The previous research showed that slow sand filtration (SSF) can remove the total coli by approximately 99% because of the schmutzecke layer in the filter. The presented study aimed to complete the previous research on SSF, especially on the schmuztdecke layer mechanism, to remove total coli. Total coli is a parameter of water quality standard in Indonesia, and the behavior of schmutzdecke affects the total coli removal. In the present study, the raw water from Amprong River was treated using horizontal roughing filter (HRF) and SSF. The variations in SSF rate used were 0.2 and 0.4 m/h. Total coliforms were analyzed using the most probable number test, and schmutzdecke visualization was conducted through scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX). The best coliform concentration in water treated by the combination of HRF and SSF was 4,386 colonies per 100 mL of sample using the filtration rate of 0.2 m/h, and its removal efficiency was 99.60%. However, the quality of water treated by the combination of HRF and SSF did not meet the drinking water quality standard because the removal of total coli must be 100%. The SEM-EDX visualization results in schmutzdecke showed that the average bacteria in the schmutzdecke layer were small, white, opaque, and circular, with entire edge and flat elevation. The Gram test results showed that the schmutzdecke bacteria consisted of Gram-positive and Gram-negative bacteria with basil as the common cell form.

The efficiency of composting method with yard waste and rumen residue amendments to reduce soil pollution by total petroleum hydrocarbon in Wonocolo public oilfields was investigated in the laboratory scale for 150 days. Crude oil contaminated soil was mixed with yard waste and rumen residue mixture at 1:1 ratio then composted in 2 replicates. Pure crude oil contaminated soil was composted in parallel. The results showed that total petroleum hydrocarbon degradation efficiency of soils amended with yard waste and rumen residue mixture was 31 times higher than contaminated soil, which fulfilled the soil quality standard (6,974.58 mg/kg). The degradation of total petroleum hydrocarbon might be performed by Bacillus sp., and Bacillus cereus as the dominant bacteria at the end of composting process. These results showed that yard waste and rumen residue transformation could accelerate the degradation of aliphatic and aromatic fractions of petroleum hydrocarbon in crude oil contaminated soil. Both of these wastes are generally easy to obtain around Wonocolo public oilfield and highly recommended to use as the main substrate in the composting process.

A pure bacterial strain of Sphingomonas sp. DSM 11572 (named 2MPII) has been isolated from a Mediterranean coastal sediment. This strain is able to use 2-methylphenanthrene (2-MP) as a growth substrate. In order to understand the degradation processes and their selectivity, we have elucidated the metabolic pathways of 2-MP degradation. In this respect, in this paper, we report the identification of several metabolites resulting from the oxidation of 2-MP by the Sphingomonas sp. Metabolites of 2-MP, identified by gas chromatography coupled to mass spectrometry in culture media, belong to two distinct metabolic pathways. The first pathway involves, in the first step, the double hydroxylation of an aromatic ring catalyzed by a di-oxygenase. This pathway generates before the opening of the aromatic ring. The exact double hydroxylation positions have not been totally elucidated. The second pathway is initiated by the hydroxylation of the methyl side chain by a mono-oxygenase. It leads, by the oxidation of the methyl group, to the formation of alcohol, aldehyde, and carboxylic acid.