81 / 2024-01-01 02:17:25

Assessing Temporal Variation of Constituents Present in Sludge Generated In Different Wastewater Treatment Plants in the Industrial Sector, Carabobo State, Venezuela

Temporal Variation,Sludge,Watewater Treatment

In this study, the temporal variation of the constituents of sludge generated in different wastewater treatment plants in the industrial sector of the Carabobo State is evaluated. The heterogeneous historical records with a time frame of 8 years, from 2009 to 2016, cover 708 results of constituents in tributaries of industries with wastewater treatment plants and attached to the Ministry of Ecosocialism and clients of Hidrolab Toro Consultores Laboratory Company. The analyzes were distributed as follows: 74.5% toxicity; 6.5% corrosivity; 6.4% flammability; 6.2% reactivity of hydrogen sulfide and 6.4% reactivity of hydrogen cyanide. The revised information was verified with updated analyzes carried out through non-probabilistic sampling from 03/10/2017 to 08/14/2017, processing 5 specimens that supported the historical records that were correlated with the information emanating from Venezuelan Decree 2635. Results obtained among the analyzed periods have showed an absolute absence of violation due to corrosivity, flammability and reactivity of hydrogen cyanide. There were 19 transgressions of the Standard, belonging to: 18 hazardous results due to toxicity and 1 due to reactivity of hydrogen sulfide. The hazardous incidence of toxicity was: 74% for total metal content and 26% for total content in sludge leachates. The metals that influenced this incidence were: cadmium, chromium, nickel, lead, zinc, and copper. The treatments considered for the treatment of metals were: chemical precipitation, biotechnology (biosorption, bioaccumulation, biomineralization, phytoremediation), solidification/stabilization. The selection of chemical precipitation was favored given its wide application history, availability of reagents, low investment and maintenance costs, it can be valued as a raw material for some processes such as cementation and the production of thermoplastics. Chemical precipitation was proposed as a technology in a sludge contact decanter, caused by the direct action of the heaviness product of the agglomeration of particles accumulated in sludge stored between wastewater treatment units, which are composed of inks and flocs of the physicochemical treatment, from an industry in the State of Carabobo, the remediation system consisted of: an effluent collection tank, a vortex centrifugal pump that drives sludge, an ejector that spreads the sludge in the reaction zone of the decanter, a hopper containing lime, a volumetric screw dispenser to apply the dose of lime to the reaction zone of the settler, a precipitate collection tank, a plate filter press to dehydrate the precipitates and two containers to collect the dehydration effluents.