long-term conditions. It is recommended that sludge and residues should be dewatered to achieve minimum shear strengths of 20 and 50 kPa for geotechnical stability at municipal landfills and dedicated monofills, respectively.

Degradation of Organic in MSW and WW sludge by Co-composting technology is one of the alternatives, are available to handle the disposal of solid wastes. Co-composting is the highest form of recycling of biodegradable solid waste and it reduces the volume of waste effective. Addition of an oily waste to a co-composting process of dairy cow manure with food waste, and the influence in the final product was evaluated. Rubber waste constitutes valuable source of organic matter but its high C/N ratio and low moisture content. The co compost from the aerobic reactor provides good humus to build up a poor physical soil and some basic plant nutrients. A chestnut burr and leaf litter with solid poultry manure co-composting mixed was assessed. The use of hair waste as agricultural fertilizer is one of its most promising applications. Agricultural value of hair can be increased by composting.
Results show that: 1) co-composting method will be an attractive solid waste management option in poor context. 2) Dairy cow manure with food waste co-composting process was feasible even at the highest fat content. It can be a feasible way of adding value to fatty wastes. 3) The final co compost can be promoted for fertilizer. The best results were obtained by mixing rubber waste with sewage sludge from municipal wastewater treatment plan, and water hyacinth. 4) The final pH of chestnut burr and leaf litter with solid poultry manure co-compost was 8.89 and the C/N ratio was 13. The germination index (GI) was obtained using the co-compost varied with the seeds used. 5) Good results were obtained when hair and de-inking co composted with raw sludge from a municipal wastewater treatment plant. In contrast, Respiratory Quotient (RQ) values were not adequate to follow the development of the process. In all cases, more stable compost was achieved at the end of the process.

Behavioral scientists have begun to research 'sludge,' excessive frictions that make it harder for people to do what they want to do. Friction is also an important concept in transaction-cost economics. Nevertheless, sludge has been discussed without explicit referral to transaction costs. Several questions arise from this observation. Is the analogy to friction used differently in both literatures? If so, what are the key differences? If not, should we develop the concept of sludge when the well-established literature on transaction costs already exists? This conceptual article shows that sludge and transaction costs are related, but distinct, concepts, and that the literature on sludge can benefit from incorporating elements from transaction-cost research. For example, we suggest defining sludge as aspects of the choice architecture that lead to the experience of costs, organize sludges using a typology inspired by the transaction-cost literature, highlight specificity, uncertainty, and frequency as important determinants of the 'sludginess' of choice architecture , and show that sludge audits can be conducted using methods developed in the transaction-cost literature.